Justin Ruggles <[email protected]> writes:

> On 04/23/2011 11:30 AM, Måns Rullgård wrote:
>
>> Diego Biurrun <[email protected]> writes:
>> 
>>> On Fri, Apr 22, 2011 at 10:19:44PM -0400, Justin Ruggles wrote:
>>>>
>>>> Based on patches by clsid2 in ffdshow-tryout.
>>>>
>>>> --- a/configure
>>>> +++ b/configure
>>>> @@ -95,6 +95,7 @@ Configuration options:
>>>>    --disable-mpegaudio-hp   faster (but less accurate) MPEG audio decoding 
>>>> [no]
>>>> +  --enable-audio-float     floating-point output from some audio decoders 
>>>> [no]
>>>
>>> The comment is not very descriptive.
>> 
>> I really would prefer runtime selection.
>
> One issue is not a big deal, just annoying.  av_find_stream_info()
> doesn't get the AVOptions, and it requires the decoder to always be
> opened to get the sample_fmt.  So in this case any requested sample_fmt
> will not be known and it will be set to default.  Because the encoders
> are opened before the decoders in ffmpeg, the encoder sample_fmt will be
> selected based on that default sample_fmt from the decoder.  Then after
> the decoder is opened it sets the input sample_fmt to the requested one
> this time, but the encoder has already been initialized with the
> original default.
>
> If the user doesn't request a sample_fmt explicitly, we have another
> issue.  Either we set the decoder sample_fmt based on the encoder or we
> set the encoder sample_fmt based on the decoder.  We could choose the
> most accurate supported sample format on one side or the other, then
> choose the best option on the other side... but anyway we solve this, it
> is a lot of mess for a temporary solution...

Sounds like something needs to be fixed then.  Anyway, why this patch at
all if it's temporary?  It's quite ugly, and the proper format
conversion API is nowhere in sight.

-- 
Måns Rullgård
[email protected]
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel

Reply via email to