[FFmpeg-soc] libavfilter audio work - qualification task

[S.N. Hemanth Meenakshisundaram]

On 05/16/2010 09:10 AM, Stefano Sabatini wrote:
> On date Tuesday 2010-05-11 01:12:37 +0200, Stefano Sabatini encoded:
>    
>> On date Monday 2010-05-10 15:52:18 -0700, S.N. Hemanth Meenakshisundaram encoded:
>>      
>>> On 05/10/2010 03:14 PM, Stefano Sabatini wrote:
>>>        
>>>> On date Sunday 2010-05-09 20:42:30 -0700, S.N. Hemanth Meenakshisundaram encoded:
>>>>          
>>>>> On 05/03/2010 01:32 PM, Stefano Sabatini wrote:
>>>>>            
>>>>>> On date Monday 2010-05-03 01:11:07 -0700, S.N. Hemanth Meenakshisundaram encoded:
>>>>>>              
>>>>>>> On 04/23/2010 05:03 PM, Stefano Sabatini wrote:
>>>>>>>                
>>>>>>>> On date Thursday 2010-04-22 17:19:16 -0700, S.N. Hemanth Meenakshisundaram encoded:
>>>>>>>> [...]
>>>>>>>>                  
>>>>          
>>>>> +    /* FIXME: av_parse_color currently sets alpha to 0 if no alpha is specified.
>>>>> +     * So we force alpha = 0xFF (opaque), here in such a case.
>>>>> +     */
>>>>> +    if (rgba[3] != 0)
>>>>> +        color[3] = rgba[3];
>>>>> +    else
>>>>> +        color[3] = 0xFF;
>>>>>            
>>>> I suppose this was to be skipped.
>>>>          
>>> If I skip this without the parseutils patch, then text specified
>>> will be invisible (alpha 0) by default when user specifies
>>> foreground color as an english string. So I left it in for the time
>>> being. Will remove it along with parseutils patch. Hope that's ok.
>>>        
>> Fine.
>>
>> Did you already thought about a syntax? My idea was:
>> color/0xXX
>> color/DDD
>>
>> maybe someone which works with web/design can suggest a more
>> familiar/natural syntax though.
>>
>>      
>>>> Apart those nits patch looks fine to me (but missing configure and
>>>> documentation parts), I assume it has been tested and works.
>>>>          
>>> Done. Other nits fixed and the redundant fixme removed. Tested and works.
>>>
>>>        
>>>> Please provide the complete patch.
>>>>          
>>> vf_drawtext.c, allfilter.c and libavfilter Makefile changes are all
>>> part of drawtext.diff which is a patch against soc/libavfilter (svn
>>> diff ./ in soc/libavfilter directory)
>>>
>>> There's no configure in soc/libavfilter, so config.diff is a patch
>>> against ffmpeg trunk. Should this be in some other form?
>>>
>>> drawtext_doc.diff is a diff with libavfilter.texi of ffmpeg trunk
>>> after it has been patched by the checkout.sh script in
>>> soc/libavfilter. I can make this a patch to the
>>> 03_libavfilter_doc.diff file in soc/libavfilter if required.
>>>        
>> No patch is OK, I think that I'll add a configure patch to soc too.
>>
>> If no one else has other comments I'll apply the patch to soc in few
>> days.
>>      
> I had to edit the patch before to apply, there were different warnings
> and a problem with the strftime() expansion rendering (only the
> characters in the provided string where loaded in init(), that
> couldn't work when the string was expanded), please test more
> accurately the next time and never ignore warnings.
>    

I saw the changes you made. I will keep those in mind when submitting my 
next patch and run more tests.

> Also I changed the way the filter is configured, with the applied
> patch the --enable-libfreetype switch is required to compile the
> drawtext filter. That looks simpler and consistent with the way
> configure deals with external libraries.
>
> As for what regards the filter: the outline quality is honestly quite
> bad especially at small font sizes, while I really appreciate the
> font/box transparency feature :-). Also maybe we should try to add
> anti-aliasing support.
>    

For anti-aliasing, I will set the freetype2 anti-aliasing flags on. As 
for outline, I guess the algorithm needs to be changed. I will work on 
these once I have gotten some of the audio filter framework done this week.

Thanks,