On Wed, Apr 10, 2019 at 9:55 AM Aman Gupta <ffm...@tmm1.net> wrote: > > On Tue, Apr 9, 2019 at 9:49 PM Hendrik Leppkes <h.lepp...@gmail.com> wrote: > > > On Wed, Apr 10, 2019 at 2:21 AM Aman Gupta <ffm...@tmm1.net> wrote: > > > > > > From: Aman Gupta <a...@tmm1.net> > > > > > > Previously, the initial seek position was recorded into > > > old_offset at the beginning of avformat_find_stream_info(), > > > and passed into estimate_timings(). In the case of mpegts > > > with a known filesize, it was further passed into > > > estimate_timings_from_pts() which called avio_seek(SEEK_SET) > > > after doing its timing related seeks. (Interestingly, this > > > seeked all the way back to the initial position before > > > the probe, rather than only back before the timing > > > related seeks to the end of the file). > > > > > > With this commit, we pull the avio_seek() out of the mpegts > > > specific code-path and unconditionally seek all streams back > > > to their original position after probing is complete. > > > > > > This effectively prevents data that is consumed during > > > avformat_find_stream_info() from being discarded, so packets > > > contained at the beginning of a file are still passed back > > > to the user for playback. > > > > > > > I don't think I ever had a case where data was apparently lost from > > the beginning of the stream. Can you give examples of what this fixes? > > > Perhaps I'm missing something. > > If I see the debug log message "After avformat_find_stream_info() pos: > 1000000 bytes seeks:0", are the packets from the first megabyte of the > file still returned from API? Maybe they are being cached somewhere and I > did not notice. >
As far as I know, the packets read during stream info probing are being cached in a buffer and returned to the caller on av_read_frame. - Hendrik _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".