[FFmpeg-devel] attribute_deprecated int avpicture_deinterlace ??

[Hendrik Leppkes]

On Sat, Nov 30, 2013 at 6:54 PM, Reimar Döffinger
<Reimar.Doeffinger at gmx.de> wrote:
>
>
> On 30.11.2013, at 15:37, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
>
>> On Sat, Nov 30, 2013 at 2:17 PM, Stefano Sabatini <stefasab at gmail.com> wrote:
>>> On date Friday 2013-11-29 08:30:51 -0500, Don Moir encoded:
>>>>
>>>> ----- Original Message ----- From: "Stefano Sabatini"
>>>> <stefasab at gmail.com>
>>>> To: "FFmpeg development discussions and patches" <ffmpeg-devel at ffmpeg.org>
>>>> Sent: Friday, November 29, 2013 8:09 PM
>>>> Subject: Re: [FFmpeg-devel] attribute_deprecated int avpicture_deinterlace ??
>>>>
>>>>
>>>>> On date Friday 2013-11-29 09:06:57 -0500, Don Moir encoded:
>>>>>> deinterlacing is directly related to decoding in that you want a
>>>>>> properly decoded image and not some effect.
>>>>>>
>>>>>> Looks like we are now pointed to avlibfilter and yadif. I have no
>>>>>> use for avlibfilter so I should link it so I can deinterlace ?
>>>>>> avlibfilter is just excess baggage from my viewpoint.
>>>>>>
>>>>>> Hate to bring this up late but seems silly or am I the only one that
>>>>>> thinks that? Hope I am misunderstanding something.
>>>>>
>>>>> Possibly: we could extract the yadif code and move it somehow to the
>>>>> library (libavfilter public low-level API or something, so you don't
>>>>> need to build a filtergraph to apply it). It might be non trivial.
>>>>
>>>> Would be good if avpicture_deinterlace was improved possibly using
>>>> yadif and left where it is. Other than that, I would probably roll
>>>> my own rather than use avfilter if avpicture_deinterlace goes away.
>>>
>>> What's exactly your problem with libavfilter (please no trolling)? The
>>> main problem seems that you are not willing to configure a filtergraph
>>> for that, so the alternative I proposed is a low level deinterlacing
>>> API, based on yadif which could be used without filters.
>>
>> A simple filtergraph just for deinterlacing is so trivial that I
>> wouldn't let this argument count for anything.
>
> I don't know. If it's more than 5 lines of code (and I suspect it's a lot more) it might be useful to have a function that just passes things through one single filter...
> Though it would probably still need a create and destroy function in addition, so I don't know if such a simplified API is worth it...


With error checks its probably 20-30 lines of code for the filtergraph
setup, and 5 lines of code for filtering the frame.

Anyhow, it looks like the API isn't even his issue, more of the
concept that yadif is in lavfi, which I hope noone considers changing
on one persons opinion (or ever, really).
Its a video filter, it belongs in the video filtering library. Even if
you consider deinterlacing quite essential, its still a
post-processing filter.

- Hendrik