[FFmpeg-devel] [PATCH] VP8 de/encode via libvpx

[James Zern]

On Thu, May 27, 2010 at 10:56, David Conrad <lessen42 at gmail.com> wrote:
> On May 27, 2010, at 8:20 AM, John Koleszar wrote:
>
>> On Thu, May 27, 2010 at 7:45 AM, Diego Biurrun <diego at biurrun.de> wrote:
>>> On Wed, May 26, 2010 at 01:01:23PM -0400, James Zern wrote:
>>>> On Tue, May 25, 2010 at 20:42, Diego Biurrun <diego at biurrun.de> wrote:
>>>>> On Tue, May 25, 2010 at 07:36:40PM -0400, James Zern wrote:
>>>>>> On Wed, May 19, 2010 at 18:22, Diego Biurrun <diego at biurrun.de> wrote:
>>>>>>> On Wed, May 19, 2010 at 02:28:10PM -0400, James Zern wrote:
>>>>>>>>
>>>>>>>> The attached will enable decode and basic encode of VP8 through
>>>>>>>> libvpx.
>>>>>>>
>>>>>> Attached is another pass at a basic encode wrapper. Formatting similar
>>>>>> to the decoder has been applied.
>>>>>>
>>>>>> --- configure (revision 23330)
>>>>>> +++ configure (working copy)
>>>>>> @@ -184,6 +184,8 @@ External library support:
>>>>>> ? ?--enable-libvorbis ? ? ? enable Vorbis encoding via libvorbis,
>>>>>> ? ? ? ? ? ? ? ? ? ? ? ? ? ? native implementation exists [no]
>>>>>> ? ?--enable-libvpx ? ? ? ? ?enable VP8 support via libvpx [no]
>>>>>> + ?--enable-libvpx-decode ? enable VP8 decode via libvpx [no]
>>>>>> + ?--enable-libvpx-encode ? enable VP8 encode via libvpx [no]
>>>>>
>>>>> I'm not sure what you are trying to achieve here. ?AFAIU libvpx supports
>>>>> both encoding and decoding, right? ?Then you do not need to introduce
>>>>> split options.
>>>>>
>>>> --disable-vp8-decoder/--disable-vp8-encoder
>>>
>>> If this was an attempt at answering my question, it failed, I'm no better
>>> informed than before. ?Again:
>>>
>>> Does libvpx support both encoding and decoding, yes or no?
>>>
>>> What are you trying to achieve here by adding split options?
>>>
>>
>> libvpx can be built decode-only, encode-only, or have both compiled
>> in. This is probably supporting building an ffmpeg that can link
>> against a libvpx that's decode-only, for example. Might be able to
>> autodetect this with nm or something like that.
>
> If linking fails, you can use that to autodetect it.
>
The thinking here being to check_cc/check_ld or nm for the symbol?
Would it be simpler to remove the -de/encode options and replace the
require2 with separate link checks for both based on the presence of
--enable-libvpx?