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video: vendor FFmpeg software AVC renderer

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Adds an LGPL FFmpeg-backed video renderer that slots ahead of Media3's
MediaCodecVideoRenderer via EXTENSION_RENDERER_MODE_PREFER. Resolves
playback failures on Huawei EMUI 11 (Mate 20, Kirin 980): the Codec2
HiSilicon AVC decoder initialises cleanly on iOS High@3.1 streams with
deep DPB + full-range yuvj420p, then errors on the first sample inside
MediaCodecVideoRenderer (init-failure fallback can't catch this).
Google's C2 SW AVC decoder hits its 8-frame output-delay cap on the
same shape and stalls on dequeueOutputBuffer.

Media3's own decoder-ffmpeg ships only an audio renderer;
ExperimentalFfmpegVideoRenderer has been a stub since 2020 (returns
FORMAT_UNSUPPORTED_TYPE, createDecoder returns null). NextLib is
GPL-3.0. So we vendor our own Apache-licensed JNI on top of LGPL
FFmpeg, dynamically linked at runtime.

Build flow:
  - android/ffmpeg/ holds the JNI source + CMakeLists + orchestrator
    script + LGPL notice. No native binaries in git.
  - :ux:buildFfmpegJni Gradle task (wired to preBuild) clones
    Media3 1.9.2 + FFmpeg release/6.0 into build/ffmpeg-work/ on
    first run, builds h264-only static libs per ABI, links
    libffmpegJNI.so per ABI into build/jniLibs/<abi>/. AGP picks
    them up via sourceSets.main.jniLibs.srcDirs +=. Gradle
    UP-TO-DATE skips the task when ffmpeg_jni.cc / CMakeLists /
    build_ffmpeg.sh are unchanged.

Renderer:
  - FfmpegVideoDecoder (SimpleDecoder) sends each packet with its
    inputBuffer.timeUs as pkt->pts; the JNI overwrites
    outputBuffer.timeUs with f->pts on receive so frames emitted in
    display order carry their true display PTS (input PTS in decode
    order scrambles ExoPlayer's drop logic and halves the render
    rate on B-frame streams).
  - FfmpegOutputSurface does YUV->RGB in one GLES2 pass against an
    EGL window surface sized to display orientation. Y plane uses
    GL_NEAREST (1:1 sized, sampling at exact texel centres
    preserves luma detail); chroma uses GL_LINEAR. Pre-rotated quad
    UVs (0/90/180/270) keep the YUV sampling correct when the
    coded frame needs rotation for display.
  - FfmpegVideoRenderer swaps the output buffer's width/height for
    90/270 streams before super.renderOutputBuffer notifies size,
    matching MediaCodecVideoRenderer's post-rotation reporting.

Decoder fallback:
  - Renderers.kt selects FfmpegVideoRenderer first when
    libffmpegJNI.so is loaded; falls through to the platform path
    for formats FFmpeg doesn't handle or ABIs without the .so.
  - MediaCodec selector deprioritises every HiSilicon decoder
    (OMX.hisi.* and c2.hisi.*) so the platform path picks
    c2.android.avc.decoder ahead of the C2 Hisi variant when FFmpeg
    isn't available. Required because the C2 Hisi failure is
    post-init, which Media3's setEnableDecoderFallback(true) can't
    intercept.

Compositor:
  - VideoCompositor.setInputSurfaceSize lets the renderer resize the
    codec-input SurfaceTexture before eglCreateWindowSurface so the
    EGL surface inherits matching buffer dimensions on creation
    (MediaCodec sizes natively; EGL doesn't).
  - VideoPlayerInstance wires Renderers.build with a sizer callback
    that calls into compositor.setInputSurfaceSize from the FFmpeg
    renderer thread.

Adds docs/architecture.md with the layered video pipeline diagram,
file map, renderer-selection rationale, build flow, and LGPL
boundary notes.
This commit is contained in:
agra
2026-05-28 19:24:17 +03:00
parent 7ad3a38d38
commit 7243ef7de4
16 changed files with 2439 additions and 16 deletions
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47
android/build.gradle
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@@ -51,6 +51,53 @@ android {
kotlinOptions {
jvmTarget = '1.8'
}
sourceSets {
main {
// libffmpegJNI.so is built by the buildFfmpegJni task into
// build/jniLibs/<abi>/ on first build (and any time the
// vendored ffmpeg_jni.cc / CMakeLists.txt change). Adding
// the directory here lets AGP package the .so into the
// AAR without committing native binaries to the repo.
jniLibs.srcDirs += "$buildDir/jniLibs"
}
}
}
// FFmpeg video decoder build — runs as part of the normal Android
// build. On first build for a given checkout it clones Media3 + FFmpeg
// into build/ffmpeg-work/ and produces libffmpegJNI.so per ABI (~30 min
// for the FFmpeg static-lib step the first time, fast after). Gradle
// UP-TO-DATE checking skips the task whenever the vendored JNI source
// + CMakeLists are unchanged. See android/ffmpeg/README.md.
def ffmpegSrcDir = file("$projectDir/ffmpeg")
def ffmpegWorkDir = file("$buildDir/ffmpeg-work")
def ffmpegOutDir = file("$buildDir/jniLibs")
def ndkCmakeBin = "${android.sdkDirectory}/cmake/3.22.1/bin"
def supportedAbis = ['armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64']
task buildFfmpegJni(type: Exec) {
group = 'build'
description = 'Clones Media3 + FFmpeg if needed, builds libffmpegJNI.so per Android ABI'
inputs.file "$ffmpegSrcDir/ffmpeg_jni.cc"
inputs.file "$ffmpegSrcDir/CMakeLists.txt"
inputs.file "$ffmpegSrcDir/build_ffmpeg.sh"
supportedAbis.each { abi ->
outputs.file "$ffmpegOutDir/$abi/libffmpegJNI.so"
}
workingDir ffmpegSrcDir
commandLine 'bash', "$ffmpegSrcDir/build_ffmpeg.sh"
environment 'JNI_SRC', ffmpegSrcDir.absolutePath
environment 'NDK_PATH', android.ndkDirectory.absolutePath
environment 'CMAKE_PATH', ndkCmakeBin
environment 'OUTPUT_DIR', ffmpegOutDir.absolutePath
environment 'WORK_DIR', ffmpegWorkDir.absolutePath
}
afterEvaluate {
preBuild.dependsOn buildFfmpegJni
}
dependencies {

64
android/ffmpeg/CMakeLists.txt Normal file
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@@ -0,0 +1,64 @@
#
# Copyright 2021 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# LINT.IfChange
cmake_minimum_required(VERSION 3.21.0 FATAL_ERROR)
# LINT.ThenChange(../../../build.gradle)
# Enable C++11 features.
set(CMAKE_CXX_STANDARD 11)
project(libffmpegJNI C CXX)
set(ffmpeg_location "${CMAKE_CURRENT_SOURCE_DIR}/ffmpeg")
set(ffmpeg_binaries "${ffmpeg_location}/android-libs/${ANDROID_ABI}")
foreach(ffmpeg_lib avutil swresample avcodec)
set(ffmpeg_lib_filename lib${ffmpeg_lib}.a)
set(ffmpeg_lib_file_path ${ffmpeg_binaries}/${ffmpeg_lib_filename})
add_library(
${ffmpeg_lib}
STATIC
IMPORTED)
set_target_properties(
${ffmpeg_lib} PROPERTIES
IMPORTED_LOCATION
${ffmpeg_lib_file_path})
endforeach()
include_directories(${ffmpeg_location})
find_library(android_log_lib log)
add_library(ffmpegJNI
SHARED
ffmpeg_jni.cc)
target_link_libraries(ffmpegJNI
PRIVATE android
PRIVATE swresample
PRIVATE avcodec
PRIVATE avutil
PRIVATE ${android_log_lib})
# Additional flags needed for "arm64-v8a" from NDK 23.1.7779620 and above.
# See https://github.com/google/ExoPlayer/issues/9933#issuecomment-1029775358.
if(ANDROID_ABI STREQUAL "arm64-v8a")
target_link_options(ffmpegJNI PRIVATE "-Wl,-Bsymbolic")
endif()
# Enable 16 KB ELF alignment.
target_link_options(ffmpegJNI
PRIVATE "-Wl,-z,max-page-size=16384")

502
android/ffmpeg/LICENSE-FFMPEG.txt Normal file
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@@ -0,0 +1,502 @@
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SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Libraries
If you develop a new library, and you want it to be of the greatest
possible use to the public, we recommend making it free software that
everyone can redistribute and change. You can do so by permitting
redistribution under these terms (or, alternatively, under the terms of the
ordinary General Public License).
To apply these terms, attach the following notices to the library. It is
safest to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least the
"copyright" line and a pointer to where the full notice is found.
<one line to give the library's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Also add information on how to contact you by electronic and paper mail.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the library, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the
library `Frob' (a library for tweaking knobs) written by James Random Hacker.
<signature of Ty Coon>, 1 April 1990
Ty Coon, President of Vice
That's all there is to it!

