Newest 'ffmpeg' Questions - Stack Overflow

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• Convert raw image buffer into JPEG using LIBAVCODEC

  24 août 2018, par user846400

  I have a raw image buffer (in memory) captured from a camera that I want to convert into JPEG (for reducing size). The problem is that saving these images into .pgm format results into a huge file size that I can't afford due to the memory limitations and latency involved in saving a huge file of this size (a constraint in the application I am working on).

  I want to know how do I compress/encode an image buffer into .jpg format using LIBAVCODEC? My image capture code is in C.

• FFMPEG : Issue with -t Option

  24 août 2018, par mf_starboi_8041

  I am using -t option with output filename to generate the Output File with certain second provided with -t option.

  Example Command,

  ffmpeg -r 30 -i  -c copy -t 10 output.mp4
  

  So For Example,

  30 Frames * 10 Seconds = 300 Frames
  

  Output.mp4 should have 300 frames. But I am getting Output.mp4 with less than 300 Frames like 272 frames and 290 frames etc.. Around 9+ Second content but not exact 10 Seconds.

  Any one faces same behavior. Please let me know. Thank you in advance.

  Logs that May help as asked by @Gyan,

  Input file #0 (input_fifo.264):
    Input stream #0:0 (video): 301 packets read (2559184 bytes); 
    Total: 301 packets (2559184 bytes) demuxed
  Output file #0 (output.mp4):
    Output stream #0:0 (video): 294 packets muxed (2509136 bytes); 
    Total: 294 packets (2509136 bytes) muxed
  0 frames successfully decoded, 0 decoding errors
  

• ffmpeg : zoom over bottom-right or bottom-left corners of an image

  24 août 2018, par Vinod Mankare

  I need to create a video with zoom effect over an image to highlight bottom right/left corner with the help of ffmpeg.

  I am trying with the following command:

  ffmpeg -loop 1 -i {image.png} -filter_complex "zoompan=z='zoom+0.002':x='trunc(380)':y='trunc(287)':d=100" -ss 0 -i {audio.mp3} -c:v libx264 -crf 0 -c:a aac -strict experimental -b:v 6M -b:a 1080k -r 25 -bufsize 1080k -shortest -s 1920x1080 -aspect 16:9 -y {output.mp4} 2>&1

  Its working for the top (right/left) and centre element but not getting proper zoom effect for bottom corners for the same image. Please suggest what am I doing wrong, or is there any other best option to do the same?

• How to get DirectShow device list with ffmpeg in c++ ?

  24 août 2018, par fyo

  I'm trying to get dshow device list with ffmpeg. I cannot get it but ffmpeg gets it by its own. Here is the code. It returns AVERROR(ENOSYS) for avdevice_list_input_sources. But avformat_open_input prints all devices. How can I get dshow devices and options in c++ code.

      avdevice_register_all();
      AVInputFormat *iformat = av_find_input_format("dshow");
      printf("========Device Info=============\n");
      AVDeviceInfoList *device_list = NULL;
      AVDictionary* options = NULL;
      //av_dict_set(&options, "list_devices", "true", 0);
      int result = avdevice_list_input_sources(iformat, NULL, options, &device_list);
  
      if (result < 0)
          printf("Error Code:%s\n", av_err2str(result));//Returns -40 AVERROR(ENOSYS)
      else printf("Devices count:%d\n", result);
  
      AVFormatContext *pFormatCtx = avformat_alloc_context();
      AVDictionary* options2 = NULL;
      av_dict_set(&options2, "list_devices", "true", 0);
      avformat_open_input(&pFormatCtx, NULL, iformat, &options2);
      printf("================================\n");
  

• How to decrease the latency of the RTP streaming with ffmpeg in Android ?

  24 août 2018, par Douglas Lima Dantas

  I'm creating a App that do a RTP streaming. It uses a ParcelFileDescriptor pipe pair, where a MediaRecorder writes in the pipe while the ffmpeg receives the audio from the pipe and sends by RTP.

  In my desktop, using the same wifi router, I receive the RTP stream using ffplay, and it has a delay between 5s ~ 10s.

  I tried capture audio using ffmpeg in Android, but itsn't possible. I tried to use ffplay -fflags nobuffer, use MIC as source, change the encoder, etc.

  I need the lowest delay possible. How can I do it?

  The code:

  public class MainActivity extends AppCompatActivity implements View.OnClickListener {
      MediaRecorder mediaRecorder;
      AudioRecord record;
      MediaPlayer mediaPlayer;
      ParcelFileDescriptor[] pipePair;
      ParcelFileDescriptor pipeRead;
      ParcelFileDescriptor pipeWrite;
      Process ffmpegProc;
      // Requesting permission to RECORD_AUDIO
      private boolean permissionsAccepted = false;
      private String [] permissions = {
              Manifest.permission.RECORD_AUDIO,
              Manifest.permission.INTERNET,
              Manifest.permission.ACCESS_NETWORK_STATE
      };
      private static final int REQUEST_PERMISSIONS = 200;
  
