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• Issues with FFmpeg Recording RTSP Stream with HEVC Codec : Blurred Bottom of Video

  31 août 2024, par user2877989

  I'm using FFmpeg to capture an RTSP stream from an IMOU camera, and I'm encountering an issue with the recorded video. The output video is encoded using the HEVC codec, but the bottom part of the video appears blurred while the top part displays correctly.

  


  Here is the command I'm using :

  


  ffmpeg -i "rtsp://admin:xxxxx@192.168.1.32:554/cam/realmonitor?channel=1&subtype=0&unicast=true&proto=Onvif" -c copy -f segment -segment_time 5 -reset_timestamps 1 -strftime 1 "./%Y_%m_%d_%H_%M_%S.mp4"


  


  Details :

  


  

  • FFmpeg Version : [Include your FFmpeg version here] Camera Model : IMOU
[Include model if known] Codec Used : HEVC (libx265) Issue : The output
video has a blurred bottom section, while the top part looks fine.

  


  


  Things I've Tried :

  


  

  • Re-encoding the video with -c:v hevc instead of -c copy.

  


  • Adding -bsf:v hevc_mp4toannexb to the command.

  


  


  None of these solutions have resolved the issue.

  


  Questions :

  


  What could be causing the bottom part of the video to appear blurred ?
Are there any additional FFmpeg options or settings that might help resolve this issue ?
Is there a better approach or command for handling RTSP streams with HEVC encoding to avoid this problem ?
Any advice or suggestions would be greatly appreciated !

  


  Thank you !

  


  

  


• Detect if an interlaced video frame is the Top or Bottom field ?

  21 décembre 2024, par Danny

  I'm decoding video PES packets (packetized elementary stream) containing H.264/AVC and H.265/HEVC using libavcodec like this :

  


  while (remainingESBytes > 0)
{
    int bytesUsed = av_parser_parse2(
            mpParser, mpDecContext,
            &mpEncPacket->data, &mpEncPacket->size,
            pIn, remainingESBytes,
            AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);

    // send encoded packet for decoding
    int ret = avcodec_send_packet(mpDecContext, mpEncPacket);
    if (ret < 0)
    {
        // failed
        continue;
    }

    while (ret >= 0)
    {
        ret = avcodec_receive_frame(mpDecContext, mpDecFrame);
        /// Do stuff with frame ///
    }

    remainingESBytes = getMoreBytes()
}


  


  Sometimes the input video is interlaced, in which case it seems avcodec_receive_frame is returning individual fields and not a merged frame of the top and bottom fields together.

  


  I couldn't find any way for avcodec_receive_frame to emit a full, non-interlaced frame.

  


  I can merge a top and bottom field together but I haven't found any way to identify if a given AVFrame is top or bottom.

  


  How can I do that ?

  


  EDIT I

  


  Looking at the log output from the decoder, it appears the decoder knows if the field is top or bottom (carried by SEI ?) but still can't figure out how to access that information via the libavcodec API...

  


  [hevc @ 0x1afcfc0] ENTER DECODE NAL TYPE 39. sei.ni_custom.type = -1
[hevc @ 0x1afcfc0] Set sei.ni_custom.type to -1.
[hevc @ 0x1afcfc0] ff_hevc_decode_nal_sei - s->ni_custom.type = -1
[hevc @ 0x1afcfc0] Decoding SEI [NAL Type 39]. ni_custom.type=-1
[hevc @ 0x1afcfc0] TOP Field
[hevc @ 0x1afcfc0] EXIT DECODE NAL TYPE 39. sei.ni_custom.type = -1


  


• Revision 26fead7ecf : Renaming in MB_MODE_INFO The macro block mode info context originally contained

  13 août 2013, par Paul Wilkins

  Changed Paths :
   Modify /vp9/common/vp9_alloccommon.c

  
   Modify /vp9/common/vp9_blockd.h

  
   Modify /vp9/common/vp9_debugmodes.c

  
   Modify /vp9/common/vp9_loopfilter.c

  
   Modify /vp9/common/vp9_mvref_common.c

  
   Modify /vp9/common/vp9_postproc.c

  
   Modify /vp9/common/vp9_pred_common.c

  
   Modify /vp9/common/vp9_pred_common.h

  
   Modify /vp9/decoder/vp9_decodemv.c

  
   Modify /vp9/decoder/vp9_decodframe.c

  
   Modify /vp9/encoder/vp9_bitstream.c

  
   Modify /vp9/encoder/vp9_encodeframe.c

  
   Modify /vp9/encoder/vp9_rdopt.c

  
   Modify /vp9/encoder/vp9_tokenize.c

  
  
  Renaming in MB_MODE_INFO

  The macro block mode info context originally contained an
  entry for each 16x16 macroblock. In VP9 each entry refers
  to an 8x8 region not a macro block, so the naming is misleading.

  This first stage clean up changes the names of 3 entries in the
  structure to remove the mb_ prefix.

  TODO clean up the nomenclature more widely in respect of
  mbmi and bmi.

  Change-Id : Ia7305c6d0cb805dfe8cdc98dad21338f502e49c6