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• How to send hevc bitstream to ffplay using PIPE on windows ?

  15 mai 2020, par Yusw_SJTU

  I have a C program that timed to generate hevc bitstreams, and I try to put the latest NALU to stdout like this :

  



  fwrite(nalu, sizeof(unsigned char),nalu_size, stdout);
fflush(stdout);


  



  And then use myprogram.exe | ffplay -i - to play the bitstream. But it doesn't work. The program will block, and finally get ffplay error :

  



  [hevc @ 000002de9f2af200] vps_reserved_ffff_16bits is not 0xffff0
[hevc @ 000002de9f2af200] VPS 0 does not exist
[hevc @ 000002de9f2af200] SPS 0 does not exist.
[hevc @ 000002de9f2af200] PPS id out of range: 0
[hevc @ 000002de9f2af200] vps_reserved_ffff_16bits is not 0xffff
[hevc @ 000002de9f2af200] VPS 0 does not exist
[hevc @ 000002de9f2af200] SPS 0 does not exist.
[hevc @ 000002de9f2af200] PPS id out of range: 0
[hevc @ 000002de9f2af200] Error parsing NAL unit #4.
[hevc @ 000002de9f29c580] decoding for stream 0 failed
[hevc @ 000002de9f29c580] Could not find codec parameters for stream 0 (Video: hevc, none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, hevc, from 'pipe:':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: hevc, none, 25 tbr, 1200k tbn, 25 tbc
[hevc @ 000002de9f2b0800] vps_reserved_ffff_16bits is not 0xffff
[hevc @ 000002de9f2b0800] vps_reserved_ffff_16bits is not 0xffff0
[hevc @ 000002de9f2b0800] VPS 0 does not exist
[hevc @ 000002de9f2b0800] SPS 0 does not exist.
[hevc @ 000002de9f2b0800] PPS id out of range: 0
[hevc @ 000002de9f2b0800] Error parsing NAL unit #4.


  



  But if I write data to a file and use fflpay to play it, it works fine. I don't know what's wrong.

  


• Merge commit '3daaa4417317ca732fb00476fdb3308d784f87e4'

  31 octobre 2017, par James Almer

  Merge commit '3daaa4417317ca732fb00476fdb3308d784f87e4'
  * commit '3daaa4417317ca732fb00476fdb3308d784f87e4' :
  
    hevc : Add names for reserved NAL unit types
  
    h264_sei : Add namespace prefix to all SEI values
  This commit is a noop, see
  
  6eb102a616364d06a4cc994339b72910b3547e5f
  
  b264810ef7a3fcd7cfc8e232877cfb2fdf7954f6
  Merged-by : James Almer <jamrial@gmail.com>
  

• What does A->A and VV->V etc. mean in the `ffmpeg -filters` command output ?

  8 janvier 2024, par Lance

  I am seeing this :

  


  Filters:
  T.. = Timeline support
  .S. = Slice threading
  ..C = Command support
  A = Audio input/output
  V = Video input/output
  N = Dynamic number and/or type of input/output
  | = Source or sink filter
... abench            A->A       Benchmark part of a filtergraph.
..C acompressor       A->A       Audio compressor.
... acontrast         A->A       Simple audio dynamic range compression/expansion filter.
... acopy             A->A       Copy the input audio unchanged to the output.
... acue              A->A       Delay filtering to match a cue.
... acrossfade        AA->A      Cross fade two input audio streams.
...
TSC colormap          VVV->V     Apply custom Color Maps to video stream.
TS. colormatrix       V->V       Convert color matrix.
TS. colorspace        V->V       Convert between colorspaces.
TSC colortemperature  V->V       Adjust color temperature of video.
TSC convolution       V->V       Apply convolution filter.
TS. convolve          VV->V      Convolve first video stream with second video stream.
...


  


  A few questions :

  


  


  1. What does this part of the filters intro mean ?

     


      A = Audio input/output
 V = Video input/output
 N = Dynamic number and/or type of input/output
 | = Source or sink filter


     


  


  2. What does the A->A and VVV->V (and any combination of 1+ A or 1+ V) mean ?

     


  


  3. Where do the N and | show up, I don't see it anywhere...

     


  


  


  I am hoping to convert this CLI data output to JSON, but don't know what those mean.