[FFmpeg-devel] [PATCH] Indeo5 decoder

Maxim max_pole
Mon Mar 30 13:31:42 CEST 2009

John Cox schrieb:
>> It's abit different in the Indeo5: there are 3 macroblock sizes as I
>> mentioned above. A macroblock can include one or four blocks depending
>> on its size. The relation between macroblocks and blocks is the following:
>> [snip]
> [snip]
>> As you can see above there are two cases where mb_size == block_size.
>> The main difference between those is that a macroblock can have a motion
>> vector/quant delta associated with it and these are shared between all
>> blocks in the same mb...
> So only one MV per MB? What distinguishes one block from another then?   This
> is going off topic - can you give me a pointer to the standard please and I'll
> go away and satisfy my own curiosity.

Unfortunately there is no standard/patents describing the indeo5
algorithm I can point to. All I know about it was collected using some
related info from Intel and RE of binary codecs...
The blocks are distinguished by their position in the mb, either they
are coded or not (aka contain coded coefficients or not)...


More information about the ffmpeg-devel mailing list