MediaMuxer 视频文件大小减小（重新压缩，降低分辨率）
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【中文标题】MediaMuxer 视频文件大小减小（重新压缩，降低分辨率）【英文标题】：MediaMuxer video file size reducing (re-compress, decrease resolution) 【发布时间】：2015-07-08 16:52:05 【问题描述】：我正在寻找减少视频重量的有效方法（作为File，用于上传），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）我已经尝试了很多应该通过很多 API 工作的方法（需要 10 个），最好的方法是使用android-ffmpeg-java，但是...... -当前的旗舰设备整个过程持续大约 length_of_video*4 秒，而且这个 lib 重量是 9 Mb，这个数量增加了我的应用程序大小......不！ （12 Mb 到 1 Mb 是不错的结果，但还是有太多的缺陷）
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；但它们也经常有“低分辨率”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”，权重有点小，但分辨率与原视频File...
那么，问题：如何使用MediaMuxer 和其他随附的类和方法来压缩和重新缩放/更改视频分辨率？
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;
PS。关于 muxer here 的很多有用的东西，上面的代码基于 MediaMuxerTest.java，方法 cloneMediaUsingMuxer
【问题讨论】：
【参考方案1】：您可以在https://software.intel.com/en-us/articles/intel-inde-media-pack-for-android-tutorials 上试用 Intel INDE Media for Mobile，教程。它有一个示例，展示了如何使用它来转码=重新压缩视频文件。
您可以设置更小的分辨率和\或比特率来输出以获得更小的文件 https://github.com/INDExOS/media-for-mobile/blob/master/Android/samples/apps/src/com/intel/inde/mp/samples/ComposerTranscodeCoreActivity.java
【讨论】：
检查了这个，但是INDE不支持MPEG4 see marked answer here【参考方案2】：MediaMuxer 不参与视频的压缩或缩放。它所做的只是从 MediaCodec 获取 H.264 输出并将其包装在 .mp4 文件包装器中。
查看您的代码，您正在使用 MediaExtractor 提取 NAL 单元，并立即使用 MediaMuxer 重新包装它们。这应该非常快，并且对视频本身没有影响，因为您只是重新包装 H.264。
要缩放视频，您需要使用 MediaCodec 解码器对视频进行解码，将来自 MediaExtractor 的 NAL 单元输入其中，然后使用 MediaCodec 编码器对其重新编码，将帧传递给 MediaMuxer。
你找到了bigflake.com；另见Grafika。这些都不是您正在寻找的东西，但各种部件都在那里。
最好解码为 Surface，而不是 ByteBuffer。这需要 API 18，但为了理智，最好忘记 MediaCodec 在此之前存在。无论如何，您都需要用于 MediaMuxer 的 API 18。
【讨论】：
谢谢，我已经阅读了一些文档和测试并完成了我想要的。您在不同堆栈问题中的 cmets 和答案非常有帮助！我已经使用了一个测试和Surface 与多个编码器和解码器:)【参考方案3】：
基于bigflake.com/mediacodec/（有关媒体类的绝佳知识来源）我尝试了几种方法，最后ExtractDecodeEditEncodeMuxTest 非常有帮助。 bigflake 网站上的文章中没有描述此测试，但可以在文本中提到的其他类旁边找到HERE。
所以，我从上面提到的ExtractDecodeEditEncodeMuxTest 类中复制了大部分代码，它就是：VideoResolutionChanger。它为我提供了 16 Mb fullHD 的 2Mb 高清视频。好的！而且快！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 秒处理。使用ffmpeg-java 大约需要 40 秒或更多（应用程序需要多 9 Mb）。
我们开始吧：
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，它们位于ExtractDecodeEditEncodeMuxTest 旁边（HERE 链接上方）。将这三个与VideoResolutionChanger 放在同一个包中并像这样使用它：
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。
我知道这不是最干净，也可能不是最有效/最有效的方式，但过去两天我一直在寻找类似的代码，发现了很多主题，其中大部分将我重定向到 INDE、ffmpeg 或 jcodec，其他没有正确的答案。所以我把它留在这里，明智地使用它！
限制：
上面 use-it-like-this sn-p 不能在主循环线程 (ui) 中启动，例如直接进入Activity。最好的方法是create IntentService 和pass 在Intents 额外Bundle 中输入文件路径String。然后你可以直接在onHandleIntent里面运行changeResolution；
API18及以上（MediaMuxer引入）；
API18当然需要WRITE_EXTERNAL_STORAGE，API19及以上有这个“内置”；
@fadden 感谢您的工作和支持！ :)
【讨论】：
嗨@snachmsm，感谢您的惊人回复。我在使用此代码时遇到问题。我每次都收到surface wait timed out 异常（无论我设置的Timeout_wait 时间是多少），就在那个异常之后，我收到new frame available，但是到那时代码已经停止运行。有什么我想念的吗？