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# Vendored FFmpeg video decoder for `ux`
This directory contains the JNI source + Gradle build wiring for
`libffmpegJNI.so`, the LGPL-licensed FFmpeg shared library that backs
`io.swipelab.ux.video.ffmpeg.FfmpegVideoRenderer`. The renderer is
slotted ahead of `MediaCodecVideoRenderer` so iOS H.264 streams with
deep DPB (`has_b_frames > 8`) and full-range YUV play on devices where
the platform decoder fails (notably Huawei Mate 20 on EMUI 11).
## How it builds
The native library is produced by the `:ux:buildFfmpegJni` Gradle task,
wired as a dependency of `preBuild`. On any consumer build
(`flutter build apk`, `./gradlew assembleRelease`, IDE sync) the task
runs automatically; Gradle's UP-TO-DATE checking skips it when nothing
relevant changed.
What the task does:
1. Clones upstream Media3 (`1.9.2`) and FFmpeg (`release/6.0`) into
`<ux-android-build>/ffmpeg-work/` if missing — once per checkout.
2. Drops the vendored `ffmpeg_jni.cc` + `CMakeLists.txt` over the
upstream Media3 copies so the build produces a video-capable JNI.
3. Builds FFmpeg static libs (`libavcodec`, `libavutil`,
`libswresample`) with H.264 decoder enabled for `armeabi-v7a`,
`arm64-v8a`, `x86`, `x86_64`. Slow part — first build only
(~30 min on a typical x86 host, ~2 min on Apple Silicon). Static
libs are cached in `ffmpeg-work/` and reused on subsequent runs.
4. Cross-compiles `libffmpegJNI.so` per ABI via CMake + Ninja and
writes the result into `<ux-android-build>/jniLibs/<abi>/`. AGP
picks them up via the `jniLibs.srcDirs +=` line in
[build.gradle](../build.gradle) and bundles them in the AAR.
What ships in git:
* `ffmpeg_jni.cc` — JNI bridge exposing the five entry points
`FfmpegVideoDecoder.java` calls: initialize / sendPacket /
receiveFrame / flush / release. Adapted from Media3's audio-only
template; the audio path was dropped (MediaCodec AAC works
everywhere we ship to).
* `CMakeLists.txt` — links the FFmpeg static libs into
`libffmpegJNI.so`.
* `build_ffmpeg.sh` — orchestrates the clone + static-lib build +
JNI link. Env-driven, invoked only by the Gradle task — not
intended to be run by hand.
* `LICENSE-FFMPEG.txt` — LGPL v2.1 text. Required attribution.
**No `.so` files in git.** Everything under `<build>/jniLibs/` is
generated on demand; `/build` is already in [.gitignore](../.gitignore).
## License
FFmpeg is LGPL v2.1. We link to it dynamically (consumer apps load
`libffmpegJNI.so` at runtime via `System.loadLibrary`), which keeps the
LGPL boundary intact and does not impose copyleft on the consuming
app. The build configuration in upstream Media3's `build_ffmpeg.sh`
intentionally omits `--enable-gpl` and `--enable-nonfree` to keep the
binaries LGPL-only. Do not add codecs that require GPL configuration
(e.g. x264) — that would taint the artifact.
## Pinned versions
* Media3 `1.9.2` (matches the version used by the rest of `ux`).
* FFmpeg `release/6.0` (matches Media3's tested compatibility window).
* Android NDK is resolved via `android.ndkDirectory` from AGP — the
NDK version your Android project pins, normally r27 on a recent
AGP. Older NDKs may fail the 16-KB page-size alignment check
enforced for Android 15.
Bumping either version: edit the `MEDIA3_TAG` / `FFMPEG_TAG`
constants near the top of `build_ffmpeg.sh`, then `./gradlew
:ux:buildFfmpegJni --rerun-tasks` to force a rebuild.
## Why we vendor this instead of using `media3-decoder-ffmpeg`
Media3's published FFmpeg extension is audio-only.
`ExperimentalFfmpegVideoRenderer` in the same library has been a stub
since 2020 — `createDecoder()` returns null, `supportsFormat()` returns
`FORMAT_UNSUPPORTED_TYPE`. The community alternative (NextLib) is
GPL-3.0, which would impose copyleft on consumers. So we built our own
on top of the same JNI skeleton.

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#!/bin/bash
# Builds libffmpegJNI.so for all 4 Android ABIs from vendored JNI sources
# (ffmpeg_jni.cc + CMakeLists.txt in this directory) against upstream
# Media3 + FFmpeg cloned into WORK_DIR. Driven entirely by environment
# variables Gradle sets in the buildFfmpegJni task — no user-facing
# flags. Reruns are cheap once WORK_DIR is populated (Gradle UP-TO-DATE
# skips the script entirely when JNI sources haven't changed, and even
# when forced, the FFmpeg static libs are reused if present).
#
# Required env:
# JNI_SRC — this directory (vendored ffmpeg_jni.cc + CMakeLists.txt)
# NDK_PATH — Android NDK root
# CMAKE_PATH — directory containing the cmake + ninja binaries
# OUTPUT_DIR — where to drop the final libffmpegJNI.so per ABI
# WORK_DIR — scratch directory for upstream clones + intermediate
# build artefacts (lives under build/ so a clean wipes it)
#
# License: FFmpeg is LGPL v2.1. We link to it dynamically (consumers
# load libffmpegJNI.so at runtime), keeping the LGPL boundary intact and
# not imposing copyleft on the consuming app. The build below
# intentionally omits --enable-gpl and --enable-nonfree.
set -euo pipefail
: "${JNI_SRC:?JNI_SRC env var not set}"
: "${NDK_PATH:?NDK_PATH env var not set}"
: "${CMAKE_PATH:?CMAKE_PATH env var not set}"
: "${OUTPUT_DIR:?OUTPUT_DIR env var not set}"
: "${WORK_DIR:?WORK_DIR env var not set}"
MEDIA3_TAG="${MEDIA3_TAG:-1.9.2}"
FFMPEG_TAG="${FFMPEG_TAG:-release/6.0}"
ABIS="${ABIS:-armeabi-v7a arm64-v8a x86 x86_64}"
MIN_SDK="${MIN_SDK:-21}"
case "$(uname -s)" in
Darwin*) HOST_PLATFORM=darwin-x86_64 ;;
Linux*) HOST_PLATFORM=linux-x86_64 ;;
*) echo "Unsupported host: $(uname -s)" >&2; exit 1 ;;
esac
mkdir -p "$WORK_DIR" "$OUTPUT_DIR"
cd "$WORK_DIR"
# 1. Upstream sources — clone once, reuse on subsequent runs.
MEDIA3_DIR="$WORK_DIR/media3"
if [[ ! -d "$MEDIA3_DIR" ]]; then
echo "[ffmpeg-build] cloning Media3 @${MEDIA3_TAG}"
git clone --depth 1 --branch "$MEDIA3_TAG" \
https://github.com/androidx/media.git "$MEDIA3_DIR"
fi
FFMPEG_DIR="$MEDIA3_DIR/libraries/decoder_ffmpeg/src/main/jni/ffmpeg"
if [[ ! -d "$FFMPEG_DIR" ]]; then
echo "[ffmpeg-build] cloning FFmpeg @${FFMPEG_TAG}"
git clone --depth 1 --branch "$FFMPEG_TAG" \
https://git.ffmpeg.org/ffmpeg.git "$FFMPEG_DIR"
fi
# 2. Drop our extended JNI source + CMake config over the upstream copies
# so the build produces a video-capable libffmpegJNI.so.
JNI_BUILD_DIR="$MEDIA3_DIR/libraries/decoder_ffmpeg/src/main/jni"
cp "$JNI_SRC/ffmpeg_jni.cc" "$JNI_BUILD_DIR/ffmpeg_jni.cc"
cp "$JNI_SRC/CMakeLists.txt" "$JNI_BUILD_DIR/CMakeLists.txt"
# 3. Build FFmpeg static libs per ABI (H.264 decoder only). The
# sentinel below skips this step if all 4 ABIs already have the
# static libs from a previous run — important because the FFmpeg
# static build is the slow part (~30 min for 4 ABIs); subsequent
# Gradle runs just need to re-link libffmpegJNI.so (~5 sec / ABI).
MODULE_PATH="$MEDIA3_DIR/libraries/decoder_ffmpeg/src/main"
NEED_STATIC_BUILD=0
for ABI in $ABIS; do
if [[ ! -f "$JNI_BUILD_DIR/ffmpeg/android-libs/$ABI/libavcodec.a" ]]; then
NEED_STATIC_BUILD=1
break
fi
done
if [[ "$NEED_STATIC_BUILD" -eq 1 ]]; then
echo "[ffmpeg-build] building FFmpeg static libs (slow on first run)"
chmod +x "$JNI_BUILD_DIR/build_ffmpeg.sh"
"$JNI_BUILD_DIR/build_ffmpeg.sh" \
"$MODULE_PATH" "$NDK_PATH" "$HOST_PLATFORM" "$MIN_SDK" h264
else
echo "[ffmpeg-build] FFmpeg static libs already present, reusing"
fi
# 4. Cross-build libffmpegJNI.so per ABI via CMake + Ninja.
export PATH="$CMAKE_PATH:$PATH"
for ABI in $ABIS; do
ABI_BUILD_DIR="$WORK_DIR/jni-out/$ABI"
mkdir -p "$ABI_BUILD_DIR"
cmake -G Ninja \
-DCMAKE_TOOLCHAIN_FILE="$NDK_PATH/build/cmake/android.toolchain.cmake" \
-DANDROID_ABI="$ABI" \
-DANDROID_PLATFORM="android-$MIN_SDK" \
-DCMAKE_BUILD_TYPE=Release \
-S "$JNI_BUILD_DIR" -B "$ABI_BUILD_DIR" >/dev/null
ninja -C "$ABI_BUILD_DIR" >/dev/null
DEST="$OUTPUT_DIR/$ABI"
mkdir -p "$DEST"
cp "$ABI_BUILD_DIR/libffmpegJNI.so" "$DEST/libffmpegJNI.so"
done
echo "[ffmpeg-build] libffmpegJNI.so ready in $OUTPUT_DIR"

