Opened 3 years ago

Last modified 3 years ago

#8768 new enhancement

libx265 passlog/mbtree file reuse for lower resolutions 2-pass encoding. $350 USD bounty.

Reported by: Mista_D Owned by:
Priority: wish Component: avcodec
Version: git-master Keywords: libx265 bounty
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


Looking for a method to run HEVC pass1 once at 4K resolution. And then re-use same one passlog file to encode ABR set - 4K, 1080p, 720p, 480p and 360p files all at various bitrates please.

This has been done before in June 2012 by "the one and only" Dark Shikari, his patch is attached for reference.

expected behaviour:

ffmpeg -y -i 4k_foo.mp4 \
-x265-params pass=1:stats=bar -c:v libx265 -f mp4 /dev/null

ffmpeg -y -i 4k_foo.mp4 \
-x265-params pass=2:stats=bar -c:v libx265 4k.mp4 \
-x265-params pass=2:stats=bar -c:v libx265 -s 1280x720 720p.mp4

Attachments (1)

rescale.diff (12.4 KB ) - added by Mista_D 3 years ago.
x264 mbtree rescale diff

Download all attachments as: .zip

Change History (3)

by Mista_D, 3 years ago

Attachment: rescale.diff added

x264 mbtree rescale diff

comment:1 by Mista_D, 3 years ago

Producing same video compression results as with uniqely produced passlog file, with at most 2-3% percent bitrate penalty.

libx264 takes 2% quality hit, when using passlog/mbtree from 1080p pass 1 to encode 720p file.

comment:2 by Carl Eugen Hoyos, 3 years ago

Component: ffmpegavcodec
Keywords: libx265 bounty added
Priority: normalwish
Version: unspecifiedgit-master
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