AVPacket doesn't correspond to NAL unit at all ( if I understand your dilemma). If you need to quickly write NAL parser, look at the H264Bitstream library at Sourceforge; You can find h264 stream parsing app with example of how to use library there. Hope that helps...
On Tue, Jan 20, 2009 at 8:31 AM, Sven Alisch <[email protected]> wrote: > Hello, > > I'm sorry to be nerve-racking again with my bad english and my problem, but I > want to start a new thread, because I know where my problem is, but I do not > find a solution. > > First of all, i want to say, I want to update my cutting application with > h.264-cut support. I must say, the ffmpeg-lib ist a really cool and good to > use library and please don't get me wrong, I don't want to stress any > libav-developer for implementing a special feature! > > My problem: > > The mpeg2-based features, I said it, are working fine. And now I was > believing, that everything works automaticly with h.264 encrypted > transportstreams. But no. They don't. > > The first thing, that irritates me is my following code: > > if (packet.flags & PKT_FLAG_KEY) > { > ... > } > > After I read a single frame from a stream, I look, if it is a keyframe. This > is working for mpeg2-files. But in an h.264 stream, is every single readed > frame a key frame. And this is problematic. So my question is here, does this > not work generally for h.264-streams? > > I thought ok and added for h.264-streams following if-clause. > > if (packet.data[i] == 0 && packet.data[i+1] == 0 && packet.data[i+2] == 0 && > packet.data[i+3] == 1 && packet.data[i+4] == 0x67) > { > cout << "IDR - Frame: " << frames() << " bei " << i << endl; > avckey = true; > allowParsing = true; > ... > } > > Now I see, it work better, but the decoder produces, if I want to extract a > sequence, no pictures. The Decoder gave me no error messages, but every > decoded picture has the same size. Really strange. > > So the next question is, does av_read_frame really read such a complete > NAL-Packet or not? > > The last question is only for my own understanding. If I want to cut > h.264-streams, then it is only possible to do that at IDR-Frames? Yes or no? > > Many thanks for any help! > > regards, > Sven > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user > _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
