Opened 4 years ago

Closed 4 years ago

#5677 closed enhancement (fixed)

Videotoolbox encoder does not preserve A53_CC side data

Reported by: tmm1 Owned by: kernrj
Priority: wish Component: avcodec
Version: git-master Keywords: videotoolbox cc
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


The rest of the h264 encoders explicitly copy side data for closed captioning, but the new videotoolbox encoder does not.

Change History (8)

comment:1 Changed 4 years ago by tmm1

  • Cc added
  • Owner set to kernrj
  • Status changed from new to open
  • Version changed from unspecified to git-master

comment:2 Changed 4 years ago by tmm1

libavcodec/libx264.c and libavcodec/qsvenc_h264.c both support a -a53cc 1 option where the caption data is copied to the encoded output. I'm trying to figure out how to pass extra SEI payloads to videotoolbox in a similar fashion so we can implement the equivalent option.

comment:3 Changed 4 years ago by tmm1

I have an initial patch at which generates an h264 encoded file with SEI NAL units. However when I try to decode the file, I see the following warnings:

[h264 @ 0x7f82ea801a00] SEI type 4 size 568 truncated at 567
Last message repeated 5 times

comment:4 Changed 4 years ago by tmm1

I have submitted a working patch to the devel ML for review:

comment:5 Changed 4 years ago by cehoyos

  • Component changed from undetermined to avcodec
  • Keywords videotoolbox cc added
  • Priority changed from normal to wish
  • Type changed from defect to enhancement

comment:6 Changed 4 years ago by kernrj

Can you provide some media samples with closed captions?

comment:8 Changed 4 years ago by cehoyos

  • Resolution set to fixed
  • Status changed from open to closed

The patches were applied today.

Note: See TracTickets for help on using tickets.