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• Read a growing MFX file for live streaming sports match file [closed]

  12 novembre 2024, par Sumit Chaudhary

  I'm struggling to read a growing MXF file in real time for a live sports streaming project in python. I can read the video in 5-minute chunks provided by the recording software, for the same match and I’m able to load the full file (around 750GB) once the match is over and file is complete. However, I need to process the file as it’s still growing. Any suggestions on how to approach this ?

  


• How to save/encode recorded raw PCM Data as AAC/MP4 format file in Android

  28 janvier 2015, par INVISIBLE

  i want to save recorder pcm data as aac/mp4 format file.
  i am using AudioRecord class for recording audio in android. i have success fully saved it as wave file by adding a wave header to raw data. but dont know how to save it as aac/mp4 file, because aac/mp4 format is compressed then wave.
  the methods i am using for saving pcm data as wave is pasted below.

  recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
  
              SavedSampleRate, RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING,
  
              bufferSize);
  
  recorder.startRecording();
  
  isRecording = true;
  
  
  
  isRecording = true;
  
  
  
  recordingThread = new Thread(new Runnable() {
  
      @Override
  
      public void run() {
  
          writeAudioDataToFile();
  
      }
  
  }, "AudioRecorder Thread");
  
  
  
  recordingThread.start();

  second

  private void writeAudioDataToFile() {
  
  
  
      byte data[] = new byte[bufferSize];
  
      // short sData[] = new short[bufferSize];
  
      String filename = getTempFilename();
  
      FileOutputStream os = null;
  
  
  
      try {
  
          os = new FileOutputStream(filename);
  
      } catch (Exception e) {
  
          e.printStackTrace();
  
      }
  
  
  
      int read = 0;
  
  
  
      if (null != os) {
  
          while (isRecording) {
  
              double sum = 0;
  
              read = recorder.read(data, 0, bufferSize);
  
  
  
              if (AudioRecord.ERROR_INVALID_OPERATION != read) {
  
                  try {
  
  
  
                      synchronized (this) {
  
  
  
  
  
                          // Necessary in order to convert negative shorts!
  
                          final int USHORT_MASK = (1 << 16) - 1;
  
  
  
                          final ByteBuffer buf = ByteBuffer.wrap(data).order(
  
                                  ByteOrder.LITTLE_ENDIAN);
  
  
  
                          final ByteBuffer newBuf = ByteBuffer.allocate(
  
                                  data.length).order(ByteOrder.LITTLE_ENDIAN);
  
  
  
                          int sample;
  
  
  
                          while (buf.hasRemaining()) {
  
  
  
  
  
  
  
                              short shortSample = buf.getShort();
  
                              sample = (int) shortSample & USHORT_MASK;
  
  
  
  
  
  
  
                              sample = sample * db_value_global;
  
                              sample = mRmsFilterSetting.filter
  
                                      .apply((((int) 0) | shortSample)
  
                                              * db_value_global);
  
  
  
  
  
  
  
                              newBuf.putShort((short) sample);
  
                          }
  
  
  
                          data = newBuf.array();
  
  
  
                          os.write(data);
  
  
  
  
  
  
  
  
  
  
  
                      }
  
  
  
                  } catch (Exception e) {
  
                      e.printStackTrace();
  
                  }
  
              }
  
          }
  
  
  
          try {
  
              os.close();
  
          } catch (Exception e) {
  
              e.printStackTrace();
  
          }
  
      }
  
  }

  and finally saving it as

  private void copyWaveFile(ArrayList<string> inFilename, String outFilename) {
  
      FileInputStream[] in = null;
  
      FileOutputStream out = null;
  
      long totalAudioLen = 0;
  
      long totalDataLen = totalAudioLen + 36;
  
      long longSampleRate = SavedSampleRate;
  
      int channels = 2;
  
      long byteRate = RECORDER_BPP * SavedSampleRate * channels / 8;
  
  
  
      byte[] data = new byte[bufferSize];
  