@Chetan 也许 [***.com/questions/22457623/… 回答）会帮助你（抱歉“小”延迟......）
优秀的工作示例虽然我遇到了一件有趣的事情 - 当触摸音频编解码器参数中的任何内容时 - 比如将音频通道从 2 更改为 1 - 编码的视频以半速播放（音频+视频是慢动作...） - 你能解释一下吗？ （实际上，即使没有改变任何东西，我也注意到它发生了，因为原始音频采样率为 48Khz，编码音频采样率为 44.1Khz，视频速度变慢了一点（±10%））
@snachmsm 我在 OutputSurface 文件中也有相同的 surface wait timed out，您可以给我一些建议吗？
目前我的工作中没有处理这个类，但我知道负责这部分代码的同事也计划添加这个功能（progres），但经过一番检查他说这很难，优先级低，所以没那么快......抱歉，目前我帮不了你【参考方案4】：
我不会介意这个问题的实现和编码问题。但是我们经历了同样的灾难，因为 ffmpeg 将我们的应用程序大小至少增加了 19MB，我正在使用这个 *** 问题来提出一个没有 ffmpeg 的库。显然linkedin 的人以前做过。检查this article。
该项目名为 LiTr 并且是available on github。它使用 android MediaCodec 和 MediaMuxer，因此如果需要，您可以参考代码以获取有关您自己的项目的帮助。这个问题是 4 年前提出的，但我希望这对现在的人有所帮助。
【讨论】：
【参考方案5】：使用 compile 'com.zolad:videoslimmer:1.0.0'
【讨论】：
【参考方案6】：VideoResolutionChanger.kt
class VideoResolutionChanger
private val TIMEOUT_USEC = 10000
private val OUTPUT_VIDEO_MIME_TYPE = "video/avc"
private val OUTPUT_VIDEO_BIT_RATE = 2048 * 1024
private val OUTPUT_VIDEO_FRAME_RATE = 60
private val OUTPUT_VIDEO_IFRAME_INTERVAL = 1
private val OUTPUT_VIDEO_COLOR_FORMAT = MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface
private val OUTPUT_AUDIO_MIME_TYPE = "audio/mp4a-latm"
private val OUTPUT_AUDIO_CHANNEL_COUNT = 2
private val OUTPUT_AUDIO_BIT_RATE = 128 * 1024
private val OUTPUT_AUDIO_AAC_PROFILE = MediaCodecInfo.CodecProfileLevel.AACObjectHE
private val OUTPUT_AUDIO_SAMPLE_RATE_HZ = 44100
private var mWidth = 1920
private var mHeight = 1080
private var mOutputFile : String? = null
private var mInputFile : String? = null
private var mTotalTime : Int = 0
@Throws(Throwable::class)
fun changeResolution(f: File): String?
mInputFile = f.absolutePath
val filePath : String? = mInputFile!!.substring(0, mInputFile!!.lastIndexOf(File.separator))
val splitByDot: Array<String> = mInputFile!!.split("\\.").toTypedArray()
var ext = ""
if (splitByDot.size > 1) ext = splitByDot[splitByDot.size - 1]
var fileName: String = mInputFile!!.substring(
mInputFile!!.lastIndexOf(File.separator) + 1,
mInputFile!!.length
)
fileName = if (ext.length > 0) fileName.replace(".$ext", "_out.mp4") else fileName + "_out.mp4"
mOutputFile = outFile.getAbsolutePath()
ChangerWrapper.changeResolutionInSeparatedThread(this)
return mOutputFile
private class ChangerWrapper private constructor(private val mChanger: VideoResolutionChanger) :
Runnable
private var mThrowable : Throwable? = null
override fun run()
try
mChanger.prepareAndChangeResolution()
catch (th: Throwable)
mThrowable = th
companion object
@Throws(Throwable::class)
fun changeResolutionInSeparatedThread(changer: VideoResolutionChanger)
val wrapper = ChangerWrapper(changer)
val th = Thread(wrapper, ChangerWrapper::class.java.simpleName)
th.start()
th.join()
if (wrapper.mThrowable != null) throw wrapper.mThrowable!!