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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* JNI bridge for the ux FFmpeg video decoder. Exposes a small surface
* (init / sendPacket / receiveFrame / flush / release) that
* FfmpegVideoDecoder.java drives. The audio path was dropped — Media3's
* MediaCodec AAC decoder handles audio on every device we ship to.
*/
#include <android/log.h>
#include <jni.h>
#include <stdlib.h>
#include <string.h>
extern "C" {
#ifdef __cplusplus
#define __STDC_CONSTANT_MACROS
#ifdef _STDINT_H
#undef _STDINT_H
#endif
#include <stdint.h>
#endif
#include <libavcodec/avcodec.h>
#include <libavutil/error.h>
#include <libavutil/imgutils.h>
#include <libavutil/opt.h>
#include <libavutil/pixfmt.h>
}
#define LOG_TAG "ux_ffmpeg_jni"
#define LOGE(...) \
((void)__android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__))
#define LOGI(...) \
((void)__android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__))
#define LOGD(...) \
((void)__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__))
#define LIBRARY_FUNC(RETURN_TYPE, NAME, ...) \
extern "C" { \
JNIEXPORT RETURN_TYPE \
Java_io_swipelab_ux_video_ffmpeg_FfmpegLibrary_##NAME(JNIEnv* env, \
jobject thiz, \
##__VA_ARGS__); \
} \
JNIEXPORT RETURN_TYPE \
Java_io_swipelab_ux_video_ffmpeg_FfmpegLibrary_##NAME( \
JNIEnv* env, jobject thiz, ##__VA_ARGS__)
#define VIDEO_DECODER_FUNC(RETURN_TYPE, NAME, ...) \
extern "C" { \
JNIEXPORT RETURN_TYPE \
Java_io_swipelab_ux_video_ffmpeg_FfmpegVideoDecoder_##NAME( \
JNIEnv* env, jobject thiz, ##__VA_ARGS__); \
} \
JNIEXPORT RETURN_TYPE \
Java_io_swipelab_ux_video_ffmpeg_FfmpegVideoDecoder_##NAME( \
JNIEnv* env, jobject thiz, ##__VA_ARGS__)
#define ERROR_STRING_BUFFER_LENGTH 256
// Mirrored in FfmpegVideoDecoder.java.
static const int VIDEO_DECODER_SUCCESS = 0;
static const int VIDEO_DECODER_ERROR_INVALID_DATA = -1;
static const int VIDEO_DECODER_ERROR_OTHER = -2;
static const int VIDEO_DECODER_READ_AGAIN = -3;
// VideoDecoderOutputBuffer.COLORSPACE_* mirror.
static const int COLORSPACE_UNKNOWN = 0;
static const int COLORSPACE_BT601 = 1;
static const int COLORSPACE_BT709 = 2;
static const int COLORSPACE_BT2020 = 3;
static jmethodID initForYuvFrameMethod;
static jfieldID dataField;
// Carries full-range info (1) vs limited-range info (0) per frame to
// Java so the GL shader picks the matching BT.709 conversion matrix.
static jfieldID decoderPrivateField;
// Reassigned per output frame to the decoded frame's actual PTS
// (NOT the input packet's PTS — for H.264 reorder, output display
// order differs from input decode order, and using the input PTS
// scrambles ExoPlayer's frame-late detection so it drops half the
// stream).
static jfieldID timeUsField;
static int colorspaceFromAVColorSpace(AVColorSpace cs) {
switch (cs) {
case AVCOL_SPC_BT709:
return COLORSPACE_BT709;
case AVCOL_SPC_BT470BG:
case AVCOL_SPC_SMPTE170M:
return COLORSPACE_BT601;
case AVCOL_SPC_BT2020_NCL:
case AVCOL_SPC_BT2020_CL:
return COLORSPACE_BT2020;
default:
return COLORSPACE_UNKNOWN;
}
}
static void logError(const char* fn, int err) {
char buf[ERROR_STRING_BUFFER_LENGTH] = {0};
av_strerror(err, buf, ERROR_STRING_BUFFER_LENGTH);
LOGE("Error in %s: %s", fn, buf);
}
static int transformError(int err) {
return err == AVERROR_INVALIDDATA ? VIDEO_DECODER_ERROR_INVALID_DATA
: VIDEO_DECODER_ERROR_OTHER;
}
// Decoder state held across JNI calls; the long handle returned by
// videoInitialize is a pointer to one of these. AVCodecContext alone
// isn't enough because we want a reusable AVFrame to avoid per-decode
// allocation churn.
struct UxFfmpegVideoContext {
AVCodecContext* codec_ctx = nullptr;
AVFrame* frame = nullptr;
};
static void releaseContext(UxFfmpegVideoContext* ctx) {
if (!ctx) return;
if (ctx->frame) {
av_frame_free(&ctx->frame);
}
if (ctx->codec_ctx) {
avcodec_free_context(&ctx->codec_ctx);
}
delete ctx;
}
jint JNI_OnLoad(JavaVM* vm, void* reserved) {
JNIEnv* env;
if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
LOGE("JNI_OnLoad: GetEnv failed");
return -1;
}
jclass clazz =
env->FindClass("androidx/media3/decoder/VideoDecoderOutputBuffer");
if (!clazz) {
LOGE("JNI_OnLoad: FindClass(VideoDecoderOutputBuffer) failed");
return -1;
}
initForYuvFrameMethod = env->GetMethodID(clazz, "initForYuvFrame", "(IIIII)Z");
if (!initForYuvFrameMethod) {
LOGE("JNI_OnLoad: GetMethodID(initForYuvFrame) failed");
return -1;
}
dataField = env->GetFieldID(clazz, "data", "Ljava/nio/ByteBuffer;");
if (!dataField) {
LOGE("JNI_OnLoad: GetFieldID(data) failed");
return -1;
}
decoderPrivateField = env->GetFieldID(clazz, "decoderPrivate", "J");
if (!decoderPrivateField) {
LOGE("JNI_OnLoad: GetFieldID(decoderPrivate) failed");
return -1;
}
// timeUs lives on the DecoderOutputBuffer base class but is
// discoverable via the concrete subclass.
timeUsField = env->GetFieldID(clazz, "timeUs", "J");
if (!timeUsField) {
LOGE("JNI_OnLoad: GetFieldID(timeUs) failed");
return -1;
}
return JNI_VERSION_1_6;
}
LIBRARY_FUNC(jstring, ffmpegGetVersion) {
return env->NewStringUTF(LIBAVCODEC_IDENT);
}
LIBRARY_FUNC(jint, ffmpegGetInputBufferPaddingSize) {
return (jint)AV_INPUT_BUFFER_PADDING_SIZE;
}
LIBRARY_FUNC(jboolean, ffmpegHasDecoder, jstring codecName) {
if (!codecName) return JNI_FALSE;
const char* name = env->GetStringUTFChars(codecName, nullptr);
const AVCodec* codec = avcodec_find_decoder_by_name(name);
env->ReleaseStringUTFChars(codecName, name);
return codec != nullptr;
}
VIDEO_DECODER_FUNC(jlong, ffmpegVideoInitialize, jstring codecName,
jbyteArray extraData, jint threads) {
if (!codecName) {
LOGE("ffmpegVideoInitialize: codecName is null");
return 0L;
}
const char* name = env->GetStringUTFChars(codecName, nullptr);
const AVCodec* codec = avcodec_find_decoder_by_name(name);
env->ReleaseStringUTFChars(codecName, name);
if (!codec) {
LOGE("ffmpegVideoInitialize: codec not found");
return 0L;
}
UxFfmpegVideoContext* ctx = new UxFfmpegVideoContext();
ctx->codec_ctx = avcodec_alloc_context3(codec);
if (!ctx->codec_ctx) {
LOGE("ffmpegVideoInitialize: avcodec_alloc_context3 failed");
releaseContext(ctx);
return 0L;
}
if (extraData) {
jsize size = env->GetArrayLength(extraData);
ctx->codec_ctx->extradata =
(uint8_t*)av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!ctx->codec_ctx->extradata) {
LOGE("ffmpegVideoInitialize: extradata alloc failed");
releaseContext(ctx);
return 0L;
}
env->GetByteArrayRegion(extraData, 0, size,
(jbyte*)ctx->codec_ctx->extradata);
ctx->codec_ctx->extradata_size = size;
}
ctx->codec_ctx->thread_count = threads > 0 ? threads : 0;
// Slice threading only. FRAME threading buffers thread_count
// input frames before producing output; that extra latency
// pushes frames past their PTS deadline and ExoPlayer drops
// them, leaving render rate well below source rate. Slice
// threading gives parallelism without the input-side delay.
ctx->codec_ctx->thread_type = FF_THREAD_SLICE;
ctx->codec_ctx->err_recognition = AV_EF_IGNORE_ERR;
// PTS values are passed in microseconds (Media3's native unit),
// and libavcodec propagates packet.pts → frame.pts through the
// reorder buffer so we can recover display-order timestamps on
// receive.
ctx->codec_ctx->time_base = AVRational{1, 1000000};
ctx->codec_ctx->pkt_timebase = AVRational{1, 1000000};
int result = avcodec_open2(ctx->codec_ctx, codec, nullptr);
if (result < 0) {
logError("avcodec_open2", result);
releaseContext(ctx);
return 0L;
}
ctx->frame = av_frame_alloc();
if (!ctx->frame) {
LOGE("ffmpegVideoInitialize: av_frame_alloc failed");
releaseContext(ctx);
return 0L;
}
return (jlong)ctx;
}
VIDEO_DECODER_FUNC(jint, ffmpegVideoSendPacket, jlong handle, jobject inputData,
jint inputSize, jlong ptsUs) {
if (!handle) {
LOGE("ffmpegVideoSendPacket: null handle");
return VIDEO_DECODER_ERROR_OTHER;
}
if (!inputData || inputSize <= 0) {
LOGE("ffmpegVideoSendPacket: bad input");
return VIDEO_DECODER_ERROR_OTHER;
}
UxFfmpegVideoContext* ctx = (UxFfmpegVideoContext*)handle;
uint8_t* buf = (uint8_t*)env->GetDirectBufferAddress(inputData);
AVPacket* pkt = av_packet_alloc();
if (!pkt) {
LOGE("ffmpegVideoSendPacket: av_packet_alloc failed");
return VIDEO_DECODER_ERROR_OTHER;
}
pkt->data = buf;
pkt->size = inputSize;
pkt->pts = (int64_t)ptsUs;
pkt->dts = AV_NOPTS_VALUE;
int result = avcodec_send_packet(ctx->codec_ctx, pkt);
av_packet_free(&pkt);
if (result == AVERROR(EAGAIN)) {
return VIDEO_DECODER_READ_AGAIN;
}
if (result < 0) {
logError("avcodec_send_packet", result);
return transformError(result);
}
return VIDEO_DECODER_SUCCESS;
}
// Pulls the next decoded frame and writes it into the Java
// VideoDecoderOutputBuffer's YUV planes. Returns:
// VIDEO_DECODER_SUCCESS -> frame written
// VIDEO_DECODER_READ_AGAIN -> no frame yet, send more packets
// VIDEO_DECODER_ERROR_* -> fatal
VIDEO_DECODER_FUNC(jint, ffmpegVideoReceiveFrame, jlong handle,
jobject outputBuffer) {
if (!handle) {
LOGE("ffmpegVideoReceiveFrame: null handle");
return VIDEO_DECODER_ERROR_OTHER;
}
UxFfmpegVideoContext* ctx = (UxFfmpegVideoContext*)handle;
int result = avcodec_receive_frame(ctx->codec_ctx, ctx->frame);
if (result == AVERROR(EAGAIN) || result == AVERROR_EOF) {
return VIDEO_DECODER_READ_AGAIN;
}
if (result < 0) {
logError("avcodec_receive_frame", result);
return transformError(result);
}
AVFrame* f = ctx->frame;
// Only planar 4:2:0 YUV is supported by VideoDecoderOutputBuffer's
// 3-plane layout. iOS H.264 produces YUV420P (limited range) or
// YUVJ420P (full range); identical memory layout, only range
// interpretation differs.
AVPixelFormat pix = (AVPixelFormat)f->format;
if (pix != AV_PIX_FMT_YUV420P && pix != AV_PIX_FMT_YUVJ420P) {
LOGE("ffmpegVideoReceiveFrame: unsupported pix_fmt=%d", pix);
av_frame_unref(f);
return VIDEO_DECODER_ERROR_OTHER;
}
int width = f->width;
int height = f->height;
int yStride = f->linesize[0];
int uvStride = f->linesize[1];
int colorspace = colorspaceFromAVColorSpace(f->colorspace);
if (colorspace == COLORSPACE_UNKNOWN) {
// iOS H.264 commonly leaves VUI fields unspecified; default to
// BT.709 for HD-shaped frames, BT.601 below SD width threshold.
colorspace = (width >= 1280 || height >= 720) ? COLORSPACE_BT709
: COLORSPACE_BT601;
}
jboolean ok = env->CallBooleanMethod(outputBuffer, initForYuvFrameMethod,
width, height, yStride, uvStride,
colorspace);
if (env->ExceptionCheck()) {
LOGE("initForYuvFrame threw");
env->ExceptionDescribe();
env->ExceptionClear();
av_frame_unref(f);
return VIDEO_DECODER_ERROR_OTHER;
}
if (!ok) {
LOGE("initForYuvFrame returned false (overflow?)");
av_frame_unref(f);
return VIDEO_DECODER_ERROR_OTHER;
}
// Display-order PTS recovered from libavcodec. The Java side
// initialised the buffer with the input packet's PTS; for B-frame
// streams that is the WRONG value because the frame we're about to
// emit was decoded out of input order. Overwriting with f->pts puts
// each output buffer back on the timeline ExoPlayer expects.
if (f->pts != AV_NOPTS_VALUE) {
env->SetLongField(outputBuffer, timeUsField, (jlong)f->pts);
}
// Copy each plane into the ByteBuffer that initForYuvFrame allocated.
jobject dataBuf = env->GetObjectField(outputBuffer, dataField);
if (!dataBuf) {
LOGE("ffmpegVideoReceiveFrame: data ByteBuffer is null after init");
av_frame_unref(f);
return VIDEO_DECODER_ERROR_OTHER;
}
uint8_t* dst = (uint8_t*)env->GetDirectBufferAddress(dataBuf);
if (!dst) {
LOGE("ffmpegVideoReceiveFrame: GetDirectBufferAddress null");
env->DeleteLocalRef(dataBuf);
av_frame_unref(f);
return VIDEO_DECODER_ERROR_OTHER;
}
int uvHeight = (height + 1) / 2;
int yLength = yStride * height;
int uvLength = uvStride * uvHeight;
// Plane 0: Y
memcpy(dst, f->data[0], yLength);
// Plane 1: U
memcpy(dst + yLength, f->data[1], uvLength);
// Plane 2: V
memcpy(dst + yLength + uvLength, f->data[2], uvLength);
// iOS yuvj420p / AVCOL_RANGE_JPEG => full-range YUV; the renderer's
// shader needs to skip the limited-range pre-scale on Y.
jlong rangeFlag = (pix == AV_PIX_FMT_YUVJ420P ||
f->color_range == AVCOL_RANGE_JPEG)
? 1L
: 0L;
env->SetLongField(outputBuffer, decoderPrivateField, rangeFlag);
env->DeleteLocalRef(dataBuf);
av_frame_unref(f);
return VIDEO_DECODER_SUCCESS;
}
VIDEO_DECODER_FUNC(void, ffmpegVideoFlush, jlong handle) {
if (!handle) return;
UxFfmpegVideoContext* ctx = (UxFfmpegVideoContext*)handle;
avcodec_flush_buffers(ctx->codec_ctx);
}
VIDEO_DECODER_FUNC(void, ffmpegVideoRelease, jlong handle) {
if (!handle) return;
releaseContext((UxFfmpegVideoContext*)handle);
}

