MediaMuxer 视频文件大小减少(重新压缩，降低分辨率) [英] MediaMuxer video file size reducing (re-compress, decrease resolution)
本文介绍了MediaMuxer 视频文件大小减少(重新压缩，降低分辨率)的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在寻找有效的方法来减少一些视频的重量(作为 File，用于上传)并且显而易见的答案是:让我们降低分辨率！(不需要全高清或 4K，简单的高清对我来说就足够了)我尝试了很多方法，这些方法应该可以通过很多 API(需要 10 个)工作，最好的方法是使用 android-ffmpeg-java，但是......在我几乎当前的旗舰设备上，整个过程持续大约 length_of_video*4 秒，还有这个 lib 重量是 9 Mb，这个数量会增加我的应用程序大小......不！(12 Mb 到 1 Mb 是不错的结果，但仍然有太多缺陷)
I'm looking for efficient way to reduce some video weight (as a File, for upload) and obvious answer for that is: lets reduce resolution! (fullHD or 4K not needed, simple HD is sufficient for me) I've tried lot of ways which should work through lot of APIs (needed 10) and best way was using android-ffmpeg-java, BUT... on my pretty fast almost-current flagship device whole process lasts about length_of_video*4 seconds and also this lib weight is 9 Mb, this amount increases my app size... No wai! (12 Mb to 1 Mb is nice result, but still too many flaws)
所以我决定使用原生 Android 方式来做到这一点，MediaMuxer 和 MediaCodec - 它们分别可从 API18 和 API16 获得(旧设备用户:抱歉；但他们也经常有低分辨率"的相机).下面的方法几乎有效 - MediaMuxer 不尊重 MediaFormat.KEY_WIDTH 和 MediaFormat.KEY_HEIGHT - 提取的 File被重新压缩"，重量小了一点，但分辨率和原视频一样File...
So I've decided to use native Android ways to do this, MediaMuxer and MediaCodec - they are available from API18 and API16 respectivelly (older devices users: sorry; but they also often have "lower-res" camera). Below method almost works - MediaMuxer do NOT respect MediaFormat.KEY_WIDTH and MediaFormat.KEY_HEIGHT - extracted File is "re-compressed", weight is a bit smaller, but resolution is the same as in original video File...
那么，问题:如何使用 MediaMuxer 和其他附带的类和方法来压缩和重新缩放/更改视频的分辨率?
So, question: How to compress and re-scale/change resolution of video using MediaMuxer and other accompanying classes and methods?
public File getCompressedFile(String videoPath) throws IOException{
MediaExtractor extractor = new MediaExtractor();
extractor.setDataSource(videoPath);
int trackCount = extractor.getTrackCount();
String filePath = videoPath.substring(0, videoPath.lastIndexOf(File.separator));
String[] splitByDot = videoPath.split("\.");
String ext="";
if(splitByDot!=null && splitByDot.length>1)
ext = splitByDot[splitByDot.length-1];
String fileName = videoPath.substring(videoPath.lastIndexOf(File.separator)+1,
videoPath.length());
if(ext.length()>0)
fileName=fileName.replace("."+ext, "_out."+ext);
else
fileName=fileName.concat("_out");
final File outFile = new File(filePath, fileName);
if(!outFile.exists())
outFile.createNewFile();
MediaMuxer muxer = new MediaMuxer(outFile.getAbsolutePath(),
MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
HashMap<Integer, Integer> indexMap = new HashMap<Integer, Integer>(trackCount);
for (int i = 0; i < trackCount; i++) {
extractor.selectTrack(i);
MediaFormat format = extractor.getTrackFormat(i);
String mime = format.getString(MediaFormat.KEY_MIME);
if(mime!=null && mime.startsWith("video")){
int currWidth = format.getInteger(MediaFormat.KEY_WIDTH);
int currHeight = format.getInteger(MediaFormat.KEY_HEIGHT);
format.setInteger(MediaFormat.KEY_WIDTH, currWidth>currHeight ? 960 : 540);
format.setInteger(MediaFormat.KEY_HEIGHT, currWidth>currHeight ? 540 : 960);
//API19 MediaFormat.KEY_MAX_WIDTH and KEY_MAX_HEIGHT
format.setInteger("max-width", format.getInteger(MediaFormat.KEY_WIDTH));
format.setInteger("max-height", format.getInteger(MediaFormat.KEY_HEIGHT));
}
int dstIndex = muxer.addTrack(format);
indexMap.put(i, dstIndex);
}
boolean sawEOS = false;
int bufferSize = 256 * 1024;
int offset = 100;
ByteBuffer dstBuf = ByteBuffer.allocate(bufferSize);
