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• LIVE555 RTSP H.264 Raw Video File Stream - ffplay Errors

  22 octobre 2015, par Chris.

  I am streaming a raw .h264 video file via RTSP using LIVE555.

  To receive the stream I am using ffplay. However, when watching the video I notice bad video quality and a bunch of errors in the ffplay-console :

  Input #0, rtsp, from 'rtsp://xx.xx.xxx.x/stream': sq=    0B f=0/0
  
    Metadata:
  
      title           : stream
  
      comment         : stream
  
  Duration: N/A, start: 0.099989, bitrate: N/A
  
      Stream #0:0: Video: h264 (High), yuv420p(tv, smpte170m/smpte170m/bt470m), 16
  
  80x1050 [SAR 1:1 DAR 8:5], 60 fps, 60 tbr, 90k tbn, 120 tbc
  
  [h264 @ 03f92100] RTP: missed 46 packetsq=   28KB sq=    0B f=1/1
  
  [h264 @ 03f92100] RTP: missed 74 packetsq=   23KB sq=    0B f=1/1
  
  [h264 @ 03f92100] RTP: missed 43 packets
  
  [h264 @ 03f92100] RTP: missed 35 packetsq=  179KB sq=    0B f=1/1
  
  [h264 @ 05710640] left block unavailable for requested intra4x4 mode -1 at 0 38
  
  [h264 @ 05710640] error while decoding MB 0 38, bytestream 48108
  
  [h264 @ 05710640] Cannot use next picture in error concealment
  
  [h264 @ 05710640] concealing 2989 DC, 2989 AC, 2989 MV errors in P frame
  
  [h264 @ 051043c0] left block unavailable for requested intra4x4 mode -1 at 0 26
  
  [h264 @ 051043c0] error while decoding MB 0 26, bytestream 5894
  
  [h264 @ 051043c0] concealing 4249 DC, 4249 AC, 4249 MV errors in I frame
  
  [h264 @ 03f92100] RTP: missed 68 packetsq=   28KB sq=    0B f=1/1
  
  [h264 @ 03f92100] RTP: missed 31 packetsq=  153KB sq=    0B f=1/1
  
  [h264 @ 052a0020] concealing 3292 DC, 3292 AC, 3292 MV errors in I frame
  
  [h264 @ 052a0020] Cannot use next picture in error concealment1/1
  
  [h264 @ 052a0020] concealing 2190 DC, 2190 AC, 2190 MV errors in P frame
  
  [h264 @ 03f92100] RTP: missed 69 packetsq=   27KB sq=    0B f=1/1
  
  [h264 @ 052a0020] concealing 3732 DC, 3732 AC, 3732 MV errors in I frame
  
  [h264 @ 03f92100] RTP: missed 26 packetsq=   30KB sq=    0B f=1/1
  
  ...

  How can I determine what’s wrong here ? Either with the stream or the file ?

• H264 keyframe issue with RTP

  3 septembre 2015, par Mat DePasquale

  I’m building an RTP encoder for H264 video. The video data provider doesn’t periodically stream the keyframe in the data, instead they have provided me with a binary file representation of the keyframe. This includes the SPS-PPS-SEI and then 8 slices of the i-frame.

  Since I am encoding RTP, I need to rebroadcast this keyframe at 2 second intervals. I am doing that in my code, along with the rest of the data as it comes in. I am using ffmpeg to connect to the RTP data via a UDP socket for display testing.

  I am noticing that every 2 seconds, the video seems to blank and resync itself, pixelate, etc. Obviously, this is highly undesirable in the video product. I’ve been trying to debug this for quite some time and the only thing I can determine is that it has to do with the keyframe. If I just send the keyframe once, and then the rest of the data, ffmpeg displays the video fine. But in a network environment, I need to send the keyframe at periodic intervals.

  Does anyone have an idea as to why this resyncing of the video happens and most importantly, how to stop it from happening ?

  Thanks !

• lavc : allow asynchronous decoders to return correct pkt_dts values

  11 septembre 2015, par wm4

  lavc : allow asynchronous decoders to return correct pkt_dts values
  The generic code in utils.c sets the AVFrame.pkt_dts field from the
  
  packet it was supposedly decoded. This does not have to be true for a
  
  fully asynchronous decoder like mmaldec. It could be overwritten with an
  
  incorrect value. Even if the decoder doesn’t determine the DTS (but sets
  
  it to AV_NOPTS_VALUE), it’s impossible to determine a correct value in
  
  utils.c.
  Decoders can now be marked with FF_CODEC_CAP_SETS_PKT_DTS, in which case
  
  utils.c won’t overwrite the field. The decoders are expected to set this
  
  field (even if they only set it to AV_NOPTS_VALUE).
  Signed-off-by : Luca Barbato <lu_zero@gentoo.org>
  

  • [DBH] libavcodec/internal.h
  • [DBH] libavcodec/mmaldec.c
  • [DBH] libavcodec/utils.c