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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.decoder.DecoderException;
@UnstableApi
public final class FfmpegDecoderException extends DecoderException {
public FfmpegDecoderException(String message) {
super(message);
}
public FfmpegDecoderException(String message, Throwable cause) {
super(message, cause);
}
}

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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import androidx.annotation.Nullable;
import androidx.media3.common.MimeTypes;
import androidx.media3.common.util.UnstableApi;
/**
* Loads libffmpegJNI.so and answers capability queries against the
* statically-linked FFmpeg build. The current native build only enables
* the H.264 decoder; queries for other MIME types return false.
*/
@UnstableApi
public final class FfmpegLibrary {
private static final Object lock = new Object();
private static boolean attempted;
private static boolean available;
private FfmpegLibrary() {}
public static boolean isAvailable() {
synchronized (lock) {
if (attempted) {
return available;
}
attempted = true;
try {
System.loadLibrary("ffmpegJNI");
available = true;
} catch (UnsatisfiedLinkError e) {
android.util.Log.w(
"UxFfmpeg",
"libffmpegJNI.so missing for this ABI; falling back to MediaCodec");
available = false;
}
return available;
}
}
public static String getVersion() {
return isAvailable() ? ffmpegGetVersion() : "";
}
public static int getInputBufferPaddingSize() {
return isAvailable() ? ffmpegGetInputBufferPaddingSize() : 0;
}
/** Whether the given MIME type maps to a decoder built into this libffmpegJNI.so. */
public static boolean supportsFormat(@Nullable String mimeType) {
if (mimeType == null || !isAvailable()) {
return false;
}
String codecName = getCodecName(mimeType);
if (codecName == null) {
return false;
}
return ffmpegHasDecoder(codecName);
}
/**
* FFmpeg decoder name for the given MIME type, or null if no mapping
* exists. Only video codecs are wired up; the JNI build excludes
* audio decoders entirely.
*/
@Nullable
public static String getCodecName(String mimeType) {
switch (mimeType) {
case MimeTypes.VIDEO_H264:
return "h264";
default:
return null;
}
}
private static native String ffmpegGetVersion();
private static native int ffmpegGetInputBufferPaddingSize();
private static native boolean ffmpegHasDecoder(String codecName);
}

