[FFmpeg-devel] [DECISION] scaletempo filter

[Marton Balint]

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.

Regards,
Marton