video-conversion-encoding.md

Video encoding and coversion with ffmpeg

Based on https://evilmartians.com/chronicles/better-web-video-with-av1-codec

h264

ffmpeg -i SOURCE.mov -map_metadata -1 -c:a libfdk_aac -c:v libx264 -crf 24 -preset veryslow -profile:v main -pix_fmt yuv420p -movflags +faststart -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" video.h264.mp4

h264 / no sound, low quality, resize to 640x360.

• change -crf 26 to change quality (higher number = lower quality)
• Change 640 in -vf "scale=640:trunc(ow/a/2)*2" to change size (upsacling is not possible)

ffmpeg -i SOURCE.mov -map_metadata -1 -an -c:v libx264 -crf 26 -preset veryslow -profile:v main -pix_fmt yuv420p -movflags +faststart -vf "scale=640:trunc(ow/a/2)*2" video.h264.mp4

av1

ffmpeg -i SOURCE.mov -map_metadata -1 -c:a libopus -c:v libaom-av1 -crf 34 -b:v 0 -pix_fmt yuv420p -movflags +faststart -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -strict experimental video.av1.mp4

av1 / no sound, low quality, resize to 640x360.

• Change 640 in -vf "scale=640:trunc(ow/a/2)*2" to change size (upsacling is not possible)
• change -crf 40 to change quality (higher number = lower quality)

ffmpeg -i SOURCE.mov -map_metadata -1 -an -c:v libaom-av1 -crf 40 -b:v 0 -pix_fmt yuv420p -movflags +faststart -vf "scale=640:trunc(ow/a/2)*2" -strict experimental video.av1.mp4

hevc

ffmpeg -i SOURCE.mov -map_metadata -1 -c:a libfdk_aac -c:v libx265 -crf 24 -preset veryslow -pix_fmt yuv420p -movflags +faststart -tag:v hvc1 -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" video.hevc.mp4

hevc / no sound, low quality, resize to 640x360.

• change -crf 26 to change quality (higher number = lower quality)
• Change 640 in -vf "scale=640:trunc(ow/a/2)*2" to change size (upsacling is not possible)

ffmpeg -i SOURCE.mov -map_metadata -1 -an -c:v libx265 -crf 26 -preset veryslow -pix_fmt yuv420p -movflags +faststart -tag:v hvc1 -vf "sscale=640:trunc(ow/a/2)*2" video.hevc.mp4

HTML

<video controls width="600" height="400">
  <source
    src="video.hevc.mp4"
    type="video/mp4; codecs=hevc,mp4a.40.2"
  />
  <source
    src="video.av1.mp4"
    type="video/mp4; codecs=av01.0.05M.08,opus"
  />
  <source
    src="video.h264.mp4"
    type="video/mp4; codecs=avc1.4D401E,mp4a.40.2"
  />
</video>

Optimized versions:

<video controls width="600" height="400">
  <source
    src="video.hevc.mp4"
    type="video/mp4; codecs=hevc"
  />
  <source
    src="video.av1.mp4"
    type="video/mp4; codecs=av01.0.05M.08"
  />
  <source
    src="video.h264.mp4"
    type="video/mp4; codecs=avc1.4D401E"
  />
</video>

Quality conversion CRF values comparison

H.264	AV1
19	27
23	33
27	39
31	45
35	51
39	57