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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import android.opengl.EGL14;
import android.opengl.EGLConfig;
import android.opengl.EGLContext;
import android.opengl.EGLDisplay;
import android.opengl.EGLSurface;
import android.opengl.GLES20;
import android.util.Log;
import android.view.Surface;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.decoder.VideoDecoderOutputBuffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
/**
* EGL/GLES2 helper that converts a decoded YUV420P/YUVJ420P frame into
* an RGB image written to an Android {@link Surface}. Lives for the
* duration of one output Surface; the renderer creates a new one when
* the Surface changes and releases this on shutdown.
*
* <p>The fragment shader handles both limited-range BT.709
* (Android-recorded H.264) and full-range BT.709 (iOS yuvj420p). The
* decoder flags per-buffer range via
* {@link VideoDecoderOutputBuffer#decoderPrivate} (0 = limited,
* 1 = full).
*/
@UnstableApi
final class FfmpegOutputSurface {
private static final String TAG = "UxFfmpegOutputSurface";
// Fullscreen quad: (x, y, u, v) per vertex in TRIANGLE_STRIP order
// (top-left, bottom-left, top-right, bottom-right). UVs encode the
// rotation that maps a coded-orientation YUV plane onto a
// display-orientation render target — for each 90° step the UV
// tuple shifts one vertex around the corner ring. Used by
// `pickQuad(rotation)` at configure time so the running shader
// doesn't need a per-frame rotation uniform.
private static final float[] QUAD_0 = {
-1f, 1f, 0f, 0f,
-1f, -1f, 0f, 1f,
1f, 1f, 1f, 0f,
1f, -1f, 1f, 1f,
};
private static final float[] QUAD_90 = {
-1f, 1f, 0f, 1f,
-1f, -1f, 1f, 1f,
1f, 1f, 0f, 0f,
1f, -1f, 1f, 0f,
};
private static final float[] QUAD_180 = {
-1f, 1f, 1f, 1f,
-1f, -1f, 1f, 0f,
1f, 1f, 0f, 1f,
1f, -1f, 0f, 0f,
};
private static final float[] QUAD_270 = {
-1f, 1f, 1f, 0f,
-1f, -1f, 0f, 0f,
1f, 1f, 1f, 1f,
1f, -1f, 0f, 1f,
};
private static float[] pickQuad(int rotation) {
switch (((rotation % 360) + 360) % 360) {
case 90:
return QUAD_90;
case 180:
return QUAD_180;
case 270:
return QUAD_270;
default:
return QUAD_0;
}
}
private static final String VERTEX_SHADER =
"attribute vec4 aPos;\n"
+ "attribute vec2 aTex;\n"
+ "varying vec2 vTex;\n"
+ "void main() {\n"
+ " gl_Position = aPos;\n"
+ " vTex = aTex;\n"
+ "}\n";
// BT.709 YUV->RGB. uFullRange selects between full-range (iOS
// yuvj420p) and limited-range conversion. uSampleScale rescales the
// horizontal texture coordinate to skip the right-side padding that
// FFmpeg's SIMD-aligned linesize introduces (yStride >= width).
private static final String FRAGMENT_SHADER =
"precision mediump float;\n"
+ "varying vec2 vTex;\n"
+ "uniform sampler2D uY;\n"
+ "uniform sampler2D uU;\n"
+ "uniform sampler2D uV;\n"
+ "uniform float uSampleScale;\n"
+ "uniform float uFullRange;\n"
+ "void main() {\n"
+ " vec2 c = vec2(vTex.x * uSampleScale, vTex.y);\n"
+ " float y = texture2D(uY, c).r;\n"
+ " float u = texture2D(uU, c).r - 0.5;\n"
+ " float v = texture2D(uV, c).r - 0.5;\n"
+ " if (uFullRange < 0.5) {\n"
+ " y = (y - 16.0/255.0) * (255.0/219.0);\n"
+ " u *= 255.0/224.0;\n"
+ " v *= 255.0/224.0;\n"
+ " }\n"
+ " float r = y + 1.5748 * v;\n"
+ " float g = y - 0.1873 * u - 0.4681 * v;\n"
+ " float b = y + 1.8556 * u;\n"
+ " gl_FragColor = vec4(clamp(vec3(r, g, b), 0.0, 1.0), 1.0);\n"
+ "}\n";
private EGLDisplay eglDisplay = EGL14.EGL_NO_DISPLAY;
private EGLContext eglContext = EGL14.EGL_NO_CONTEXT;
private EGLSurface eglSurface = EGL14.EGL_NO_SURFACE;
private EGLConfig eglConfig;
private int program;
private int aPosLoc;
private int aTexLoc;
private int uYLoc;
private int uULoc;
private int uVLoc;
private int uSampleScaleLoc;
private int uFullRangeLoc;
private final int[] textures = new int[3];
// Per-plane allocated dimensions; -1 forces a glTexImage2D on the
// next upload (initial frame or size change). Subsequent frames use
// glTexSubImage2D which only copies pixels and avoids the driver-
// side reallocation that glTexImage2D triggers.
private final int[] allocatedStride = { -1, -1, -1 };
private final int[] allocatedRows = { -1, -1, -1 };
private FloatBuffer quadBuffer;
// Width/height the EGL window surface was created for; taken from
// the first decoded frame, not eglQuerySurface (which can return
// stale 1×1 dimensions if the SurfaceTexture's defaultBufferSize
// wasn't set before window creation).
private int surfaceWidth;
private int surfaceHeight;
// Rotation (clockwise) the configure() call selected the quad UVs
// for. Used to detect mid-stream rotation changes and rebuild.
private int configuredRotation;
/**
* Binds this helper to the given surface and creates EGL context +
* GL resources sized for the supplied DISPLAY dimensions (i.e.
* already swapped for 90°/270° rotated streams). Caller must have
* already resized the underlying SurfaceTexture (via
* setDefaultBufferSize) so the EGL window surface picks up matching
* buffer dimensions on creation.
*
* @param rotation 0 / 90 / 180 / 270 — the clockwise rotation that
* should be applied to the coded YUV to display correctly.
* Selects which set of pre-rotated quad UVs the shader samples
* with.
*/
void configure(Surface surface, int width, int height, int rotation)
throws FfmpegDecoderException {
if (eglContext != EGL14.EGL_NO_CONTEXT && eglSurface != EGL14.EGL_NO_SURFACE) {
return;
}
surfaceWidth = width;
surfaceHeight = height;
this.configuredRotation = rotation;
eglDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
if (eglDisplay == EGL14.EGL_NO_DISPLAY) {
throw new FfmpegDecoderException("eglGetDisplay failed");
}
int[] version = new int[2];
if (!EGL14.eglInitialize(eglDisplay, version, 0, version, 1)) {
throw new FfmpegDecoderException("eglInitialize failed");
}
int[] cfgAttribs = {
EGL14.EGL_RED_SIZE, 8,
EGL14.EGL_GREEN_SIZE, 8,
EGL14.EGL_BLUE_SIZE, 8,
EGL14.EGL_ALPHA_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
EGL14.EGL_SURFACE_TYPE, EGL14.EGL_WINDOW_BIT,
EGL14.EGL_NONE
};
EGLConfig[] cfgs = new EGLConfig[1];
int[] numCfgs = new int[1];
if (!EGL14.eglChooseConfig(eglDisplay, cfgAttribs, 0, cfgs, 0, 1, numCfgs, 0)
|| numCfgs[0] < 1) {
throw new FfmpegDecoderException("eglChooseConfig failed");
}
eglConfig = cfgs[0];
int[] ctxAttribs = { EGL14.EGL_CONTEXT_CLIENT_VERSION, 2, EGL14.EGL_NONE };
eglContext =
EGL14.eglCreateContext(eglDisplay, eglConfig, EGL14.EGL_NO_CONTEXT, ctxAttribs, 0);
if (eglContext == EGL14.EGL_NO_CONTEXT) {
throw new FfmpegDecoderException("eglCreateContext failed");
}
int[] surfAttribs = { EGL14.EGL_NONE };
eglSurface =
EGL14.eglCreateWindowSurface(eglDisplay, eglConfig, surface, surfAttribs, 0);
if (eglSurface == EGL14.EGL_NO_SURFACE) {
throw new FfmpegDecoderException("eglCreateWindowSurface failed");
}
if (!EGL14.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext)) {
throw new FfmpegDecoderException("eglMakeCurrent failed");
}
initGl();
}
private void initGl() throws FfmpegDecoderException {
int vs = compileShader(GLES20.GL_VERTEX_SHADER, VERTEX_SHADER);
int fs = compileShader(GLES20.GL_FRAGMENT_SHADER, FRAGMENT_SHADER);
program = GLES20.glCreateProgram();
GLES20.glAttachShader(program, vs);
GLES20.glAttachShader(program, fs);
GLES20.glLinkProgram(program);
int[] linked = new int[1];
GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linked, 0);
if (linked[0] == 0) {
String log = GLES20.glGetProgramInfoLog(program);
throw new FfmpegDecoderException("Program link failed: " + log);
}
GLES20.glDeleteShader(vs);
GLES20.glDeleteShader(fs);
aPosLoc = GLES20.glGetAttribLocation(program, "aPos");
aTexLoc = GLES20.glGetAttribLocation(program, "aTex");
uYLoc = GLES20.glGetUniformLocation(program, "uY");
uULoc = GLES20.glGetUniformLocation(program, "uU");
uVLoc = GLES20.glGetUniformLocation(program, "uV");
uSampleScaleLoc = GLES20.glGetUniformLocation(program, "uSampleScale");
uFullRangeLoc = GLES20.glGetUniformLocation(program, "uFullRange");
GLES20.glGenTextures(3, textures, 0);
for (int i = 0; i < 3; i++) {
int t = textures[i];
// Y plane (i=0) is 1:1 sized to the EGL surface, so GL_NEAREST
// samples the exact texel value at each pixel center and
// preserves luma detail. Chroma planes (i=1,2) are 4:2:0
// subsampled — bilinear filtering reconstructs the smooth
// colour transitions the encoder expected.
int filter = i == 0 ? GLES20.GL_NEAREST : GLES20.GL_LINEAR;
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, t);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, filter);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, filter);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
GLES20.GL_CLAMP_TO_EDGE);
}
float[] quad = pickQuad(configuredRotation);
quadBuffer =
ByteBuffer.allocateDirect(quad.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer();
quadBuffer.put(quad).position(0);
GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1);
}
private static int compileShader(int type, String src) throws FfmpegDecoderException {
int s = GLES20.glCreateShader(type);
GLES20.glShaderSource(s, src);
GLES20.glCompileShader(s);
int[] ok = new int[1];
GLES20.glGetShaderiv(s, GLES20.GL_COMPILE_STATUS, ok, 0);
if (ok[0] == 0) {
String log = GLES20.glGetShaderInfoLog(s);
GLES20.glDeleteShader(s);
throw new FfmpegDecoderException(
(type == GLES20.GL_VERTEX_SHADER ? "Vertex" : "Fragment")
+ " shader compile failed: "
+ log);
}
return s;
}
/**
* Uploads the YUV planes from {@code buffer} into GL textures and
* draws the conversion shader to the EGL window surface. Caller is
* responsible for calling {@code buffer.release()} afterwards.
*
* @param rotation rotation degrees from the source format. Must
* match the value passed to {@link #configure} (used here only
* to recover the CODED Y-plane dimensions — needed for the
* stride-vs-width sample-scale calculation — from the buffer's
* DISPLAY-orientation width/height).
*/
void render(VideoDecoderOutputBuffer buffer, int rotation) throws FfmpegDecoderException {
if (eglContext == EGL14.EGL_NO_CONTEXT || eglSurface == EGL14.EGL_NO_SURFACE) {
throw new FfmpegDecoderException("render called before configure");
}
if (buffer.yuvPlanes == null || buffer.yuvStrides == null) {
throw new FfmpegDecoderException("output buffer has no YUV data");
}
EGL14.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext);
int yStride = buffer.yuvStrides[0];
int uvStride = buffer.yuvStrides[1];
// For 90°/270° streams the renderer swapped buffer.width/height
// to display orientation so ExoPlayer's size notification was
// correct, but the YUV planes are still stored in coded
// orientation — undo the swap here so sampleScale = codedWidth /
// yStride lands on the correct value.
boolean rotated = rotation == 90 || rotation == 270;
int codedWidth = rotated ? buffer.height : buffer.width;
int codedHeight = rotated ? buffer.width : buffer.height;
int uvHeight = (codedHeight + 1) / 2;
GLES20.glViewport(0, 0, surfaceWidth, surfaceHeight);
GLES20.glClearColor(0f, 0f, 0f, 1f);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
GLES20.glUseProgram(program);
uploadPlane(0, textures[0], buffer.yuvPlanes[0], yStride, codedHeight);
uploadPlane(1, textures[1], buffer.yuvPlanes[1], uvStride, uvHeight);
uploadPlane(2, textures[2], buffer.yuvPlanes[2], uvStride, uvHeight);
GLES20.glUniform1i(uYLoc, 0);
GLES20.glUniform1i(uULoc, 1);
GLES20.glUniform1i(uVLoc, 2);
GLES20.glUniform1f(uSampleScaleLoc, yStride > 0 ? (float) codedWidth / yStride : 1f);
GLES20.glUniform1f(uFullRangeLoc, buffer.decoderPrivate == 1L ? 1f : 0f);
quadBuffer.position(0);
GLES20.glVertexAttribPointer(aPosLoc, 2, GLES20.GL_FLOAT, false, 16, quadBuffer);
quadBuffer.position(2);
GLES20.glVertexAttribPointer(aTexLoc, 2, GLES20.GL_FLOAT, false, 16, quadBuffer);
GLES20.glEnableVertexAttribArray(aPosLoc);
GLES20.glEnableVertexAttribArray(aTexLoc);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
GLES20.glDisableVertexAttribArray(aPosLoc);
GLES20.glDisableVertexAttribArray(aTexLoc);
if (!EGL14.eglSwapBuffers(eglDisplay, eglSurface)) {
Log.w(TAG, "eglSwapBuffers failed; client may have detached the surface");
}
}
private void uploadPlane(
int unit, int texture, ByteBuffer src, int stride, int rows) {
GLES20.glActiveTexture(GLES20.GL_TEXTURE0 + unit);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);
src.position(0);
if (allocatedStride[unit] == stride && allocatedRows[unit] == rows) {
GLES20.glTexSubImage2D(
GLES20.GL_TEXTURE_2D,
0,
0, 0,
stride, rows,
GLES20.GL_LUMINANCE,
GLES20.GL_UNSIGNED_BYTE,
src);
} else {
GLES20.glTexImage2D(
GLES20.GL_TEXTURE_2D,
0,
GLES20.GL_LUMINANCE,
stride,
rows,
0,
GLES20.GL_LUMINANCE,
GLES20.GL_UNSIGNED_BYTE,
src);
allocatedStride[unit] = stride;
allocatedRows[unit] = rows;
}
}
void release() {
if (eglDisplay != EGL14.EGL_NO_DISPLAY) {
EGL14.eglMakeCurrent(eglDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
EGL14.EGL_NO_CONTEXT);
if (textures[0] != 0) {
GLES20.glDeleteTextures(3, textures, 0);
textures[0] = textures[1] = textures[2] = 0;
}
if (program != 0) {
GLES20.glDeleteProgram(program);
program = 0;
}
if (eglSurface != EGL14.EGL_NO_SURFACE) {
EGL14.eglDestroySurface(eglDisplay, eglSurface);
eglSurface = EGL14.EGL_NO_SURFACE;
}
if (eglContext != EGL14.EGL_NO_CONTEXT) {
EGL14.eglDestroyContext(eglDisplay, eglContext);
eglContext = EGL14.EGL_NO_CONTEXT;
}
EGL14.eglReleaseThread();
EGL14.eglTerminate(eglDisplay);
eglDisplay = EGL14.EGL_NO_DISPLAY;
}
quadBuffer = null;
}
}

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android/src/main/java/io/swipelab/ux/video/ffmpeg/FfmpegSurfaceSizer.java Normal file
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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import androidx.media3.common.util.UnstableApi;
/**
* Resizes the SurfaceTexture backing the player's output Surface
* before the FFmpeg renderer's EGL window surface is created. Without
* this the SurfaceTexture's default buffer size is whatever
* implementation default Android picked (often 1×1) — the EGL surface
* inherits that, our quad renders into one pixel, and the compositor
* stretches it across the Flutter texture.
*
* <p>The compositor's player listener also calls
* setDefaultBufferSize, but only on the main thread after the player
* fires onVideoSizeChanged. By then the FFmpeg renderer has already
* created its EGL window surface on the player thread. Threading this
* hook through ensures resize-before-window-create.
*/
@UnstableApi
public interface FfmpegSurfaceSizer {
void resize(int width, int height);
}