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
muxer.start();
while (!sawEOS) {
bufferInfo.offset = offset;
bufferInfo.size = extractor.readSampleData(dstBuf, offset);
if (bufferInfo.size < 0) {
sawEOS = true;
bufferInfo.size = 0;
} else {
bufferInfo.presentationTimeUs = extractor.getSampleTime();
bufferInfo.flags = extractor.getSampleFlags();
int trackIndex = extractor.getSampleTrackIndex();
muxer.writeSampleData(indexMap.get(trackIndex), dstBuf,
bufferInfo);
extractor.advance();
}
}
muxer.stop();
muxer.release();
return outFile;
}
附注.关于 muxer 的很多有用的东西这里，上面的代码基于 MediaMuxerTest.java，方法cloneMediaUsingMuxer
PS. lot of usefull stuff about muxer here, above code bases on MediaMuxerTest.java, method cloneMediaUsingMuxer
推荐答案
基于 bigflake.com/mediacodec/(关于媒体类的很棒的知识来源)我尝试了几种方法，最后 ExtractDecodeEditEncodeMuxTest 结果非常有帮助.bigflake 网站上的文章中未描述此测试，但可以在 此处 旁边的文本中提到的其他类.
Basing on bigflake.com/mediacodec/ (awesome source of knowledge about Media-classes) I've tried few ways and finally ExtractDecodeEditEncodeMuxTest turned out very helpfull. This test wasn't described in article on bigflake site, but it can be found HERE next to other classes mentioned in text.
所以，我从上面提到的 ExtractDecodeEditEncodeMuxTest 类中复制了大部分代码，它是:VideoResolutionChanger.它为我提供了来自 16 Mb fullHD 的 2Mb 高清视频.好的！而且速度快！在我的设备上，整个过程比输入视频持续时间长一点，例如10 秒视频输入 ->11-12 秒的处理.使用 ffmpeg-java 大约需要 40 秒或更长时间(应用程序需要 9 Mb).
So, I've copied most of code from above mentioned ExtractDecodeEditEncodeMuxTest class and there it is: VideoResolutionChanger. It gives me 2Mb HD video from 16 Mb fullHD. Nice! And fast! On my device whole process is a bit longer than input video duration, e.g. 10 secs video input -> 11-12 secs of processing. With ffmpeg-java it would be smth about 40 secs or more (and 9 Mb more for app).
我们开始:
VideoResolutionChanger:
@TargetApi(18)
public class VideoResolutionChanger {
private static final int TIMEOUT_USEC = 10000;
private static final String OUTPUT_VIDEO_MIME_TYPE = "video/avc";
private static final int OUTPUT_VIDEO_BIT_RATE = 2048 * 1024;
private static final int OUTPUT_VIDEO_FRAME_RATE = 30;
private static final int OUTPUT_VIDEO_IFRAME_INTERVAL = 10;
private static final int OUTPUT_VIDEO_COLOR_FORMAT =
MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface;
private static final String OUTPUT_AUDIO_MIME_TYPE = "audio/mp4a-latm";
private static final int OUTPUT_AUDIO_CHANNEL_COUNT = 2;
private static final int OUTPUT_AUDIO_BIT_RATE = 128 * 1024;
private static final int OUTPUT_AUDIO_AAC_PROFILE =
MediaCodecInfo.CodecProfileLevel.AACObjectHE;
private static final int OUTPUT_AUDIO_SAMPLE_RATE_HZ = 44100;
private int mWidth = 1280;
private int mHeight = 720;
private String mOutputFile, mInputFile;
public String changeResolution(File f)
throws Throwable {
mInputFile=f.getAbsolutePath();
String filePath = mInputFile.substring(0, mInputFile.lastIndexOf(File.separator));
String[] splitByDot = mInputFile.split("\.");
String ext="";
if(splitByDot!=null && splitByDot.length>1)
ext = splitByDot[splitByDot.length-1];
String fileName = mInputFile.substring(mInputFile.lastIndexOf(File.separator)+1,
mInputFile.length());
if(ext.length()>0)
fileName=fileName.replace("."+ext, "_out.mp4");
else
fileName=fileName.concat("_out.mp4");
final File outFile = new File(Environment.getExternalStorageDirectory(), fileName);
if(!outFile.exists())
outFile.createNewFile();
mOutputFile=outFile.getAbsolutePath();
ChangerWrapper.changeResolutionInSeparatedThread(this);
return mOutputFile;
}
private static class ChangerWrapper implements Runnable {
private Throwable mThrowable;
private VideoResolutionChanger mChanger;
