ref: 866f8f4086e4de41a793eb1961c3d6af69a02850
dir: /src/h264bsd_cavlc.c/
/*
* Copyright (C) 2009 The Android Open Source Project
* Modified for use by h264bsd standalone library
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*------------------------------------------------------------------------------
Table of contents
1. Include headers
2. External compiler flags
3. Module defines
4. Local function prototypes
5. Functions
DecodeCoeffToken
DecodeLevelPrefix
DecodeTotalZeros
DecodeRunBefore
DecodeResidualBlockCavlc
------------------------------------------------------------------------------*/
/*------------------------------------------------------------------------------
1. Include headers
------------------------------------------------------------------------------*/
#include "h264bsd_cavlc.h"
#include "h264bsd_util.h"
/*------------------------------------------------------------------------------
2. External compiler flags
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
3. Module defines
------------------------------------------------------------------------------*/
/* Following descriptions use term "information field" to represent combination
* of certain decoded symbol value and the length of the corresponding variable
* length code word. For example, total_zeros information field consists of
* 4 bits symbol value (bits [4,7]) along with four bits to represent length
* of the VLC code word (bits [0,3]) */
/* macro to obtain length of the coeff token information field, bits [0,4] */
#define LENGTH_TC(vlc) ((vlc) & 0x1F)
/* macro to obtain length of the other information fields, bits [0,3] */
#define LENGTH(vlc) ((vlc) & 0xF)
/* macro to obtain code word from the information fields, bits [4,7] */
#define INFO(vlc) (((vlc) >> 4) & 0xF) /* 4 MSB bits contain information */
/* macro to obtain trailing ones from the coeff token information word,
* bits [5,10] */
#define TRAILING_ONES(coeffToken) ((coeffToken>>5) & 0x3F)
/* macro to obtain total coeff from the coeff token information word,
* bits [11,15] */
#define TOTAL_COEFF(coeffToken) (((coeffToken) >> 11) & 0x1F)
#define VLC_NOT_FOUND 0xFFFFFFFEU
/* VLC tables for coeff_token. Because of long codes (max. 16 bits) some of the
* tables have been splitted into multiple separate tables. Each array/table
* element has the following structure:
* [5 bits for tot.coeff.] [6 bits for tr.ones] [5 bits for VLC length]
* If there is a 0x0000 value, it means that there is not corresponding VLC
* codeword for that index. */
/* VLC lengths up to 6 bits, 0 <= nC < 2 */
static const u16 coeffToken0_0[32] = {
0x0000,0x0000,0x0000,0x2066,0x1026,0x0806,0x1865,0x1865,
0x1043,0x1043,0x1043,0x1043,0x1043,0x1043,0x1043,0x1043,
0x0822,0x0822,0x0822,0x0822,0x0822,0x0822,0x0822,0x0822,
0x0822,0x0822,0x0822,0x0822,0x0822,0x0822,0x0822,0x0822};
/* VLC lengths up to 10 bits, 0 <= nC < 2 */
