See this picture?
I don’t know why it appears in quite a few VC-1 Advanced Profile official test samples (the rest I could decode are football trainings as in SP/MP samples).
Yesterday I’ve written VC-1 Elementary Stream demuxer and now have enough material to test interlaced decoding and other AP features (when I implement them).
And another task – make work VC-1 embedded in .EVO – official format of BlueRay/HD-DVD.
Let’s see what I have done in 2006:
And here are my plans for this year. Warning! This is not the final list and may be changed in process.
Known fourccs:
Known meaning of flags:
X8 frames use their own Huffman codes (code lengths are stored as nibbles somewhere in bitstream) and also blocks looks like to be decoded in this way:
for(y=0;y
for(x=0;x< mb_width*2;x++){
decode luma blockif( x & y & 1)
decode both chroma blocks
}
}
Ever heard of codec with fourcc WMVP? That is another Windows Media variant designed for slideshows, video albums, ets. Why I have got interested in it? WMV3 Complex Profile (aka Ye Olde Undocumented and Incompatible Advanced Profile) uses exactly the same coding method to store I-frames when flag RES_X8 is set (if it is not set then VC-1 Main Profile decoder may decode that movies).
While standard decoder output mostly garbage, some blocks are decoded correctly thus I hope it’ll be possible to add support for both WMVP and WMV3 CP.
I’ve just committed fully working (I hope) support for newer Fraps videos. While RE’ing that stuff I made two big mistakes: misunderstood bit reader to read only 31 bits from 32-bit word (which is not correct) and that Fraps version 4 is not identical to Fraps version 2. All of these is corrected now.
And now is a new category that Mike forgot to add to MultimediaWiki (hint, hint).
Supported screen capture codecs:
Unsupported screen capture codecs:
Interesting – all those unsupported codecs use arithmetic coding (and as I suspect don’t work with palletized images).
Here is what I currently know about Fraps v2 (v1 is supported by FFmpeg):
Here is a quick list of what has been done recently:
Ah, I still remember those days when FFmpeg got one new decoder once week or two.
Mike once mentioned here that one coder searches for ideas to implement. My situation is rather complimentary – I hardly manage to fullfill all requests from other people. Recently I’ve added two image decoders to FFmpeg – Targa (.tga) and TIFF. Both of them were done by request. The same situation was with Worms Video.
WavPack decoder was written by my own wish but there are already some people asking to write MPEG-4 ALS and Monkey’s Audio decoders. While the later is not possible to implement right now, I’ll implement both MP4 ALS decoder and encoder.
There are currently 14 lossless audio codecs mentioned on MultiMedia Wiki page (look here for further links):
FFmpeg currently has decoders for Bonk, FLAC, Shorten, TrueAudio and Apple Lossless. So, there are at least MPEG-4 ALS, Monkey’s Audio and WavPack decoders can be added.
I will work on WavPack decoder and ALS (I hope standard will appear soon). What about Monkey’s Audio? Yes, it’s popular but it has following difficulties for implementation:
Well, I still hope it will be implemented some day.
OK, Now B-frames for simple and main profile work. Now there are only some exotic features left to implement as spatial downsampling and sync markers. And a lot of RE’ing to implement old WMV3 P-frames decoding and complex profile.
As for advanced profile, B-frames are still not implemented.