private ChangerWrapper(VideoResolutionChanger changer) {
mChanger = changer;
}
@Override
public void run() {
try {
mChanger.prepareAndChangeResolution();
} catch (Throwable th) {
mThrowable = th;
}
}
public static void changeResolutionInSeparatedThread(VideoResolutionChanger changer)
throws Throwable {
ChangerWrapper wrapper = new ChangerWrapper(changer);
Thread th = new Thread(wrapper, ChangerWrapper.class.getSimpleName());
th.start();
th.join();
if (wrapper.mThrowable != null)
throw wrapper.mThrowable;
}
}
private void prepareAndChangeResolution() throws Exception {
Exception exception = null;
MediaCodecInfo videoCodecInfo = selectCodec(OUTPUT_VIDEO_MIME_TYPE);
if (videoCodecInfo == null)
return;
MediaCodecInfo audioCodecInfo = selectCodec(OUTPUT_AUDIO_MIME_TYPE);
if (audioCodecInfo == null)
return;
MediaExtractor videoExtractor = null;
MediaExtractor audioExtractor = null;
OutputSurface outputSurface = null;
MediaCodec videoDecoder = null;
MediaCodec audioDecoder = null;
MediaCodec videoEncoder = null;
MediaCodec audioEncoder = null;
MediaMuxer muxer = null;
InputSurface inputSurface = null;
try {
videoExtractor = createExtractor();
int videoInputTrack = getAndSelectVideoTrackIndex(videoExtractor);
MediaFormat inputFormat = videoExtractor.getTrackFormat(videoInputTrack);
MediaMetadataRetriever m = new MediaMetadataRetriever();
m.setDataSource(mInputFile);
int inputWidth, inputHeight;
try {
inputWidth = Integer.parseInt(m.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH));
inputHeight = Integer.parseInt(m.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT));
} catch (Exception e) {
Bitmap thumbnail = m.getFrameAtTime();
inputWidth = thumbnail.getWidth();
inputHeight = thumbnail.getHeight();
thumbnail.recycle();
}
if(inputWidth>inputHeight){
if(mWidth<mHeight){
int w = mWidth;
mWidth=mHeight;
mHeight=w;
}
}
else{
if(mWidth>mHeight){
int w = mWidth;
mWidth=mHeight;
mHeight=w;
}
}
MediaFormat outputVideoFormat =
MediaFormat.createVideoFormat(OUTPUT_VIDEO_MIME_TYPE, mWidth, mHeight);
outputVideoFormat.setInteger(
MediaFormat.KEY_COLOR_FORMAT, OUTPUT_VIDEO_COLOR_FORMAT);
outputVideoFormat.setInteger(MediaFormat.KEY_BIT_RATE, OUTPUT_VIDEO_BIT_RATE);
outputVideoFormat.setInteger(MediaFormat.KEY_FRAME_RATE, OUTPUT_VIDEO_FRAME_RATE);
outputVideoFormat.setInteger(
MediaFormat.KEY_I_FRAME_INTERVAL, OUTPUT_VIDEO_IFRAME_INTERVAL);
AtomicReference<Surface> inputSurfaceReference = new AtomicReference<Surface>();
videoEncoder = createVideoEncoder(
videoCodecInfo, outputVideoFormat, inputSurfaceReference);
inputSurface = new InputSurface(inputSurfaceReference.get());
inputSurface.makeCurrent();
outputSurface = new OutputSurface();
videoDecoder = createVideoDecoder(inputFormat, outputSurface.getSurface());
audioExtractor = createExtractor();
int audioInputTrack = getAndSelectAudioTrackIndex(audioExtractor);
MediaFormat inputAudioFormat = audioExtractor.getTrackFormat(audioInputTrack);
MediaFormat outputAudioFormat =
MediaFormat.createAudioFormat(inputAudioFormat.getString(MediaFormat.KEY_MIME),
inputAudioFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE),
inputAudioFormat.getInteger(MediaFormat.KEY_CHANNEL_COUNT));
outputAudioFormat.setInteger(MediaFormat.KEY_BIT_RATE, OUTPUT_AUDIO_BIT_RATE);
outputAudioFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, OUTPUT_AUDIO_AAC_PROFILE);
audioEncoder = createAudioEncoder(audioCodecInfo, outputAudioFormat);
audioDecoder = createAudioDecoder(inputAudioFormat);
muxer = new MediaMuxer(mOutputFile, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
changeResolution(videoExtractor, audioExtractor,
videoDecoder, videoEncoder,
