[FFmpeg-user] A query on FFmpeg's s12m timecode in H264 NVENC

[Dennis Mungai]

On Sat, 22 Feb 2025 at 23:15, Timo Rothenpieler <timo at rothenpieler.org>
wrote:

> On 17.02.2025 23:45, Dennis Mungai wrote:
> > Hello there,
> >
> > In FFmpeg's HEVC & AV1 encoder wrappers, the private codec option -
> > s12m_tc , documented as  "Use timecode (if available)", is present, but
> > unmapped in the H.264 encode wrapper.
> >
> > This, however, should also be present in h264_nvenc, as indicated in
> > ffnvcodec's https://github.com/FFmpeg/nv-codec-headers/blob/master/
> > include/ffnvcodec/nvEncodeAPI.h#L2432 <https://github.com/FFmpeg/nv-
> > codec-headers/blob/master/include/ffnvcodec/nvEncodeAPI.h#L2432>
> >
> > Is there a reason why this timecode SEI is omitted in h264_nvenc?
>
> Those time codes are not S12M side data, they'd be a completely new
> thing to implement, of which I'm not sure where to source the data for.
> Not sure what exactly they are or what the difference is, but h264 does
> not seem to support S12M time code sitedata, at least from looking at
> the lavc code.
>


This is well noted.
FFmpeg  4.1 (as per the changelog)
https://github.com/FFmpeg/FFmpeg/blob/master/Changelog does support
decoding S12M timecode in h264.

Circling back to the original question(s) with your additions above:
1.  Can h264_nvenc be likewise configured to emit the equivalent "s12m
timecode(s)" with a similar option as the av1 & hevc_nvenc encoder wrappers?
2. Is pic timing SEI signalling implemented in h264_nvenc?