[FFmpeg-devel] [PATCH] Make h264idct.c compilation optional

Panagiotis Issaris takis.issaris
Tue May 22 11:23:15 CEST 2007

Hash: SHA1


Panagiotis Issaris wrote:
> Loren Merritt wrote:
>> On Mon, 14 May 2007, Aurelien Jacobs wrote:
>>> Panagiotis Issaris wrote:
>>>> The attached patch tries to make the h264idct.c compilation optional.
>>>> Not meant for direct inclusion, as I am not sure about the correctness...
>>>> In dsputil_init() currently [1], for lowres decoding, when idct_algo's
>>>> other than FF_IDCT_INT or FF_IDCT_AUTO are selected, h264 related
>>>> functions (ff_h264_lowres_idct_put|add_c) are being used. Are these two
>>>> functions in fact more generic then their name implies (in fact just
>>>> misnamed), and should they be relocated to some other common file?
>>>> Or are they really H.264 specific functions? ... but in that case it
>>>> seems weird that selecting f.e. FF_IDCT_VP3 or FF_IDCT_SIMPLEMMX would
>>>> result in using these H.264 specific functions.
>>> Patch seems ok, but I also would like to hear first what's the purpose
>>> of ff_h264_lowres_idct_put/add_c (is it h264 only or more general ?).
>> ff_h264_lowres_idct* are not used in h264. They're so named because 
>> they apply h264's idct algo to other codecs, when whe user requests 
>> non-standards-compliant speedups. They're not the default because they're 
>> even less precise than the other lowres idct.
> I see; thanks for the explanation.
> So, I could:
> * Move both functions to dsputil.c as they are only used there.
> * Keep them in h264idct.c, but disable their usage when H.264 decoder
> support is not compiled in. This shouldn't break anything as in that
> case ff_jref_idct4_put() would be used instead for lowres==1.
> Any opinions?

This is an updated patch of above mentioned option 2, which was what the
patch that started this thread did.

Basic patch:
 Makefile  |    3 +--
 dsputil.c |    5 +++--
 2 files changed, 4 insertions(+), 4 deletions(-)

 dsputil.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

With friendly regards,
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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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