audioDecoder, audioEncoder,
muxer, inputSurface, outputSurface);
} finally {
try {
if (videoExtractor != null)
videoExtractor.release();
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (audioExtractor != null)
audioExtractor.release();
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (videoDecoder != null) {
videoDecoder.stop();
videoDecoder.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (outputSurface != null) {
outputSurface.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (videoEncoder != null) {
videoEncoder.stop();
videoEncoder.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (audioDecoder != null) {
audioDecoder.stop();
audioDecoder.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (audioEncoder != null) {
audioEncoder.stop();
audioEncoder.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (muxer != null) {
muxer.stop();
muxer.release();
}
} catch(Exception e) {
if (exception == null)
exception = e;
}
try {
if (inputSurface != null)
inputSurface.release();
} catch(Exception e) {
if (exception == null)
exception = e;
}
}
if (exception != null)
throw exception;
}
private MediaExtractor createExtractor() throws IOException {
MediaExtractor extractor;
extractor = new MediaExtractor();
extractor.setDataSource(mInputFile);
return extractor;
}
private MediaCodec createVideoDecoder(MediaFormat inputFormat, Surface surface) throws IOException {
MediaCodec decoder = MediaCodec.createDecoderByType(getMimeTypeFor(inputFormat));
decoder.configure(inputFormat, surface, null, 0);
decoder.start();
return decoder;
}
private MediaCodec createVideoEncoder(MediaCodecInfo codecInfo, MediaFormat format,
AtomicReference<Surface> surfaceReference) throws IOException {
MediaCodec encoder = MediaCodec.createByCodecName(codecInfo.getName());
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
surfaceReference.set(encoder.createInputSurface());
encoder.start();
return encoder;
}
private MediaCodec createAudioDecoder(MediaFormat inputFormat) throws IOException {
MediaCodec decoder = MediaCodec.createDecoderByType(getMimeTypeFor(inputFormat));
decoder.configure(inputFormat, null, null, 0);
decoder.start();
return decoder;
}
private MediaCodec createAudioEncoder(MediaCodecInfo codecInfo, MediaFormat format) throws IOException {
MediaCodec encoder = MediaCodec.createByCodecName(codecInfo.getName());
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
encoder.start();
return encoder;
}
private int getAndSelectVideoTrackIndex(MediaExtractor extractor) {
for (int index = 0; index < extractor.getTrackCount(); ++index) {
if (isVideoFormat(extractor.getTrackFormat(index))) {
extractor.selectTrack(index);
return index;
}
}
return -1;
}
private int getAndSelectAudioTrackIndex(MediaExtractor extractor) {
for (int index = 0; index < extractor.getTrackCount(); ++index) {
if (isAudioFormat(extractor.getTrackFormat(index))) {
extractor.selectTrack(index);
return index;
}
}
return -1;
}
private void changeResolution(MediaExtractor videoExtractor, MediaExtractor audioExtractor,
MediaCodec videoDecoder, MediaCodec videoEncoder,
MediaCodec audioDecoder, MediaCodec audioEncoder,
MediaMuxer muxer,
InputSurface inputSurface, OutputSurface outputSurface) {
ByteBuffer[] videoDecoderInputBuffers = null;
ByteBuffer[] videoDecoderOutputBuffers = null;
ByteBuffer[] videoEncoderOutputBuffers = null;
MediaCodec.BufferInfo videoDecoderOutputBufferInfo = null;
MediaCodec.BufferInfo videoEncoderOutputBufferInfo = null;
videoDecoderInputBuffers = videoDecoder.getInputBuffers();
videoDecoderOutputBuffers = videoDecoder.getOutputBuffers();
videoEncoderOutputBuffers = videoEncoder.getOutputBuffers();