@Throws(Exception::class)
private fun prepareAndChangeResolution()
var exception: Exception? = null
val videoCodecInfo = selectCodec(OUTPUT_VIDEO_MIME_TYPE) ?: return
val audioCodecInfo = selectCodec(OUTPUT_AUDIO_MIME_TYPE) ?: return
var videoExtractor : MediaExtractor? = null
var audioExtractor : MediaExtractor? = null
var outputSurface : OutputSurface? = null
var videoDecoder : MediaCodec? = null
var audioDecoder : MediaCodec? = null
var videoEncoder : MediaCodec? = null
var audioEncoder : MediaCodec? = null
var muxer : MediaMuxer? = null
var inputSurface : InputSurface? = null
try
videoExtractor = createExtractor()
val videoInputTrack = getAndSelectVideoTrackIndex(videoExtractor)
val inputFormat = videoExtractor!!.getTrackFormat(videoInputTrack)
val m = MediaMetadataRetriever()
m.setDataSource(mInputFile)
var inputWidth: Int
var inputHeight: Int
try
inputWidth =
m.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH)!!.toInt()
inputHeight =
m.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT)!!.toInt()
mTotalTime =
m.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)!!.toInt() * 1000
catch (e: Exception)
val thumbnail = m.frameAtTime
inputWidth = thumbnail!!.width
inputHeight = thumbnail.height
thumbnail.recycle()
if (inputWidth > inputHeight)
if (mWidth < mHeight)
val w = mWidth
mWidth = mHeight
mHeight = w
else
if (mWidth > mHeight)
val w = mWidth
mWidth = mHeight
mHeight = w
val 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
)
val inputSurfaceReference: AtomicReference<Surface> = AtomicReference<Surface>()
videoEncoder = createVideoEncoder(
videoCodecInfo, outputVideoFormat, inputSurfaceReference
)
inputSurface = InputSurface(inputSurfaceReference.get())
inputSurface.makeCurrent()
outputSurface = OutputSurface()
videoDecoder = createVideoDecoder(inputFormat, outputSurface!!.surface!!);
audioExtractor = createExtractor()
val audioInputTrack = getAndSelectAudioTrackIndex(audioExtractor)
val inputAudioFormat = audioExtractor!!.getTrackFormat(audioInputTrack)
val 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 = MediaMuxer(mOutputFile!!, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4)
changeResolution(
videoExtractor, audioExtractor,
videoDecoder, videoEncoder,
audioDecoder, audioEncoder,
muxer, inputSurface, outputSurface
)
finally
try
videoExtractor?.release()
catch (e: Exception)
if (exception == null) exception = e
try
audioExtractor?.release()
catch (e: Exception)
if (exception == null) exception = e
try
if (videoDecoder != null)
videoDecoder.stop()
videoDecoder.release()
catch (e: Exception)
if (exception == null) exception = e
try
outputSurface?.release()
catch (e: Exception)
if (exception == null) exception = e
try
if (videoEncoder != null)
videoEncoder.stop()
videoEncoder.release()
catch (e: Exception)
if (exception == null) exception = e
try
if (audioDecoder != null)
audioDecoder.stop()
audioDecoder.release()
catch (e: Exception)
if (exception == null) exception = e
try
if (audioEncoder != null)
audioEncoder.stop()
audioEncoder.release()
catch (e: Exception)
if (exception == null) exception = e
try
if (muxer != null)
muxer.stop()
muxer.release()
catch (e: Exception)
if (exception == null) exception = e
try
inputSurface?.release()
catch (e: Exception)
if (exception == null) exception = e
if (exception != null) throw exception
@Throws(IOException::class)
private fun createExtractor(): MediaExtractor?
val extractor : MediaExtractor = MediaExtractor()
mInputFile?.let extractor.setDataSource(it)
return extractor
@Throws(IOException::class)
private fun createVideoDecoder(inputFormat: MediaFormat, surface: Surface): MediaCodec?
val decoder = MediaCodec.createDecoderByType(getMimeTypeFor(inputFormat)!!)
decoder.configure(inputFormat, surface, null, 0)
decoder.start()
return decoder
@Throws(IOException::class)
private fun createVideoEncoder(
codecInfo: MediaCodecInfo, format: MediaFormat,
surfaceReference: AtomicReference<Surface>
): MediaCodec?
val encoder = MediaCodec.createByCodecName(codecInfo.name)
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE)
surfaceReference.set(encoder.createInputSurface())
encoder.start()
return encoder
@Throws(IOException::class)
private fun createAudioDecoder(inputFormat: MediaFormat): MediaCodec?
val decoder = MediaCodec.createDecoderByType(getMimeTypeFor(inputFormat)!!)
decoder.configure(inputFormat, null, null, 0)
decoder.start()
return decoder
@Throws(IOException::class)
private fun createAudioEncoder(codecInfo: MediaCodecInfo, format: MediaFormat): MediaCodec?
val encoder = MediaCodec.createByCodecName(codecInfo.name)
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE)
encoder.start()
return encoder
private fun getAndSelectVideoTrackIndex(extractor: MediaExtractor?): Int
for (index in 0 until extractor!!.trackCount)
if (isVideoFormat(extractor.getTrackFormat(index)))
extractor.selectTrack(index)
return index
return -1
private fun getAndSelectAudioTrackIndex(extractor: MediaExtractor?): Int
for (index in 0 until extractor!!.trackCount)
if (isAudioFormat(extractor.getTrackFormat(index)))
extractor.selectTrack(index)
return index
return -1
private fun changeResolution(
videoExtractor: MediaExtractor?, audioExtractor: MediaExtractor?,
videoDecoder: MediaCodec?, videoEncoder: MediaCodec?,
audioDecoder: MediaCodec?, audioEncoder: MediaCodec?,
muxer: MediaMuxer,
inputSurface: InputSurface?, outputSurface: OutputSurface?
