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• Conversion failed ! FFMpeg with custom exe in a pipe

  17 juin 2021, par Aleksey Timoshchenko

  I need to use a batch file with FFmpeg pipe query. I have a set of images (img0.bmp, img1.bmp, img2.bmp) and I need FFmpeg to iterate through them and pass raw data to my custom .exe.

  


  So, the query looks like this

  


  ffmpeg -y -hide_banner -i img%01d.bmp -vf format=gray -f rawvideo pipe: | MY_CUSTOM_EXE


  


  and code of the custom exe is really simple like this

  


  int main()
{
    return 0;
}


  


  The trick of this story is that if I pass to FFmpeg exe just one image like this ... -i img0.bmp ... it works, but if there is a set ... -i img%01d.bmp ..., so I get such an error after the very first interaction :

  


  Input #0, image2, from 'img%01d.bmp':
  Duration: 00:00:00.12, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: bmp, pal8, 4096x3000, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (bmp (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, rawvideo, to 'pipe:':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: rawvideo (Y800 / 0x30303859), gray, 4096x3000, q=2-31, 2457600 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.54.100 rawvideo
av_interleaved_write_frame(): Invalid argument
Error writing trailer of pipe:: Invalid argument
frame=    1 fps=0.0 q=-0.0 Lsize=   12000kB time=00:00:00.04 bitrate=2457600.0kbits/s speed=0.999x
video:12000kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
Conversion failed!
Press any key to continue . . .


  


  In addition if I use this query like this

  


  ffmpeg -y -hide_banner -i img%01d.bmp -vf format=gray -f rawvideo pipe :

  


  or with other ffmpeg pipe commands

  


  ffmpeg -y -hide_banner -i %input% -vf format=gray -f rawvideo pipe : | ffmpeg -hide_banner -y -framerate 30 ...

  


  it also works perfectly.

  


  So the problem in the MY_CUSTOM_EXE, but what could it be if it has only one line of code ?

  


• FFmpeg decoding H264

  25 septembre 2011, par Steve McFarlin

  I am decoding a H264 stream using FFmpeg on the iPhone. I know the H264 stream is valid and the SPS/PPS are correct as VLC, Quicktime, Flash all decode the stream properly. The issue I am having on the iPhone is best shown by this picture.

  

  It is as if the motion vectors are being drawn. This picture was snapped while there was a lot of motion in the image. If the scene is static then there are dots in the corners. This always occurs with predictive frames. The blocky colors are also an issue.

  I have tried various build settings for FFmpeg such as turning off optimizations, asm, neon, and many other combinations. Nothing seems to alter the behavior of the decoder. I have also tried the Works with HTML, Love and Peace releases, and also the latest GIT sources. Is there maybe a setting I am missing, or maybe I have inadvertently enabled some debug setting in the decoder.

  Edit

  I am using sws_scale to convert the image to RGBA. I have tried various different pixel formats with the same results.

  sws_scale(convertCtx, (const uint8_t**)srcFrame->data, srcFrame->linesize, 0, codecCtx->height, dstFrame->data, dstFrame->linesize);

  I am using PIX_FMT_YUV420P as the source format when setting up my codec context.

• FFmpeg decoding H264

  27 juillet 2020, par Steve McFarlin

  I am decoding a H264 stream using FFmpeg on the iPhone. I know the H264 stream is valid and the SPS/PPS are correct as VLC, Quicktime, Flash all decode the stream properly. The issue I am having on the iPhone is best shown by this picture.

  



  

  



  It is as if the motion vectors are being drawn. This picture was snapped while there was a lot of motion in the image. If the scene is static then there are dots in the corners. This always occurs with predictive frames. The blocky colors are also an issue.

  



  I have tried various build settings for FFmpeg such as turning off optimizations, asm, neon, and many other combinations. Nothing seems to alter the behavior of the decoder. I have also tried the Works with HTML, Love and Peace releases, and also the latest GIT sources. Is there maybe a setting I am missing, or maybe I have inadvertently enabled some debug setting in the decoder.

  



  Edit

  



  I am using sws_scale to convert the image to RGBA. I have tried various different pixel formats with the same results.

  



  sws_scale(convertCtx, (const uint8_t**)srcFrame->data, srcFrame->linesize, 0, codecCtx->height, dstFrame->data, dstFrame->linesize);


  



  I am using PIX_FMT_YUV420P as the source format when setting up my codec context.