El 29/03/17 a las 09:45, Gonzalo Garramuño escribió:
I would like to use the PNG reader that comes with FFMPEG in my program as it is multithreaded and quite fast. However, I don't know how to set the starting frame number ( -start_number ) nor the length of frames to read. Reading img2dec.c, I found out about VideoDemuxData. Currently, the class VideoDemuxData is private to libavformat, and is located in a private .h file (img2.h). So I am stumped.

My question is: is there any way in libav to set the value of -start_number or, more to the point, have the png reader start/end at a particular frame?

Thanks in advance.

To answer my own question:


      AVDictionary *opts = NULL;
      av_dict_set(&opts, "initial_pause", "1", 0);

      char buf[64];
      sprintf( buf, "%" PRId64, _frameStart );

      av_dict_set(&opts, "start_number", buf, 0);

      AVInputFormat*     format = NULL;
      // We must open fileroot for png sequences to work
      int error = avformat_open_input( &_context, fileroot(),
                       format, &opts );

--
Gonzalo Garramuño

_______________________________________________
Libav-user mailing list
[email protected]
http://ffmpeg.org/mailman/listinfo/libav-user

Reply via email to