      @Override
      public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
          super.onRequestPermissionsResult(requestCode, permissions, grantResults);
          switch (requestCode){
              case REQUEST_PERMISSIONS:
                  permissionsAccepted  = grantResults[0] == PackageManager.PERMISSION_GRANTED;
                  break;
          }
          if (!permissionsAccepted ) finish();
  
      }
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          ActivityCompat.requestPermissions(this, permissions, REQUEST_PERMISSIONS);
  
          TextView hello = (TextView) findViewById(R.id.hello);
          hello.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  Toast.makeText(MainActivity.this, "Clicado",Toast.LENGTH_SHORT)
                          .show();
                  copiarFFMpeg();
  
              }
          });
  
      }
  
      private void executarFFMpeg(final String[] cmd, ParcelFileDescriptor read) {
  
          try {
              ffmpegProc = Runtime.getRuntime().exec(cmd);
          } catch (IOException e) {
              e.printStackTrace();
          }
  
          (new Thread(new Runnable() {
              @Override
              public void run() {
                  try {
                      InputStream inStream = ffmpegProc.getInputStream();
                      InputStreamReader sReader = new InputStreamReader(inStream);
                      BufferedReader bufferedReader = new BufferedReader(sReader);
                      String line;
                      while ((line = bufferedReader.readLine()) != null) {
                          Log.d("FFMPEG",line);
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
          })).start();
  
          (new Thread(new Runnable() {
              @Override
              public void run() {
                  byte[] buffer = new byte[8192];
                  int read = 0;
  
                  OutputStream ffmpegInput = ffmpegProc.getOutputStream();
                  FileInputStream reader = new FileInputStream(pipeRead.getFileDescriptor());
  
                  try {
  
                      while (true) {
  
                          if (reader.available()>0) {
                              read = reader.read(buffer);
                              ffmpegInput.write(buffer, 0, read);
                              ffmpegInput.flush();
                          } else {
                              Thread.sleep(10);
                          }
  
                      }
  
                  } catch (InterruptedException e) {
                      e.printStackTrace();
  
                  } catch (IOException e) {
                      e.printStackTrace();
  
                      onDestroy();
                  }
              }
          })).start();
  
          Log.d("FFMPEG","Executado");
      }
  
      private boolean estaExecutando(Process ffmpegProc) {
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
              return ffmpegProc.isAlive();
          } else {
              try {
                  ffmpegProc.exitValue();
                  return false;
              } catch (Exception e) {
                  return true;
              }
          }
      }
  
      private void criarMediaRecorder() {
          if (pipeWrite != null) {
              try {
                  //ffplay.exe -protocol_whitelist rtp,file,udp ..\file.sdp
                  mediaRecorder = new MediaRecorder();
                  mediaRecorder.setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION);
                  mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.AAC_ADTS);
                  mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
                  //mediaRecorder.setAudioChannels(2);
                  mediaRecorder.setOutputFile(pipeWrite.getFileDescriptor());
                  mediaRecorder.prepare();
                  mediaRecorder.start();
                  Log.d("MREC","MediaRecorder criado");
              } catch (Exception e) {
                  e.printStackTrace();
              }
          }
      }
  
      private void criarPipe() {
          try {
              pipePair =ParcelFileDescriptor.createPipe();
          } catch (IOException e) {
              Log.e("PIPE","Deu zica na criação do pipe");
              e.printStackTrace();
              finish();
          }
          pipeRead = new ParcelFileDescriptor(pipePair[0]);
          pipeWrite  = new ParcelFileDescriptor(pipePair[1]);
      }
  
      private void copiarFFMpeg() {
          FFmpeg ffmpeg = FFmpeg.getInstance(this);
          try {
              ffmpeg.loadBinary(new LoadBinaryResponseHandler() {
  
                  @Override
                  public void onStart() {
                      Log.d("FFMPEG","Iniciar cópia");
                  }
  
                  @Override
                  public void onFailure() {
                      Log.e("FFMPEG","Cópia falhou");
                  }
  
                  @Override
                  public void onSuccess() {
                      Log.d("FFMPEG","Cópiado com sucesso");
  
                      criarPipe();
                      //mediaRecorder.start();
                      File ffmpegBin = new File(getFilesDir().getAbsolutePath()+"/ffmpeg");
                      String[] cmd = new String[] {
                              ffmpegBin.getAbsolutePath(),
                              "-re",
                              "-thread_queue_size","4",
                              "-i","pipe:",
                              //"-c:a","libx264",
                              //"-preset","veryfast",
                              //"-tune","zerolatency",
                              "-f",
                              "rtp",
                              "rtp://192.168.0.33:1234"
                      };
  
                      executarFFMpeg(cmd, pipeRead);
  
                      criarMediaRecorder();
                  }
  
                  @Override
                  public void onFinish() {
                  }
              });
          } catch (FFmpegNotSupportedException e) {
              // Handle if FFmpeg is not supported by device
              Log.e("FFMPEG", "Não sou suportado :/");
          }
      }
  
      @Override
      protected void onDestroy() {
          super.onDestroy();
      }
  
      @Override
      public void onClick(View view) {
  
      }
  }
  

  The command:

  ffplay rtp://192.168.0.33:1234
  
  ffplay -fflags nobuffer rtp://192.168.0.33:1234