[FFmpeg-devel] Google Summer of Code participation

Thilo Borgmann thilo.borgmann
Sat Mar 28 13:48:07 CET 2009

compn schrieb:
> On Sat, 28 Mar 2009 12:20:32 +0100, Thilo Borgmann wrote:
>> I'm still looking for a task, so the other two remain for consideration:
>> no. 12: "16-bit Interplay Video Decoder"
>> Sounds interesting and as there is a working 8-bit decoder, wich throws 
>> some errors if operating on the 16-bit demo file, there seems to be a 
>> good starting point. Unfortunately, the section about 16-bit opcodes is 
>> far from useful, if opcodes would have to be changed, this task becomes 
>> very difficult...
>> http://wiki.multimedia.cx/index.php?title=Interplay_Video
>> -> The suggestion in the wiki is to ask the development community (you!) 
>> about a good start-off with that problem. So I do: Anyone who can help 
>> on this? Anyone with more information about the 16-bit mode?
>> (Already inspected the code here... sounds like altering the #define'd 
>> functions but how to know if it is 8-bit palette mode or 16-bit 
>> whatsoever mode?)
> ah, this task seems poorly defined without a spec or implementation to
> follow. ask mike melanson, he may be able to dig something up.
>> no. 23: "CorePNG Decoder"
>> Well, the descriptions sound quite easy, BUT the current svn version of 
>> ffmpeg (as well as my very old one) say that it "could not find codec 
>> parameters". Thus, I suppose there is no existing PNG1 decoder wich 
>> decodes RGB I-Frame video? Is there a PNG1 coded RGB I-Frame demo video? 
>> So this task seems to me like implementing a whole decoder on top of the 
>> png image decoder?
>> http://samples.mplayerhq.hu/V-codecs/PNG1/
> ffmpeg's png decoder can handle a few of the frames in the above sample
> video. you can test this by adding the codec_id_png to PNG1 in
> libavformat/riff.c
> (or by playing the above sample with mplayer)
> the corepng codec has source code. from there you can read how to
> decode such frames.
> http://www.jory.info/serendipity/archives/28-CorePNG-v0.8.2.html
> please feel free to ask any questions , we like students that can keep
> good communication :)
Thanks a lot!

That thing about the new tag to PNG1 was exectly what was missing there 
to give me a start. Never to find this on my own in such a quite complex 
project like FFmpeg.

Ok, I will try to solve this for my qualification task to lead to a 
summer of code.


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