[FFmpeg-devel] Bounties?

Robert Swain robert.swain
Thu May 24 14:52:09 CEST 2007


On 24 May 2007, at 13:39, Luca Barbato wrote:
> Robert Swain wrote:
>> On 24 May 2007, at 07:43, Panagiotis Issaris wrote:
>>> As Victor noted, that was the exact purpose of these patches:
>>>
>>> http://article.gmane.org/gmane.comp.video.ffmpeg.devel/37220
>>> http://article.gmane.org/gmane.comp.video.ffmpeg.devel/37244
>>>
>>> The idea was that people could then maintain their own website with
>>> different profiles for different devices.
>>>
>>> The reason I did not repost the patch yet, is that -if I recall
>>> correctly- for it to work, the AVOptions conversion stuff should be
>>> completed first.
>>
>> That's what you stated in the thread. What exactly needs to be done
>> to 'complete the AVOptions conversion'? I'm eager to have such
>> profiles available such that essentially good speed/quality defaults
>> can be set for various targets, be they defined by hardware (VCD,
>> SVCD, DVD, [I know those are implemented] iPod, PSP, AppleTV, PS3,
>> some other portable media player, some other home theatre PC, some
>> other standalone device...) or to make encoding for general use
>> easier which would mainly entail speed/quality settings.
>>
>> Rather than 'profiles' (which may overlap with some future option to
>> do with MPEG profiles maybe...?), I would be inclined to call them
>> 'presets'. Would it be reasonable to consider the order of the
>> specification of a preset as to whether it overwrites other options
>> or other options overwrite it? For example, for a device that
>> supports iPod 640x480 H.264 but only up to 1000kbps:
>>
>> ffmpeg -i infile -preset ipod_h264_640 -b 1M -maxrate 1M outfile.mp4
>>
>> Or, if there were quality presets for h.264 that had some overlap
>> with the iPod specifications (a h.264 high quality preset could
>> specify 5 reference frames while the iPod H.264 640x480 preset would
>> only allow 1 reference frame for example) then:
>>
>> ffmpeg -i infile -preset h264_hq -preset ipod_h264_640 outfile.mp4
>>
>> Would result in the latter preset options overwriting the former.
>>
>
> what about having a nice plain text file with
>
> ipods:
>
> line1
> line2
>
> psp:
>
> line...

That wasn't the point of my discussion above. If you look at the  
suggested layout of presets from Takis (I'm intrigued, is Takis a  
short version of Panagiotis? :) ), they use a layout very similar to  
what you suggest.

The point I was making was that I think options preceeding a preset  
(including specification of another preset) should be overwritten by  
said preset and similarly options proceeding a preset should  
overwrite the options specified in a preset.

> or just a script that calls ffmpeg accordingly?

Well this could be and has been done, but the point is to make using  
FFmpeg easier so people don't have to look for third party scripts  
and frontends to be able to use the program. We get a large number of  
requests in the IRC channel for help encoding files that will be  
compatible with various devices and also for options to improve the  
quality of video output because the defaults aren't good enough.

Rob




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