Thanks. I have tried it just now but unfortunately it won't enter the second while loop (so it doesn't seem to decode anything for the 2nd time..)
Now I have also tried avformat_seek_file(pFormatCtx, -1, 0, 0, 0, AVSEEK_FLAG_BACKWARD); (correct usage?) and it makes no difference. Is it maybe the case that once the whole file is decoded, you cannot go back? On 18 June 2014 15:04, Info || Non-Lethal Applications < [email protected]> wrote: > I’d say av_seek_frame (or avformat_seek_file) is what you’re after. > > av_seek_frame(pFormatContext, -1, 0, AVSEEK_FLAG_BACKWARD); > > Best, > > Flo > > On 18 Jun 2014, at 14:54, Slash <[email protected]> wrote: > > Hello, > > I'm developing a crypto-related application using h264 streams (only > video). I'd like to decode the frames multiple times after changing some > info in them (dct, mv, whatever), so the decoded result is always different > a little bit but I always want to deal with same input file. > > I followed the tutorial here (tutorial01.c): > https://github.com/chelyaev/ffmpeg-tutorial > > so the decoding code in question looks like this: > > while (av_read_frame(pFormatCtx, &packet) >= 0) { > // Is this a packet from the video stream? > if (packet.stream_index == videoStream) { > // Decode video frame > avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet); > } > } > // Free the packet that was allocated by av_read_frame > av_free_packet(&packet); > } > > After this while loop, all the frames are decoded. What I want is to > change something and then redo the previous while loop to decode the frames > again. How can I start it all over again? > > I have tried using av_seek_frame(pFormatCtx, videoStream, 0, > AVSEEK_FLAG_ANY) to jump back to the beginning but apparently I didn't get > any new decoded data so it is not doing what I need. > > Thanks for help. > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user > > > > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user > >
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