  
  
      try {
  
          out = new FileOutputStream(outFilename);
  
  
  
          in = new FileInputStream[inFilename.size()];
  
  
  
          for (int i = 0; i &lt; in.length; i++) {
  
              in[i] = new FileInputStream(inFilename.get(i));
  
              totalAudioLen += in[i].getChannel().size();
  
          }
  
  
  
          totalDataLen = totalAudioLen + 36;
  
  
  
          WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
  
                  longSampleRate, channels, byteRate);
  
  
  
          for (int i = 0; i &lt; in.length; i++) {
  
              while (in[i].read(data) != -1) {
  
                  out.write(data);
  
              }
  
  
  
              in[i].close();
  
          }
  
  
  
          out.close();
  
      } catch (Exception e) {
  
          e.printStackTrace();
  
      } 
  
  }
  
  
  
  
  
  
  
  private void WriteWaveFileHeader(FileOutputStream out, long totalAudioLen,
  
          long totalDataLen, long longSampleRate, int channels, long byteRate)
  
          throws IOException {
  
  
  
      byte[] header = new byte[44];
  
  
  
      header[0] = 'R'; // RIFF/WAVE header
  
      header[1] = 'I';
  
      header[2] = 'F';
  
      header[3] = 'F';
  
      header[4] = (byte) (totalDataLen &amp; 0xff);
  
      header[5] = (byte) ((totalDataLen >> 8) &amp; 0xff);
  
      header[6] = (byte) ((totalDataLen >> 16) &amp; 0xff);
  
      header[7] = (byte) ((totalDataLen >> 24) &amp; 0xff);
  
      header[8] = 'W';
  
      header[9] = 'A';
  
      header[10] = 'V';
  
      header[11] = 'E';
  
      header[12] = 'f'; // 'fmt ' chunk
  
      header[13] = 'm';
  
      header[14] = 't';
  
      header[15] = ' ';
  
      header[16] = 16; // 4 bytes: size of 'fmt ' chunk
  
      header[17] = 0;
  
      header[18] = 0;
  
      header[19] = 0;
  
      header[20] = 1; // format = 1
  
      header[21] = 0;
  
      header[22] = (byte) channels;
  
      header[23] = 0;
  
      header[24] = (byte) (longSampleRate &amp; 0xff);
  
      header[25] = (byte) ((longSampleRate >> 8) &amp; 0xff);
  
      header[26] = (byte) ((longSampleRate >> 16) &amp; 0xff);
  
      header[27] = (byte) ((longSampleRate >> 24) &amp; 0xff);
  
      header[28] = (byte) (byteRate &amp; 0xff);
  
      header[29] = (byte) ((byteRate >> 8) &amp; 0xff);
  
      header[30] = (byte) ((byteRate >> 16) &amp; 0xff);
  
      header[31] = (byte) ((byteRate >> 24) &amp; 0xff);
  
      header[32] = (byte) (2 * 16 / 8); // block align
  
      header[33] = 0;
  
      header[34] = RECORDER_BPP; // bits per sample
  
      header[35] = 0;
  
      header[36] = 'd';
  
      header[37] = 'a';
  
      header[38] = 't';
  
      header[39] = 'a';
  
      header[40] = (byte) (totalAudioLen &amp; 0xff);
  
      header[41] = (byte) ((totalAudioLen >> 8) &amp; 0xff);
  
      header[42] = (byte) ((totalAudioLen >> 16) &amp; 0xff);
  
      header[43] = (byte) ((totalAudioLen >> 24) &amp; 0xff);
  
  
  
      out.write(header, 0, 44);
  
  }
  
  </string>

  in this piece of code i am recording small PCM files with AudioRecord and saving them as wave file by adding wave header.

  is there any step by step tutorial for how to save pcm data as mp4/aac file.

  thanks in advance.

• Révision 116059 : Positionner une classe particulière pour le préfixe dans la liste des plugins.

  20 juillet 2019, par eric@smellup.net