As I understand, eof_reached sets to 1 when ffmpeg reads all the data from the buffer. This is needed 'cause some decoders have internal buffer and if you want to get all frames from them when end of file is reached, you should feed them with empty data (google for 'B-frames').
2011/1/27 Bob Sopplor <[email protected]> > Thank you very much! That did the trick. > > Is it the expected behavior when pushing streamed video data chunk by chunk > into > ffmpeg ... to set "iocontext->eof_reached = 0" when new video data is > arriving? > Or is it just a symptom or workaround if a missed to set something else > correctly? > > After all... when disabling the flag before entering the read_frame loop, > the > decoding works for me. > > Thank you very much! > > > > > > ----- Ursprüngliche Mail ---- > Von: Max The Quantum <[email protected]> > An: Libav* user questions and discussions <[email protected]> > Gesendet: Donnerstag, den 27. Januar 2011, 10:51:01 Uhr > Betreff: Re: [libav-user] av_read_frame() stopped reading. > > try to check > > iocontext->eof_reached > > > if it is true av_read_frame won't actually read any more > > 2011/1/26 Bob Sopplor <[email protected]> > > > Hello, > > > > I've a problem feeding the av_read_frame function with my h.264 video > > data—after > > reading the first frame (from memory): it simply stopped and won't read > > anymore. > > > > I've build the FormatContext using av_alloc_put_byte() ... the > pVideoBuffer > > is > > allocated using av_malloc and it's size is 256k. My[Read|Write|Seek]Func > > are > > static hooks I use using the this_ptr as (void*) opaque to get the call > > back to > > my object. > > > > pFormatCtx->pb = av_alloc_put_byte( pVideoBuffer, int(pVideoBufferSize), > 1, > > (void*)this, MyReadFunc, MyWriteFunc, MySeekFunc ); > > > > After that I probe the input stream using my video data from my internal > > buffer, > > I make a call to "av_open_input_stream" and successfully open the stream. > > > > In the next step av_read_frame() is called, which calls my MyReadFunc() > > function. From there I copy the video data from my interal buffer to the > > "buf" > > parameter in the read function - but after a call to av_read_frame(), the > > buffer > > from the ByteIOContext changes and its the 256k buffer I allocated but a > > different one and 32k large. I copy 17k of video data and quit. After > that > > a > > second call goes to MyReadFunc() but at that moment no more video data is > > available ... so I copy 0 bytes. I quit the function and return from > > av_read_frame() successfully with >=0. > > > > I start decoding with avcodec_decode_video2() and I get told my frame is > > finished ... no problem there (the decoded output inside the frame looks > > okay > > and like YUV420P). > > > > > > After that i free the AVPacket and make another call to av_read_frame() > but > > know > > no video data is available—but I also won't jump to MyReadFunc() trying > to > > read > > data. The read-loop is started again when the next chunks of data come in > > and my > > internal buffer is filled. But all subsequent calls to av_read_frame() > > directly > > return without leaving me a chance to copy the video data to the buffer. > > > > I've checked the ByteIOContext after that: pb->buffer_size is still at > 32k, > > pb->buf_ptr is the same as pb->buf_end (same address) and pos is at 17k. > > > > Did I do something wrong with the internal buffers I allocated or didn't > I > > understood the use of the buffers? I don't know why this is happening, > but > > after > > that no frames will get read although I've plenty of video data > available. > > > > Any ideas? > > > > thank you very much... > > > > > > > > _______________________________________________ > > 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 > > > > _______________________________________________ > 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
