[FFmpeg-devel] [PATCH v2 6/6] avformat/subtitles: guess UTF-16 if no BOM present

[Reimar Döffinger]

On 06.09.2014, at 00:23, wm4 <nfxjfg at googlemail.com> wrote:
> On Sat, 6 Sep 2014 00:00:10 +0200
> Michael Niedermayer <michaelni at gmx.at> wrote:
> 
>> On Thu, Sep 04, 2014 at 10:40:27PM +0200, wm4 wrote:
>>> ---
>>> Follows reimar's suggestion for detecting UTF-16. If the detection goes
>>> wrong, probing the format won't succeed, so this should not break
>>> anything.
>>> 
>> 
>>> I didn't use ffio_ensure_seekback), because this apparently reallocates
>>> the buffer - which we certainly don't want, because the probe API
>>> doesn't allow this.
>> 
>> the format probe API doesnt provide a AVIOContext, and if one is
>> provided, it could use a allocated and reallocatable buffer
>> or do i misunderstand ?
>> 
>> [...]
> 
> I'm ffio_init_context() to initialize an AVIOContext on a buffer (the
> probe buffer)

I do not know the actual behaviour for sure, but for a context based on a buffer, seekback should never ever be possible to fail...
So if we can detect that case, I think the ensure function should behave like a NOP.