188
android/src/main/java/io/swipelab/ux/video/ffmpeg/FfmpegVideoDecoder.java Normal file
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/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.common.util.Util;
import androidx.media3.decoder.DecoderInputBuffer;
import androidx.media3.decoder.SimpleDecoder;
import androidx.media3.decoder.VideoDecoderOutputBuffer;
import java.nio.ByteBuffer;
import java.util.List;
/**
* FFmpeg H.264 video decoder. Mirrors the Media3 audio pattern but
* targets {@link VideoDecoderOutputBuffer}. Two-step send/receive maps
* directly onto libavcodec's avcodec_send_packet / avcodec_receive_frame
* lifecycle so we can drain multiple reordered frames out of a single
* input packet.
*/
@UnstableApi
public final class FfmpegVideoDecoder
extends SimpleDecoder<
DecoderInputBuffer, VideoDecoderOutputBuffer, FfmpegDecoderException> {
// Mirrored from ffmpeg_jni.cc.
private static final int VIDEO_DECODER_SUCCESS = 0;
private static final int VIDEO_DECODER_ERROR_INVALID_DATA = -1;
private static final int VIDEO_DECODER_ERROR_OTHER = -2;
private static final int VIDEO_DECODER_READ_AGAIN = -3;
private final String codecName;
@Nullable private final byte[] extraData;
private final long nativeContext;
private volatile @C.VideoOutputMode int outputMode;
public FfmpegVideoDecoder(
Format format, int numInputBuffers, int numOutputBuffers, int initialInputBufferSize, int threads)
throws FfmpegDecoderException {
super(
new DecoderInputBuffer[numInputBuffers],
new VideoDecoderOutputBuffer[numOutputBuffers]);
if (!FfmpegLibrary.isAvailable()) {
throw new FfmpegDecoderException("Failed to load decoder native libraries.");
}
String mime = format.sampleMimeType;
if (mime == null) {
throw new FfmpegDecoderException("Format has null sampleMimeType.");
}
String name = FfmpegLibrary.getCodecName(mime);
if (name == null) {
throw new FfmpegDecoderException("No FFmpeg codec mapped for " + mime);
}
codecName = name;
extraData = flattenInitializationData(format.initializationData);
nativeContext = ffmpegVideoInitialize(codecName, extraData, threads);
if (nativeContext == 0) {
throw new FfmpegDecoderException("Initialization failed.");
}
setInitialInputBufferSize(initialInputBufferSize);
}
@Override
public String getName() {
return "ffmpeg" + FfmpegLibrary.getVersion() + "-" + codecName;
}
@Override
protected DecoderInputBuffer createInputBuffer() {
return new DecoderInputBuffer(
DecoderInputBuffer.BUFFER_REPLACEMENT_MODE_DIRECT,
FfmpegLibrary.getInputBufferPaddingSize());
}
@Override
protected VideoDecoderOutputBuffer createOutputBuffer() {
return new VideoDecoderOutputBuffer(this::releaseOutputBuffer);
}
@Override
protected FfmpegDecoderException createUnexpectedDecodeException(Throwable error) {
return new FfmpegDecoderException("Unexpected decode error", error);
}
@Override
@Nullable
protected FfmpegDecoderException decode(
DecoderInputBuffer inputBuffer, VideoDecoderOutputBuffer outputBuffer, boolean reset) {
if (reset) {
ffmpegVideoFlush(nativeContext);
}
ByteBuffer inputData = Util.castNonNull(inputBuffer.data);
int inputSize = inputData.limit();
int sendResult =
ffmpegVideoSendPacket(nativeContext, inputData, inputSize, inputBuffer.timeUs);
if (sendResult == VIDEO_DECODER_ERROR_INVALID_DATA) {
// Treat invalid bitstream as non-fatal — match MediaCodec behavior.
outputBuffer.shouldBeSkipped = true;
return null;
} else if (sendResult == VIDEO_DECODER_ERROR_OTHER) {
return new FfmpegDecoderException("avcodec_send_packet failed (see logcat).");
}
// sendResult is VIDEO_DECODER_SUCCESS or VIDEO_DECODER_READ_AGAIN.
// EAGAIN on send means the decoder needs to be drained first — but
// SimpleDecoder gives us one input + one output per decode() call,
// so on the next iteration we'll be called with a fresh output
// buffer and try receive again. Drop this input on EAGAIN.
// init seeds outputBuffer.timeUs from the input PTS; the native
// receive path overwrites it with the decoded frame's true
// display-order PTS (recovered from libavcodec) before returning
// success.
outputBuffer.init(inputBuffer.timeUs, outputMode, /* supplementalData= */ null);
outputBuffer.format = inputBuffer.format;
int receiveResult = ffmpegVideoReceiveFrame(nativeContext, outputBuffer);
if (receiveResult == VIDEO_DECODER_READ_AGAIN) {
// No frame ready yet (decoder still building reorder buffer).
// Skip this output buffer; subsequent send/receive cycles will
// drain frames once the pipeline fills.
outputBuffer.shouldBeSkipped = true;
return null;
} else if (receiveResult == VIDEO_DECODER_ERROR_INVALID_DATA) {
outputBuffer.shouldBeSkipped = true;
return null;
} else if (receiveResult == VIDEO_DECODER_ERROR_OTHER) {
return new FfmpegDecoderException("avcodec_receive_frame failed (see logcat).");
}
return null;
}
@Override
public void release() {
super.release();
ffmpegVideoRelease(nativeContext);
}
public void setOutputMode(@C.VideoOutputMode int outputMode) {
this.outputMode = outputMode;
}
/**
* Coalesces the codec-specific data into one contiguous byte array
* for FFmpeg's extradata pointer. For AVC the MP4 extractor delivers
* a single avcC blob in slot 0; some demuxers split SPS/PPS into
* separate NAL units (Annex B). In both cases libavcodec auto-detects
* the layout from the first byte.
*/
@Nullable
private static byte[] flattenInitializationData(List<byte[]> initializationData) {
if (initializationData == null || initializationData.isEmpty()) {
return null;
}
if (initializationData.size() == 1) {
return initializationData.get(0);
}
int total = 0;
for (byte[] part : initializationData) total += part.length;
byte[] out = new byte[total];
int off = 0;
for (byte[] part : initializationData) {
System.arraycopy(part, 0, out, off, part.length);
off += part.length;
}
return out;
}
private native long ffmpegVideoInitialize(
String codecName, @Nullable byte[] extraData, int threads);
private native int ffmpegVideoSendPacket(
long context, ByteBuffer inputData, int inputSize, long ptsUs);
private native int ffmpegVideoReceiveFrame(long context, VideoDecoderOutputBuffer outputBuffer);
private native void ffmpegVideoFlush(long context);
private native void ffmpegVideoRelease(long context);
}

220
android/src/main/java/io/swipelab/ux/video/ffmpeg/FfmpegVideoRenderer.java Normal file
View File

@@ -0,0 +1,220 @@
/*
* Copyright 2026 swipelab.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*/
package io.swipelab.ux.video.ffmpeg;
import static androidx.media3.exoplayer.DecoderReuseEvaluation.DISCARD_REASON_MIME_TYPE_CHANGED;
import static androidx.media3.exoplayer.DecoderReuseEvaluation.REUSE_RESULT_NO;
import static androidx.media3.exoplayer.DecoderReuseEvaluation.REUSE_RESULT_YES_WITHOUT_RECONFIGURATION;
import android.os.Handler;
import android.view.Surface;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.MimeTypes;
import androidx.media3.common.util.TraceUtil;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.decoder.CryptoConfig;
import androidx.media3.decoder.DecoderException;
import androidx.media3.decoder.VideoDecoderOutputBuffer;
import androidx.media3.exoplayer.DecoderReuseEvaluation;
import androidx.media3.exoplayer.RendererCapabilities;
import androidx.media3.exoplayer.video.DecoderVideoRenderer;
import androidx.media3.exoplayer.video.VideoRendererEventListener;
import java.util.Objects;
/**
* ExoPlayer renderer that decodes video with our vendored FFmpeg
* extension and converts the YUV frame to RGB via a GLES2 shader before
* presenting on the output Surface. Slotted ahead of
* MediaCodecVideoRenderer via EXTENSION_RENDERER_MODE_PREFER so files
* that exceed platform decoder caps (deep DPB, iOS yuvj420p) work on
* devices where Media3's hardware path fails.
*/
@UnstableApi
public final class FfmpegVideoRenderer extends DecoderVideoRenderer {
private static final String TAG = "FfmpegVideoRenderer";
private static final int DEFAULT_NUM_INPUT_BUFFERS = 4;
// iOS H.264 records with max_num_reorder_frames up to 16, and our
// shouldBeSkipped-on-EAGAIN path consumes one output buffer per
// input until the DPB fills. With 8 buffers the pipeline ran out
// before steady state and the renderer dropped frames waiting on
// free output buffers; 16 covers the worst iOS reorder shape.
private static final int DEFAULT_NUM_OUTPUT_BUFFERS = 16;
// 480x848 baseline; the decoder grows the buffer if a packet exceeds.
private static final int DEFAULT_INPUT_BUFFER_SIZE = 256 * 1024;
private final int threads;
private final int numInputBuffers;
private final int numOutputBuffers;
private final FfmpegSurfaceSizer surfaceSizer;
@Nullable private FfmpegVideoDecoder decoder;
@Nullable private FfmpegOutputSurface outputSurface;
@Nullable private Surface currentSurface;
private int surfaceWidth = -1;
private int surfaceHeight = -1;
private int surfaceRotation = 0;
public FfmpegVideoRenderer(
long allowedJoiningTimeMs,
@Nullable Handler eventHandler,
@Nullable VideoRendererEventListener eventListener,
int maxDroppedFramesToNotify,
FfmpegSurfaceSizer surfaceSizer) {
this(
allowedJoiningTimeMs,
eventHandler,
eventListener,
maxDroppedFramesToNotify,
surfaceSizer,
/* threads= */ 0,
DEFAULT_NUM_INPUT_BUFFERS,
DEFAULT_NUM_OUTPUT_BUFFERS);
}
public FfmpegVideoRenderer(
long allowedJoiningTimeMs,
@Nullable Handler eventHandler,
@Nullable VideoRendererEventListener eventListener,
int maxDroppedFramesToNotify,
FfmpegSurfaceSizer surfaceSizer,
int threads,
int numInputBuffers,
int numOutputBuffers) {
super(allowedJoiningTimeMs, eventHandler, eventListener, maxDroppedFramesToNotify);
this.threads = threads;
this.numInputBuffers = numInputBuffers;
this.numOutputBuffers = numOutputBuffers;
this.surfaceSizer = surfaceSizer;
}
@Override
public String getName() {
return TAG;
}
@Override
public @Capabilities int supportsFormat(Format format) {
String mime = format.sampleMimeType;
if (!FfmpegLibrary.isAvailable() || mime == null || !MimeTypes.isVideo(mime)) {
return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_TYPE);
}
if (!FfmpegLibrary.supportsFormat(mime)) {
return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_SUBTYPE);
}
if (format.cryptoType != C.CRYPTO_TYPE_NONE) {
return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_DRM);
}
return RendererCapabilities.create(
C.FORMAT_HANDLED, ADAPTIVE_SEAMLESS, TUNNELING_NOT_SUPPORTED);
}
@Override
protected FfmpegVideoDecoder createDecoder(Format format, @Nullable CryptoConfig cryptoConfig)
throws FfmpegDecoderException {
TraceUtil.beginSection("createFfmpegVideoDecoder");
int initialInputBufferSize =
format.maxInputSize != Format.NO_VALUE ? format.maxInputSize : DEFAULT_INPUT_BUFFER_SIZE;
FfmpegVideoDecoder d =
new FfmpegVideoDecoder(
format, numInputBuffers, numOutputBuffers, initialInputBufferSize, threads);
decoder = d;
TraceUtil.endSection();
return d;
}
/// Pre-swap buffer dims for 90°/270° rotated streams so the
/// {@code maybeNotifyVideoSizeChanged} call inside the base
/// renderOutputBuffer reports DISPLAY-orientation dimensions (matching
/// what MediaCodecVideoRenderer does for the hardware path). Without
/// this swap, portrait iOS videos report their coded landscape size
/// and the downstream compositor lays out the Flutter texture
/// rotated.
@Override
protected void renderOutputBuffer(
VideoDecoderOutputBuffer outputBuffer, long presentationTimeUs, Format outputFormat)
throws DecoderException {
if (outputFormat != null
&& (outputFormat.rotationDegrees == 90 || outputFormat.rotationDegrees == 270)
&& outputBuffer.width != outputBuffer.height) {
int tmp = outputBuffer.width;
outputBuffer.width = outputBuffer.height;
outputBuffer.height = tmp;
}
super.renderOutputBuffer(outputBuffer, presentationTimeUs, outputFormat);
}
@Override
protected void renderOutputBufferToSurface(
VideoDecoderOutputBuffer outputBuffer, Surface surface) throws FfmpegDecoderException {
int rotation = outputBuffer.format != null ? outputBuffer.format.rotationDegrees : 0;
if (outputSurface == null
|| currentSurface != surface
|| surfaceWidth != outputBuffer.width
|| surfaceHeight != outputBuffer.height
|| surfaceRotation != rotation) {
releaseOutputSurface();
// Resize the SurfaceTexture before creating the EGL window
// surface — the EGL surface inherits the SurfaceTexture's buffer
// dimensions at creation and won't auto-resize later.
surfaceSizer.resize(outputBuffer.width, outputBuffer.height);
outputSurface = new FfmpegOutputSurface();
outputSurface.configure(surface, outputBuffer.width, outputBuffer.height, rotation);
currentSurface = surface;
surfaceWidth = outputBuffer.width;
surfaceHeight = outputBuffer.height;
surfaceRotation = rotation;
}
try {
outputSurface.render(outputBuffer, rotation);
} finally {
outputBuffer.release();
}
}
@Override
protected void setDecoderOutputMode(@C.VideoOutputMode int outputMode) {
if (decoder != null) {
decoder.setOutputMode(outputMode);
}
}
@Override
protected DecoderReuseEvaluation canReuseDecoder(
String decoderName, Format oldFormat, Format newFormat) {
boolean sameMime = Objects.equals(oldFormat.sampleMimeType, newFormat.sampleMimeType);
return new DecoderReuseEvaluation(
decoderName,
oldFormat,
newFormat,
sameMime ? REUSE_RESULT_YES_WITHOUT_RECONFIGURATION : REUSE_RESULT_NO,
sameMime ? 0 : DISCARD_REASON_MIME_TYPE_CHANGED);
}
@Override
protected void onDisabled() {
releaseOutputSurface();
decoder = null;
super.onDisabled();
}
private void releaseOutputSurface() {
if (outputSurface != null) {
outputSurface.release();
outputSurface = null;
}
currentSurface = null;
surfaceWidth = -1;
surfaceHeight = -1;
surfaceRotation = 0;
}
}