)
var videoDecoderInputBuffers : Array<ByteBuffer?>? = null
var videoDecoderOutputBuffers : Array<ByteBuffer?>? = null
var videoEncoderOutputBuffers : Array<ByteBuffer?>? = null
var videoDecoderOutputBufferInfo : MediaCodec.BufferInfo? = null
var videoEncoderOutputBufferInfo : MediaCodec.BufferInfo? = null
videoDecoderInputBuffers = videoDecoder!!.inputBuffers
videoDecoderOutputBuffers = videoDecoder.outputBuffers
videoEncoderOutputBuffers = videoEncoder!!.outputBuffers
videoDecoderOutputBufferInfo = MediaCodec.BufferInfo()
videoEncoderOutputBufferInfo = MediaCodec.BufferInfo()
var audioDecoderInputBuffers : Array<ByteBuffer?>? = null
var audioDecoderOutputBuffers : Array<ByteBuffer>? = null
var audioEncoderInputBuffers : Array<ByteBuffer>? = null
var audioEncoderOutputBuffers : Array<ByteBuffer?>? = null
var audioDecoderOutputBufferInfo : MediaCodec.BufferInfo? = null
var audioEncoderOutputBufferInfo : MediaCodec.BufferInfo? = null
audioDecoderInputBuffers = audioDecoder!!.inputBuffers
audioDecoderOutputBuffers = audioDecoder.outputBuffers
audioEncoderInputBuffers = audioEncoder!!.inputBuffers
audioEncoderOutputBuffers = audioEncoder.outputBuffers
audioDecoderOutputBufferInfo = MediaCodec.BufferInfo()
audioEncoderOutputBufferInfo = MediaCodec.BufferInfo()
var encoderOutputVideoFormat : MediaFormat? = null
var encoderOutputAudioFormat : MediaFormat? = null
var outputVideoTrack = -1
var outputAudioTrack = -1
var videoExtractorDone = false
var videoDecoderDone = false
var videoEncoderDone = false
var audioExtractorDone = false
var audioDecoderDone = false
var audioEncoderDone = false
var pendingAudioDecoderOutputBufferIndex = -1
var muxing = false
while (!videoEncoderDone || !audioEncoderDone)
while (!videoExtractorDone
&& (encoderOutputVideoFormat == null || muxing)
)
val decoderInputBufferIndex = videoDecoder.dequeueInputBuffer(TIMEOUT_USEC.toLong())
if (decoderInputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break
val decoderInputBuffer: ByteBuffer? =
videoDecoderInputBuffers[decoderInputBufferIndex]
val size = decoderInputBuffer?.let videoExtractor!!.readSampleData(it, 0)
val presentationTime = videoExtractor?.sampleTime
if (presentationTime != null)
if (size != null)
if (size >= 0)
if (videoExtractor != null)
videoDecoder.queueInputBuffer(
decoderInputBufferIndex,
0,
size,
presentationTime,
videoExtractor.sampleFlags
)
if (videoExtractor != null)
videoExtractorDone = (!videoExtractor.advance() && size == -1)
if (videoExtractorDone)
videoDecoder.queueInputBuffer(
decoderInputBufferIndex,
0,
0,
0,
MediaCodec.BUFFER_FLAG_END_OF_STREAM
)
break
while (!audioExtractorDone
&& (encoderOutputAudioFormat == null || muxing)
)
val decoderInputBufferIndex = audioDecoder.dequeueInputBuffer(TIMEOUT_USEC.toLong())
if (decoderInputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break
val decoderInputBuffer: ByteBuffer? =
audioDecoderInputBuffers[decoderInputBufferIndex]
val size = decoderInputBuffer?.let audioExtractor!!.readSampleData(it, 0)
val presentationTime = audioExtractor?.sampleTime
if (presentationTime != null)
if (size != null)
if (size >= 0)
audioDecoder.queueInputBuffer(
decoderInputBufferIndex,
0,
size,
presentationTime,
audioExtractor.sampleFlags
)
if (audioExtractor != null)
audioExtractorDone = (!audioExtractor.advance() && size == -1)
if (audioExtractorDone)
audioDecoder.queueInputBuffer(
decoderInputBufferIndex,
0,
0,
0,
MediaCodec.BUFFER_FLAG_END_OF_STREAM
)
break
while (!videoDecoderDone
&& (encoderOutputVideoFormat == null || muxing)
)
val decoderOutputBufferIndex = videoDecoder.dequeueOutputBuffer(
videoDecoderOutputBufferInfo, TIMEOUT_USEC.toLong()
)
if (decoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
videoDecoderOutputBuffers = videoDecoder.outputBuffers
break
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
decoderOutputVideoFormat = videoDecoder.outputFormat
break
val decoderOutputBuffer: ByteBuffer? =
videoDecoderOutputBuffers!![decoderOutputBufferIndex]
if (videoDecoderOutputBufferInfo.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG
!= 0
)
videoDecoder.releaseOutputBuffer(decoderOutputBufferIndex, false)
break
val render = videoDecoderOutputBufferInfo.size != 0
