[FFmpeg-cvslog] r24213 - trunk/libavcodec/dca.c

[Ronald S. Bultje]

Hi,

2010/7/12 M?ns Rullg?rd <mans at mansr.com>:
> Vitor Sessak <vitor1001 at gmail.com> writes:
>> On 07/12/2010 02:32 PM, benoit wrote:
>>> Author: benoit
>>> Date: Mon Jul 12 14:32:24 2010
>>> New Revision: 24213
>>>
>>> Log:
>>> Use math constant instead of hardcoded rounded value for sqrt(0.5).
>>> Patch by Christophe.Gisquet (gmail)
>>>
>>> Modified:
>>> ? ? trunk/libavcodec/dca.c
>>>
>>> Modified: trunk/libavcodec/dca.c
>>> ==============================================================================
>>> --- trunk/libavcodec/dca.c ? Mon Jul 12 12:17:20 2010 ? ? ? ?(r24212)
>>> +++ trunk/libavcodec/dca.c ? Mon Jul 12 14:32:24 2010 ? ? ? ?(r24213)
>>> @@ -1403,8 +1403,8 @@ static int dca_decode_frame(AVCodecConte
>>> ? ? ? ? ? ? ? float* rt_chan ? = s->samples + s->channel_order_tab[s->xch_base_channel - 1] * 256;
>>> ? ? ? ? ? ? ? int j;
>>> ? ? ? ? ? ? ? for(j = 0; j< ?256; ++j) {
>>> - ? ? ? ? ? ? ? ?lt_chan[j] -= (back_chan[j] - s->add_bias) * 0.707107f;
>>> - ? ? ? ? ? ? ? ?rt_chan[j] -= (back_chan[j] - s->add_bias) * 0.707107f;
>>> + ? ? ? ? ? ? ? ?lt_chan[j] -= (back_chan[j] - s->add_bias) * M_SQRT1_2;
>>> + ? ? ? ? ? ? ? ?rt_chan[j] -= (back_chan[j] - s->add_bias) * M_SQRT1_2;
>>
>> Won't this patch make it use double-precision floating point math when
>> not needed?
>
> Time for f-versions of those constants?

They're defines, just add a "f" behind it when using it, e.g. M_SQRT1_2 f.

Ronald