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• Convert SDR-JPEG to HDR-AVIF [closed]

  27 avril 2024, par Jonas Janzen

  I would like to convert a jpg file into an avif file that is to be saved in HDR10-capable metadata (PQ curve, 2020 color space, 10 bit).

  


  The idea is to save normal SDR images in HDR-capable containers so that they can be displayed in all their glory on HDR-capable displays.

  


  I want to play with inverse tone mapping, to manipulate the output, so I implemented in Python via subprocess.

  


  So far I just want the input image to be saved in AVIF as HDR and look the same at the end as before, so that I can then make changes in the next step.

  


  I used the following command for this :

  


  ffmpeg_command = [
'ffmpeg',

  


  Input File
'-i', temp_file,

  


  Used Library
'-c', 'libaom-av1',

  


  '-still-picture', '1',

  


  Output Metadata
'-pix_fmt', 'yuv420p10le',
'-strict', 'experimental',
'-color_primaries', 'bt2020',
'-color_trc', 'smpte2084',
'-colorspace', 'bt2020nc',
'-color_range', 'pc',

  


  Output File
output_file
]

  


  So far my attempts have only been successful with the HLG characteristic. Here you can see that the images are really brighter in the peaks on my HDR monitor.

  


  With the PQ characteristic curve, the images are far too oversaturated.

  


  I guess this is because the HLG curve is compatible with the gamma curve, but PQ is not.

  


  Now my question is what I need to change.

  


  Which curve does FFMpeg expect as input.

  


  In Python I can change the images mathematically without any problems.

  


  The Example Images are again tone mapped down to jpg, to show what happened.

  


  enter image description here
enter image description here

  


• swscale : rename SwsContext to SwsInternal

  9 octobre 2024, par Niklas Haas

  swscale : rename SwsContext to SwsInternal
  And preserve the public SwsContext as separate name. The motivation here
  
  is that I want to turn SwsContext into a public struct, while keeping the
  
  internal implementation hidden. Additionally, I also want to be able to
  
  use multiple internal implementations, e.g. for GPU devices.
  This commit does not include any functional changes. For the most part, it is
  
  a simple rename. The only complications arise from the public facing API
  
  functions, which preserve their current type (and hence require an additional
  
  unwrapping step internally), and the checkasm test framework, which directly
  
  accesses SwsInternal.
  For consistency, the affected functions that need to maintain a distionction
  
  have generally been changed to refer to the SwsContext as *sws, and the
  
  SwsInternal as *c.
  In an upcoming commit, I will provide a backing definition for the public
  
  SwsContext, and update `sws_internal()` to dereference the internal struct
  
  instead of merely casting it.
  Sponsored-by : Sovereign Tech Fund
  
  Signed-off-by : Niklas Haas <git@haasn.dev>
  

  • [DH] libswscale/aarch64/hscale.S
  • [DH] libswscale/aarch64/swscale.c
  • [DH] libswscale/aarch64/swscale_unscaled.c
  • [DH] libswscale/alphablend.c
  • [DH] libswscale/arm/swscale.c
  • [DH] libswscale/arm/swscale_unscaled.c
  • [DH] libswscale/gamma.c
  • [DH] libswscale/hscale.c
  • [DH] libswscale/hscale_fast_bilinear.c
  • [DH] libswscale/input.c
  • [DH] libswscale/loongarch/input_lasx.c
  • [DH] libswscale/loongarch/input_lsx.c
  • [DH] libswscale/loongarch/output_lasx.c
  • [DH] libswscale/loongarch/output_lsx.c
  • [DH] libswscale/loongarch/swscale.S
  • [DH] libswscale/loongarch/swscale_init_loongarch.c
  • [DH] libswscale/loongarch/swscale_lasx.c
  • [DH] libswscale/loongarch/swscale_loongarch.h
  • [DH] libswscale/loongarch/swscale_lsx.c
  • [DH] libswscale/loongarch/yuv2rgb_lasx.c
  • [DH] libswscale/loongarch/yuv2rgb_lsx.c
  • [DH] libswscale/options.c
  • [DH] libswscale/output.c
  • [DH] libswscale/ppc/swscale_altivec.c
  • [DH] libswscale/ppc/swscale_ppc_template.c
  • [DH] libswscale/ppc/swscale_vsx.c
  • [DH] libswscale/ppc/yuv2rgb_altivec.c
  • [DH] libswscale/ppc/yuv2rgb_altivec.h
  • [DH] libswscale/ppc/yuv2yuv_altivec.c
  • [DH] libswscale/riscv/swscale.c
  • [DH] libswscale/slice.c
  • [DH] libswscale/swscale.c
  • [DH] libswscale/swscale_internal.h
  • [DH] libswscale/swscale_unscaled.c
  • [DH] libswscale/tests/floatimg_cmp.c
  • [DH] libswscale/tests/swscale.c
  • [DH] libswscale/utils.c
  • [DH] libswscale/vscale.c
  • [DH] libswscale/x86/hscale_fast_bilinear_simd.c
  • [DH] libswscale/x86/output.asm
  • [DH] libswscale/x86/scale.asm
  • [DH] libswscale/x86/scale_avx2.asm
  • [DH] libswscale/x86/swscale.c
  • [DH] libswscale/x86/swscale_template.c
  • [DH] libswscale/x86/w64xmmtest.c
  • [DH] libswscale/x86/yuv2rgb.c
  • [DH] libswscale/yuv2rgb.c
  • [DH] tests/checkasm/sw_gbrp.c
  • [DH] tests/checkasm/sw_range_convert.c
  • [DH] tests/checkasm/sw_rgb.c
  • [DH] tests/checkasm/sw_scale.c
  • [DH] tests/checkasm/sw_yuv2rgb.c
  • [DH] tests/checkasm/sw_yuv2yuv.c

• ffmpeg always gives me input/output error for the first time running the command

  15 novembre 2023, par Simon Lau

  I'm using ffmpeg to push raspberrypi video feeds (CSI camera) to a nginx-RTMP server then the nginx push it to youtube.
My problem is, every time when I run the ffmpeg command, it always gives me input/out error. Then it is working fine when I run the exact same ffmpeg command for the 2nd time.
How do I resolve this problem ?
I want to start the ffmpeg command in a script file and put the script in crontab so that it can start the live streaming automatically. But this error makes it impossible to do that.

  



  my ffmpeg command is as below(change the real domain name to mydomain.com) :

  



  ffmpeg -thread_queue_size 512 -f v4l2  -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100  -input_format yuyv422 -video_size 1280x720 -framerate 30 -i /dev/video0 -vf eq=gamma=1.5:saturation=1.3 -c:v h264_omx -b:v 20480K -vsync 1 -g 16  -f flv rtmp://mydomain.com:1935/live/


  



  the error log :

  



  Input #1, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 474200.421802, bitrate: 442368 kb/s
    Stream #1:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1280x720, 442368 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
rtmp://rtmp.simonliu.space:1935/live/: Input/output error