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• FFMPEG - Add (white, color-less, analog) grain to the video without desaturating video itself

  2 décembre 2018, par dd_code

  I am working on old videos where I am basically converting them to HVEC and sharpening, so i.e. my command can look like this

  .\ffmpeg.exe -i F:\file.mkv -vf unsharp=3:3:1.5 -c:v hevc_nvenc -qp 27 -a:c copy file_new.mkv

  inherent problem with this is, of course that with reducing bitrate and sharpening every now and then I can notice some nasty artifacts around the edges and on at plain-color objects.

  I noticed with some older, many times remastered movies/series that they have quite a lot of grain in the video, so I was thinking - what if I add grain and help it to mask the compression and sharpening artifacts ?

  After bit of searching I got to
  https://ffmpeg.org/ffmpeg-filters.html#noise
  and now I am using this command

  .\ffmpeg.exe -i F:\file.mkv -vf unsharp=3:3:1.5,noise=alls=14:allf=t+u -c:v hevc_nvenc -qp 30 -a:c copy file_new.mkv

  however this has one big problem, it is merely a digital RGB noise, is there a way to make it desaturated, analog-ish ? I tried adding h=s=0, however this is applying 0 saturation to the video track as a whole. Is there an effect which would achieve this or is there a way that I can reduce the saturation only of the very effect which then gets to "overlay" the video track, so the track would not be touched ?

• Extracting a bit broken AC3 audio from a video file

  3 janvier 2023, par WYSIWYG

  I Googled for about 2 hours for this problem and I can't seem to find the answer anywhere.

  


  So I have a 1080p video file which has about 2 seconds within it that's broken (at 3 minutes and 53 seconds). I found a way to extract the non-broken parts of it, also I got a replacement for the broken frames from another version of the same video (in 720p), upscaled them to 1080p and replaced them in the 1080p file (reencoding the whole file in the process). Here comes the problematic part - at the same time (3 min 53 sec), the audio is also broken and it's in Dolby Digital 5.1 AC3 format. When I try to extract the audio track from the original 1080p file and place the result in the new fixed version, which contains the upscaled video frames, the audio obviously is cut at the problematic 2 seconds and it desyncs (starts to play earlier) for the rest of the file.

  


  What I want to do and I'm unable to understand how to do it is to extract the AC3 stream in such a way that the 2 broken seconds are filled with silence and the total length of the audio stay the same as the original, so it won't desync. Is this possible and if it is, what is the correct FFMPEG command for it ?

  


  Thank you in advance.

  


  I've tried :

  


  ffmpeg -i broken.mkv -c:a copy audio.ac3

  


  which presented an output AC3 file, which is missing the 2 seconds from 03:53 to 03:55

  


  so when I combine the resulting AC3 file with the repaired video, by using :

  


  ffmpeg -i fixed.mkv -i audio.ac3 -c copy fixed-with-audio.mkv

  


  it is desynced, so at video time 03:53 I hear the audio that should play at 03:55

  


• capture DV video and audio with ffmpeg and dshow

  18 novembre 2016, par andrixnet

  Trying to capture video and audio from a DV camera, using ffmpeg, I got into a problem.
  Before anything, I first tried to see (and hear) with ffplay.

  ffmpeg version :

  ffplay version 3.0 Copyright (c) 2003-2016 the FFmpeg developers
  
    built with gcc 5.3.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  
    libavutil      55. 17.103 / 55. 17.103
  
    libavcodec     57. 24.102 / 57. 24.102
  
    libavformat    57. 25.100 / 57. 25.100
  
    libavdevice    57.  0.101 / 57.  0.101
  
    libavfilter     6. 31.100 /  6. 31.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100

  Getting list of DirectShow devices :
  ffplay -hide_banner -f dshow -list_devices true -i dummy

  [dshow @ 035c4240] DirectShow video devices (some may be both video and audio devices)
  
  [dshow @ 035c4240]  "Microsoft DV Camera and VCR" sq=    0B f=0/0
  
  [dshow @ 035c4240]     Alternative name "@device_pnp_\\?\avc#canon&mvx3i&camcorder&dv#5126800000850000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global"
  
  [dshow @ 035c4240] DirectShow audio devices
  
  [dshow @ 035c4240]  "1-ESI MAYA44 Ch12"
  
  [dshow @ 035c4240]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\1-ESI MAYA44 Ch12"
  
  [dshow @ 035c4240]  "2-ESI MAYA44 Ch34"
  
  [dshow @ 035c4240]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\2-ESI MAYA44 Ch34"
  
  [dshow @ 035c4240]  "3-ESI MAYA44 Ch1234"
  
  [dshow @ 035c4240]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\3-ESI MAYA44 Ch1234"
  
  [dshow @ 035c4240]  "Realtek HD Audio Input"
  
  [dshow @ 035c4240]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Realtek HD Audio Input"
  
  [dshow @ 035c4240]  "Realtek HD Digital input"
  
  [dshow @ 035c4240]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\Realtek HD Digital input"
  
  dummy: Immediate exit requested

  I can use VLC with "Capture device" as input, selecting "Microsoft DV Camera and VCR" as video device and leaving "Default" as audio device and I get both video and audio.

  With ffmpeg I get only video stream, no audio.

  C:\>ffplay -hide_banner -f dshow -i video="Microsoft DV Camera and VCR"
  
  Input #0, dshow, from 'video=Microsoft DV Camera and VCR':B f=0/0
  
    Duration: N/A, start: 0.010035, bitrate: N/A
  
      Stream #0:0: Video: dvvideo (dvsd / 0x64737664), yuv420p, 720x576 [SAR 16:15
  
   DAR 4:3], 25 tbr, 10000k tbn, 25 tbc
  
     0.48 M-V:  0.013 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0

  I don’t know how to tell ffmpeg the equivalent of "Default" audio device as VLC recognizes it.

  Device options show there are 2 pins for video device (DV device has both video and audio) but how can I tell ffmpeg such that it captures both video and audio ?

  C:\>ffplay -hide_banner -f dshow -list_options true -i video="Microsoft DV Camera and VCR"
  
  [dshow @ 035c3260] DirectShow video device options (from video devices)
  
  [dshow @ 035c3260]  Pin "DV Vid Out" (alternative pin name "0")
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x480 fps=29.97 max s=720x480 fps=2
  
  9.97
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x576 fps=25 max s=720x576 fps=25
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x480 fps=29.97 max s=720x480 fps=2
  
  9.97
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x576 fps=25 max s=720x576 fps=25
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x480 fps=29.97 max s=720x480 fps=2
  
  9.97
  
  [dshow @ 035c3260]   vcodec=dvvideo  min s=720x576 fps=25 max s=720x576 fps=25
  
  [dshow @ 035c3260]  Pin "DV A/V Out" (alternative pin name "1")
  
  video=Microsoft DV Camera and VCR: Immediate exit requested f=0/0

  Thank you.