[vlc-devel] [PATCH 01/10] Enable secondary SPU ES and selection from the GUI

[Roland Bewick]

On 5/05/2019 6:57 PM, Jean-Baptiste Kempf wrote:
> On Sun, 5 May 2019, at 12:17, Roland Bewick wrote:
>> This set of patches is regarding the feedback I received from my initial
>> patch to support dual subtitles in VLC.
> As dual-subtitle is one of the two most asked features, thank you very much.
>
>> I've changed how the secondary SPU ES is selected and how the alignment
>> is set without having to touch individual decoders.
>>
>> I've added configuration for the secondary subtitles (enable, alignment
>> and margin). Dual subtitles are disabled by default.
> I don't think this needs a configuration option. If the spu selected has 2 values, both are activated.
> This is related to VLC_VAR_HASCHOICE or something.

Before I added the configuration option that was the case - select 
another sub track and they will both be selected.

My main concern here is the following scenario, considering that the 
majority of people are not interested in using dual subtitles:

1. Install clean copy of VLC (or reset your settings)

2. Open .MKV or other video type that has multiple embedded subtitle 
languages.

3. By default, the first sub track will be selected because "Preferred 
Subtitle Language" is unset in VLC preferences.

4. The selected sub track may not be the subtitle language you want, but 
you do want subtitles. (See https://prnt.sc/nkvxir - I can't speak 
Arabic, but I do want English subtitles)

5. I select English subtitles. Now *both* Arabic and English subtitles 
are selected. Also: English is marked as secondary, and Arabic is marked 
as primary because it was selected first.

6. User must manually deselect Arabic (Introduced extra step for people 
who don't care about dual subs).

I feel like this is undesirable behaviour - any thoughts on this?

I'm happy to remove the configuration option if my worries are unwarranted.


>> I added a new hotkey (toggle) which allows you to use the existing
>> subtitle controls to control the secondary subtitles.
>>
>> I also adjusted the QT GUI synchronization to allow users to set the
>> secondary subtitle delay from the GUI.
>>
>> Unfortunately I don't have access to a mac, but hopefully the hotkeys
>> should suffice until the mac GUI can also be updated.
>>
>> If you have any questions or suggestions, please let me know.
> Just my thanks. This is really cool.

Thank you too. I'm glad to be able to make a valuable contribution.

Roland Bewick