static const u16 coeffToken0_1[48] = {
0x0000,0x0000,0x0000,0x0000,0x406a,0x304a,0x282a,0x200a,
0x3869,0x3869,0x2849,0x2849,0x2029,0x2029,0x1809,0x1809,
0x3068,0x3068,0x3068,0x3068,0x2048,0x2048,0x2048,0x2048,
0x1828,0x1828,0x1828,0x1828,0x1008,0x1008,0x1008,0x1008,
0x2867,0x2867,0x2867,0x2867,0x2867,0x2867,0x2867,0x2867,
0x1847,0x1847,0x1847,0x1847,0x1847,0x1847,0x1847,0x1847};
/* VLC lengths up to 14 bits, 0 <= nC < 2 */
static const u16 coeffToken0_2[56] = {
0x606e,0x584e,0x502e,0x500e,0x586e,0x504e,0x482e,0x480e,
0x400d,0x400d,0x484d,0x484d,0x402d,0x402d,0x380d,0x380d,
0x506d,0x506d,0x404d,0x404d,0x382d,0x382d,0x300d,0x300d,
0x486b,0x486b,0x486b,0x486b,0x486b,0x486b,0x486b,0x486b,
0x384b,0x384b,0x384b,0x384b,0x384b,0x384b,0x384b,0x384b,
0x302b,0x302b,0x302b,0x302b,0x302b,0x302b,0x302b,0x302b,
0x280b,0x280b,0x280b,0x280b,0x280b,0x280b,0x280b,0x280b};
/* VLC lengths up to 16 bits, 0 <= nC < 2 */
static const u16 coeffToken0_3[32] = {
0x0000,0x0000,0x682f,0x682f,0x8010,0x8050,0x8030,0x7810,
0x8070,0x7850,0x7830,0x7010,0x7870,0x7050,0x7030,0x6810,
0x706f,0x706f,0x684f,0x684f,0x602f,0x602f,0x600f,0x600f,
0x686f,0x686f,0x604f,0x604f,0x582f,0x582f,0x580f,0x580f};
/* VLC lengths up to 6 bits, 2 <= nC < 4 */
static const u16 coeffToken2_0[32] = {
0x0000,0x0000,0x0000,0x0000,0x3866,0x2046,0x2026,0x1006,
0x3066,0x1846,0x1826,0x0806,0x2865,0x2865,0x1025,0x1025,
0x2064,0x2064,0x2064,0x2064,0x1864,0x1864,0x1864,0x1864,
0x1043,0x1043,0x1043,0x1043,0x1043,0x1043,0x1043,0x1043};
/* VLC lengths up to 9 bits, 2 <= nC < 4 */
static const u16 coeffToken2_1[32] = {
0x0000,0x0000,0x0000,0x0000,0x4869,0x3849,0x3829,0x3009,
0x2808,0x2808,0x3048,0x3048,0x3028,0x3028,0x2008,0x2008,
0x4067,0x4067,0x4067,0x4067,0x2847,0x2847,0x2847,0x2847,
0x2827,0x2827,0x2827,0x2827,0x1807,0x1807,0x1807,0x1807};
/* VLC lengths up to 14 bits, 2 <= nC < 4 */
static const u16 coeffToken2_2[128] = {
0x0000,0x0000,0x786d,0x786d,0x806e,0x804e,0x802e,0x800e,
0x782e,0x780e,0x784e,0x702e,0x704d,0x704d,0x700d,0x700d,
0x706d,0x706d,0x684d,0x684d,0x682d,0x682d,0x680d,0x680d,
0x686d,0x686d,0x604d,0x604d,0x602d,0x602d,0x600d,0x600d,
0x580c,0x580c,0x580c,0x580c,0x584c,0x584c,0x584c,0x584c,
0x582c,0x582c,0x582c,0x582c,0x500c,0x500c,0x500c,0x500c,
0x606c,0x606c,0x606c,0x606c,0x504c,0x504c,0x504c,0x504c,
0x502c,0x502c,0x502c,0x502c,0x480c,0x480c,0x480c,0x480c,
0x586b,0x586b,0x586b,0x586b,0x586b,0x586b,0x586b,0x586b,
0x484b,0x484b,0x484b,0x484b,0x484b,0x484b,0x484b,0x484b,
0x482b,0x482b,0x482b,0x482b,0x482b,0x482b,0x482b,0x482b,
0x400b,0x400b,0x400b,0x400b,0x400b,0x400b,0x400b,0x400b,
0x506b,0x506b,0x506b,0x506b,0x506b,0x506b,0x506b,0x506b,
0x404b,0x404b,0x404b,0x404b,0x404b,0x404b,0x404b,0x404b,
0x402b,0x402b,0x402b,0x402b,0x402b,0x402b,0x402b,0x402b,
0x380b,0x380b,0x380b,0x380b,0x380b,0x380b,0x380b,0x380b};
/* VLC lengths up to 6 bits, 4 <= nC < 8 */
static const u16 coeffToken4_0[64] = {