videoDecoder.releaseOutputBuffer(decoderOutputBufferIndex, render)
if (render)
if (outputSurface != null)
outputSurface.awaitNewImage()
outputSurface.drawImage()
if (inputSurface != null)
inputSurface.setPresentationTime(
videoDecoderOutputBufferInfo.presentationTimeUs * 1000
)
inputSurface.swapBuffers()
if ((videoDecoderOutputBufferInfo.flags
and MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0
)
videoDecoderDone = true
videoEncoder.signalEndOfInputStream()
break
while (!audioDecoderDone && pendingAudioDecoderOutputBufferIndex == -1 && (encoderOutputAudioFormat == null || muxing))
val decoderOutputBufferIndex = audioDecoder.dequeueOutputBuffer(
audioDecoderOutputBufferInfo, TIMEOUT_USEC.toLong()
)
if (decoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
audioDecoderOutputBuffers = audioDecoder.outputBuffers
break
if (decoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
decoderOutputAudioFormat = audioDecoder.outputFormat
break
val decoderOutputBuffer: ByteBuffer =
audioDecoderOutputBuffers!![decoderOutputBufferIndex]
if (audioDecoderOutputBufferInfo.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG
!= 0
)
audioDecoder.releaseOutputBuffer(decoderOutputBufferIndex, false)
break
pendingAudioDecoderOutputBufferIndex = decoderOutputBufferIndex
break
while (pendingAudioDecoderOutputBufferIndex != -1)
val encoderInputBufferIndex = audioEncoder.dequeueInputBuffer(TIMEOUT_USEC.toLong())
val encoderInputBuffer: ByteBuffer =
audioEncoderInputBuffers[encoderInputBufferIndex]
val size = audioDecoderOutputBufferInfo.size
val presentationTime = audioDecoderOutputBufferInfo.presentationTimeUs
if (size >= 0)
val decoderOutputBuffer: ByteBuffer =
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
and MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0
) audioDecoderDone = true
break
while (!videoEncoderDone
&& (encoderOutputVideoFormat == null || muxing)
)
val encoderOutputBufferIndex = videoEncoder.dequeueOutputBuffer(
videoEncoderOutputBufferInfo, TIMEOUT_USEC.toLong()
)
if (encoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER) break
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
videoEncoderOutputBuffers = videoEncoder.outputBuffers
break
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
encoderOutputVideoFormat = videoEncoder.outputFormat
break
val encoderOutputBuffer: ByteBuffer? =
videoEncoderOutputBuffers!![encoderOutputBufferIndex]
if (videoEncoderOutputBufferInfo.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG
!= 0
)
videoEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false)
break
if (videoEncoderOutputBufferInfo.size != 0)
if (encoderOutputBuffer != null)
muxer.writeSampleData(
outputVideoTrack, encoderOutputBuffer, videoEncoderOutputBufferInfo
)
if (videoEncoderOutputBufferInfo.flags and MediaCodec.BUFFER_FLAG_END_OF_STREAM
!= 0
)
videoEncoderDone = true
videoEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false)
break
while (!audioEncoderDone
&& (encoderOutputAudioFormat == null || muxing)
)
val encoderOutputBufferIndex = audioEncoder.dequeueOutputBuffer(
audioEncoderOutputBufferInfo, TIMEOUT_USEC.toLong()
)
if (encoderOutputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
break
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
audioEncoderOutputBuffers = audioEncoder.outputBuffers
break
if (encoderOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
encoderOutputAudioFormat = audioEncoder.outputFormat
break
val encoderOutputBuffer: ByteBuffer? =
audioEncoderOutputBuffers!![encoderOutputBufferIndex]
if (audioEncoderOutputBufferInfo.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG
!= 0
)
audioEncoder.releaseOutputBuffer(encoderOutputBufferIndex, false)
break
if (audioEncoderOutputBufferInfo.size != 0) encoderOutputBuffer?.let
muxer.writeSampleData(
outputAudioTrack, it, audioEncoderOutputBufferInfo
)
if (audioEncoderOutputBufferInfo.flags and 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 fun isVideoFormat(format: MediaFormat): Boolean
return getMimeTypeFor(format)!!.startsWith("video/")
private fun isAudioFormat(format: MediaFormat): Boolean
return getMimeTypeFor(format)!!.startsWith("audio/")
private fun getMimeTypeFor(format: MediaFormat): String?
