Or, I was originally thinking:
rice_parameter = 0; k = partition_samples;
if (k < mean) {
int n = mean - k;
rice_parameter += n;
k <<= n;
}
(sorry for the hasty post)
On Oct 11, 2013, at 10:34, Brian Willoughby wrote:
> Hmm, maybe I'm missing something, but what about this:
>
> rice_parameter = 0; k = partition_samples;
> int n = mean - k;
> if (n > 0) {
> rice_parameter += n;
> k <<= n;
> }
>
> I've not looked at this code in its context within stream_encoder.c,
> so it's easily possible that I left out something.
>
> Brian Willoughby
> Sound Consulting
>
>
> On Oct 9, 2013, at 08:54, lvqcl wrote:
>> MSVS profiler shows that the following code in stream_encoder.c takes
>> several percent of CPU time:
>>
>> for(rice_parameter = 0, k = partition_samples; k < mean;
>> rice_parameter++, k <<= 1)
>> ;
>>
>> this code is equivalent to:
>>
>> rice_parameter = 0; k = partition_samples;
>> while(k < mean) {
>> rice_parameter++; k <<= 1;
>> }
>>
>> The idea was to accelerate it:
>>
>> rice_parameter = 0; k = partition_samples;
>> while(k*2 < mean) {
>> rice_parameter+=2; k <<= 2;
>> }
>> while(k < mean) {
>> rice_parameter++; k <<= 1;
>> }
>>
>> or:
>> rice_parameter = 0; k = partition_samples;
>> while(k*4 < mean) {
>> rice_parameter+=3; k <<= 3;
>> }
>> while(k < mean) {
>> rice_parameter++; k <<= 1;
>> }
_______________________________________________
flac-dev mailing list
flac-dev@xiph.org
http://lists.xiph.org/mailman/listinfo/flac-dev
