[FFmpeg-devel] [PATCH] avfilter: take_samples: do not directly return frame when samples are skipped

[Muhammad Faiz]

On Thu, May 18, 2017 at 10:56 PM, James Almer <jamrial at gmail.com> wrote:
> On 5/18/2017 12:49 PM, Paul B Mahol wrote:
>> On 5/18/17, Nicolas George <george at nsup.org> wrote:
>>> Le nonidi 29 floreal, an CCXXV, Muhammad Faiz a ecrit :
>>>> Should fix Ticket6349.
>>>> Modifying data pointer may make it unaligned.
>>>>
>>>> Also change frame->nb_samples < max to frame->nb_samples <= max.
>>>> This improves performance. Benchmark:
>>>> ./ffmpeg -filter_complex "aevalsrc=0:n=1166,firequalizer=fixed=on" -f null
>>>> null
>>>> old:
>>>>   25767 decicycles in take_samples,    1023 runs,      1 skips
>>>>   25422 decicycles in take_samples,    2047 runs,      1 skips
>>>>   25181 decicycles in take_samples,    4095 runs,      1 skips
>>>>   24904 decicycles in take_samples,    8191 runs,      1 skips
>>>>
>>>> new:
>>>>     550 decicycles in take_samples,    1024 runs,      0 skips
>>>>     548 decicycles in take_samples,    2048 runs,      0 skips
>>>>     545 decicycles in take_samples,    4096 runs,      0 skips
>>>>     544 decicycles in take_samples,    8192 runs,      0 skips
>>>>
>>>> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
>>>> ---
>>>>  libavfilter/avfilter.c   | 3 ++-
>>>>  libavfilter/framequeue.c | 2 ++
>>>>  libavfilter/framequeue.h | 5 +++++
>>>>  3 files changed, 9 insertions(+), 1 deletion(-)
>>>
>>> This is an interesting idea, but...
>>>
>>>>
>>>> diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
>>>> index 08b86b0..1b6c432 100644
>>>> --- a/libavfilter/avfilter.c
>>>> +++ b/libavfilter/avfilter.c
>>>> @@ -1191,7 +1191,7 @@ static int take_samples(AVFilterLink *link, unsigned
>>>> min, unsigned max,
>>>>         called with enough samples. */
>>>>      av_assert1(samples_ready(link, link->min_samples));
>>>>      frame0 = frame = ff_framequeue_peek(&link->fifo, 0);
>>>> -    if (frame->nb_samples >= min && frame->nb_samples < max) {
>>>> +    if (!link->fifo.samples_skipped && frame->nb_samples >= min &&
>>>> frame->nb_samples <= max) {
>>>>          *rframe = ff_framequeue_take(&link->fifo);
>>>>          return 0;
>>>>      }
>>>> @@ -1522,6 +1522,7 @@ int ff_inlink_consume_frame(AVFilterLink *link,
>>>> AVFrame **rframe)
>>>>      *rframe = NULL;
>>>>      if (!ff_inlink_check_available_frame(link))
>>>>          return 0;
>>>
>>>> +    av_assert1(!link->fifo.samples_skipped);
>>>
>>> ... I am pretty sure that this assert can fail. Not with the current
>>> code, but with future filters that use the ff_inlink API directly.
>>
>> Missingle single thing about future filters, and why would they use
>> ff_inlink API
>> directly.
>>
>> If you can not cooperate, have very short time to work on FFmpeg, can not stand
>> criticism of other FFmpeg developers,.. just leave the project for once.
>
> Let's work on a solution instead of fighting and shit flinging for once...

I'm sorry. I've answered to Nicolas (falsely to Nicolas, not to
ffmpeg-devel, that's my fault), and he gives positive review.

Thank's.