Patent ID: 7620103

Claim:
An apparatus comprising: an encoder circuit configured to generate a plurality of coefficient values and motion vectors in response to a video stream, a first control signal selecting between intra and inter modes, a second control signal selecting between a plurality of transforms, and a number of quantized values; a quantizer circuit configured to generate said number of quantized values in response to said coefficient values, a quantizer index signal, two or more quantization dead zones and two or more offsets, wherein a first coefficient value is quantized using a first quantization dead zone and a first offset, a second coefficient value is quantized using a second quantization dead zone and a second offset, said first and second quantization dead zones have different values and said first and second offsets have different values; a control circuit configured to (i) generate said first control signal, said second control signal, said quantizer index signal, and a status signal indicating a transmission status and (ii) set said two or more quantization dead zones and said two or more offsets to different values, wherein said quantization dead zones and said offsets are independently programmable; and an entropy encoder circuit configured to generate a compressed bit stream in response to the first control signal, the quantizer index signal, the status signal, the quantized values and the motion vectors, wherein 4×4 luma and chroma quantization is performed according to a first equation comprising Y QQ ⁡ ( i , j ) = [ Y ⁡ ( i , j ) · Q ⁡ ( QP ⁢ %6 , i , j ) + ( ( ( Off ⁢ ⁢ ( i , j ) + 1 ) · 2 17 + QP / 6 ) / 16 ) ] / 2 17 - 3 + QP / 6 , i , j = 0 ⁢ ⁢ … ⁢ ⁢ 3 Y Q ⁡ ( i , j ) = { 0 , if ⁢ ⁢ abs ⁡ ( Y QQ ⁡ ( i , j ) ) ≤ 7 + DZ ⁡ ( i , j ) Y QQ ⁡ ( i , j ) / 8 , else where Y represents the coefficient values, Q represents the quantization coefficients, Off(i,j) represents the offset values and DZ(i,j) represents the quantization dead zone values, 4×4 luma DC quantization is performed according to a second equation comprising Y QQD ⁡ ( i , j ) = [ Y D ⁡ ( i , j ) · Q ⁡ ( QP ⁢ %6 , 0 , 0 ) + ( ( sgn ⁡ ( Y D ⁡ ( i , j ) ) · ( o LDC + 1 ) · 2 17 + QP / 6 ) ⁢ / ⁢ 16 ) ] ⁢ / ⁢ 2 17 - 3 + QP / 6 , i , j = 0 ⁢ …3 ⁢ ⁢ Y QD ⁡ ( i , j ) = { 0 , abs ⁡ ( Y QQD ⁡ ( i , j ) ) ⁢ < _ ⁢ 7 + d LDC Y QQD ⁡ ( i , j ) ⁢ / ⁢ 8 , else where O LDC =0 . . . 7 has a value ranging from zero through 7 and d LDC has a value ranging from zero through 15, and 2×2 chroma DC quantization is performed according to a third equation comprising Y QQD ⁡ ( i , j ) = [ Y D ⁡ ( i , j ) · Q ⁡ ( QP ⁢ %6 , 0 , 0 ) + ( ( sgn ⁡ ( Y D ⁡ ( i , j ) ) · ( o CDC + 1 ) · 2 17 + QP / 6 ) ⁢ / ⁢ 16 ) ] ⁢ / ⁢ 2 17 - 3 + QP / 6 , i , j = 0 ⁢ …3 ⁢ ⁢ Y QD ⁡ ( i , j ) = { 0 , abs ⁡ ( Y QQD ⁡ ( i , j ) ) ⁢ < _ ⁢ 7 + d CDC Y QQD ⁡ ( i , j ) ⁢ / ⁢ 8 , else where O CDC has a value ranging from zero through 7 and d CDC has a value ranging from zero through 15.