[FFmpeg-devel] [PATCH 5/7] avformat/mpegts: add s337m support

[Kieran Kunhya]

On Fri, 13 Dec 2024, 00:39 Michael Niedermayer, <michael at niedermayer.cc>
wrote:

> Hi
>
> On Thu, Dec 12, 2024 at 12:54:29PM +0000, Nicolas Gaullier wrote:
> [...]
> > This is a significant work with some weird things like dealing with a
> truncated sample rate
> > and droping one sample from time to time to keep sync. And with no active
> > maintainer of the dolby_e decoder, so that won't help.
>
> why would the decoder need to drop a sample from time to time ?
> the timestamps on audio should be enough.
>
> Yes it would mean the samplerate and the timestamps and the number of
> samples
> would mismatch but that can be corrected by a resampler following after the
> decoder or by other means, none of which really are specific to this.
> Recording audio with cheap hardware is unlikely to have its sample rate
> synchronized to an atomic clock either.
>
> but maybe i misunderstand something ?
>
> thx
>

One of the features of Dolby E is output is resampled to a 1602, 1601,
1602, 1601, 1602 cadence ( 48000*5*1001/30000 = 8008)  number of samples so
that it doesn't drift relative to 29.97 video.

I'm not really sure how an atomic clock is relevant.

Kieran

>