return format.getString(MediaFormat.KEY_MIME)
private fun selectCodec(mimeType: String): MediaCodecInfo?
val numCodecs = MediaCodecList.getCodecCount()
for (i in 0 until numCodecs)
val codecInfo = MediaCodecList.getCodecInfoAt(i)
if (!codecInfo.isEncoder)
continue
val types = codecInfo.supportedTypes
for (j in types.indices)
if (types[j].equals(mimeType, ignoreCase = true))
return codecInfo
return null
【讨论】：
您需要将 mOutputFile 行更改为 getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS) 中的文件路径。我的字符用完了。 使用后台线程调用： val progressThread = Thread ( Runnable kotlin.run val outputFile = VideoResolutionChanger().changeResolution(File(videoUri!!.path!!)) println("outputFile: $outputFile") ) progressThread.start()【参考方案7】：OutputSurface.kt
/*
* Copyright (C) 2013 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.
*/
/**
* Holds state associated with a Surface used for MediaCodec decoder output.
*
*
* The (width,height) constructor for this class will prepare GL, create a SurfaceTexture,
* and then create a Surface for that SurfaceTexture. The Surface can be passed to
* MediaCodec.configure() to receive decoder output. When a frame arrives, we latch the
* texture with updateTexImage, then render the texture with GL to a pbuffer.
*
*
* The no-arg constructor skips the GL preparation step and doesn't allocate a pbuffer.
* Instead, it just creates the Surface and SurfaceTexture, and when a frame arrives
* we just draw it on whatever surface is current.
*
*
* By default, the Surface will be using a BufferQueue in asynchronous mode, so we
* can potentially drop frames.
*/
internal class OutputSurface : OnFrameAvailableListener
private var mEGLDisplay = EGL14.EGL_NO_DISPLAY
private var mEGLContext = EGL14.EGL_NO_CONTEXT
private var mEGLSurface = EGL14.EGL_NO_SURFACE
private var mSurfaceTexture: SurfaceTexture? = null
/**
* Returns the Surface that we draw onto.
*/
var surface: Surface? = null
private set
private val mFrameSyncObject = Object() // guards mFrameAvailable
private var mFrameAvailable = false
private var mTextureRender: TextureRender? = null
/**
* Creates an OutputSurface backed by a pbuffer with the specifed dimensions. The new
* EGL context and surface will be made current. Creates a Surface that can be passed
* to MediaCodec.configure().
*/
constructor(width: Int, height: Int)
println("OutputSurface constructor width: $width height: $height")
require(!(width <= 0 || height <= 0))
eglSetup(width, height)
makeCurrent()
setup()
/**
* Creates an OutputSurface using the current EGL context (rather than establishing a
* new one). Creates a Surface that can be passed to MediaCodec.configure().
*/
constructor()
println("OutputSurface constructor")
setup()
/**
* Creates instances of TextureRender and SurfaceTexture, and a Surface associated
* with the SurfaceTexture.
*/
private fun setup()
println("OutputSurface setup")
mTextureRender = TextureRender()
mTextureRender!!.surfaceCreated()
// Even if we don't access the SurfaceTexture after the constructor returns, we
// still need to keep a reference to it. The Surface doesn't retain a reference
// at the Java level, so if we don't either then the object can get GCed, which
// causes the native finalizer to run.
if (VERBOSE) Log.d(TAG, "textureID=" + mTextureRender!!.textureId)
mSurfaceTexture = SurfaceTexture(mTextureRender!!.textureId)
// This doesn't work if OutputSurface is created on the thread that CTS started for
// these test cases.
//
// The CTS-created thread has a Looper, and the SurfaceTexture constructor will
// create a Handler that uses it. The "frame available" message is delivered
// there, but since we're not a Looper-based thread we'll never see it. For
// this to do anything useful, OutputSurface must be created on a thread without
// a Looper, so that SurfaceTexture uses the main application Looper instead.
//
// Java language note: passing "this" out of a constructor is generally unwise,
// but we should be able to get away with it here.
mSurfaceTexture!!.setOnFrameAvailableListener(this)
surface = Surface(mSurfaceTexture)
/**
* Prepares EGL. We want a GLES 2.0 context and a surface that supports pbuffer.
