[FFmpeg-devel] [RFC] AST subtitles

[Michael Niedermayer]

On Sat, Nov 24, 2012 at 10:08:33PM +0100, Clément Bœsch wrote:
> Hi there,
> 
> I wrote a new prototype for storing text subtitles instead of a custom ASS
> line like we currently do. It's trying to be flexible enough to be able to
> deal with any kind of text subtitles markups, while being as simple as
> possible for our users, but also for decoders and encoders.
> 
> Of course, we will have to deal with retro compat. The simpler I found
> here was to introduce a new AVSubtitleType (SUBTITLE_AST), and we would
> use a new field AVSubtitleRect->ast instead of AVSubtitleRect->ass.
> 
> I used "AST" initially, but it's actually not an AST, so far it's just
> kind of a list, feel free to propose a better random name; I took this
> name because it expresses the fact that it's an arbitrary structure
> layout, and not a data buffer like currently.
> 
> Anyway, here are the basic structures:
> 
>     typedef struct AVSubtitleASTChunk {

>         int type;           ///< one of the AVSUBTITLE_AST_SETTING_TYPE_*

enum


>         int reset;          /**< this chunk restores the setting to the default
>                                  value (or disable the previous one in nested
>                                  mode) */

what does "previous" refer to here ?
it could be previous in the list, previous as in from the last packet
or possibly something else


>         union {
>             char *s;        ///< must be a av_malloc'ed string if string type

>             double d;
>             int i;
>             int64_t i64;
>             uint32_t u32;

isnt double or double+int64 enough for these ?

also i was wondering if having a pointer to the string that was
parsed could be usefull or allow some simplifications.
What i had in mind here would be along the lines of parsing a
marked up string and point back into the string where text is needed
from it.
If for nothing else such a additional field could help debuging

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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