usage.txt

$ ffcvt

Usage:
 ffcvt [flags] 

Flags:

  -aes  audio encoding method set (FFCVT_AES)
  -ves  video encoding method set (FFCVT_VES)
  -aea  audio encoding method append (FFCVT_AEA)
  -vea  video encoding method append (FFCVT_VEA)
  -abr  audio bitrate (64k for opus, 256k for mp3) (FFCVT_ABR)
  -crf  the CRF value: 0-51. Higher CRF gives lower quality
  (28 for x265, ~ 23 for x264) (FFCVT_CRF)

  -t    target type: x265-opus/x264-mp3 (FFCVT_T)
  -d    directory that hold input files (FFCVT_D)
  -f    input file name (either -d or -f must be specified) (FFCVT_F)
  -suf  suffix to the output file names (FFCVT_SUF)

  -ac   copy audio codec (FFCVT_AC)
  -vc   copy video codec (FFCVT_VC)
  -an   no audio, output video only (FFCVT_AN)
  -vn   no video, output audio only (FFCVT_VN)
  -vss  video: same size (FFCVT_VSS)
  -o    more options that will pass to ffmpeg program (FFCVT_O)
  -ato-opus     audio encode to opus, using -abr (FFCVT_ATO_OPUS)
  -vto-x265     video video encode to x265, using -crf (FFCVT_VTO_X265)

  -force        overwrite any existing none-empty file (FFCVT_FORCE)
  -debug        debugging level (FFCVT_DEBUG)
  -ffmpeg       ffmpeg program executable name (FFCVT_FFMPEG)

Details:

  -abr="": audio bitrate (64k for opus, 256k for mp3)
  -ac=false: copy audio codec
  -aea="": audio encoding method append
  -aes="": audio encoding method set
  -an=false: no audio, output video only
  -ato-opus=false: audio encode to opus, using -abr
  -crf="": the CRF value: 0-51. Higher CRF gives lower quality
  (28 for x265, ~ 23 for x264)
  -d="": directory that hold input files
  -debug=0: debugging level
  -f="": input file name (either -d or -f must be specified)
  -ffmpeg="ffmpeg": ffmpeg program executable name
  -force=false: overwrite any existing none-empty file
  -o="": more options that will pass to ffmpeg program
  -suf="": suffix to the output file names
  -t="x265-opus": target type: x265-opus/x264-mp3
  -vc=false: copy video codec
  -vea="": video encoding method append
  -ves="": video encoding method set
  -vn=false: no video, output audio only
  -vss=true: video: same size
  -vto-x265=false: video video encode to x265, using -crf

The `ffcvt -f testf.mp4 -debug 1 -force` will invoke

  ffmpeg -i testf.mp4 -c:a libopus -b:a 64k -c:v libx265 -x265-params crf=28 -y testf_.mkv

To use `preset`, do the following or set it in env var FFCVT_O

  cm=medium
  ffcvt -f testf.mp4 -debug 1 -force -suf $cm -- -preset $cm

Which will invoke

  ffmpeg -i testf.mp4 -c:a libopus -b:a 64k -c:v libx265 -x265-params crf=28 -y -preset medium testf_medium_.mkv

Here are the final sizes and the conversion time (in seconds):

  2916841  testf.mp4
  1807513  testf_.mkv
  1743701  testf_veryfast_.mkv   41
  2111667  testf_faster_.mkv     44
  1793216  testf_fast_.mkv       85
  1807513  testf_medium_.mkv    120
  1628502  testf_slow_.mkv      366
  1521889  testf_slower_.mkv    964
  1531154  testf_veryslow_.mkv 1413

I.e., if `preset` is not used, the default is `medium`.

Here is another set of results, sizes and the conversion time (in minutes):

 171019470  testf.avi
  55114663  testf_veryfast_.mkv  39.2
  57287586  testf_faster_.mkv    51.07
  52950504  testf_fast_.mkv     147.11
  55641838  testf_medium_.mkv   174.25