*/
private fun eglSetup(width: Int, height: Int)
mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY)
if (mEGLDisplay === EGL14.EGL_NO_DISPLAY)
throw RuntimeException("unable to get EGL14 display")
val version = IntArray(2)
if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1))
mEGLDisplay = null
throw RuntimeException("unable to initialize EGL14")
// Configure EGL for pbuffer and OpenGL ES 2.0. We want enough RGB bits
// to be able to tell if the frame is reasonable.
val attribList = intArrayOf(
EGL14.EGL_RED_SIZE, 8,
EGL14.EGL_GREEN_SIZE, 8,
EGL14.EGL_BLUE_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
EGL14.EGL_SURFACE_TYPE, EGL14.EGL_PBUFFER_BIT,
EGL14.EGL_NONE
)
val configs = arrayOfNulls<EGLConfig>(1)
val numConfigs = IntArray(1)
if (!EGL14.eglChooseConfig(
mEGLDisplay, attribList, 0, configs, 0, configs.size,
numConfigs, 0
)
)
throw RuntimeException("unable to find RGB888+recordable ES2 EGL config")
// Configure context for OpenGL ES 2.0.
val attrib_list = intArrayOf(
EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
EGL14.EGL_NONE
)
mEGLContext = EGL14.eglCreateContext(
mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
attrib_list, 0
)
checkEglError("eglCreateContext")
if (mEGLContext == null)
throw RuntimeException("null context")
// Create a pbuffer surface. By using this for output, we can use glReadPixels
// to test values in the output.
val surfaceAttribs = intArrayOf(
EGL14.EGL_WIDTH, width,
EGL14.EGL_HEIGHT, height,
EGL14.EGL_NONE
)
mEGLSurface = EGL14.eglCreatePbufferSurface(mEGLDisplay, configs[0], surfaceAttribs, 0)
checkEglError("eglCreatePbufferSurface")
if (mEGLSurface == null)
throw RuntimeException("surface was null")
/**
* Discard all resources held by this class, notably the EGL context.
*/
fun release()
if (mEGLDisplay !== EGL14.EGL_NO_DISPLAY)
EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface)
EGL14.eglDestroyContext(mEGLDisplay, mEGLContext)
EGL14.eglReleaseThread()
EGL14.eglTerminate(mEGLDisplay)
surface!!.release()
// this causes a bunch of warnings that appear harmless but might confuse someone:
// W BufferQueue: [unnamed-3997-2] cancelBuffer: BufferQueue has been abandoned!
//mSurfaceTexture.release();
mEGLDisplay = EGL14.EGL_NO_DISPLAY
mEGLContext = EGL14.EGL_NO_CONTEXT
mEGLSurface = EGL14.EGL_NO_SURFACE
mTextureRender = null
surface = null
mSurfaceTexture = null
/**
* Makes our EGL context and surface current.
*/
private fun makeCurrent()
if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext))
throw RuntimeException("eglMakeCurrent failed")
/**
* Replaces the fragment shader.
*/
fun changeFragmentShader(fragmentShader: String?)
if (fragmentShader != null)
mTextureRender?.changeFragmentShader(fragmentShader)
/**
* Latches the next buffer into the texture. Must be called from the thread that created
* the OutputSurface object, after the onFrameAvailable callback has signaled that new
* data is available.
*/
fun awaitNewImage()
//println("awaitNewImage")
val TIMEOUT_MS = 500
synchronized(mFrameSyncObject)
while (!mFrameAvailable)
try
// Wait for onFrameAvailable() to signal us. Use a timeout to avoid
// stalling the test if it doesn't arrive.
mFrameSyncObject.wait(TIMEOUT_MS.toLong())
if (!mFrameAvailable)
// TODO: if "spurious wakeup", continue while loop
//throw RuntimeException("Surface frame wait timed out")
catch (ie: InterruptedException)
// shouldn't happen
throw RuntimeException(ie)
mFrameAvailable = false
// Latch the data.
mTextureRender?.checkGlError("before updateTexImage")
mSurfaceTexture!!.updateTexImage()
/**
* Draws the data from SurfaceTexture onto the current EGL surface.
*/
fun drawImage()
mSurfaceTexture?.let mTextureRender?.drawFrame(it)
override fun onFrameAvailable(st: SurfaceTexture)
//println("onFrameAvailable")
if (VERBOSE) Log.d(TAG, "new frame available")
synchronized(mFrameSyncObject)
if (mFrameAvailable)
throw RuntimeException("mFrameAvailable already set, frame could be dropped")
mFrameAvailable = true
mFrameSyncObject.notifyAll()
/**
* Checks for EGL errors.
*/
private fun checkEglError(msg: String)
var error: Int
if (EGL14.eglGetError().also error = it != EGL14.EGL_SUCCESS)
throw RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error))
companion object
private const val TAG = "OutputSurface"
private const val VERBOSE = false
【讨论】：
【参考方案8】：InputSurface.kt
/*
* Copyright (C) 2013 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.
*/
/**
* Holds state associated with a Surface used for MediaCodec encoder input.
