#6494: Concat'ing HEVC streams with different encoding parameters produces
gibberish
-------------------------------------+-------------------------------------
Reporter: birdie | Type: defect
Status: new | Priority: normal
Component: ffmpeg | Version: git-
Keywords: concat, | master
hevc | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug: after you concat two HEVC streams with '''different'''
encoding parameters and you try to play the resulting file, when
ffplay/mpv/mplayer reaches the second file, you see garbage instead of the
actual output.
How to reproduce:
{{{
The first file parameters:
$ ffmpeg -i input1 -an -c:v libx265 -preset veryslow -x265-params crf=20
:no-sao=1 file1.mkv
The second file parameters:
$ ffmpeg -i input2 -an -c:v libx265 -preset veryslow -tune grain
-x265-params crf=20 file2.mkv
$ cat list.txt
file file1.mkv
file file2.mkv
Concat:
$ ffmpeg -f concat -i list.txt -c copy out.mkv
}}}
When reaching the second part of the output multiple messages like this
one are logged in console:
{{{
[ffmpeg/video] hevc: The cu_qp_delta -56 is outside the valid range [-26,
25].
}}}
mkvtoolnix produces the same broken output.
However if you first transcode the mkv files to TS and then concat the
resulting ts files, then everything works fine:
{{{
$ ffmpeg -i part1.mkv -c copy output1.ts
$ ffmpeg -i part2.mkv -c copy output2.ts
}}}
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6494>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
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