82
android/src/main/kotlin/io/swipelab/ux/video/Renderers.kt
View File

@@ -1,28 +1,77 @@
package io.swipelab.ux.video
import android.content.Context
import android.os.Handler
import androidx.media3.common.util.UnstableApi
import androidx.media3.exoplayer.DefaultRenderersFactory
import androidx.media3.exoplayer.Renderer
import androidx.media3.exoplayer.RenderersFactory
import androidx.media3.exoplayer.mediacodec.MediaCodecInfo
import androidx.media3.exoplayer.mediacodec.MediaCodecSelector
import androidx.media3.exoplayer.video.VideoRendererEventListener
import io.swipelab.ux.video.ffmpeg.FfmpegLibrary
import io.swipelab.ux.video.ffmpeg.FfmpegSurfaceSizer
import io.swipelab.ux.video.ffmpeg.FfmpegVideoRenderer
/// Renderer factory configured for Banlu. Two non-default tweaks:
/// Renderer factory configured for Banlu.
///
/// - `setEnableDecoderFallback(true)` — Media3's default refuses to
/// fall back if the primary decoder fails to start. On Huawei
/// EMUI (Mate 20 Pro / LYA-L29 / API 29) the hardware AVC decoder
/// `OMX.hisi.video.decoder.avc` fails codec start; without
/// fallback the surface stays black.
/// - `MediaCodecSelector` deprioritises `OMX.hisi.*` so Media3
/// picks the working software decoder first
/// (`c2.android.avc.decoder` on the affected device). The
/// hardware decoder stays as a last-resort option for devices
/// where it works correctly.
/// Video path is tiered:
/// 1. `FfmpegVideoRenderer` — vendored Media3 FFmpeg extension that
/// decodes H.264 with libavcodec and converts YUV→RGB via a GLES2
/// shader. Selected first for any MIME type FFmpeg supports. Has
/// no DPB cap, handles iOS yuvj420p full-range streams that defeat
/// both `c2.hisi.avc.decoder` (EMUI 11 Mate 20 stalls on the first
/// sample after init) and `c2.android.avc.decoder` (Google C2 SW
/// caps output delay at 8 frames; iOS H.264 with `has_b_frames=16`
/// starves the decoder until CCodec's queue timeout). When
/// `libffmpegJNI.so` is missing for the current ABI, FfmpegLibrary
/// returns isAvailable()=false and selection falls through.
/// 2. `MediaCodec` path with `setEnableDecoderFallback(true)`. Init
/// failures (EMUI 10 `OMX.hisi.video.decoder.avc`) bounce to the
/// next decoder.
/// 3. `MediaCodecSelector` deprioritises every HiSilicon decoder
/// (`OMX.hisi.*` and `c2.hisi.*`) so Media3 picks
/// `c2.android.avc.decoder` ahead of `c2.hisi.avc.decoder` when
/// FFmpeg isn't available. Without this, the EMUI 11 C2 Hisi
/// decoder is chosen and fails after init — which decoder
/// fallback doesn't catch.
@UnstableApi
internal object Renderers {
fun build(context: Context): RenderersFactory {
return DefaultRenderersFactory(context)
fun build(context: Context, surfaceSizer: FfmpegSurfaceSizer): RenderersFactory {
return object : DefaultRenderersFactory(context) {
override fun buildVideoRenderers(
context: Context,
extensionRendererMode: Int,
mediaCodecSelector: MediaCodecSelector,
enableDecoderFallback: Boolean,
eventHandler: Handler,
eventListener: VideoRendererEventListener,
allowedVideoJoiningTimeMs: Long,
out: ArrayList<Renderer>,
) {
if (FfmpegLibrary.isAvailable()) {
out.add(
FfmpegVideoRenderer(
allowedVideoJoiningTimeMs,
eventHandler,
eventListener,
MAX_DROPPED_VIDEO_FRAME_COUNT_TO_NOTIFY,
surfaceSizer,
),
)
}
super.buildVideoRenderers(
context,
extensionRendererMode,
mediaCodecSelector,
enableDecoderFallback,
eventHandler,
eventListener,
allowedVideoJoiningTimeMs,
out,
)
}
}
.setEnableDecoderFallback(true)
.setMediaCodecSelector { mimeType, requiresSecure, requiresTunneling ->
val infos = MediaCodecSelector.DEFAULT.getDecoderInfos(
@@ -31,7 +80,12 @@ internal object Renderers {
val ok = ArrayList<MediaCodecInfo>(infos.size)
val broken = ArrayList<MediaCodecInfo>()
for (info in infos) {
if (info.name.startsWith("OMX.hisi.")) broken.add(info) else ok.add(info)
val name = info.name.lowercase()
if (name.startsWith("omx.hisi.") || name.startsWith("c2.hisi.")) {
broken.add(info)
} else {
ok.add(info)
}
}
ok.addAll(broken)
ok

19
android/src/main/kotlin/io/swipelab/ux/video/VideoCompositor.kt
View File

@@ -77,7 +77,7 @@ internal class VideoCompositor(
private var eglPbufferSurface: EGLSurface = EGL14.EGL_NO_SURFACE
private var eglWindowSurface: EGLSurface = EGL14.EGL_NO_SURFACE
private var inputTextureId: Int = 0
private var inputSurfaceTexture: SurfaceTexture? = null
@Volatile private var inputSurfaceTexture: SurfaceTexture? = null
private var inputSurface: Surface? = null
private var program: Int = 0
@@ -128,6 +128,23 @@ internal class VideoCompositor(
}
}
/// Sizes the codec-input SurfaceTexture's buffer dimensions. For
/// MediaCodec this is unnecessary — the codec writes via native
/// surface APIs that auto-size the SurfaceTexture buffer to the
/// encoded frame. For our FFmpeg path the codec writes via an EGL
/// window surface (created from this Surface), and eglCreateWindow
/// Surface inherits the SurfaceTexture's defaultBufferSize at
/// creation time and never re-queries. Without this hook the EGL
/// surface is created at whatever default the SurfaceTexture is in
/// (1×1 in practice) and the rendered quad is squashed to one pixel
/// that the downstream blit then stretches across the whole Flutter
/// texture — looks like a solid fill. Safe to call from any thread.
fun setInputSurfaceSize(width: Int, height: Int) {
if (disposed) return
if (width <= 0 || height <= 0) return
inputSurfaceTexture?.setDefaultBufferSize(width, height)
}
fun setDisplaySize(width: Int, height: Int) {
if (disposed) return
if (width <= 0 || height <= 0) return

