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• Trim and loop audio to the length of video

  20 mai 2020, par Nguyễn Trọng

  I have a 30 second video and a 120 second audio.
I ran the following command to loop audio into the video but it only stopped when the audio length was reached even though I added "-shortest".
Help me. (sorry for my bad english)

  



  String[] cmd = {"-y", "-i", video.mp4, "-i", audio.mp3,
            "-filter_complex",
            "[1:a]atrim=0:100,asetpts=PTS-STARTPTS," +
                    "asetrate=44100,aloop=1:size=1*44100," +
                    "aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=stereo,volume=1.0[bg];" +
                    "[0:v][bg]concat=n=1:v=1:a=1[video]", "-shortest",
            "-map", "[video]", "-c:v", "libx264", "-c:a", "aac",
            "-preset", "veryfast", output, "-hide_banner"};


  


• FFMPEG color range cropped to 15-235 in RGB

  20 décembre 2017, par Some1Else

  I have a series of BMPs (or PNG) images that I want to convert to XVID and MP5 movie formats.

  Encoding works but the resulting movie has a washed out color look to it and the blacks are somehow moved to RGB 16 and the brightest 255 values are moved down to 235. I want the output movie to use the same 0 to 255 colors as the source frames.

  Now there are all sorts of conflicting doco out there for FFMPEG so I am hopinbg someone has an example command line that does what I need. I have tried all sorts of pix_fmt flags but none of them get the output movie in the full color range.

  For XVID

  ffmpeg.exe -framerate 60 -i "D:\SRC%05d.BMP"  -c:v mpeg4 -vtag xvid -qscale 1 -y "D:\OUTPUT.AVI""

  For H265

  ffmpeg.exe -framerate 60 -i "D:\SRC%05d.BMP" -c:v libx265 -x265-params lossless=1 -s 3840x2160 -pix_fmt yuvj420p -an -y "D:\OUTPUT.MP4""

  The yuvj420p is supposed to give the full color range but ffmpeg complains "Incompatible pixel format ’yuvj420p’ for codec ’libx265’, auto-selecting format ’yuv420p’"

  So, are there any FFMPEG gurus out there that can give me the magic switches to get my output movies with black blacks and colors that maintain the original frame files 0-255 RGB values.

• avcodec/ljpegenc : Allow full range yuv420p, yuv422p, yuv444p by default

  6 avril 2021, par Andreas Rheinhardt

  avcodec/ljpegenc : Allow full range yuv420p, yuv422p, yuv444p by default
  The documentation for AV_PIX_FMT_YUVJ420P reads :
  
  "planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of
  
  AV_PIX_FMT_YUV420P and setting color_range"
  
  Yet the LJPEG encoder only accepts full scale yuv420p when strictness is
  
  set to unofficial or lower ; with default strictness it emits a nonsense
  
  error message that says that limit range YUV is unofficial. This has
  
  been changed to allow full range yuv420p, yuv422p and yuv444p irrespective
  
  of the level of strictness.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/ljpegenc.c