0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,
0x1806,0x3846,0x3826,0x1006,0x4866,0x3046,0x3026,0x0806,
0x2825,0x2825,0x2845,0x2845,0x2025,0x2025,0x2045,0x2045,
0x1825,0x1825,0x4065,0x4065,0x1845,0x1845,0x1025,0x1025,
0x3864,0x3864,0x3864,0x3864,0x3064,0x3064,0x3064,0x3064,
0x2864,0x2864,0x2864,0x2864,0x2064,0x2064,0x2064,0x2064,
0x1864,0x1864,0x1864,0x1864,0x1044,0x1044,0x1044,0x1044,
0x0824,0x0824,0x0824,0x0824,0x0004,0x0004,0x0004,0x0004};
/* VLC lengths up to 10 bits, 4 <= nC < 8 */
static const u16 coeffToken4_1[128] = {
0x0000,0x800a,0x806a,0x804a,0x802a,0x780a,0x786a,0x784a,
0x782a,0x700a,0x706a,0x704a,0x702a,0x680a,0x6829,0x6829,
0x6009,0x6009,0x6849,0x6849,0x6029,0x6029,0x5809,0x5809,
0x6869,0x6869,0x6049,0x6049,0x5829,0x5829,0x5009,0x5009,
0x6068,0x6068,0x6068,0x6068,0x5848,0x5848,0x5848,0x5848,
0x5028,0x5028,0x5028,0x5028,0x4808,0x4808,0x4808,0x4808,
0x5868,0x5868,0x5868,0x5868,0x5048,0x5048,0x5048,0x5048,
0x4828,0x4828,0x4828,0x4828,0x4008,0x4008,0x4008,0x4008,
0x3807,0x3807,0x3807,0x3807,0x3807,0x3807,0x3807,0x3807,
0x3007,0x3007,0x3007,0x3007,0x3007,0x3007,0x3007,0x3007,
0x4847,0x4847,0x4847,0x4847,0x4847,0x4847,0x4847,0x4847,
0x2807,0x2807,0x2807,0x2807,0x2807,0x2807,0x2807,0x2807,
0x5067,0x5067,0x5067,0x5067,0x5067,0x5067,0x5067,0x5067,
0x4047,0x4047,0x4047,0x4047,0x4047,0x4047,0x4047,0x4047,
0x4027,0x4027,0x4027,0x4027,0x4027,0x4027,0x4027,0x4027,
0x2007,0x2007,0x2007,0x2007,0x2007,0x2007,0x2007,0x2007};
/* fixed 6 bit length VLC, nC <= 8 */
static const u16 coeffToken8[64] = {
0x0806,0x0826,0x0000,0x0006,0x1006,0x1026,0x1046,0x0000,
0x1806,0x1826,0x1846,0x1866,0x2006,0x2026,0x2046,0x2066,
0x2806,0x2826,0x2846,0x2866,0x3006,0x3026,0x3046,0x3066,
0x3806,0x3826,0x3846,0x3866,0x4006,0x4026,0x4046,0x4066,
0x4806,0x4826,0x4846,0x4866,0x5006,0x5026,0x5046,0x5066,
0x5806,0x5826,0x5846,0x5866,0x6006,0x6026,0x6046,0x6066,
0x6806,0x6826,0x6846,0x6866,0x7006,0x7026,0x7046,0x7066,
0x7806,0x7826,0x7846,0x7866,0x8006,0x8026,0x8046,0x8066};
/* VLC lengths up to 3 bits, nC == -1 */
static const u16 coeffTokenMinus1_0[8] = {
0x0000,0x1043,0x0002,0x0002,0x0821,0x0821,0x0821,0x0821};
/* VLC lengths up to 8 bits, nC == -1 */
static const u16 coeffTokenMinus1_1[32] = {
0x2067,0x2067,0x2048,0x2028,0x1847,0x1847,0x1827,0x1827,
0x2006,0x2006,0x2006,0x2006,0x1806,0x1806,0x1806,0x1806,
0x1006,0x1006,0x1006,0x1006,0x1866,0x1866,0x1866,0x1866,
0x1026,0x1026,0x1026,0x1026,0x0806,0x0806,0x0806,0x0806};
/* VLC tables for total_zeros. One table containing longer code, totalZeros_1,
* has been broken into two separate tables. Table elements have the
* following structure:
* [4 bits for info] [4 bits for VLC length] */
/* VLC lengths up to 5 bits */
static const u8 totalZeros_1_0[32] = {
0x00,0x00,0x65,0x55,0x44,0x44,0x34,0x34,
0x23,0x23,0x23,0x23,0x13,0x13,0x13,0x13,
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01};
/* VLC lengths up to 9 bits */
static const u8 totalZeros_1_1[32] = {
