[FFmpeg-devel] [PATCH] WebM muxer writes WebVTT subtitle track

Timothy Gu timothygu99 at gmail.com
Tue Jul 9 03:20:54 CEST 2013


On Jul 8, 2013 6:16 PM, "Michael Niedermayer" <michaelni at gmx.at> wrote:
>
> On Mon, Jul 08, 2013 at 04:25:30PM -0700, Matthew Heaney wrote:
> > The Matroska muxer now allows WebVTT subtitle tracks to be written
> > while in WebM muxing mode.
> >
> > WebVTT subtitle tracks have four kinds: "subtitles", "captions",
> > "descriptions", and "metadata". Each text track kind has a distinct
> > Mastroska CodecID and track type, as described in the temporal
> > metadata guidelines here:
> >
> >
http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-in-webm
> >
> > When the stream has codec id AV_CODEC_ID_WEBVTT, the stream packet is
> > serialized per the temporal metadata guidelines cited above. The
> > WebVTT cue is written as a Matroska block group. The block frame
> > comprises the WebVTT cue id, followed by the cue settings, followed by
> > the cue text.  (The block timestamp is synthesized from the cue
> > timestamp.)
> > ---
> >  libavformat/matroska.h    |  1 +
> >  libavformat/matroskaenc.c | 97
++++++++++++++++++++++++++++++++++++++++-------
> >  2 files changed, 85 insertions(+), 13 deletions(-)
>
> patch applied
>
> thanks

Finally. I guess Matthew's getting desperate with patches and git...

Timothy


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