10
android/src/main/kotlin/io/swipelab/ux/video/VideoPlayerInstance.kt
View File

@@ -35,7 +35,6 @@ internal class VideoPlayerInstance(
val textureId: Long get() = textureEntry.id()
private val mainHandler = Handler(Looper.getMainLooper())
private val player: ExoPlayer = ExoPlayer.Builder(context, Renderers.build(context)).build()
/// Wrapped around the Flutter `SurfaceTextureEntry`'s `SurfaceTexture`.
/// We deliberately do NOT call `setDefaultBufferSize` here — that
@@ -77,6 +76,15 @@ internal class VideoPlayerInstance(
},
)
private val player: ExoPlayer = ExoPlayer.Builder(
context,
// FFmpeg renderer calls this on its own thread before it builds
// an EGL window surface against the codec-input Surface. Sizes
// the compositor's INPUT SurfaceTexture so the EGL surface
// inherits matching buffer dimensions on creation.
Renderers.build(context) { w, h -> compositor.setInputSurfaceSize(w, h) },
).build()
private var disposed = false
private var firstFrameRendered = false
private var stateReady = false

167
docs/architecture.md Normal file
View File

@@ -0,0 +1,167 @@
# ux — architecture
This doc maps the load-bearing modules in the `ux` Flutter package: where
each lives, what it owns, and which native pieces back it on each
platform. Banlu is the primary consumer; everything here is meant to be
reusable across other Flutter apps that depend on `ux`.
Conventions:
* Source paths are anchored at the package root (e.g. `lib/src/...`).
* Native paths use `android/...` and `darwin/...` (shared
iOS+macOS sources) or `ios/` / `macos/` (platform-specific).
* "Banned" means: don't reintroduce. Lints and tests exist to catch
regressions where applicable.
---
## Module map
| Module | Dart | Android | Apple |
|---|---|---|---|
| `XKeyboard` — frame-accurate keyboard tracking + interactive dismiss | [lib/src/keyboard/](../lib/src/keyboard/) | [android/src/main/jni/keyboard_bridge.c](../android/src/main/jni/keyboard_bridge.c) | [darwin/Keyboard/](../darwin/Keyboard/) |
| `XSensors` — gyro / accelerometer over JNI/FFI | [lib/src/sensors/](../lib/src/sensors/) | [android/src/main/jni/sensor_bridge.c](../android/src/main/jni/sensor_bridge.c) | [darwin/Sensors/](../darwin/Sensors/) |
| `XCamera` — CameraX (Android) / AVCaptureSession (Apple) | [lib/src/camera/](../lib/src/camera/) | [android/src/main/kotlin/io/swipelab/ux/camera/](../android/src/main/kotlin/io/swipelab/ux/camera/) | [darwin/Camera/](../darwin/Camera/) |
| `XScanner` — ZXing QR scanner (Android) / VNDetect (Apple) | [lib/src/scanner/](../lib/src/scanner/) | [android/src/main/kotlin/io/swipelab/ux/scanner/](../android/src/main/kotlin/io/swipelab/ux/scanner/) | [darwin/Scanner/](../darwin/Scanner/) |
| `XVideoPlayer` — ExoPlayer (Android) / AVPlayer (Apple) | [lib/src/video/](../lib/src/video/) | [android/src/main/kotlin/io/swipelab/ux/video/](../android/src/main/kotlin/io/swipelab/ux/video/) | [darwin/Video/](../darwin/Video/) |
| `XFile`, `XNotifications`, `XWindow`, navi — see source | [lib/src/](../lib/src/) | mixed | mixed |
---
## Video pipeline (Android)
The Android video stack is the most involved piece in `ux` because it
spans four cooperating layers (Dart controller → Kotlin player
instance → Media3 ExoPlayer → GL compositor → Flutter texture). It
also carries the most production-load-bearing fix: a vendored FFmpeg
video decoder that fronts the platform `MediaCodec` path for files
the OEM hardware decoder can't handle.
### Layers
```
Dart XVideoPlayerController (lib/src/video/x_video_player.dart)
│ MethodChannel `ux/video`
▼
Kotlin VideoPlayerInstance (one per Dart controller)
│ owns:
│ ├── ExoPlayer (Media3 1.9.2; renderers wired via Renderers.kt)
│ ├── VideoCompositor (codec output → Flutter texture; GL blit)
│ └── Flutter SurfaceTextureEntry (the texture id Dart Texture() samples)
▼
Native Media3 video renderer
│ tier 1: FfmpegVideoRenderer (libavcodec, SW decode, GL YUV→RGB)
│ tier 2: MediaCodecVideoRenderer (HW path; HiSilicon C2 decoders
│ deprioritised so EMUI 10/11 falls through to c2.android.avc.decoder)
▼
GL SurfaceTexture (compositor input)
│ compositor reads + applies SurfaceTexture transform
│ blits to Flutter SurfaceTexture (output)
▼
Flutter Texture widget samples the SurfaceTexture, scales to widget size
```
### Files
| What | Where |
|---|---|
| Dart controller | [lib/src/video/x_video_player.dart](../lib/src/video/x_video_player.dart) |
| MethodChannel binding | [lib/src/video/x_video_player_channel.dart](../lib/src/video/x_video_player_channel.dart) |
| Texture widget | [lib/src/video/x_video_player_view.dart](../lib/src/video/x_video_player_view.dart) |
| Per-controller native player | [android/src/main/kotlin/io/swipelab/ux/video/VideoPlayerInstance.kt](../android/src/main/kotlin/io/swipelab/ux/video/VideoPlayerInstance.kt) |
| ExoPlayer renderer factory | [android/src/main/kotlin/io/swipelab/ux/video/Renderers.kt](../android/src/main/kotlin/io/swipelab/ux/video/Renderers.kt) |
| GL blit between codec and Flutter texture | [android/src/main/kotlin/io/swipelab/ux/video/VideoCompositor.kt](../android/src/main/kotlin/io/swipelab/ux/video/VideoCompositor.kt) |
| FFmpeg renderer (Java) | [android/src/main/java/io/swipelab/ux/video/ffmpeg/](../android/src/main/java/io/swipelab/ux/video/ffmpeg/) |
| FFmpeg JNI source | [android/ffmpeg/ffmpeg_jni.cc](../android/ffmpeg/ffmpeg_jni.cc) |
| FFmpeg build orchestrator | [android/ffmpeg/build_ffmpeg.sh](../android/ffmpeg/build_ffmpeg.sh) |
### Renderer selection (`Renderers.kt`)
`Renderers.build(context, surfaceSizer)` returns a `DefaultRenderersFactory`
subclass that builds the video renderer list with FFmpeg first and
MediaCodec second:
1. **`FfmpegVideoRenderer`** — picked when `FfmpegLibrary.isAvailable()`
returns true (i.e. `libffmpegJNI.so` is loaded for the device's ABI)
*and* the format is H.264. Software decode via libavcodec, no DPB
cap, handles iOS `yuvj420p` (full-range) and deep B-frame reorder
structures that defeat platform decoders on older Huawei silicon.
YUV→RGB happens in a one-pass GLES2 shader inside
`FfmpegOutputSurface`. Y plane uses `GL_NEAREST` filtering (1:1
sized to the EGL surface, sampling at exact texel centres preserves
luma detail); chroma uses `GL_LINEAR` for clean 4:2:0 upsampling.
2. **`MediaCodecVideoRenderer`** (Media3 default) — picked for any
other format, or if FFmpeg is unavailable. Two non-default tweaks:
* `setEnableDecoderFallback(true)` so init-time failures bounce to
the next decoder.
* Custom `MediaCodecSelector` deprioritises every HiSilicon
decoder (`OMX.hisi.*` and `c2.hisi.*`). The EMUI 10 OMX variant
fails codec start (caught by fallback); the EMUI 11 C2 variant
initialises cleanly but errors on the first sample, which
fallback can't catch — name-based deprioritisation is the only
way past it when FFmpeg is unavailable for that ABI.
The two-tier design is intentional: FFmpeg adds a slight battery cost
vs. hardware decoding, but it's the only path that reliably plays the
full range of producer-side content (iOS recordings in particular).
Hardware stays as the fallback for the formats and devices where it
works.
### Why we vendor an FFmpeg video renderer
Media3's published `decoder-ffmpeg` is audio-only.
`ExperimentalFfmpegVideoRenderer` in the same library has been a stub
since 2020 (`createDecoder` returns null, `supportsFormat` returns
`FORMAT_UNSUPPORTED_TYPE`). The only well-maintained community
alternative (NextLib) is GPL-3.0 — would impose copyleft on every
consumer. So we ship our own Apache-licensed JNI on top of the LGPL
FFmpeg, vendored under `android/ffmpeg/`.
### How the FFmpeg `.so` gets built
There are no native binaries in the repo. The `:ux:buildFfmpegJni`
Gradle task (wired to `preBuild` in
[android/build.gradle](../android/build.gradle)) handles everything:
1. Clones Media3 (`1.9.2`) and FFmpeg (`release/6.0`) into the
consumer's `build/ffmpeg-work/` on first run.
2. Drops the vendored `ffmpeg_jni.cc` + `CMakeLists.txt` over the
upstream copies (so the produced JNI exposes the video entry points
`FfmpegVideoDecoder.java` calls).
3. Cross-builds FFmpeg static libs (H.264 only) for all 4 Android ABIs.
4. Links `libffmpegJNI.so` per ABI and writes them into
`<ux-build>/jniLibs/<abi>/`, which AGP picks up via
`sourceSets.main.jniLibs.srcDirs +=`.
Up-to-date checking on `ffmpeg_jni.cc` + `CMakeLists.txt` +
`build_ffmpeg.sh` means subsequent builds skip the task entirely. The
slow part (FFmpeg static-lib build, ~30 min on an x86 host, ~2 min on
Apple Silicon) only happens on the first build for a given checkout,
or after a `gradle clean`.
License: FFmpeg is LGPL v2.1, linked dynamically at runtime via
`System.loadLibrary("ffmpegJNI")` — the LGPL boundary stays intact.
The build config omits `--enable-gpl` and `--enable-nonfree`. See
[android/ffmpeg/LICENSE-FFMPEG.txt](../android/ffmpeg/LICENSE-FFMPEG.txt)
and [android/ffmpeg/README.md](../android/ffmpeg/README.md).
### Looping and end-of-stream
`XVideoPlayerController.setLooping(true)` maps to ExoPlayer's
`REPEAT_MODE_ONE` (the entire seek-to-0-and-resume cycle is handled
in-engine). Non-looping playback emits a `completed` event when
`STATE_ENDED` is reached without repeat — see
`VideoPlayerInstance.kt`. Consumers that need tap-play-at-end-restarts
behavior (Telegram parity) check `position` against `duration` on the
Dart side and call `seekTo(Duration.zero)` before `play()` when within
2 seconds of the end.
---
## Video pipeline (Apple)
`AVPlayer` + `AVPlayerItem` + `AVPlayerItemVideoOutput`. No FFmpeg
fallback needed — `AVFoundation` handles iOS-produced H.264 (and HEVC)
directly without the DPB-cap / full-range quirks the Android platform
decoders trip over. See
[darwin/Video/VideoPlayerInstance.swift](../darwin/Video/VideoPlayerInstance.swift).