如何使用MediaMuxer合并音频和视频？

我正在开发一个带有mp3音频文件和mp4视频文件（没有声音）的Android应用程序。如何使用MediaMuxer合并音频和视频？

现在我想混合它们并创建一个新的mp4视频文件（带声音）。从Android 4.3开始，Google建议使用MediaMuxer类来混合音频和视频流。我尝试过很多次而没有成功。

下面是代码：

private void muxing() { 

    String outputFile = ""; 

    try { 

     File file = new File(Environment.getExternalStorageDirectory() + "/final2.mp4"); 
     file.createNewFile(); 
     outputFile = file.getAbsolutePath(); 
     MediaExtractor videoExtractor = new MediaExtractor(); 
     videoExtractor.setDataSource(Environment.getExternalStorageDirectory().toString()+"/vd1.h264"); 
     MediaExtractor audioExtractor = new MediaExtractor(); 
     audioExtractor.setDataSource(Environment.getExternalStorageDirectory()+"/audioVideoDir/audio.m4a"); 
     MediaMuxer muxer = new MediaMuxer(outputFile, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); 

     videoExtractor.selectTrack(0); 
     MediaFormat videoFormat = videoExtractor.getTrackFormat(0); 
     int videoTrack = muxer.addTrack(videoFormat); 

     audioExtractor.selectTrack(0); 
     MediaFormat audioFormat = audioExtractor.getTrackFormat(0); 
     int audioTrack = muxer.addTrack(audioFormat); 
     boolean sawEOS = false; 
     int frameCount = 0; 
     int offset = 100; 
     int sampleSize = 256 * 1024; 
     ByteBuffer videoBuf = ByteBuffer.allocate(sampleSize); 
     ByteBuffer audioBuf = ByteBuffer.allocate(sampleSize); 
     MediaCodec.BufferInfo videoBufferInfo = new MediaCodec.BufferInfo(); 
     MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo(); 


     videoExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC); 
     audioExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC); 

     muxer.start(); 

     while (!sawEOS) 
     { 
      videoBufferInfo.offset = offset; 
      videoBufferInfo.size = videoExtractor.readSampleData(videoBuf, offset); 


      if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0) 
      { 
       // Log.d(TAG, "saw input EOS."); 
       sawEOS = true; 
       videoBufferInfo.size = 0; 

      } 
      else 
      { 
       videoBufferInfo.presentationTimeUs = videoExtractor.getSampleTime(); 
       videoBufferInfo.flags = videoExtractor.getSampleFlags(); 
       muxer.writeSampleData(videoTrack, videoBuf, videoBufferInfo); 
       videoExtractor.advance(); 


       frameCount++; 

      } 
     } 

     Toast.makeText(getApplicationContext() , "frame:" + frameCount , Toast.LENGTH_SHORT).show(); 



     boolean sawEOS2 = false; 
     int frameCount2 =0; 
     while (!sawEOS2) 
     { 
      frameCount2++; 

      audioBufferInfo.offset = offset; 
      audioBufferInfo.size = audioExtractor.readSampleData(audioBuf, offset); 

      if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0) 
      { 
       // Log.d(TAG, "saw input EOS."); 
       sawEOS2 = true; 
       audioBufferInfo.size = 0; 
      } 
      else 
      { 
       audioBufferInfo.presentationTimeUs = audioExtractor.getSampleTime(); 
       audioBufferInfo.flags = audioExtractor.getSampleFlags(); 
       muxer.writeSampleData(audioTrack, audioBuf, audioBufferInfo); 
       audioExtractor.advance(); 

      } 
     } 

     Toast.makeText(getApplicationContext() , "frame:" + frameCount2 , Toast.LENGTH_SHORT).show(); 

     muxer.stop(); 
     muxer.release(); 


    } catch (IOException e) { 

    } catch (Exception e) { 

    } 
}

我得到下面的错误：

未知的MIME类型 '音频/ MPEG'。 12-09 11：58：33.569：A/MPEG4Writer（332）：frameworks/av/media/libstagefright/MPEG4Writer.cpp：2699 CHECK（！“should not be here，unknown mime type。”）

Any解决方案来解决Google的MediaMuxer API问题？即使我尝试使用ffmpeg合并音频和视频后，视频不会在Android设备的默认视频播放器中播放，但会在Vlc播放器中加载。

FFMPEG其次从这里：https://github.com/WritingMinds/ffmpeg-android-java

来源

2016-08-04 VijayRagavan