0x00,0xf9,0xe9,0xd9,0xc8,0xc8,0xb8,0xb8,
0xa7,0xa7,0xa7,0xa7,0x97,0x97,0x97,0x97,
0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,
0x76,0x76,0x76,0x76,0x76,0x76,0x76,0x76};
static const u8 totalZeros_2[64] = {
0xe6,0xd6,0xc6,0xb6,0xa5,0xa5,0x95,0x95,
0x84,0x84,0x84,0x84,0x74,0x74,0x74,0x74,
0x64,0x64,0x64,0x64,0x54,0x54,0x54,0x54,
0x43,0x43,0x43,0x43,0x43,0x43,0x43,0x43,
0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33,
0x23,0x23,0x23,0x23,0x23,0x23,0x23,0x23,
0x13,0x13,0x13,0x13,0x13,0x13,0x13,0x13,
0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03};
static const u8 totalZeros_3[64] = {
0xd6,0xb6,0xc5,0xc5,0xa5,0xa5,0x95,0x95,
0x84,0x84,0x84,0x84,0x54,0x54,0x54,0x54,
0x44,0x44,0x44,0x44,0x04,0x04,0x04,0x04,
0x73,0x73,0x73,0x73,0x73,0x73,0x73,0x73,
0x63,0x63,0x63,0x63,0x63,0x63,0x63,0x63,
0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33,
0x23,0x23,0x23,0x23,0x23,0x23,0x23,0x23,
0x13,0x13,0x13,0x13,0x13,0x13,0x13,0x13};
static const u8 totalZeros_4[32] = {
0xc5,0xb5,0xa5,0x05,0x94,0x94,0x74,0x74,
0x34,0x34,0x24,0x24,0x83,0x83,0x83,0x83,
0x63,0x63,0x63,0x63,0x53,0x53,0x53,0x53,
0x43,0x43,0x43,0x43,0x13,0x13,0x13,0x13};
static const u8 totalZeros_5[32] = {
0xb5,0x95,0xa4,0xa4,0x84,0x84,0x24,0x24,
0x14,0x14,0x04,0x04,0x73,0x73,0x73,0x73,
0x63,0x63,0x63,0x63,0x53,0x53,0x53,0x53,
0x43,0x43,0x43,0x43,0x33,0x33,0x33,0x33};
static const u8 totalZeros_6[64] = {
0xa6,0x06,0x15,0x15,0x84,0x84,0x84,0x84,
0x93,0x93,0x93,0x93,0x93,0x93,0x93,0x93,
0x73,0x73,0x73,0x73,0x73,0x73,0x73,0x73,
0x63,0x63,0x63,0x63,0x63,0x63,0x63,0x63,
0x53,0x53,0x53,0x53,0x53,0x53,0x53,0x53,
0x43,0x43,0x43,0x43,0x43,0x43,0x43,0x43,
0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33,
0x23,0x23,0x23,0x23,0x23,0x23,0x23,0x23};
static const u8 totalZeros_7[64] = {
0x96,0x06,0x15,0x15,0x74,0x74,0x74,0x74,
0x83,0x83,0x83,0x83,0x83,0x83,0x83,0x83,
0x63,0x63,0x63,0x63,0x63,0x63,0x63,0x63,
0x43,0x43,0x43,0x43,0x43,0x43,0x43,0x43,
0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33,
0x23,0x23,0x23,0x23,0x23,0x23,0x23,0x23,
0x52,0x52,0x52,0x52,0x52,0x52,0x52,0x52,
0x52,0x52,0x52,0x52,0x52,0x52,0x52,0x52};
static const u8 totalZeros_8[64] = {
0x86,0x06,0x25,0x25,0x14,0x14,0x14,0x14,
0x73,0x73,0x73,0x73,0x73,0x73,0x73,0x73,
0x63,0x63,0x63,0x63,0x63,0x63,0x63,0x63,
0x33,0x33,0x33,0x33,0x33,0x33,0x33,0x33,
0x52,0x52,0x52,0x52,0x52,0x52,0x52,0x52,
0x52,0x52,0x52,0x52,0x52,0x52,0x52,0x52,
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42};
static const u8 totalZeros_9[64] = {
0x16,0x06,0x75,0x75,0x24,0x24,0x24,0x24,
0x53,0x53,0x53,0x53,0x53,0x53,0x53,0x53,
0x62,0x62,0x62,0x62,0x62,0x62,0x62,0x62,
0x62,0x62,0x62,0x62,0x62,0x62,0x62,0x62,
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
0x32,0x32,0x32,0x32,0x32,0x32,0x32,0x32,
0x32,0x32,0x32,0x32,0x32,0x32,0x32,0x32};
static const u8 totalZeros_10[32] = {
0x15,0x05,0x64,0x64,0x23,0x23,0x23,0x23,
