id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
1601	STILL_B_1 / STILL_B_ERICSSON_1 checksum and OPL difference	ksuehring	ksuehring	"Test bitstreams in the FDIS and FDIS_r1 directory are supposed to be the same, except for removal of company names.

It was found though, that in the transition of STILL_B_ERICSSON_1 to STILL_B_1 both YUV MD5 hash and OPL file changed.

The bitstream files are identical and contain five frames. The OPL file of the STILL_B_ERICSSON_1 stream contains all the frames in the stream. The OPL file for STILL_B_1 contains only the first frame. The change for the YUV file looks similar.

The stream is specified as follows:

> Test bitstream STILL_B_ERICSSON
> 
> Specification: This bitstream tests a Main 10 Still Picture decoder’s  capability of decoding the first picture of a bitstream conforming to the Main 10 profile when the first picture of the bitstream is a GDR picture with ph_recovery_poc_cnt equal to 0.
> 
> Functional stage: Still picture
> 
> Purpose: Check that a Main 10 Still Picture decoder can decode the  first picture of a Main 10 bitstream when the first picture of the  bitstream is a GDR picture with ph_recovery_poc_cnt equal to 0.

The bitstream is a Main 10 bistream, not a still picture profile as the name may suggest. A multi-profile decoder like VTM cannot determine from the bitstream that it would be expected to only decode the first picture. A Main 10 Still Picture profile bitstream would only be allowed to contain a single picture.

If a Main 10 capable decoder sees a bitstream that is marked as Main 10, it should obviously decode all pictures in the stream. The single frame decoding case seems like a special case for a Main 10 stream being tested with a still picture only decoder. Expecting that behavior as the default seems confusing.

Thus I think the change of OPL and MD5 may be not intentional. For an intentional change, I would also expect the version of the stream to be incremented.

A similar issue seems to exist in STILL444_B_ERICSSON_1 and STILL444_B_1."	defect	closed	minor		Conformance		fixed		ksuehring fbossen jvet@…