使用Jcodec在Android上创建mp4文件 [英] Create mp4 files on Android using Jcodec
问题描述
我在使用MediaRecorder和Jcodec在Android上编写mp4文件时遇到了一些麻烦，这是我的代码
i have some troubles with writing mp4 files on Android using MediaRecorder and Jcodec, here is my code
public class SequenceEncoder {
private final static String CLASSTAG = SequenceEncoder.class.getSimpleName();
private SeekableByteChannel ch;
private byte[] yuv = null;
private ArrayList<ByteBuffer> spsList;
private ArrayList<ByteBuffer> ppsList;
private CompressedTrack outTrack;
private int frameNo;
private MP4Muxer muxer;
ArrayList<ByteBuffer> spsListTmp = new ArrayList<ByteBuffer>();
ArrayList<ByteBuffer> ppsListTmp = new ArrayList<ByteBuffer>();
// Encoder
private MediaCodec mediaCodec = null;
public SequenceEncoder(File out) throws IOException {
this.ch = NIOUtils.writableFileChannel(out);
// Muxer that will store the encoded frames
muxer = new MP4Muxer(ch, Brand.MP4);
// Add video track to muxer
outTrack = muxer.addTrackForCompressed(TrackType.VIDEO, 25);
// Encoder extra data ( SPS, PPS ) to be stored in a special place of
// MP4
spsList = new ArrayList<ByteBuffer>();
ppsList = new ArrayList<ByteBuffer>();
}
@SuppressWarnings("unchecked")
public void encodeImage(ByteBuffer buffer, int width, int height) throws IOException {
if (yuv == null) {
int bufferSize = width * height * 3 / 2;
yuv = new byte[bufferSize];
int bitRate = bufferSize;
int frameRate = 25;
String mimeType = "video/avc";
// "video/avc"
mediaCodec = MediaCodec.createEncoderByType(mimeType);
MediaFormat mediaFormat = MediaFormat.createVideoFormat(mimeType, width, height);
mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, bitRate); // 125000);
mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, frameRate);
mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar);
mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
mediaCodec.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mediaCodec.start();
}
byte[] rgba = buffer.array();
// Convert RGBA image to NV12 (YUV420SemiPlanar)
Rgba2Yuv420.convert(rgba, yuv, width, height);
synchronized (mediaCodec) {
try {
ByteBuffer[] inputBuffers = mediaCodec.getInputBuffers();
ByteBuffer[] outputBuffers = mediaCodec.getOutputBuffers();
int inputBufferIndex = mediaCodec.dequeueInputBuffer(-1);
if (inputBufferIndex >= 0) {
ByteBuffer inputBuffer = inputBuffers[inputBufferIndex];
inputBuffer.clear();
inputBuffer.put(yuv);
mediaCodec.queueInputBuffer(inputBufferIndex, 0,
yuv.length, 0, 0);
}
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
int outputBufferIndex = mediaCodec.dequeueOutputBuffer(
bufferInfo, 0);
while (outputBufferIndex >= 0) {
ByteBuffer outputBuffer = outputBuffers[outputBufferIndex];
byte[] outData = new byte[bufferInfo.size];
outputBuffer.get(outData);
ByteBuffer frameBuffer = ByteBuffer.wrap(outData);
spsListTmp.clear();
ppsListTmp.clear();
H264Utils.encodeMOVPacket(frameBuffer, spsListTmp, ppsListTmp);
if (!spsListTmp.isEmpty())
spsList = (ArrayList<ByteBuffer>) spsListTmp.clone();
if (!ppsListTmp.isEmpty())
ppsList = (ArrayList<ByteBuffer>) ppsListTmp.clone();
outTrack.addFrame(new MP4Packet(frameBuffer, frameNo, 25, 1,
frameNo, true, null, frameNo, 0));
frameNo++;
mediaCodec.releaseOutputBuffer(outputBufferIndex, false);
outputBufferIndex = mediaCodec.dequeueOutputBuffer(
bufferInfo, 0);
}
if (outputBufferIndex < 0)
switch (outputBufferIndex) {
case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
outputBuffers = mediaCodec.getOutputBuffers();
break;
case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
break;
case MediaCodec.INFO_TRY_AGAIN_LATER:
break;
default:
break;
}
} catch (Exception e) {
}
}
}
public void finish() throws IOException {
if (!ch.isOpen())
return;
if (mediaCodec != null) {
mediaCodec.stop();
mediaCodec.release();
}
outTrack.addSampleEntry(H264Utils.createMOVSampleEntry(spsList, ppsList));
// Write MP4 header and finalize recording
muxer.writeHeader();
NIOUtils.closeQuietly(ch);
ch.close();
}
}
我们可以看到Android MediaCodec期望YUV420SemiPlanar作为输入图像，所以我给了他正确的图像.结果，我有一个无效颜色的mp4文件，当我从AVCon打开此mp4文件时，我看到输出文件中的颜色格式为yuv420p，所以可能是问题所在?请提出解决方法.
As we can see Android MediaCodec expect YUV420SemiPlanar as input image, so i'm giving him the correct one. As a result i have a corrupted mp4 file with invalid colors, when i open this mp4 file from AVCon i see that color format in output file is yuv420p, so maybe that the problem? Please suggest how to fix this.
还有另一个问题，如何将压缩的音频流添加到多路复用器，还没有找到示例.
Also have another question, how to add compressed audio stream to muxer, have not found examples.
推荐答案
Android 4.3(API 18)具有两个可能有用的新功能.
Android 4.3 (API 18) has two new features that may be useful.
首先，MediaCodec类接受来自Surface的输入，因此可以记录任何可以解码到Surface或使用OpenGL ES渲染的内容，而无需摆弄YUV色彩平面.
First, the MediaCodec class accepts input from a Surface, so anything you can decode to a Surface or render with OpenGL ES can be recorded without having to fiddle with YUV color planes.
第二，新的 MediaMuxer 类提供了一种组合音频的方法和H.264视频转换成.mp4文件.
Second, the new MediaMuxer class provides a way to combine audio and H.264 video into a .mp4 file.
示例源代码(主要用于视频方面)可以在此处找到.
Sample source code (primarily for the video aspects) can be found here.
这篇关于使用Jcodec在Android上创建mp4文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