0x52,0x52,0x52,0x52,0x52,0x52,0x52,0x52,
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
0x32,0x32,0x32,0x32,0x32,0x32,0x32,0x32};
static const u8 totalZeros_11[16] = {
0x04,0x14,0x23,0x23,0x33,0x33,0x53,0x53,
0x41,0x41,0x41,0x41,0x41,0x41,0x41,0x41};
static const u8 totalZeros_12[16] = {
0x04,0x14,0x43,0x43,0x22,0x22,0x22,0x22,
0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31};
static const u8 totalZeros_13[8] = {0x03,0x13,0x32,0x32,0x21,0x21,0x21,0x21};
static const u8 totalZeros_14[4] = {0x02,0x12,0x21,0x21};
/* VLC tables for run_before. Table elements have the following structure:
* [4 bits for info] [4bits for VLC length]
*/
static const u8 runBefore_6[8] = {0x13,0x23,0x43,0x33,0x63,0x53,0x02,0x02};
static const u8 runBefore_5[8] = {0x53,0x43,0x33,0x23,0x12,0x12,0x02,0x02};
static const u8 runBefore_4[8] = {0x43,0x33,0x22,0x22,0x12,0x12,0x02,0x02};
static const u8 runBefore_3[4] = {0x32,0x22,0x12,0x02};
static const u8 runBefore_2[4] = {0x22,0x12,0x01,0x01};
static const u8 runBefore_1[2] = {0x11,0x01};
/* following four macros are used to handle stream buffer "cache" in the CAVLC
* decoding function */
/* macro to initialize stream buffer cache, fills the buffer (32 bits) */
#define BUFFER_INIT(value, bits) \
{ \
bits = 32; \
value = h264bsdShowBits32(pStrmData); \
}
/* macro to read numBits bits from the buffer, bits will be written to
* outVal. Refills the buffer if not enough bits left */
#define BUFFER_SHOW(value, bits, outVal, numBits) \
{ \
if (bits < (numBits)) \
{ \
if(h264bsdFlushBits(pStrmData,32-bits) == END_OF_STREAM) \
return(HANTRO_NOK); \
value = h264bsdShowBits32(pStrmData); \
bits = 32; \
} \
(outVal) = value >> (32 - (numBits)); \
}
/* macro to flush numBits bits from the buffer */
#define BUFFER_FLUSH(value, bits, numBits) \
{ \
value <<= (numBits); \
bits -= (numBits); \
}
/* macro to read and flush numBits bits from the buffer, bits will be written
* to outVal. Refills the buffer if not enough bits left */
#define BUFFER_GET(value, bits, outVal, numBits) \
{ \
if (bits < (numBits)) \
{ \
if(h264bsdFlushBits(pStrmData,32-bits) == END_OF_STREAM) \
return(HANTRO_NOK); \
value = h264bsdShowBits32(pStrmData); \
bits = 32; \
} \
(outVal) = value >> (32 - (numBits)); \
value <<= (numBits); \
bits -= (numBits); \
}
/*------------------------------------------------------------------------------
4. Local function prototypes
------------------------------------------------------------------------------*/
static u32 DecodeCoeffToken(u32 bits, u32 nc);
static u32 DecodeLevelPrefix(u32 bits);
static u32 DecodeTotalZeros(u32 bits, u32 totalCoeff, u32 isChromaDC);
static u32 DecodeRunBefore(u32 bits,u32 zerosLeft);
/*------------------------------------------------------------------------------
Function: DecodeCoeffToken
Functional description:
Function to decode coeff_token information field from the stream.