videoDecoderOutputBufferInfo = new MediaCodec.BufferInfo();
videoEncoderOutputBufferInfo = new MediaCodec.BufferInfo();
ByteBuffer[] audioDecoderInputBuffers = null;
ByteBuffer[] audioDecoderOutputBuffers = null;
ByteBuffer[] audioEncoderInputBuffers = null;
ByteBuffer[] audioEncoderOutputBuffers = null;
MediaCodec.BufferInfo audioDecoderOutputBufferInfo = null;
MediaCodec.BufferInfo audioEncoderOutputBufferInfo = null;
audioDecoderInputBuffers = audioDecoder.getInputBuffers();
audioDecoderOutputBuffers = audioDecoder.getOutputBuffers();
audioEncoderInputBuffers = audioEncoder.getInputBuffers();
audioEncoderOutputBuffers = audioEncoder.getOutputBuffers();
audioDecoderOutputBufferInfo = new MediaCodec.BufferInfo();
audioEncoderOutputBufferInfo = new MediaCodec.BufferInfo();
MediaFormat decoderOutputVideoFormat = null;
MediaFormat decoderOutputAudioFormat = null;
MediaFormat encoderOutputVideoFormat = null;
MediaFormat encoderOutputAudioFormat = null;
int outputVideoTrack = -1;
int outputAudioTrack = -1;
boolean videoExtractorDone = false;
boolean videoDecoderDone = false;
boolean videoEncoderDone = false;
boolean audioExtractorDone = false;
boolean audioDecoderDone = false;
boolean audioEncoderDone = false;
int pendingAudioDecoderOutputBufferIndex = -1;
boolean muxing = false;
while ((!videoEncoderDone) || (!audioEncoderDone)) {
while (!videoExtractorDone
&& (encoderOutputVideoFormat == null || muxing)) {
int decoderInputBufferIndex = videoDecoder.dequeueInputBuffer(TIMEOUT_USEC);
if (decoderInputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break;
ByteBuffer decoderInputBuffer = videoDecoderInputBuffers[decoderInputBufferIndex];
int size = videoExtractor.readSampleData(decoderInputBuffer, 0);
long presentationTime = videoExtractor.getSampleTime();
if (size >= 0) {
videoDecoder.queueInputBuffer(
decoderInputBufferIndex,
0,
size,
presentationTime,
videoExtractor.getSampleFlags());
}
videoExtractorDone = !videoExtractor.advance();
if (videoExtractorDone)
videoDecoder.queueInputBuffer(decoderInputBufferIndex,
0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
break;
}
while (!audioExtractorDone
&& (encoderOutputAudioFormat == null || muxing)) {
int decoderInputBufferIndex = audioDecoder.dequeueInputBuffer(TIMEOUT_USEC);
if (decoderInputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break;
ByteBuffer decoderInputBuffer = audioDecoderInputBuffers[decoderInputBufferIndex];
int size = audioExtractor.readSampleData(decoderInputBuffer, 0);
long presentationTime = audioExtractor.getSampleTime();
if (size >= 0)
audioDecoder.queueInputBuffer(decoderInputBufferIndex, 0, size,
presentationTime, audioExtractor.getSampleFlags());
audioExtractorDone = !audioExtractor.advance();
if (audioExtractorDone)
audioDecoder.queueInputBuffer(decoderInputBufferIndex, 0, 0,
0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
break;
}
while (!videoDecoderDone
&& (encoderOutputVideoFormat == null || muxing)) {
int decoderOutputBufferIndex =
videoDecoder.dequeueOutputBuffer(
videoDecoderOutputBufferInfo, TIMEOUT_USEC);
if (decoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break;
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
videoDecoderOutputBuffers = videoDecoder.getOutputBuffers();
break;
}
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
decoderOutputVideoFormat = videoDecoder.getOutputFormat();
break;
}
ByteBuffer decoderOutputBuffer =
videoDecoderOutputBuffers[decoderOutputBufferIndex];
if ((videoDecoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG)
!= 0) {
videoDecoder.releaseOutputBuffer(decoderOutputBufferIndex, false);
break;
}
boolean render = videoDecoderOutputBufferInfo.size != 0;
