[FFmpeg-devel] [PATCH] avcodec/tak: reset filter buffers

[James Almer]

On 22/02/15 9:13 AM, Paul B Mahol wrote:
> On 2/21/15, James Almer <jamrial at gmail.com> wrote:
>> On 21/02/15 3:47 PM, Paul B Mahol wrote:
>>> On 2/21/15, James Almer <jamrial at gmail.com> wrote:
>>>> On 21/02/15 8:49 AM, Paul B Mahol wrote:
>>>>> Have you measured performance drop before and after?
>>>>
>>>> filter_order 8 in decorrelate()
>>>>
>>>> Before
>>>> 903 decicycles in scalarproduct, 8388364 runs, 244 skips
>>>> After
>>>> 858 decicycles in scalarproduct, 8388215 runs, 393 skips
>>>>
>>>>
>>>> filter_order 24 in decode_subframe()
>>>>
>>>> Before
>>>> 993 decicycles in scalarproduct, 16776849 runs, 367 skips
>>>> After
>>>> 887 decicycles in scalarproduct, 16776783 runs, 433 skips
>>>>
>>>
>>> But what about other filter orders?
>>
>> filter order 12 in decode_subframe()
>>
>> Before
>> 963 decicycles in scalarproduct, 8388426 runs, 182 skips
>> After
>> 873 decicycles in scalarproduct, 8388410 runs, 198 skips
>>
>>
>> filter_order 8 in decode_subframe()
>>
>> Before
>> 900 decicycles in scalarproduct, 4194020 runs, 284 skips
>> After
>> 858 decicycles in scalarproduct, 4194198 runs, 106 skips
>>
>>
>> filter order 4 in decode_subframe()
>>
>> Before
>> 827 decicycles in scalarproduct, 1048561 runs, 15 skips
>> After
>> 876 decicycles in scalarproduct, 1048556 runs, 20 skips
>>
>>
>> Seems like only filter_order 4 is slower. I could leave the C code for that
>> one
>> case if you prefer.
> 
> I'm more afraid of overhead that memset() does.
> 
> Feel free to apply patch.

Pushed a version Christophe wrote some time ago that uses AV_ZERO instead of memset(), 
so that should not be a problem now.