
SDH_A_Orange_4:

conformance: HM-10.0
category: Entropy coding
sub category: Sign Data Hiding

resolution: 1920x1080
# of frames: 2

Specification:
A. sign_data_hiding_flag is on:
	At least 100 CGs have lastSigScanPos-firstSigScanPos = 3.
	At least 2000 CGs have lastSigScanPos-firstSigScanPos < 3.
	At least 1000 CGs have lastSigScanPos-firstSigScanPos > 3 and infer the sign bit to be positive.
	At least 1000 CGS have lastSigScanPos-firstSigScanPos > 3 and infer the sign bit to be negative.
o	Testing position of CG with SDH:
	    Sign inference happens for all possible combinations of (TU size, CG position in TU) at least once in the frame.
o	Testing significance positions:
	    All possible combinations for (lastSigScanPos, firstSigScanPos ) in a CG appear at least once in the frame.
o	Testing the correctness of the inference of the sign (odd/even) and testing if the calculation of the sum creates
	overflows (e.g. implementations with 8, 16 or 32 bits adder):
    *	4x4 TU
     1.	lastSigScanPos-firstSigScanPos = 3, 4 combinations of (first sign bit, sum parity): (negative, even), (positive, odd).
     2.	lastSigScanPos-firstSigScanPos < 3, 4 combinations of (first sign bit, sum parity) : (negative, even), (positive, odd).
     3.	lastSigScanPos-firstSigScanPos > 3, first sign bit even, sum of signed values, not including initial sign-inferred coeff,
        include at least
	    (0, 2, 4, 6, 8, 10, 12, 14, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384) 
     4.	lastSigScanPos-firstSigScanPos  > 3, first sign bit odd, sum of signed values, not including initial sign-inferred coeff,
        include at least
	    (1, 3, 5, 7, 9, 11, 13, 15, 17, 33, 129, 257, 513, 1025, 2049, 4097, 8193, 16385) 
     5.	One CG with all coefficients to maximum absolute value and sign inference.
     6.	One CG with all coefficients to minimum absolute value and sign inference.
    *	8x8 TU
     1.	Repeat the test cases for 4x4 TU for all 4 CGs. 
    *	16x16 TU
     1.	Repeat the test cases for 4x4 TU for all 16 CGs. 
    *	32x32 TU
     1.	Repeat the test cases for 4x4 TU for all 64 CGs.

B. sign_data_hiding_flag is on:
	At least 500 CGs have lastSigScanPos-firstSigScanPos > 3  and the CU they belong to has cu_transquant_bypass_flag=1.
	At least 500 CGs have lastSigScanPos-firstSigScanPos > 3  and the CU they belong to has cu_transquant_bypass_flag=0.



Purpose:
Test SDH sign inference, and test SDH in conjunction with cu_transquant_bypass_flag.

MD5: SEI message in the bitstream
