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• Saving highest quality video from video-capture card

  23 décembre 2013, par DusteD

  I have a machine with 2x3 3ghz dual-core xeon and 4x10krpm scsi 320 disks in raid0.
  The capture card is an osprey 560 64 bit pci card.
  Operating system is currently Windows Server 2003.

  The video-stream that I can open with VLC using direct show is rather nice quality.
  However, trying to save this video-stream without loss of quality has proven quite difficult,
  using the h264 codec I am able to achieve a satisfying quality, however, all 4 cores jump to 100% load after a few second and then it start dropping frames, the machine is not powerful enough for realtime encoding. I've not been able to achieve satisfying mpeg1 or 4 quality, no matter which bitrate I set..

  Thing is, the disks in this machine are pretty fast even by todays standard, and they are bored.. I don't care about disk-usage, I want quality.
  I have searched in vain for a way to pump that beautiful videostream that I see in VLC onto the disk for later encoding, I reckon the disks would be fast enough, or maybe something which would apply a light compression, enough that the disks can keep up, but not so much as to loose visible quality.

  I have tried FFMPEG as it seems capable of streaming a yuv4 stream down to the disk, but ofcause FFMPEG is unable to open the dshow device ( same error as this guy Ffmpeg streaming from capturing device Osprey 450e fails )

  Please recommend a capable and (preferably) software which can do this.

• awkward behaviour in bash find-loop with ffmpeg

  25 avril 2018, par Alexander

  There is something weird going on when running following script with Docker.

  The dockerfile for this is :

  FROM debian:9
  
  WORKDIR /app
  
  RUN apt-get -y update && \
  
      apt-get -y install ffmpeg curl
  
  COPY . /app

  The script run.sh :

  #!/bin/bash
  
  find /pfs/in -maxdepth 1 -name "*.flac" -print0 | while IFS= read -r -d $'\0' inFile; do
  
      echo "\n##### Process '${inFile}' #####"
  
      ffmpeg -y -i ${inFile} -ar 16000 tmp.wav # use 16kHz - default for EML
  
  done

  Starting this, when mounting 3 files into the container :

  $ ls pfs/in/
  
  Testaudio16k_2.flac  Testaudio16k.flac  Testaudio16k.wav  TestSprache_Saetze.flac
  
  $ docker run --rm -t -v $(pwd)/pfs/in:/pfs/in test-img:latest /bin/bash run.sh

  I get an error on processing the second file : pfs/in/Testaudio16k_2.flac: No such file or directory. The leading / is missing. It is also missing in the preceeding echo. Indeed this happens every second file (if I put more than 3 files in that folder).

  Now coming to the counter example :
  If I comment out the ffmpeg line in the script, rebuild and run, The echo prints for every file the correct path.

  Does anybody have an idea about this ?
  Is it about the find or is the ffmpegdoing something weird ? Something completely different ?

• FFmpeg hardcoding subtitles fontconfig error

  14 septembre 2017, par The Lemon

  I was trying to run the command : ffmpeg -i vid1.mp4 -vf "ass=subtitle.ass" vidOut.mp4 on a virtual machine and ran into the error :

  Fontconfig error: Cannot load default config file
  
  No usable fontconfig configuration file found, using fallback.
  
  Fontconfig error: cannot load default config file

  ffmpeg then finished running through the command but the video it produced had no subtitles. I’ve tried adding a fonts.conf file, and setting FC_CONFIG_FILE= C:\ffmpeg\fonts.conf and FC_CONFIG_DIR= C:\ffmpeg\ but I still get the same error.

  I ran the same code with the same ASS and mp4 files on my normal machine and the code worked fine. Any advice on my problem would be greatly appreciated.

  Edit : I’m using the static build of FFmpeg version 3.3.3