[FFmpeg-devel] [PATCH] Enable swscale by default

Benjamin Larsson banan
Sun Sep 14 21:34:50 CEST 2008

Justin Ruggles wrote:
> Michael Niedermayer wrote:
>> On Sun, Sep 14, 2008 at 03:14:08PM +0100, M?ns Rullg?rd wrote:
>>> Michael Niedermayer <michaelni at gmx.at> writes:
>>>> On Sun, Sep 14, 2008 at 02:12:00PM +0100, M?ns Rullg?rd wrote:
>>>>> Diego Biurrun <diego at biurrun.de> writes:
>>>>>> On Sat, Sep 13, 2008 at 03:27:44PM -0700, Baptiste Coudurier wrote:
>>>>>>> Michael Niedermayer wrote:
>>>>>>>> I thought it was agreed in the droping of the old scaler thread
>>>>>>>> that whoever wants a lgpl scaler will have to do the work.
>>>>>>> I didn't agree _at all_ with that, and I will vote against.
>>>>>> While I surely do not want to fan the flames, this has been a long time
>>>>>> coming - I think it's time for the LGPL faction to stand up and work...
>>>>> Until last night, I was under the impression that the switch to
>>>>> swscale would only be done when the mmx parts were separated from the
>>>>> main code, and an lgpl version could be built.  It would appear that I
>>>>> was mistaken, if not misled.  Making the scaler and colourspace
>>>>> converter gpl is effectively making all of ffmpeg gpl.
>>>> I must admit i was myself not fully aware of a few consequences of droping
>>>> the old scaler, like ./configure failing. Though i thought it was obvious
>>>> that droping the old scaler would implicate one way or another no lgpl
>>>> scaler until walkens yuv2rgb code was rewritten.
>>> Why has it been repeatedly stated in the past, that the GPL-only parts
>>> were only needed for mmx, and that a plain-C LGPL swscale is easily
>>> possible, if this is not true?  If I were prone to conspiracy theories
>>> (and I sometimes am), I might suspect this was an underhanded attempt
>>> to make FFmpeg GPL without anyone noticing before it was too late.
>>> I'm in a good mood today, so I won't make such accusations just yet.
>> The only plain C GPL code that iam aware of that we need in there are
>> 220 lines of yuv2rgb table generation code.
>> Rewriting this is easy, luca did it already IIRC but walken
>> claimed copyright on the rewritten table generator. Noone else dared to
>> try again and i simply have no personal interrest in rewriting FOSS code
>> due to its license being disliked by some other people.
> Can someone post the output of these tables somewhere (maybe
> ftp/incoming if they're really big)?  I have not seen the table
> generation code, and to output the tables, I assume one would have to
> locate this code and look at it to know where to add printf's.
> -Justin

I remember Michael writing a detailed description about what needs to be
done to rewrite the table generator code. It was around the time Luca
rewrote the code.

Benjamin Larsson

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