videoDecoder.releaseOutputBuffer(decoderOutputBufferIndex, render);
if (render) {
outputSurface.awaitNewImage();
outputSurface.drawImage();
inputSurface.setPresentationTime(
videoDecoderOutputBufferInfo.presentationTimeUs * 1000);
inputSurface.swapBuffers();
}
if ((videoDecoderOutputBufferInfo.flags
& MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
videoDecoderDone = true;
videoEncoder.signalEndOfInputStream();
}
break;
}
while (!audioDecoderDone && pendingAudioDecoderOutputBufferIndex == -1
&& (encoderOutputAudioFormat == null || muxing)) {
int decoderOutputBufferIndex =
audioDecoder.dequeueOutputBuffer(
audioDecoderOutputBufferInfo, TIMEOUT_USEC);
if (decoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break;
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
audioDecoderOutputBuffers = audioDecoder.getOutputBuffers();
break;
}
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
decoderOutputAudioFormat = audioDecoder.getOutputFormat();
break;
}
ByteBuffer decoderOutputBuffer =
audioDecoderOutputBuffers[decoderOutputBufferIndex];
if ((audioDecoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG)
!= 0) {
audioDecoder.releaseOutputBuffer(decoderOutputBufferIndex, false);
break;
}
pendingAudioDecoderOutputBufferIndex = decoderOutputBufferIndex;
break;
}
while (pendingAudioDecoderOutputBufferIndex != -1) {
int encoderInputBufferIndex = audioEncoder.dequeueInputBuffer(TIMEOUT_USEC);
ByteBuffer encoderInputBuffer = audioEncoderInputBuffers[encoderInputBufferIndex];
int size = audioDecoderOutputBufferInfo.size;
long presentationTime = audioDecoderOutputBufferInfo.presentationTimeUs;
if (size >= 0) {
ByteBuffer decoderOutputBuffer =
audioDecoderOutputBuffers[pendingAudioDecoderOutputBufferIndex]
.duplicate();
decoderOutputBuffer.position(audioDecoderOutputBufferInfo.offset);
decoderOutputBuffer.limit(audioDecoderOutputBufferInfo.offset + size);
encoderInputBuffer.position(0);
encoderInputBuffer.put(decoderOutputBuffer);
audioEncoder.queueInputBuffer(
encoderInputBufferIndex,
0,
size,
presentationTime,
audioDecoderOutputBufferInfo.flags);
}
audioDecoder.releaseOutputBuffer(pendingAudioDecoderOutputBufferIndex, false);
pendingAudioDecoderOutputBufferIndex = -1;
if ((audioDecoderOutputBufferInfo.flags
& MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0)
audioDecoderDone = true;
break;
}
while (!videoEncoderDone
&& (encoderOutputVideoFormat == null || muxing)) {
int encoderOutputBufferIndex = videoEncoder.dequeueOutputBuffer(
videoEncoderOutputBufferInfo, TIMEOUT_USEC);
if (encoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break;
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
videoEncoderOutputBuffers = videoEncoder.getOutputBuffers();
break;
}
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
encoderOutputVideoFormat = videoEncoder.getOutputFormat();
break;
}
ByteBuffer encoderOutputBuffer =
videoEncoderOutputBuffers[encoderOutputBufferIndex];
if ((videoEncoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG)
!= 0) {
videoEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false);
break;
}
if (videoEncoderOutputBufferInfo.size != 0) {
muxer.writeSampleData(
outputVideoTrack, encoderOutputBuffer, videoEncoderOutputBufferInfo);
}
if ((videoEncoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM)
!= 0) {
videoEncoderDone = true;
}
videoEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false);
break;
}
while (!audioEncoderDone
&& (encoderOutputAudioFormat == null || muxing)) {
int encoderOutputBufferIndex = audioEncoder.dequeueOutputBuffer(
audioEncoderOutputBufferInfo, TIMEOUT_USEC);