*
*
* The constructor takes a Surface obtained from MediaCodec.createInputSurface(), and uses that
* to create an EGL window surface. Calls to eglSwapBuffers() cause a frame of data to be sent
* to the video encoder.
*/
internal class InputSurface(surface: Surface?)
private var mEGLDisplay = EGL14.EGL_NO_DISPLAY
private var mEGLContext = EGL14.EGL_NO_CONTEXT
private var mEGLSurface = EGL14.EGL_NO_SURFACE
/**
* Returns the Surface that the MediaCodec receives buffers from.
*/
var surface: Surface?
private set
/**
* Prepares EGL. We want a GLES 2.0 context and a surface that supports recording.
*/
private fun eglSetup()
mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY)
if (mEGLDisplay === EGL14.EGL_NO_DISPLAY)
throw RuntimeException("unable to get EGL14 display")
val version = IntArray(2)
if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1))
mEGLDisplay = null
throw RuntimeException("unable to initialize EGL14")
// Configure EGL for recordable and OpenGL ES 2.0. We want enough RGB bits
// to minimize artifacts from possible YUV conversion.
val attribList = intArrayOf(
EGL14.EGL_RED_SIZE, 8,
EGL14.EGL_GREEN_SIZE, 8,
EGL14.EGL_BLUE_SIZE, 8,
EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
EGL_RECORDABLE_ANDROID, 1,
EGL14.EGL_NONE
)
val configs = arrayOfNulls<EGLConfig>(1)
val numConfigs = IntArray(1)
if (!EGL14.eglChooseConfig(
mEGLDisplay, attribList, 0, configs, 0, configs.size,
numConfigs, 0
)
)
throw RuntimeException("unable to find RGB888+recordable ES2 EGL config")
// Configure context for OpenGL ES 2.0.
val attrib_list = intArrayOf(
EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
EGL14.EGL_NONE
)
mEGLContext = EGL14.eglCreateContext(
mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
attrib_list, 0
)
checkEglError("eglCreateContext")
if (mEGLContext == null)
throw RuntimeException("null context")
// Create a window surface, and attach it to the Surface we received.
val surfaceAttribs = intArrayOf(
EGL14.EGL_NONE
)
mEGLSurface = EGL14.eglCreateWindowSurface(
mEGLDisplay, configs[0], surface,
surfaceAttribs, 0
)
checkEglError("eglCreateWindowSurface")
if (mEGLSurface == null)
throw RuntimeException("surface was null")
/**
* Discard all resources held by this class, notably the EGL context. Also releases the
* Surface that was passed to our constructor.
*/
fun release()
if (mEGLDisplay !== EGL14.EGL_NO_DISPLAY)
EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface)
EGL14.eglDestroyContext(mEGLDisplay, mEGLContext)
EGL14.eglReleaseThread()
EGL14.eglTerminate(mEGLDisplay)
surface!!.release()
mEGLDisplay = EGL14.EGL_NO_DISPLAY
mEGLContext = EGL14.EGL_NO_CONTEXT
mEGLSurface = EGL14.EGL_NO_SURFACE
surface = null
/**
* Makes our EGL context and surface current.
*/
fun makeCurrent()
if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext))
throw RuntimeException("eglMakeCurrent failed")
fun makeUnCurrent()
if (!EGL14.eglMakeCurrent(
mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
EGL14.EGL_NO_CONTEXT
)
)
throw RuntimeException("eglMakeCurrent failed")
/**
* Calls eglSwapBuffers. Use this to "publish" the current frame.
*/
fun swapBuffers(): Boolean
//println("swapBuffers")
return EGL14.eglSwapBuffers(mEGLDisplay, mEGLSurface)
/**
* Queries the surface's width.
*/
val width: Int
get()
val value = IntArray(1)
EGL14.eglQuerySurface(mEGLDisplay, mEGLSurface, EGL14.EGL_WIDTH, value, 0)
return value[0]
/**
* Queries the surface's height.
*/
val height: Int
get()
val value = IntArray(1)
EGL14.eglQuerySurface(mEGLDisplay, mEGLSurface, EGL14.EGL_HEIGHT, value, 0)
return value[0]
/**
* Sends the presentation time stamp to EGL. Time is expressed in nanoseconds.
*/
fun setPresentationTime(nsecs: Long)
EGLExt.eglPresentationTimeANDROID(mEGLDisplay, mEGLSurface, nsecs)
/**
* Checks for EGL errors.
*/
private fun checkEglError(msg: String)
var error: Int
if (EGL14.eglGetError().also error = it != EGL14.EGL_SUCCESS)
throw RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error))
companion object
private const val TAG = "InputSurface"
private const val VERBOSE = false
private const val EGL_RECORDABLE_ANDROID = 0x3142
/**
* Creates an InputSurface from a Surface.
*/
init
if (surface == null)
throw NullPointerException()
this.surface = surface
eglSetup()
【讨论】：
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