Subject: Re: mcp10ccett



Dear Gerard and Video Conformance AHG Members,

I checked the mcp10ccett bitstream, and I got a perfect match with the
reconstructed frames.

However my decoder found that the vbv_delay values encoded are
wrong.

I have enclosed a trace of the vbv_values showing the problem.

Also the associated 'README' file (mcp10ccett.doc) is virtually non-existent.
Gerard, could you please provide a detailed README file with your bitstreams.
You can look at the README files given with other conformance
bitstreams if you need a model.

Regards,

--Tristan ([email-masked])

############################################## Decoding...
frame index: 0
Buffer_fullness (before removing any headers): 164405.33 bits
Buffer_fullness (after removing picture start-code): 164133.33 bits
Buffer_fullness (after removing picture data): -42.67 bits
warning: VBV underflow violation: Buffer_fullness = -42.67 bits, should be >= 0.
Buffer_fullness (after adding next incoming bits): 159957.33 bits
############################################## Decoding...
frame index: 3
Buffer_fullness (before removing any headers): 159957.33 bits
Buffer_fullness (after removing picture start-code): 159925.33 bits
warning: vbv_delay = 3592, VBV says that it should be 3599 or 5399
Buffer_fullness (after removing picture data): 79957.33 bits
Buffer_fullness (after adding next incoming bits): 239957.33 bits
############################################## Decoding...
frame index: 1
Buffer_fullness (before removing any headers): 239957.33 bits
Buffer_fullness (after removing picture start-code): 239925.33 bits
warning: vbv_delay = 3592, VBV says that it should be 5399
Buffer_fullness (after removing picture data): 79957.33 bits
Buffer_fullness (after adding next incoming bits): 239957.33 bits
############################################## Decoding...
frame index: 2
Buffer_fullness (before removing any headers): 239957.33 bits
Buffer_fullness (after removing picture start-code): 239925.33 bits
warning: vbv_delay = 4581, VBV says that it should be 5399
Buffer_fullness (after removing picture data): 79957.33 bits
Buffer_fullness (after adding next incoming bits): 239957.33 bits
############################################## Decoding...

----------------------------------------------------------------------------------

The mcp10ccett bitstream does not test all cases and all situations.
A similar test should be extended to field-pictures and should include
all possible types of prediction modes, including Dual prime and 16x8 field.

--Tristan