Newest 'ffmpeg' Questions - Stack Overflow

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• FFMpeg not merging videos well in Nodejs on same file

  5 mai 2017, par G.Darcan

  I am using MediaStreamRecorder to make a stream, I am getting video blobs from there every 5 seconds and i want to concatenate them in one file on server-side. So lets say i have a video named sample_1.mp4 . When i get the next video, i want to save it as sample_2.mp4 , and append it to sample_1.mp4 with ffmpeg, and after that save the output as sample_2.mp4 again.But it only saves first video and the last video parts.Can you help me please? Thanks.

              var fs = require('fs');
              fs.writeFileSync("/sample_2.mp4", message.binaryData );
              console.log("The file3 was saved!");
              var firstFile = "/sample_1.mp4";
              var secondFile = "/sample_2.mp4";
              var output = "/sample_2.mp4";
              var proc = ffmpeg(firstFile)
              .input(secondFile)
              .on('end', function() {
                  console.log('files3 have been merged succesfully');
              })
              .on('error', function(err) {
                  console.log('an error happened: ' + err.message);
              })
              .mergeToFile(output, "/tmp");
  

• how to apply LUT filter with movie filter in ffmpeg

  5 mai 2017, par Nayan

  movie=logo [watermark]; [in][watermark] overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2[out];

  By giving image input using movie filter, I want to make watermark image transparent.I written code in visual c++. Please help to correct command syntax to pass filter description into filter graph.

• Ffmpeg transcoding video .vob (vcodec MPEG-2)

  5 mai 2017, par Aminesrine

  I want to transcode a file .vob to get the bitrate 1500 with 16/9 ratio I execute this command ffmpeg

  ffmpeg -i /path/video.vob -vcodec libx264 -vf scale=1280:-2 -strict experimental -b:v 1308k -b:a 192k -ar 44100 -r 25 /path/video_1500.mp4 2>&1
  

  But I got a video with size: 1280 x 1024. What options I should add to my command ffmpeg?

• How to let FFMpeg 'see' self-registered DShow filters

  5 mai 2017, par user7967599

  I'm trying to capture screen and voice/sound with ffmpeg. First I installed screen-capture-recorder and it includes 2 virtual dshow filters, after installation, ffmpeg could discover the 2:

  ffmpeg -list_devices true -f dshow -i dummy
  ffmpeg version N-45279-g6b86dd5... 
  [dshow @ 03ACF580] DirectShow video devices
  [dshow @ 03ACF580]  "Integrated Camera"
  [dshow @ 03ACF580]  "screen-capture-recorder"
  [dshow @ 03ACF580] DirectShow audio devices
  [dshow @ 03ACF580]  "Internal Microphone (Conexant 2"
  [dshow @ 03ACF580]  "virtual-audio-capturer"
  dummy: Immediate exit requested
  

  In order to customize the audio capturer, I compiled the source for "virtual-audio-capturer" and registered it with regsvr32. But this time ffmpeg could not find the registered filter. What steps should I add to let ffmpeg aware of the new filter?

  P.S. the registered filter could be listed with GraphStudioNext in category "Audio Capture Sources".

• x264 Encoding use x264_picture_clean crash

  5 mai 2017, par Wong Sam

  When I use iphone encoding CMSampleBufferRef To H264, it offen crash at x264_picture_clean I dont't know how to deal it

  enter image description here

  x264_picture_t* pPic_in; 
  

  here is my init about pPic_in

  pPic_in = (x264_picture_t*)malloc(sizeof(x264_picture_t));
  pPic_out = (x264_picture_t*)malloc(sizeof(x264_picture_t));
  
  x264_picture_init(pPic_out);
  
  x264_picture_init(pPic_in);
  x264_picture_alloc(pPic_in, csp, pParam->i_width, pParam->i_height);
  
  pPic_in->img.i_stride[0] = width;
  pPic_in->img.i_stride[1] = width / 2;
  pPic_in->img.i_stride[2] = width / 2;
  pPic_in->img.i_plane = 3;
  

  and i set data here

      picture_buf = yuv420_data;
      pPic_in->img.plane[0] = picture_buf;
      pPic_in->img.plane[1] = picture_buf + y_size;
      pPic_in->img.plane[2] = picture_buf + y_size*5/4;
  

  it looks well , when i run it on my iphone,but sometimes it will crash at

  x264_picture_clean
  

  here is more detail abuot pPic_in when crash occer enter image description here

  Thank u very much