0000049: sps->mb_adaptive_frame_field_flag should be initialized to 0

ID	Project	Category	View Status	Date Submitted	Last Update

0000049	JVT JM H.264/AVC reference software	decoder	public	2007-05-19 01:03	2008-09-02 16:30

Reporter	Peter Farkas	Assigned To	Karsten Suehring
Priority	normal	Severity	minor	Reproducibility	N/A
Status	resolved	Resolution	no change required
Product Version	JM 12.2

Summary	0000049: sps->mb_adaptive_frame_field_flag should be initialized to 0
Description	If I am not mistaken, the standard says: When mb_adaptive_frame_field_flag is not present, it shall be inferred to be equal to 0. On the other hand, in parset.c I see if (!sps->frame_mbs_only_flag) { sps->mb_adaptive_frame_field_flag = u_1("SPS: mb_adaptive_frame_field_flag", s); } (spacing changed for readability) as the only place where sps->mb_adaptive_frame_field_flag is given a value. It seems to me that somewhere before this if block sps->mb_adaptive_frame_field_flag should be set to 0, to make sure that if not present, it shall be inferred to be equal to 0. I confess that I did not follow through the use of this variable in the reference code, so maybe it is set to zero implicitely elsewhere, or maybe its value is not used explicitely in the code when it is not 0. If so, initializing it to 0 would not be not necessary. However, it may not hurt, even in these cases.
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Date Modified	Username	Field	Change
2007-05-19 01:03	Peter Farkas	New Issue
2007-05-23 13:37	Karsten Suehring	Assigned To	=> Karsten Suehring
2007-05-23 13:37	Karsten Suehring	Status	new => acknowledged
2008-09-02 16:30	Karsten Suehring	Note Added: 0000229
2008-09-02 16:30	Karsten Suehring	Status	acknowledged => resolved
2008-09-02 16:30	Karsten Suehring	Resolution	open => no change required

Karsten Suehring 2008-09-02 16:30 administrator ~0000229	We allocate SPS using calloc() which implicitly initializes all fields with zero. So we don't have to explicitly take care of the frame_mbs_only_flag.