Re: [Bino-list] SubTitles?

[Martin Lambers]

Hi Joe!

On 09/04/11 12:00, Joe wrote:
> Hi!
> 
> On Saturday 09 April 2011 11:36:19 Martin Lambers wrote:
>> On 07/04/11 02:50, Joe wrote:
>>> please see attached patch that implements all the GUI parts. Applies
>>> clearly to current git head.
>>
>> Thanks a lot, it is now merged, with the only exception of the encoding
>> setting (see below).
>>
>>>> In summary, the current state of subtitle support is:
>>>> - Subtitles in plain text and SSA/ASS format can be decoded and
>>>> rendered
>>>> (via libass) with support for alpha blending.
>>>> - Subtitles in bitmap format (mostly DVD subtitles) currently only
>>>> decode to the string '???'. Proper support will be added later.
>>>> - Subtitle selection is currently only possible via the command line,
>>>> but code for GUI selection and keyboard shortcuts is available in your
>>>> repository and will be merged soon.
>>>> - Subtitle parameters cannot yet be set. The most important parameter
>>>> is
>>>> probably the subtitle depth for 3D video. Other parameters seem less
>>>> important because they can be easily adjusted in the subtitle file.
>>>
>>> Other parameters are important as well. There are almost no subtitles
>>> that has defined styles in header and users does not set subtitle style
>>> inside subtitle file. It is crucial to be able to force at least size
>>> and color in Bino. Therefore the patch override the ASS font, font size
>>> and font color using ass_set_style_overrides.
>>
>> OK, merged. I adjusted the settings so that the user can override them
>> separately. This is useful for ASS, where subtitle files usually define
>> a style and you may only want to change one parameter.
> 
> At least in my country no one has ever seen subtitles in ASS format. All the 
> subs are in SRT (previously in SUB) format. So that everybody will force 
> subtitles size, font and color to some sane values (bigger fonts, sometimes 
> yellow color and national encoding).

OK - I never saw either SRT or ASS in my life before you sent your
initial patch, so I have no idea how and where they are used :-)

>>> There is also an issue with font encoding. ASS does not perform encoding
>>> so I think we will have to do it ourselves. I know you want to avoid
>>> using Qt, so should we use iconv?
>>
>> I'm not sure that I understand the problem completely. According to the
>> spec, ASS files should be UTF-8, and if they are not, they should set a
>> special "Encoding" field. When FFmpeg converts SRT to ASS, it should
>> also handle this for us.
>>
>> Are there in fact SRT files that use old 8 bit encodings instead of
>> UTF-8? If so, is there SRT metadata that tells us what encoding the file
>> is in?
>>
>> If we require the user to set the encoding for each SRT file
>> individually, wouldn't it be easier for the user to just convert all SRT
>> files to UTF-8 and solve the problem once and for all?
> 
> I suppose you are from English speaking country, so you don't need to use 
> subtitles with almost every movie you watch. For example I'm from Czech 
> Republic and we have encoding cp1250 in Windows and iso8859-2 in Unix. All 
> the 
> subtitles that we use every day are in cp1250 simply because most of the 
> people translating movies are using Windows and cp1250 was the default 
> encoding. It has became de facto standard and even now when default changed 
> to 
> UTF-8 are still all subtitles in cp1250, because for media players it is 
> almost impossible to detect correct encoding (there are no metadata). So in 
> every media player I go to settings and select cp1250 (for example my 
> mplayer.conf contains "subcp=cp1250"). Please merge also encoding selection, 
> default will be utf-8 and hopefully ffmpeg will handle encoding conversion (I 
> have not noticed it is possible to change encoding during subtitle decoding).
> 
> I hope my country is not the only one with these weird demands :-) If someone 
> non-native-english is reading this, please comment on situation with 
> subtitles 
> in your country.

Thanks for your explanations, now I understand much better. It just
seemed weird to me that the SRT subtitle format would be widely used
internationally but cannot handle different encodings - but it seems
this has historical reasons.

So I'll merge your enconding patch, most probably using iconv.

Martin