On Mon, Nov 20, 2017 at 2:33 PM, Carl Eugen Hoyos <ceffm...@gmail.com> wrote:
> 2017-11-20 23:12 GMT+01:00 Tyler Brooks <tylerjbro...@gmail.com>: > > > My encoder gives me a timestamp on every frame (int64_t in microseconds). > > The hardware is pretty good and the timestamps are very nearly always > > separated to 1/framerate. In my case the framerate is 30fps so the > frames > > come out of the encoder about every 30ms (lets just say for easy math for > > now). > > > > Of course, I could use those timestamps for my pts/dts. Indeed, I have > > tried. > > > > But here is the root of my problem. The key frames are handed to me as > four > > NAL packets (SPS, PPS, SEI, key_frame) all at the same time and all with > the > > same timestamp. That makes sense. The metadata meant for the decoder > (SPS, > > PPS and SEI) should to be associated with the leading key_frame and they > > should all share the same timestamp. My problem is I don't know how to > make > > a multi-packet 'AVPacket' to submit as a single frame to the > > 'av_write_frame' call. > > Did you try to concatenate SPS, PPS and SEI with > the first key-frame? > > Carl... I tried concatenating the meta data with the key frame but no joy. So, a friend pointed out to me that I might be going at this the wrong way. The basic problem I am having is that I don't have an input context so there is no h264 parser that can take the SPS, PPS and SEI packets and do anything with them. I suspect that my loop appears to be working because I am writing to an 'mpegts' file which, I think, is just h264 packets with the leading NAL zeroes replace with length words (some bit-stream filter must be doing that). But that would mean that there isn't much chance that I can get the timestamps right because I have to submit them as frames. I can't submit them as 'extradata/sidedata' because there is no codec to catch them. Apparently I am supposed to write a custom IO context for the output of my encoder and then do a normal input context. I have done some experiments with this approach and it seems to work. Thank you for your help Carl.
_______________________________________________ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
