Does anyone know about transcoding between H.264 and other standards?

[Mitnick]

I am studying on transcoding between H.264 and H.263, but I don't have any soruce code about transcoding, I it's difficult for only one people to complete the hole project. I am glad to study and discuss with anyone on transcoding.
E-mail:cz_cs2000@yahoo.com.cn

[Sirber]

What about virtualdub?

[Doom9]

Just install ffdshow, access it via VirtualDub, activate h264 decoding in the decoding tab, then load your source and encode to H.263 via ffdshow.

[Mitnick]

Thanks, I mean not using tools to transcoding between h.263 and h.264, but to work out a algorithm to do this work faster, in another way, I want to develop a software:open a h.263 file, and the output is h.264 file.vice versa.

[bond]

well than your tool, needs
1) a h.263 decoder
2) a h.264 encoder
3) a fileparser able to parse the input file format where the h.263 stream is placed
4) a filewriter, unless you want to output raw .264

[berrinam]

Perhaps Mitnick meant software that doesn't do a full re-encode, by using some of the elements to take shortcuts (using the same motion vectors, quantisation or whatever)?

[Mitnick]

berrinam is right. that's my idea.

[bond]

berrinam is right. that's my idea.would be interesting but i doubt such a tool is existing already and i also dunno if its doable at all

the only tool i know which can do something like this is the ms mpeg-4 -> iso mpeg-4 converter patch for ffmpeg, but the two formats are very similar to begin with