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• ffmpeg with libsoxr resolve dependecies

  15 février 2014, par Jelly

  I'm trying to compile ffmpeg with libsoxr, so I use the flag --enable-libsoxr when calling ./configure. I have installed libsoxr, and the location of the headers added to PATH. However when I try to compile it I get an error: ERROR: libsoxr not found, and in config.log it says:

  fatal error: soxr.h: No such file or directory
   #include 
  

  I think ./configure doesn't make use of PATH or something...Is there another way to specify dependencies for ffmpeg?

• FFMpeg Mobile video encoding stutter

  15 février 2014, par Sammaye

  I have been playing around with ffmpeg and video encoding and even though my mp4's work great on desktop, they are smooth etc they are terrible on mobile devices. They stutter and load very slowly and I am trying to figure out the problem.

  As an example I made a page using the media element plugin: http://mediaelementjs.com/ and on it I first placed the video that comes with mediaelementjs and it worked well, it scaled to desktop and mobile and loaded quickly and played without any stutter.

  However I loaded my video and it was slow and full of stutter, but only on mobile. So I thought it might be S3 (where it is hosted) but saved the file locally and same thing.

  I am hoping someone who knows h.264 and/or ffmpeg can point me in the direction of why; here is the current command I am running on ffmpeg:

  ffmpeg -i $input_file_name -vcodec libx264 -r 100 -bt 300k -ac 2 -ar 48000 -ab 192k -strict -2 -y $output_temp_file 2>&1
  

  So what have I missed?

• ffmpeg how to calculate complete frame ['I' frame ] from [ 'P' frame ]. It is conceptually correct ?

  15 février 2014, par Whoami

  I am trying to get the knowledge of ffmpeg streaming video handling.

  what I understood:

  I get from the IPed Camaera, the frames like 'IPPPPPPPPPPPPPPPPIPPPPPPP'..

  Frame 'I' is a complete frame, where as frame 'P' depends on the previous either 'P' or 'I' frame which ever is the closes.

  I get the frame by using avcodec_decode_video2

  while (av_read_frame (context, &packet) >=0)
  {   
          //LOGD (" Received PACKET...DTS and PTS  %ld and %ld ", packet.pts, packet.dts);
  
          if(packet.stream_index == videoStreamIndex ) { 
                  avcodec_decode_video2 (pCodecCtx, pFrame, &finished, &packet);
                  if ( finished) {
                  // Here is my frame, getting the type by av_get_picture_type_char(pFrame->pict_type).
            }
   }
  

  Now, When i display just the frames that i have received, looks like whenever 'I' frame received, it displays properly, when received 'P' frames, the image goes for a toss.

  1) We need to manually do any calculation to convert 'P' Frame to 'I' Frame so that it can be rendered?

  2) If not (1), what do i have to take care?..Does DTS/PTS calcuation do the magic here ?

• Create thumbnails tile for time range of video

  15 février 2014, par Dmitry Mikhaylov

  I need to create, let's say, 12 thumbnails from video, but skip 10 percent in the beginning and in the ending. I found this thing, but it just takes every 1000th frame. In my case this range will be variable and it will be better if it will be in seconds. Can't figure out how to do this with ffmpeg, don't work with it much.

• ffmpeg : Could not find codec parameters for stream 0 (Video : h264) unspecified size [on hold]

  15 février 2014, par dempap

  I try to convert a video from .raw to .mp4. For this reason I did download, build and install both x264 and ffmpeg. However, command:

  ffmpeg -f h264 -i output.raw -vcodec copy output.mp4

  fails with error (shown in picture below). Is there any way to fix this?