[FFmpeg-devel] [PATCH] Add opaque to avfilter_graph_parse()

Vitor Sessak vitor1001
Fri May 8 12:52:08 CEST 2009

V??ctor Paesa wrote:
> Hi,
> On Sun, April 5, 2009 21:45, Vitor Sessak wrote:
>> V??ctor Paesa wrote:
>>> Hi,
>>> On Sat, March 28, 2009 19:46, V??ctor Paesa wrote:
>>>> Hi,
>>>> On Sat, March 28, 2009 17:01, Michael Niedermayer wrote:
>>>>> On Fri, Mar 27, 2009 at 04:50:43PM +0100, V??ctor Paesa wrote:
>>>>>> Hi,
>>>>>> I'd like to add a void *opaque to avfilter_graph_parse(), so that
>>>>>> it passes it on to avfilter_init_filter(), instead of passing NULL.
>>>>>> This extension to the API is not used by ffmpeg.c, but I imagine
>>>>>> other applications may want to use the graph parsing facilities,
>>>>>> and be happier if it is possible to give some value to opaque
>>>>>> (even if the same for every filter in graph).
>>>>> humans write plain/text, computers like text/plain
>>>>> my mutt is pretty robust in displaying patches with wrong mime types
>>>>> inline and colored but this one was too much.
>>>> Sorry, I'm afraid the computer I used to send my patches from didn't
>>>> had applied this .reg to set the mime types:
>>>> -------------------------------
>>>> Windows Registry Editor Version 5.00
>>>> [HKEY_CLASSES_ROOT\.diff]
>>>> @="txtfile"
>>>> "PerceivedType"="diff"
>>>> "Content Type"="text/x-patch"
>>>> -------------------------------
>>>> Here are attached again, as text/x-patch
>> I'm not against the patch per see, but I'd like someone who followed
>> lavfi development from the start to explain why an opaque arg is needed.
>>  From memory, I don't remember anything thats uses it and it begs for
>> been misused...
> Lacking a better explanation from the author, I have the feeling that
> the avfilter pipe is effectively isolated: video in, video out, but no way
> to report back to the application that there is something interesting in one
> particular frame.
> Imagine a video surveillance application, that detects strangers entering
> the door. The opaque pointer would contain a callback function,
> for example.

Patch ok them, even if I'm not completely happy with the "opaque" 
concept. Sorry for the delay...


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