[XviD-devel] MPEG-4 SP Levels and framerates

[Carl Eric Codere]

Greetings,
         This may seem stupid, but I have a small question regarding config.c and profile levels of MPEG-4 Simple Profile (vfw profile table):

According to the MPEG-4 Standanrd, Part 2:

The VCV (Video Complexity Verifier) decoder rate is the vcv_decoder_rate (H) referred in [MPEG4-2; subclause D.4]; this parameter is the number of macroblocks/second based on the typical spatial and temporal resolutions, as follows:

    * 1485 MBs/s corresponds to QCIF at 15Hz
    * 5940 MBs/s corresponds to CIF at 15 Hz and also twice QCIF at 30 Hz
    * 11880 MB/s corresponds to CIF at 30 Hz
    * 7425 MB/s corresponds to 1.25 times CIF at 15 Hz
    * 23760 MB/s corresponds to twice CIF at 30 Hz
    * 97200 MB/s corresponds to twice ITU-R 601 at 30 Hz
    * 489600 MB/s corresponds to twice 1920x1088 at 30 Hz 

Therefore this should give us the max. framerate allowed, is that the case?

{ "Simple @ L1",      0x01,  176, 144, 15,  4,  198,   99,   1485, 100,    { "Simple @ L2",      0x02,  352, 288, 15,  4,  792,  396,   5940, 100,  
{ "Simple @ L3",      0x03,  352, 288, 15,  4,  792,  396,  11880, 100,  

Now, Simple @ L1 max framerate is 15 fps, because VCV Decoder rate is 1485, correct?
Now, Simple @ L2 max framerate is 15 fps  @ CIF and 30 fps @ QCIF, correct?
But what about Simple @ L3, since the specs gives us a max framerate of 30 fps (30 Hz?) Why is the config.c indicating a max framerate of 15 fps?

Maybe its something i do not understand about the standard?

If not, maybe this should also be fixed?

Best regards,
Carl