[FFmpeg-devel] [PATCH] Add new vf_tiltandshift filter

Vittorio Giovara vittorio.giovara at gmail.com
Thu Dec 21 23:43:32 EET 2023


On Wed, Dec 20, 2023 at 2:56 PM Vittorio Giovara <vittorio.giovara at gmail.com>
wrote:

>
>
> On Wed, Dec 20, 2023 at 2:50 PM Nicolas George <george at nsup.org> wrote:
>
>> Vittorio Giovara (12023-12-20):
>> > If there are no more comments, I'll push this today or tomorrow.
>>
>> I think the change you made after the last request might go too far, but
>> I have not had time to look at the code carefully enough to be sure.
>>
>> If a filter can produce several output frames from one input, then it
>> must send at lease one of the NEW frames.
>>
>> An illustration to make it clear: if I1 allows to compute O1a, O1b, O1c,
>> I2 allows to compute O2a, O2b, O2c, etc.
>>
>> Then when I1 arrives, the filter must output at least O1a, it can output
>> O1b and O1c or not.
>>
>> But when I2 arrives, it must output at lease O2a, which means it must
>> output O1b and O1c if that was not done at the time of I1.
>>
>> Your filter only outputs one frame per input, but it seems to me it can
>> create several frames.
>>
>
> the filter needs at least $width input frames to generate an output frame,
> so it queues them
> when the buffer is full, it will pop the head and generate the output
> frame when the next input frame arrives, but the amount of input frames in
> the queue needed to generate new frames is constant so it cannot output any
> additional frames
> at the end it will flush the buffer and generate the remaining output
> frames
> --
>

pushed thanks
-- 
Vittorio


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