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• Converting mkv to mp4 using avconv with given set of configuration

  7 juin 2016, par Ankit Dhanna

  I have an mkv video and I want to convert it into mp4 but when I do so using avconv command, it loses its quality.

  avconv -i source.mkv -vcodec libx264 -acodec libvo_aacenc -b:a 92k destination.mp4

  I want that my mp4 file should have the following characteristics :

  Stream #0.0: Video: libvpx, yuv420p, 640x480 [PAR 1:1 DAR 4:3], q=2-31, 90k tbn, 1k tbc
  
  Stream #0.1: Audio: pcm_mulaw, 8000 Hz, 1 channels, 64 kb/s

  How can I achieve that ?

  I tried
  avconv -i input.mkv -codec copy output.mp4
  But it says " Could not write header for output file #0 (incorrect codec parameters ?"

  Please help guys .. thanks

• Decode Frame into a byte array to IplImage

  20 février 2015, par Ernesto Luis

  I have a .drv file with 4 channels of videos. I already remove the owner headers of each frame and I get a byte array that contains the frame bytes in Mpeg4 without any header. So what I need is decode this frame (byte array) using javaCv / ffmpeg to obtain a IplImage or .jpeg image.
  Here you have some code for ideas.

  public static void main(String[] args) throws IOException

      byte [] dvr1= new byte[8*1024];
  
      byte [] dvr;      
  
      try {   
  
  
  
         System.out.println("Leyendo...");    
  
         FileInputStream fileInput= new FileInputStream("D:\\muestra.drv");
  
         ByteArrayOutputStream baos= new ByteArrayOutputStream(); 
  
  
  
         if(fileInput!=null){
  
               BufferedInputStream bufferedInput = new BufferedInputStream(fileInput);
  
  
  
         // Streams y buffers de escritura.
  
  
  
  
  
          //Leer el fichero completo y ponerlo en memoria
  
                  int leidos = 0;
  
                   while((leidos= bufferedInput.read(dvr1))>=0){
  
                      baos.write(dvr1, 0, leidos);
  
                   } 
  
                   //Pasar el contenido del fichero almacenado en memoria al arreglo de Bytes                         
  
                        dvr= baos.toByteArray();
  
                        baos.reset();
  
                        baos.close();
  
                        int lon= dvr.length;  
  
  
  
  
  
                    //Buscar el comienzo del header
  
                        int offset=0;
  
                        while(offset=dvr.length)
  
                                break;
  
                        } 
  
  
  
                        byte[] head= Arrays.copyOfRange(dvr, offset, offset+32);
  
                        offset+=32;
  
                            BasicHeader bHeader= new BasicHeader(head); 
  
                            ExtraHeader xHeader= new ExtraHeader(head);
  
                            offset+=xHeader.SuperExtraSize;
  
                            PESHeader pesHeader= new PESHeader(Arrays.copyOfRange(dvr, offset,offset+32));
  
                            offset+=32;
  
                            byte[]frame;   
  
  
  
                            if(offset+bHeader.Size/ Here is the problem
  
                                    DecodeFrame(frame);                             
  
  
  
                        }                
  
  
  
       //  System.out.println("No se encontro el archivo");
  
      } catch (java.lang.Exception e) {
  
          // TODO: handle exception
  
           System.out.println(e.getMessage());
  
      }

• avformat/mpegtsenc : Fix mpegts_write_pes() for private_stream_2 and other types

  25 avril 2021, par zheng qian

  avformat/mpegtsenc : Fix mpegts_write_pes() for private_stream_2 and other types
  According to the PES packet definition defined in Table 2-17 of ISO_IEC_13818-1
  
  specification, some fields like PTS/DTS or pes_extension could only appears if
  
  the stream_id meets the condition :
  if (stream_id != 0xBC &&  // program_stream_map
  
      stream_id != 0xBE &&  // padding_stream
  
      stream_id != 0xBF &&  // private_stream_2
  
      stream_id != 0xF0 &&  // ECM
  
      stream_id != 0xF1 &&  // EMM
  
      stream_id != 0xFF &&  // program_stream_directory
  
      stream_id != 0xF2 &&  // DSMCC_stream
  
      stream_id != 0xF8)    // ITU-T Rec. H.222.1 type E stream
  And the following stream_id types don't have fields like PTS/DTS :
  else if ( stream_id == program_stream_map
  
  || stream_id == private_stream_2
  
  || stream_id == ECM
  
  || stream_id == EMM
  
  || stream_id == program_stream_directory
  
  || stream_id == DSMCC_stream
  
  || stream_id == ITU-T Rec. H.222.1 type E stream ) 
  
      for (i = 0 ; i < PES_packet_length ; i++) 
  
          PES_packet_data_byte
  
      
  
  
  Current implementation skipped the check of stream_id causing some kind of
  
  streams like private_stream_2 to be incorrectly written with actually a
  
  private_stream_1-like PES header with PTS/DTS field. For example, Japan DTV
  
  transmits news and alerts through ARIB superimpose that utilizes
  
  private_stream_2 still could not be remuxed correctly for now.
  This patch set fixes the remuxing for private_stream_2 and
  
  other stream_id types.
  Signed-off-by : zheng qian <xqq@xqq.im>
  
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] libavformat/mpegtsenc.c