Inputs:
u32 bits next 16 stream bits
u32 nc nC, see standard for details
Outputs:
u32 information field (11 bits for value, 5 bits for length)
------------------------------------------------------------------------------*/
u32 DecodeCoeffToken(u32 bits, u32 nc)
{
/* Variables */
u32 value;
/* Code */
/* standard defines that nc for decoding of chroma dc coefficients is -1,
* represented by u32 here -> -1 maps to 2^32 - 1 */
ASSERT(nc <= 16 || nc == (u32)(-1));
if (nc < 2)
{
if (bits >= 0x8000)
{
value = 0x0001;
}
else if (bits >= 0x0C00)
value = coeffToken0_0[bits >> 10];
else if (bits >= 0x0100)
value = coeffToken0_1[bits >> 6];
else if (bits >= 0x0020)
value = coeffToken0_2[(bits>>2)-8];
else
value = coeffToken0_3[bits];
}
else if (nc < 4)
{
if (bits >= 0x8000)
{
value = bits & 0x4000 ? 0x0002 : 0x0822;
}
else if (bits >= 0x1000)
value = coeffToken2_0[bits >> 10];
else if (bits >= 0x0200)
value = coeffToken2_1[bits >> 7];
else
value = coeffToken2_2[bits>>2];
}
else if (nc < 8)
{
value = coeffToken4_0[bits >> 10];
if (!value)
value = coeffToken4_1[bits>>6];
}
else if (nc <= 16)
{
value = coeffToken8[bits>>10];
}
else
{
value = coeffTokenMinus1_0[bits >> 13];
if (!value)
value = coeffTokenMinus1_1[bits>>8];
}
return(value);
}
/*------------------------------------------------------------------------------
Function: DecodeLevelPrefix
Functional description:
Function to decode level_prefix information field from the stream
Inputs:
u32 bits next 16 stream bits
Outputs:
u32 level_prefix information field or VLC_NOT_FOUND
------------------------------------------------------------------------------*/
u32 DecodeLevelPrefix(u32 bits)
{
/* Variables */
u32 numZeros;
/* Code */
if (bits >= 0x8000)
numZeros = 0;
else if (bits >= 0x4000)
numZeros = 1;
else if (bits >= 0x2000)
numZeros = 2;
else if (bits >= 0x1000)
numZeros = 3;
else if (bits >= 0x0800)
numZeros = 4;
else if (bits >= 0x0400)
numZeros = 5;
else if (bits >= 0x0200)
numZeros = 6;
else if (bits >= 0x0100)
numZeros = 7;
else if (bits >= 0x0080)
numZeros = 8;
else if (bits >= 0x0040)
numZeros = 9;
else if (bits >= 0x0020)
numZeros = 10;
else if (bits >= 0x0010)
numZeros = 11;
else if (bits >= 0x0008)
numZeros = 12;
else if (bits >= 0x0004)
numZeros = 13;
else if (bits >= 0x0002)
numZeros = 14;
else if (bits >= 0x0001)
numZeros = 15;
else /* more than 15 zeros encountered which is an error */
return(VLC_NOT_FOUND);
return(numZeros);
}
/*------------------------------------------------------------------------------
Function: DecodeTotalZeros
Functional description:
Function to decode total_zeros information field from the stream
Inputs:
u32 bits next 9 stream bits
u32 totalCoeff total number of coefficients for the block
being decoded
u32 isChromaDC flag to indicate chroma DC block
Outputs:
u32 information field (4 bits value, 4 bits length)
------------------------------------------------------------------------------*/
u32 DecodeTotalZeros(u32 bits, u32 totalCoeff, u32 isChromaDC)
{
/* Variables */
u32 value = 0x0;
/* Code */
ASSERT(totalCoeff);
if (!isChromaDC)
{
ASSERT(totalCoeff < 16);
switch (totalCoeff)
{
case 1:
value = totalZeros_1_0[bits >> 4];