if (encoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER) {
break;
}
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
audioEncoderOutputBuffers = audioEncoder.getOutputBuffers();
break;
}
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
encoderOutputAudioFormat = audioEncoder.getOutputFormat();
break;
}
ByteBuffer encoderOutputBuffer =
audioEncoderOutputBuffers[encoderOutputBufferIndex];
if ((audioEncoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG)
!= 0) {
audioEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false);
break;
}
if (audioEncoderOutputBufferInfo.size != 0)
muxer.writeSampleData(
outputAudioTrack, encoderOutputBuffer, audioEncoderOutputBufferInfo);
if ((audioEncoderOutputBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM)
!= 0)
audioEncoderDone = true;
audioEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false);
break;
}
if (!muxing && (encoderOutputAudioFormat != null)
&& (encoderOutputVideoFormat != null)) {
outputVideoTrack = muxer.addTrack(encoderOutputVideoFormat);
outputAudioTrack = muxer.addTrack(encoderOutputAudioFormat);
muxer.start();
muxing = true;
}
}
}
private static boolean isVideoFormat(MediaFormat format) {
return getMimeTypeFor(format).startsWith("video/");
}
private static boolean isAudioFormat(MediaFormat format) {
return getMimeTypeFor(format).startsWith("audio/");
}
private static String getMimeTypeFor(MediaFormat format) {
return format.getString(MediaFormat.KEY_MIME);
}
private static MediaCodecInfo selectCodec(String mimeType) {
int numCodecs = MediaCodecList.getCodecCount();
for (int i = 0; i < numCodecs; i++) {
MediaCodecInfo codecInfo = MediaCodecList.getCodecInfoAt(i);
if (!codecInfo.isEncoder()) {
continue;
}
String[] types = codecInfo.getSupportedTypes();
for (int j = 0; j < types.length; j++) {
if (types[j].equalsIgnoreCase(mimeType)) {
return codecInfo;
}
}
}
return null;
}
}
它还需要InputSurface、OutputSurface和TextureRender，它们放在ExtractDecodeEditEncodeMuxTest旁边(VideoResolutionChanger 放在同一个包中并像这样使用它:
it needs also InputSurface, OutputSurface and TextureRender, which are placed next to ExtractDecodeEditEncodeMuxTest (above HERE link). Put these three in same package with VideoResolutionChanger and use it like this:
try{
String pathToReEncodedFile =
new VideoResolutionChanger().changeResolution(videoFilePath);
}catch(Throwable t){/* smth wrong :( */}
其中 videoFilePath 可以使用 file.getAbsolutePath() 从 File 获得.
Where videoFilePath might be obtained from File using file.getAbsolutePath().
我知道这不是最干净的，也可能不是最有效/最高效的方式，但我最近两天一直在寻找类似的代码并找到了很多主题，这些主题大多数将我重定向到 INDE、ffmpeg 或 jcodec，其他没有得到正确的答案.所以我把它留在这里，明智地使用它！
I know it's not the cleanest and probably not most-effective/efficient way, but I've been looking for similar code for last two days and found lot of topics, which most redirected me to INDE, ffmpeg or jcodec, other were left without proper answer. So I'm leaving it here, use this wisely!
限制:
- 上面的 use-it-like-this 片段不能在主循环线程 (ui) 中启动，例如直接在
Activity里面.最好的方法是创建IntentService和 pass 输入文件路径Bundle中的>String.然后你可以直接在onHandleIntent; 中运行 - API18 及以上(引入了
MediaMuxer)； - API18当然需要
WRITE_EXTERNAL_STORAGE，API19及以上都有这个内置"；
changeResolution- above use-it-like-this snippet can not be started in main looper thread (ui), e.g. straight inside
Activity. best way is to createIntentServiceand pass input file pathStringinIntents extraBundle. Then you can runchangeResolutionstright insideonHandleIntent; - API18 and above (
MediaMuxerintroduced); - API18 needs of course
WRITE_EXTERNAL_STORAGE, API19 and above has this "built-in";
@fadden 谢谢您的工作和支持！:)
@fadden THANK YOU for your work and support! :)
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