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• checkasm : updated tests for sw_scale

  13 août 2022, par Swinney, Jonathan

  checkasm : updated tests for sw_scale
  Change the reference to exactly match the C reference in swscale,
  
  instead of exactly matching the x86 SIMD implementations (which
  
  differs slightly). Test with and without SWS_ACCURATE_RND - if this
  
  flag isn't set, the output must match the C reference exactly,
  
  otherwise it is allowed to be off by 2.
  Mark a couple x86 functions as unavailable when SWS_ACCURATE_RND
  
  is set - apparently this discrepancy hasn't been noticed in other
  
  exact tests before.
  Add a test for yuv2plane1.
  Signed-off-by : Jonathan Swinney <jswinney@amazon.com>
  
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libswscale/x86/swscale.c
  • [DH] tests/checkasm/sw_scale.c

• How to stich images into a video with resolution larger then 4K using FFMPEG ?

  14 janvier 2023, par Aviram Fireberger

  I have a folder with images that I've extracted from one video.
The resolution for each image is 5760 X 2880.
All images are in the following format :
out-1.jpg, out-2.jpg , out-3.jpg ..... out-1000.jpg

  


  I tried couple of different ways to stich them :

  


  Using CPU - libx264

  


  ffmpeg -r 30 -f image2 -s 5760X2880 -start_number 1 -i "AllFrames/out-%d.jpg" -vframes 119 -vcodec libx264 -crf 25  -pix_fmt yuv420p "/AllVideoChunks/Chunk_1.mp4"


  


  Worked well but the speed is about X0.05 only.

  


  Using GPU - h264_nvenc

  


  ffmpeg -r 30 -f image2 -s 4000X2000 -start_number 1 -i "AllFrames/out-%d.jpg" -vframes 119 -vcodec h264_nvenc -gpu  0 -preset slow -b:v 75M  -pix_fmt yuv420p"/AllVideoChunks/Chunk_1.mp4"


  


  Working very fast and high quality, but the problem is that I can't use it for images and output bigger then width 4096

  


  Using GPU - hevc_nvenc

  


  ffmpeg -r 30 -f image2 -s 5760X2880 -start_number 1 -i "AllFrames/out-%d.jpg" -vframes 119 -vcodec hevc_nvenc -gpu  0 -preset slow -b:v 75M  -pix_fmt yuv420p"/AllVideoChunks/Chunk_1.mp4"


  


  Working X10 more then the CPU at the speed of X0.5, good quality, but the problem is that I can't use it in normal players (can't play it in Unity)

  


  Is there another video codec that can work on GPU that support more then 4K resolution ?
Can I transform the 'hevc_nvenc ' output to 'h264' on GPU in higher resolution ? should I do this transformation on CPU ?

  


• Why does ffmpeg stop recording at midnight ?

  22 septembre 2019, par peter

  I have a shellscript like this under Kubuntu 19.10,

  #!/bin/bash
  
  
  
  while true
  
  do
  
      FILE=/media/petermc/Security5/Camera2/Camera2_.mp4  
  
      FILE=${FILE%.*}`date +%Y-%m-%d_%H-%M-%S-%N`.${FILE#*.}
  
      echo $FILE
  
  
  
      ffmpeg -rtsp_transport tcp -t 00:15:00 -i rtsp://*user*:*password*@192.168.1.60:554/ch02/0 -c copy -map 0 $FILE
  
  done

  It records files like this,

  Camera2_2019-09-21_23-36-57-874602376.mp4
  
  Camera2_2019-09-21_23-51-57-876639147.mp4

  Basically recording 15 minutes at a time from the RTSP feed, then starting a new file.

  However it stops working at midnight, the last few lines from the log file are this,

  frame= 3987 fps= 13 q=-1.0 size=  117760kB time=00:05:06.51 bitrate=3147.3kbits/s speed=1.01x    
  
  frame= 3994 fps= 13 q=-1.0 size=  118016kB time=00:05:07.07 bitrate=3148.4kbits/s speed=1.01x    
  
  frame= 4001 fps= 13 q=-1.0 size=  118016kB time=00:05:07.59 bitrate=3143.1kbits/s speed=1.01x    
  
  frame= 4008 fps= 13 q=-1.0 size=  118272kB time=00:05:08.11 bitrate=3144.6kbits/s speed=1.01x 

  So there doesn’t seem to be any error, it stops recording at 5 minutes into the last file with no error.

  Another piece of information is that I have 6 cameras, and 4 stopped recording, the ones connected to a DVR. I have a couple of IP cameras and they kept recording.

  What could be the cause of this ? Plus, what else could I do to work around this or diagnose this ?

  UPDATE :

  I believe the issue is because the DVR has a maintenance setup to restart once at week at midnight. If this is what happened, is there any way I can configure ffmpeg to restart if it has lost the stream ?