[FFmpeg-devel] [PATCH] SubRip decoder

[Aurelien Jacobs]

On Wed, Dec 08, 2010 at 02:03:48AM -0500, Alexander Strange wrote:
> 
> On Dec 4, 2010, at 9:58 AM, Aurelien Jacobs wrote:
> 
> > On Sun, Nov 28, 2010 at 05:53:04PM -0500, Alexander Strange wrote:
> >> 
> >> On Nov 28, 2010, at 5:31 PM, Aurelien Jacobs wrote:
> >> 
> >>> Hi,
> >>> 
> >>> $subject
> >>> 
> >>> This SubRip decoder supports all the SubRip features that I know about.
> >>> It especially support everything tested by the sample files from
> >>> http://ale5000.altervista.org/subtitles.htm
> >> 
> >> [...]
> >> 
> >>> +    snprintf(header, sizeof(header),
> >>> +             "[Script Info]\r\n"
> >>> +             "ScriptType: v4.00+\r\n"
> >>> +             "\r\n"
> >>> +             "[V4+ Styles]\r\n"
> >> 
> >> Watch out for the weird default PlayRes* values.
> > 
> > The default is 384x288.
> > Do you think I should choose another default value ?
> 
> If you're happy with the current font size, I guess it's OK.
> 
> But actually there's another problem - this sets a hardcoded style
> named Default,

Yes.

> so players will render with that style.

No. At least that's not what the ASS spec says:

5. Dialogue event lines, [Events] section
[...]
Field 4: Style
         Style name. If it is "Default", then your own *Default style
         will be subtituted.
         However, the Default style used by the script author IS stored
         in the script even though SSA ignores it - so if you want to
         use it, the information is there - you could even change the
         Name in the Style definition line, so that it will appear in
         the list of "script" styles.

So we store the Default style of the "authoring software" in the script,
as a reference (or for non-compilant software) but the player should
ignore it and use its own default style.

> I think it's expected that srt should be rendered with the "default"
> style of the player.

Yes,and that's exactly how the generated ASS should be rendered too.

> How about not emitting a Style: line at all, and setting the style
> of each subtitle to "*Default" (IIRC what the built-in default ASS
> style is called)?

I'm pretty certain this would break some renderer.

Aurel