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• Intel IPP RGBToYUV420 function is getting IppStsSizeErr result code

  6 février 2018, par yesilcimen.ahmet

  I am using IPP 2017.0.3(r55431) and Delphi 10.2, I am trying convert RGB to YUV420P, but I am getting IppStsSizeErr result code.

  I have m_dst_picture, m_src_picture: AVPicture structure created by FFMPEG.

  { allocate the encoded raw picture }
  
  
  
   ret := avpicture_alloc(@m_dst_picture, AV_PIX_FMT_YUV420P, c^.width, c^.height);
  
  
  
   if (ret < 0) then
  
      Exit(False);
  
  
  
   { allocate BGR frame that we can pass to the YUV frame }
  
   ret := avpicture_alloc(@m_src_picture, AV_PIX_FMT_BGR24, c^.width, c^.height);
  
   if (ret < 0) then
  
     Exit(False);
  
   //It works fine.
  
   { convert BGR frame (m_src_picture) to and YUV frame (m_dst_picture) }
  
   sws_scale(sws_ctx, @m_src_picture.data[0], @m_src_picture.linesize, 0, c^.height, @m_dst_picture.data[0], @m_dst_picture.linesize);

  I want to convert the RGB buffer directly to YUV420P. The original code first loads RGB into the AVPicture then convert RGB to YUV420P with sws_scale and it causes slowness.

  Here I copy the BGR buffer to m_src_picture of FFMPEG. But this leads to performance loss, so I want to convert it directly to YUV420P using Intel IPP.

  procedure WriteFrameBGR24(frame: PByte);
  
  var
  
    y: Integer;
  
  begin
  
    for y := 0 to m_c^.height - 1 do
  
      Move(PByte(frame - (y * dstStep))^, PByte(m_src_picture.data[0] + (y * m_src_picture.linesize[0]))^, dstStep);
  
  end;

  In the code below I am trying to convert using Intel IPP.

  { Converting RGB to YUV420P. }
  
  
  
  **roiSize is 1920 and 1080
  
  
  
  **The values created by FFMPEG for YUV420P in m_dst_picture.linesize are [0]=1920,[1]=960,[2]=960 respectively.

  Do I need to convert the values of the linesize to another value ?

  **The reason why the srcStep parameter is a minus sign is the Bottom-Up Bitmap and the frame pointer indicates the Bmp.ScanLine[0] address, which indicates the highest pointer address.

  srcStep := (((width * (3 * 8)) + 31) and not 31) div 8; //for 24 bitmap
  
  
  
  { Swap of BGR channels to RGB. }
  
  //It works fine    
  
  st := ippiSwapChannels_8u_C3IR(frame, -srcStep, roiSize, @BGRToRGBArray[0]); 
  
  
  
  { Convert RGB to YUV420P. }
  
  //IppStsSizeErr  
  
  st := ippiRGBToYUV420_8u_C3P3R(frame, -srcStep, @m_dst_picture.data[0], @m_dst_picture.linesize[0], roiSize);

  How do I solve this problem ?

  Thank you.

• avformat_write_header return error code when trying to write PCMU encoded frame into avi/mov file

  9 août 2015, par Kaidul Islam

  I am trying to write PCMU G.711 enocded data into avi multimedia container using below program which yields Error occurred when opening output file: Operation not permitted and when using mov container, it yields Error occurred when opening output file: Invalid argument. I set AV_CODEC_ID_PCM_U16LE as audio codec of output format and AV_SAMPLE_FMT_S16 as sample format.

  What’s the problem here ? Thanks in advance !

• ffmpeg unexpected exit code 1 for -list_devices and -list_options

  8 janvier 2024, par djvg

  Description

  


  If I run any of the following commands from the examples in the documentation, using ffmpeg 4.2.2 on Windows 10, the requested information is successfully displayed in the console, but the process exits with exit code 1, instead of the expected 0 (success).

  


  ffmpeg -list_devices true -f dshow -i dummy

ffmpeg -list_options true -f dshow -i video="MyCamera"


  


  As far as I know, exit code 1 on Windows implies "Incorrect function", so I consider this behavior to be unexpected.

  


  If I stream camera input to disk, using e.g. ffmpeg -f dshow -i video="MyCamera" "myfile.mp4", then stop using q, the exit code is 0, as expected.

  


  Question

  


  Does the exit code 1 constitute normal behavior for ffmpeg, or am I doing something wrong ?

  


  Relevance

  


  When running the commands manually, from the command line, the exit code does not make much difference, as long as the requested information is displayed.

  


  However, when running the commands programmatically, it may cause trouble. For example, using Python's subprocess.run(..., check=True), the nonzero exit code causes a CalledProcessError.

  


  Of course there are ways around this, e.g. use check=False, but the point is that a workaround would not be necessary if ffmpeg behaved as expected, i.e. returned 0.