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• Android Video Compression [on hold]

  10 mars 2015, par Arif Gencosmanoglu

  I am planning to build a small Android JAVA application that compresses images and videos. I did the image compression part and my .apk size is 1.5MB. However when I do the video compression part by using ffmpeg the application size goes up to 20.0MB. This library has tons of features that I am not using. I only need a simple video compression module to add.

  Is there any other video compression methods or functions that will be useful ?

  Thanks.

• ffmpeg won't start until java exits

  9 août 2014, par user3925332

  I am trying to make a java program that automatically converts wtv files in an input folder to mpg files in output folder. The twist is that I make it run periodically, so it acts as a synchronizer.

  The following code works for converting the .wtv to a .dvr-ms, which is required by ffmpeg since it cannot convert .wtv files directly.

      Process p = Runtime.getRuntime().exec("C:\\Windows\\ehome\\WTVConverter C:\\Users\\Andrew\\Desktop\\test\\input\\input.wtv C:\\Users\\Andrew\\Desktop\\test\\output\\input.dvr-ms");
  
      p.waitFor();

  WTVConverter has no problems running from a java application. ffmpeg is a different story. Once the above line runs, I then run this...

      Process p = Runtime.getRuntime().exec("ffmpeg\\bin\\ffmpeg -y -i \"C:\\Users\\Andrew\\Desktop\\test\\output\\input.dvr-ms'" -vcodec copy -acodec copy -f dvd \"C:\Users\Andrew\Desktop\test\output\input.mpg\"");
  
      p.waitFor();

  Suddenly, there is a problem... The application ffmpeg shows up in the task manager, but it’s cpu usage is 0, and no mpeg files is being generated. If I force the java application to close, though, suddenly it starts working ! Huh ?

  What reason would there be for a command line application to wait for its calling application to quit before it executes ? I’m not incredibly command line savvy, so I don’t really know how to diagnose this problem.

• avcodec on C, frozen image

  11 décembre 2017, par gogoer

  I write video packets from video stream to buffer. and then i’m trying to write them to file.

              av_init_packet( &pkt );
  
              int bufer_size=250;
  
  
  
              while ( av_read_frame( ifcx, &pkt ) >= 0 && start_flag==0 && stop_flag==0){
  
                  printf("reading packet - %i \n", pkg_index);
  
                  if ( pkt.stream_index == i_index ) {
  
                      pkt.stream_index = ost->id;
  
                      pkt.pts = av_rescale_q_rnd(pkt.pts, ist->time_base, ost->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
  
                      pkt.dts = av_rescale_q_rnd(pkt.dts, ist->time_base, ost->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
  
                      pkt.duration = av_rescale_q(pkt.duration, ist->time_base, ost->time_base);
  
                      pkt.pos = -1;
  
                      av_copy_packet(&pkt_arr[pkg_index],&pkt);
  
                  }
  
                  av_free_packet( &pkt );
  
                  av_init_packet( &pkt );
  
                  pkg_index++;
  
  
  
                  if(pkg_index>=bufer_size){
  
  
  
                      int ret = avformat_write_header(ofcx, NULL);
  
                      av_dump_format( ofcx, 0, ofcx->filename, 1 );
  
  
  
                          int i;
  
                          int start_frame=0;
  
                          for(i=start_frame; ipb );
  
                            printf("END \n");
  
                            return 0;
  
  
  
                  }
  
              }

  now the problem : if start_frame=0 everithing is ok, i have 10 sec video file. But if start_frame=125 (for example) in resault i have video file with 5 sec frozen picture and 5 sec video.

  what is wrong ?

  also at the end i have errors :

  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 1
  
  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 2
  
  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 3
  
  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 4
  
  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 5
  
  [avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 6

  maybe you know what is it.