[FFmpeg-devel] [PATCH] avformat/movenc: implicitly enable negative CTS offsets for ismv

[Michael Niedermayer]

On Thu, Jul 26, 2018 at 02:51:38AM +0300, Jan Ekström wrote:
> ISMV lacks any sort of edit list support, as well as tfxd is
> effectively the PTS of the fragment for most intents and purposes.
> 
> Thus, if b-frames are requested without negative CTS offsets you
> end up with N frames' worth of delay (tfxd PTS plus the CTS offset
> of the first sample). Negative CTS offsets enable the first sample
> to have CTS=DTS, and thus a/v desync due to b-frame reorder delay
> is avoided.
> ---
>  doc/muxers.texi       | 2 ++
>  libavformat/movenc.c  | 2 +-
>  tests/ref/fate/movenc | 4 ++--
>  3 files changed, 5 insertions(+), 3 deletions(-)

breaks fate

TEST    lavf-ismv
--- ./tests/ref/lavf/ismv	2018-07-20 13:20:28.137581113 +0200
+++ tests/data/fate/lavf-ismv	2018-07-27 00:29:48.709348455 +0200
@@ -1,9 +1,9 @@
-a9ccbb4cd1436d222ef4425567b4e03d *./tests/data/lavf/lavf.ismv
+96053075a3f60d271131fe2d0765c267 *./tests/data/lavf/lavf.ismv
 312542 ./tests/data/lavf/lavf.ismv
 ./tests/data/lavf/lavf.ismv CRC=0x9d9a638a
-440d85f9fd5b9f63c2676638782b5c15 *./tests/data/lavf/lavf.ismv
+7022701b4c693bc4ffe1e9f96dd82a02 *./tests/data/lavf/lavf.ismv
 321448 ./tests/data/lavf/lavf.ismv
 ./tests/data/lavf/lavf.ismv CRC=0xe8130120
-a9ccbb4cd1436d222ef4425567b4e03d *./tests/data/lavf/lavf.ismv
+96053075a3f60d271131fe2d0765c267 *./tests/data/lavf/lavf.ismv
 312542 ./tests/data/lavf/lavf.ismv
 ./tests/data/lavf/lavf.ismv CRC=0x9d9a638a
Test lavf-ismv failed. Look at tests/data/fate/lavf-ismv.err for details.
make: *** [fate-lavf-ismv] Error 1

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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