Hi, Some time ago (actually, in 2013): http://lists.live555.com/pipermail/live-devel/2013-December/017843.html
I reported an issue with Vorbis RTP Sink: valgrind would whine that the sendto syscall was accessing some uninitialized data, and the RTSP clients (vlc, using live555 for RTP depacketization, and ffplay, using ffmpeg) would complain about invalid vorbis data when decoding the frames received via RTP. The file allowing to reproduce this issue being: https://xenomai.org/video-tests/big_buck_bunny/bbb-audio.mkv Disabling the packing of multiple vorbis frames in one packet avoided the issue, so I did it in my local copy of live555, but this caused issues with files containing very small frames. So, I finally had a look at the issue, I made a test program combining live555 media server and testRTSPClient, the server would serve the problematic file on the 127.0.0.1 address, the RTSP client would connect to the server and also demux the file, and compare the frames received via RTP with the data extracted directly from the file. I can post this test program somewhere if anyone is interested. When the problem happens, the data extracted from the RTP packet are (much) larger than the data extracted from the file, and the "good data" is preceded by two bytes. It seems the problem happens in MultiFramedRTPSink, when a frame would overflow the packet size, and is put aside as overflow data. When the overflow data are reused, and setFrameSpecificHeaderBytes() is called by the vorbis doSpecialFrameHandling() method the offset used to store the frame specific header is an offset that was valid when the frame was at the end of the previous packet. This causes the frame size to be larger than it should. Recomputing the frame specific header offset as in the following patch before reusing the overflow data seems to avoid the issue: diff -Naurdp live/liveMedia/MultiFramedRTPSink.cpp live.fixed/liveMedia/MultiFramedRTPSink.cpp --- live/liveMedia/MultiFramedRTPSink.cpp 2016-04-21 20:56:32.000000000 +0200 +++ live.fixed/liveMedia/MultiFramedRTPSink.cpp 2016-05-15 21:57:44.423448155 +0200 @@ -201,6 +201,10 @@ void MultiFramedRTPSink::buildAndSendPac void MultiFramedRTPSink::packFrame() { // Get the next frame. + fCurFrameSpecificHeaderPosition = fOutBuf->curPacketSize(); + fCurFrameSpecificHeaderSize = frameSpecificHeaderSize(); + fOutBuf->skipBytes(fCurFrameSpecificHeaderSize); + // First, see if we have an overflow frame that was too big for the last pkt if (fOutBuf->haveOverflowData()) { // Use this frame before reading a new one from the source @@ -214,9 +218,6 @@ void MultiFramedRTPSink::packFrame() { // Normal case: we need to read a new frame from the source if (fSource == NULL) return; - fCurFrameSpecificHeaderPosition = fOutBuf->curPacketSize(); - fCurFrameSpecificHeaderSize = frameSpecificHeaderSize(); - fOutBuf->skipBytes(fCurFrameSpecificHeaderSize); fTotalFrameSpecificHeaderSizes += fCurFrameSpecificHeaderSize; fSource->getNextFrame(fOutBuf->curPtr(), fOutBuf->totalBytesAvailable(), Regards. -- Gilles. https://click-hack.org _______________________________________________ live-devel mailing list live-devel@lists.live555.com http://lists.live555.com/mailman/listinfo/live-devel