if (!value)
value = totalZeros_1_1[bits];
break;
case 2:
value = totalZeros_2[bits >> 3];
break;
case 3:
value = totalZeros_3[bits >> 3];
break;
case 4:
value = totalZeros_4[bits >> 4];
break;
case 5:
value = totalZeros_5[bits >> 4];
break;
case 6:
value = totalZeros_6[bits >> 3];
break;
case 7:
value = totalZeros_7[bits >> 3];
break;
case 8:
value = totalZeros_8[bits >> 3];
break;
case 9:
value = totalZeros_9[bits >> 3];
break;
case 10:
value = totalZeros_10[bits >> 4];
break;
case 11:
value = totalZeros_11[bits >> 5];
break;
case 12:
value = totalZeros_12[bits >> 5];
break;
case 13:
value = totalZeros_13[bits >> 6];
break;
case 14:
value = totalZeros_14[bits >> 7];
break;
default: /* case 15 */
value = (bits >> 8) ? 0x11 : 0x01;
break;
}
}
else
{
ASSERT(totalCoeff < 4);
bits >>= 6;
if (bits > 3)
value = 0x01;
else
{
if (totalCoeff == 3)
value = 0x11;
else if (bits > 1)
{
value = 0x12;
}
else if (totalCoeff == 2)
value = 0x22;
else if (bits)
value = 0x23;
else
value = 0x33;
}
}
return(value);
}
/*------------------------------------------------------------------------------
Function: DecodeRunBefore
Functional description:
Function to decode run_before information field from the stream
Inputs:
u32 bits next 11 stream bits
u32 zerosLeft number of zeros left for the current block
Outputs:
u32 information field (4 bits value, 4 bits length)
------------------------------------------------------------------------------*/
u32 DecodeRunBefore(u32 bits, u32 zerosLeft)
{
/* Variables */
u32 value = 0x0;
/* Code */
switch (zerosLeft)
{
case 1:
value = runBefore_1[bits>>10];
break;
case 2:
value = runBefore_2[bits>>9];
break;
case 3:
value = runBefore_3[bits>>9];
break;
case 4:
value = runBefore_4[bits>>8];
break;
case 5:
value = runBefore_5[bits>>8];
break;
case 6:
value = runBefore_6[bits>>8];
break;
default:
if (bits >= 0x100)
value = ((7-(bits>>8))<<4)+0x3;
else if (bits >= 0x80)
value = 0x74;
else if (bits >= 0x40)
value = 0x85;
else if (bits >= 0x20)
value = 0x96;
else if (bits >= 0x10)
value = 0xa7;
else if (bits >= 0x8)
value = 0xb8;
else if (bits >= 0x4)
value = 0xc9;
else if (bits >= 0x2)
value = 0xdA;
else if (bits)
value = 0xeB;
if (INFO(value) > zerosLeft)
value = 0;
break;
}
return(value);
}
/*------------------------------------------------------------------------------
Function: DecodeResidualBlockCavlc
Functional description:
Function to decode one CAVLC coded block. This corresponds to
syntax elements residual_block_cavlc() in the standard.
Inputs:
pStrmData pointer to stream data structure
nc nC value
maxNumCoeff maximum number of residual coefficients
Outputs:
coeffLevel stores decoded coefficient levels
Returns:
numCoeffs on bits [4,11] if successful
coeffMap on bits [16,31] if successful, this is bit map
where each bit indicates if the corresponding
coefficient was zero (0) or non-zero (1)
HANTRO_NOK end of stream or error in stream
------------------------------------------------------------------------------*/
u32 h264bsdDecodeResidualBlockCavlc(
strmData_t *pStrmData,
i32 *coeffLevel,
i32 nc,
u32 maxNumCoeff)
{
/* Variables */
u32 i, tmp, totalCoeff, trailingOnes, suffixLength, levelPrefix;
