[FFmpeg-devel] [PATCH v5 0/4] Initial implementation of TTML encoding/muxing

[Jan Ekström]

On Mon, Feb 22, 2021 at 3:19 PM Jan Ekström <jeebjp at gmail.com> wrote:
>
> I've intentionally kept this initial version simple (no styling etc) to focus
> on the basics. As this goes through review, additional features can be added
> (I had initial PoC for styling implemented some time around previous VDD), and
> there is another patch set in my queue which would then add support for muxing
> TTML into MP4.
>
> Changes from the fourth version:
>   - Switched from separate escaping modes back to a single AV_ESCAPE_MODE_XML,
>     with additional flags for single and double quote escaping for attributes
>     (Anton noted that the AV_ESCAPE_FLAG_XML prefix makes it all long enough,
>     so ATTR was left away from these).
>   - Added the libavutil minor bump, which was forgotten so far.
>   - ff_ass_split_override_codes calls are now checked for errors and a warning
>     or error is logged depending on whether it was an invalid input error,
>     and if AV_EF_EXPLODE was set. In case of invalid input and AV_EF_EXPLODE,
>     a malformed ASS dialog will cause the encoder to fail. By default it will
>     not, which matches the current behavior of all other subtitle encoders,
>     which do not test the return value of ff_ass_split_override_codes at all,
>     and thus just skip malformed parts of an ASS dialog.
>
>     Thank you to Anton for giving the idea of the AV_EF_EXPLODE usage.
>   - Documented that AV_EF_EXPLODE is now usable for subtitle encoders.

For the record, if this seems unacceptable I can switch it to a
specifically named AVOption in the subtitle encoder.

Either way is fine by me, the explode flag was just what was noted as
an alternative first.

Jan