[FFmpeg-devel] [PATCH] doc/bitstream_filters: add filter_units practical examples for removing closed captions

[Stefano Sabatini]

On date Saturday 2024-03-09 19:56:49 -0600, Marth64 wrote:
> Following up on this from December 2023. I simplified the content and
> hopefully addressed the feedback.
> 
> Signed-off-by: Marth64 <marth64 at proxyid.net>
> ---
>  doc/bitstream_filters.texi | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
> index e06de1a73a..61539d2473 100644
> --- a/doc/bitstream_filters.texi
> +++ b/doc/bitstream_filters.texi
> @@ -213,6 +213,21 @@ To remove all AUDs, SEI and filler from an H.265 stream:
>  ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=35|38-40' OUTPUT
>  @end example
>  
> +To remove all user data from a MPEG-2 stream, including Closed Captions:
> + at example
> +ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=178' OUTPUT
> + at end example
> +
> +To remove all SEI from a H264 stream, including Closed Captions:
> + at example
> +ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=6' OUTPUT
> + at end example
> +
> +To remove all prefix and suffix SEI from a HEVC stream, including Closed Captions and dynamic HDR:
> + at example
> +ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=39|40' OUTPUT
> + at end example
> +

Not against, but I'm not super convinced this is super useful as it
does not really explain what these values come from.  Probably it
would be more useful a table, or even better make the parser somehow
expose the supported types with the meaning (this would enable having
e.g. a symbolic type "cc" abstracting the containter format).

OTOH I agree thius would provide some practical examples, therefore
I'll apply while we have no smarter way to expose the logic in a more
effective way.

Thanks.