diff options
Diffstat (limited to 'media/libvpx/vp8/common/quant_common.c')
| -rw-r--r-- | media/libvpx/vp8/common/quant_common.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/media/libvpx/vp8/common/quant_common.c b/media/libvpx/vp8/common/quant_common.c new file mode 100644 index 000000000..05f921070 --- /dev/null +++ b/media/libvpx/vp8/common/quant_common.c @@ -0,0 +1,135 @@ +/* + * Copyright (c) 2010 The WebM project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + + +#include "quant_common.h" + +static const int dc_qlookup[QINDEX_RANGE] = +{ + 4, 5, 6, 7, 8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 17, + 18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 28, + 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, + 44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, + 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, + 75, 76, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, + 91, 93, 95, 96, 98, 100, 101, 102, 104, 106, 108, 110, 112, 114, 116, 118, + 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 143, 145, 148, 151, 154, 157, +}; + +static const int ac_qlookup[QINDEX_RANGE] = +{ + 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, + 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, + 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, + 52, 53, 54, 55, 56, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, + 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, + 110, 112, 114, 116, 119, 122, 125, 128, 131, 134, 137, 140, 143, 146, 149, 152, + 155, 158, 161, 164, 167, 170, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, + 213, 217, 221, 225, 229, 234, 239, 245, 249, 254, 259, 264, 269, 274, 279, 284, +}; + + +int vp8_dc_quant(int QIndex, int Delta) +{ + int retval; + + QIndex = QIndex + Delta; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + retval = dc_qlookup[ QIndex ]; + return retval; +} + +int vp8_dc2quant(int QIndex, int Delta) +{ + int retval; + + QIndex = QIndex + Delta; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + retval = dc_qlookup[ QIndex ] * 2; + return retval; + +} +int vp8_dc_uv_quant(int QIndex, int Delta) +{ + int retval; + + QIndex = QIndex + Delta; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + retval = dc_qlookup[ QIndex ]; + + if (retval > 132) + retval = 132; + + return retval; +} + +int vp8_ac_yquant(int QIndex) +{ + int retval; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + retval = ac_qlookup[ QIndex ]; + return retval; +} + +int vp8_ac2quant(int QIndex, int Delta) +{ + int retval; + + QIndex = QIndex + Delta; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + /* For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16. + * The smallest precision for that is '(x*6349) >> 12' but 16 is a good + * word size. */ + retval = (ac_qlookup[ QIndex ] * 101581) >> 16; + + if (retval < 8) + retval = 8; + + return retval; +} +int vp8_ac_uv_quant(int QIndex, int Delta) +{ + int retval; + + QIndex = QIndex + Delta; + + if (QIndex > 127) + QIndex = 127; + else if (QIndex < 0) + QIndex = 0; + + retval = ac_qlookup[ QIndex ]; + return retval; +} |