[FFmpeg-devel] [DECISION] scaletempo filter

[Marton Balint]

On Mon, 6 May 2019, Marton Balint wrote:

>
>
> On Mon, 6 May 2019, Paul B Mahol wrote:
>
>> On 5/6/19, Marton Balint <cus at passwd.hu> wrote:
>>>
>>>
>>> On Sat, 4 May 2019, John Warburton wrote:
>>>
>>>> On Sat, May 4, 2019 at 3:34 PM Nicolas George <george at nsup.org> wrote:
>>>>
>>>>> John Warburton (12019-05-04):
>>>>>
>>>>> > Is there a patch I can use to test scaletempo to compare it against
>>>>> atempo?
>>>>> > It'll be no trouble to do that with the normal audio that is
>>>>> time-adjusted
>>>>> > on that radio station. It may be that its increased quality is most
>>>>>
>>>>> John, we would appreciate your input about whether these new
>>>>> implementation of atempo is superior or equal to the existing one with
>>>>> regard to your needs.
>>>
>>> I tested scaletempo (with default settings) and it is definitely worse
>>> than atempo for small scaling factors like 25/24.
>>>
>>
>> Have you tried other scaling factors?
>> How you done testing?
>
> Simple hearing tests. I hear audible artifacts (a kind of audio 
> stuttering) with scaletempo. Here are some files where it is noticable:
>
> fate-suite/delphine-cin/LOGO-partial.CIN
> fate-suite/real/spygames-2MB.rmvb
> fate-suite/wmapro/Beethovens_9th-1_small.wma
> fate-suite/dts/dts.ts
>
> The last one is noticable even with 2x scaling.

Another one, audible with any (0.5, ~1, 2) scaling:

fate-suite/paf/hod1-partial.paf

Regards,
Marton