[FFmpeg-devel] [PATCH] configure: really enable libvpx-vp9 encoder and decoder

James Almer jamrial at gmail.com
Mon Mar 4 14:40:00 EET 2019


On 3/4/2019 9:27 AM, Guo, Yejun wrote:
> 
> 
>> -----Original Message-----
>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
>> Of James Almer
>> Sent: Monday, March 04, 2019 8:21 PM
>> To: ffmpeg-devel at ffmpeg.org
>> Subject: Re: [FFmpeg-devel] [PATCH] configure: really enable libvpx-vp9
>> encoder and decoder
>>
>> On 3/4/2019 12:40 PM, Guo, Yejun wrote:
>>> Signed-off-by: Guo, Yejun <yejun.guo at intel.com>
>>> ---
>>>  configure | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/configure b/configure
>>> index 3042ab9..3e2a487 100755
>>> --- a/configure
>>> +++ b/configure
>>> @@ -6236,11 +6236,11 @@ enabled libvpx            && {
>>>      }
>>>      enabled libvpx_vp9_decoder && {
>>>          check_pkg_config libvpx_vp9_decoder "vpx >= 1.4.0"
>> "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_vp9_dx ||
>>> -            check_lib libvpx_vp9_decoder "vpx/vpx_decoder.h vpx/vp8dx.h"
>> "vpx_codec_vp9_dx VPX_IMG_FMT_HIGHBITDEPTH" "-lvpx $libm_extralibs"
>>> +            check_lib libvpx_vp9_decoder "vpx/vpx_decoder.h vpx/vp8dx.h"
>> "vpx_codec_dec_init_ver VPX_IMG_FMT_HIGHBITDEPTH" "-lvpx
>> $libm_extralibs"
>>>      }
>>>      enabled libvpx_vp9_encoder && {
>>>          check_pkg_config libvpx_vp9_encoder "vpx >= 1.4.0"
>> "vpx/vpx_encoder.h vpx/vp8cx.h" vpx_codec_vp9_cx ||
>>> -            check_lib libvpx_vp9_encoder "vpx/vpx_encoder.h vpx/vp8cx.h"
>> "vpx_codec_vp9_cx VPX_IMG_FMT_HIGHBITDEPTH" "-lvpx $libm_extralibs"
>>> +            check_lib libvpx_vp9_encoder "vpx/vpx_encoder.h vpx/vp8cx.h"
>> "vpx_codec_enc_init_ver VPX_IMG_FMT_HIGHBITDEPTH" "-lvpx
>> $libm_extralibs"
>>>      }
>>>      if disabled_all libvpx_vp8_decoder libvpx_vp9_decoder
>> libvpx_vp8_encoder libvpx_vp9_encoder; then
>>>          die "libvpx enabled but no supported decoders found"
>>
>> What do you mean with "Really enable"? We're checking for
>> vpx_codec_vp9_dx and vpx_codec_vp9_cx because they are symbols that
>> will
>> allegedly be present only if the relevant module was enabled during
>> libvpx compilation.
> 
> the check for vpx_codec_vp9_dx/cx will always fail since it requires the build option "-lpthread".
> (this pthread libvpx issue is another issue and I just sent out a patch for the fix, see https://groups.google.com/a/webmproject.org/forum/#!topic/codec-devel/JwufiANnwaA)

If the issue is a missing -lpthread in the non pkg-config check, then
just add $pthreads_extralibs between -lvpx and $libm_extralibs at the
end of it.

> 
> so I choose the same way as vp8, I guess this is a typo for vp9.

No, it's a typo for vp8, and it should be fixed.

> 
> to see the issue, just run configure for ffmpeg and check the decoder/encoder outputs.

The change you're proposing will allegedly enable vp9 decoder and
encoder regardless of the relevant symbols being present in the library
or not, so it's not acceptable as compiling libavcodec will ultimately
fail if they aren't.


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