u32 levelSuffix, zerosLeft, bit;
i32 level[16];
u32 run[16];
/* stream "cache" */
u32 bufferValue;
u32 bufferBits;
/* Code */
ASSERT(pStrmData);
ASSERT(coeffLevel);
ASSERT(nc > -2);
ASSERT(maxNumCoeff == 4 || maxNumCoeff == 15 || maxNumCoeff == 16);
ASSERT(VLC_NOT_FOUND != END_OF_STREAM);
/* assume that coeffLevel array has been "cleaned" by caller */
BUFFER_INIT(bufferValue, bufferBits);
/*lint -e774 disable lint warning on always false comparison */
BUFFER_SHOW(bufferValue, bufferBits, bit, 16);
/*lint +e774 */
tmp = DecodeCoeffToken(bit, (u32)nc);
if (!tmp)
return(HANTRO_NOK);
BUFFER_FLUSH(bufferValue, bufferBits, LENGTH_TC(tmp));
totalCoeff = TOTAL_COEFF(tmp);
if (totalCoeff > maxNumCoeff)
return(HANTRO_NOK);
trailingOnes = TRAILING_ONES(tmp);
if (totalCoeff != 0)
{
i = 0;
/* nonzero coefficients: +/- 1 */
if (trailingOnes)
{
BUFFER_GET(bufferValue, bufferBits, bit, trailingOnes);
tmp = 1 << (trailingOnes - 1);
for (; tmp; i++)
{
level[i] = bit & tmp ? -1 : 1;
tmp >>= 1;
}
}
/* other levels */
if (totalCoeff > 10 && trailingOnes < 3)
suffixLength = 1;
else
suffixLength = 0;
for (; i < totalCoeff; i++)
{
BUFFER_SHOW(bufferValue, bufferBits, bit, 16);
levelPrefix = DecodeLevelPrefix(bit);
if (levelPrefix == VLC_NOT_FOUND)
return(HANTRO_NOK);
BUFFER_FLUSH(bufferValue, bufferBits, levelPrefix+1);
if (levelPrefix < 14)
tmp = suffixLength;
else if (levelPrefix == 14)
{
tmp = suffixLength ? suffixLength : 4;
}
else
{
/* setting suffixLength to 1 here corresponds to adding 15
* to levelCode value if levelPrefix == 15 and
* suffixLength == 0 */
if (!suffixLength)
suffixLength = 1;
tmp = 12;
}
if (suffixLength)
levelPrefix <<= suffixLength;
if (tmp)
{
BUFFER_GET(bufferValue, bufferBits, levelSuffix, tmp);
levelPrefix += levelSuffix;
}
tmp = levelPrefix;
if (i == trailingOnes && trailingOnes < 3)
tmp += 2;
level[i] = (tmp+2)>>1;
if (suffixLength == 0)
suffixLength = 1;
if ((level[i] > (3 << (suffixLength - 1))) && suffixLength < 6)
suffixLength++;
if (tmp & 0x1)
level[i] = -level[i];
}
/* zero runs */
if (totalCoeff < maxNumCoeff)
{
BUFFER_SHOW(bufferValue, bufferBits, bit,9);
zerosLeft = DecodeTotalZeros(bit, totalCoeff,
(u32)(maxNumCoeff == 4));
if (!zerosLeft)
return(HANTRO_NOK);
BUFFER_FLUSH(bufferValue, bufferBits, LENGTH(zerosLeft));
zerosLeft = INFO(zerosLeft);
}
else
zerosLeft = 0;
for (i = 0; i < totalCoeff - 1; i++)
{
if (zerosLeft > 0)
{
BUFFER_SHOW(bufferValue, bufferBits, bit,11);
tmp = DecodeRunBefore(bit, zerosLeft);
if (!tmp)
return(HANTRO_NOK);
BUFFER_FLUSH(bufferValue, bufferBits, LENGTH(tmp));
run[i] = INFO(tmp);
zerosLeft -= run[i]++;
}
else
{
run[i] = 1;
}
}
/* combining level and run, levelSuffix variable used to hold coeffMap,
* i.e. bit map indicating which coefficients had non-zero value. */
/*lint -esym(771,level,run) level and run are always initialized */
tmp = zerosLeft;
coeffLevel[tmp] = level[totalCoeff-1];
levelSuffix = 1 << tmp;
for (i = totalCoeff-1; i--;)
{
tmp += run[i];
levelSuffix |= 1 << tmp;
coeffLevel[tmp] = level[i];
}
}
else
levelSuffix = 0;
if (h264bsdFlushBits(pStrmData, 32-bufferBits) != HANTRO_OK)
return(HANTRO_NOK);
return((totalCoeff << 4) | (levelSuffix << 16));
}