1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19/**
20 * @file
21 * H.264 decoder/parser shared code
22 */
23
24#ifndef AVCODEC_H264_PARSE_H
25#define AVCODEC_H264_PARSE_H
26
27#include "config.h"
28
29#include <stdint.h>
30
31#include "libavutil/attributes.h"
32
33#include "get_bits.h"
34#include "h264_ps.h"
35
36#define MB_TYPE_REF0       MB_TYPE_ACPRED // dirty but it fits in 16 bit
37#define MB_TYPE_8x8DCT     0x01000000
38
39// This table must be here because scan8[constant] must be known at compiletime
40static const uint8_t scan8[16 * 3 + 3] = {
41    4 +  1 * 8, 5 +  1 * 8, 4 +  2 * 8, 5 +  2 * 8,
42    6 +  1 * 8, 7 +  1 * 8, 6 +  2 * 8, 7 +  2 * 8,
43    4 +  3 * 8, 5 +  3 * 8, 4 +  4 * 8, 5 +  4 * 8,
44    6 +  3 * 8, 7 +  3 * 8, 6 +  4 * 8, 7 +  4 * 8,
45    4 +  6 * 8, 5 +  6 * 8, 4 +  7 * 8, 5 +  7 * 8,
46    6 +  6 * 8, 7 +  6 * 8, 6 +  7 * 8, 7 +  7 * 8,
47    4 +  8 * 8, 5 +  8 * 8, 4 +  9 * 8, 5 +  9 * 8,
48    6 +  8 * 8, 7 +  8 * 8, 6 +  9 * 8, 7 +  9 * 8,
49    4 + 11 * 8, 5 + 11 * 8, 4 + 12 * 8, 5 + 12 * 8,
50    6 + 11 * 8, 7 + 11 * 8, 6 + 12 * 8, 7 + 12 * 8,
51    4 + 13 * 8, 5 + 13 * 8, 4 + 14 * 8, 5 + 14 * 8,
52    6 + 13 * 8, 7 + 13 * 8, 6 + 14 * 8, 7 + 14 * 8,
53    0 +  0 * 8, 0 +  5 * 8, 0 + 10 * 8
54};
55
56/**
57 * Memory management control operation opcode.
58 */
59typedef enum MMCOOpcode {
60    MMCO_END = 0,
61    MMCO_SHORT2UNUSED,
62    MMCO_LONG2UNUSED,
63    MMCO_SHORT2LONG,
64    MMCO_SET_MAX_LONG,
65    MMCO_RESET,
66    MMCO_LONG,
67} MMCOOpcode;
68
69typedef struct H264PredWeightTable {
70    int use_weight;
71    int use_weight_chroma;
72    int luma_log2_weight_denom;
73    int chroma_log2_weight_denom;
74    int luma_weight_flag[2];    ///< 7.4.3.2 luma_weight_lX_flag
75    int chroma_weight_flag[2];  ///< 7.4.3.2 chroma_weight_lX_flag
76    // The following 2 can be changed to int8_t but that causes a 10 CPU cycles speed loss
77    int luma_weight[48][2][2];
78    int chroma_weight[48][2][2][2];
79    int implicit_weight[48][48][2];
80} H264PredWeightTable;
81
82typedef struct H264POCContext {
83    int poc_lsb;
84    int poc_msb;
85    int delta_poc_bottom;
86    int delta_poc[2];
87    int frame_num;
88    int prev_poc_msb;           ///< poc_msb of the last reference pic for POC type 0
89    int prev_poc_lsb;           ///< poc_lsb of the last reference pic for POC type 0
90    int frame_num_offset;       ///< for POC type 2
91    int prev_frame_num_offset;  ///< for POC type 2
92    int prev_frame_num;         ///< frame_num of the last pic for POC type 1/2
93} H264POCContext;
94
95int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
96                              const int *ref_count, int slice_type_nos,
97                              H264PredWeightTable *pwt,
98                              int picture_structure, void *logctx);
99
100/**
101 * Check if the top & left blocks are available if needed & change the
102 * dc mode so it only uses the available blocks.
103 */
104int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
105                                     int top_samples_available, int left_samples_available);
106
107/**
108 * Check if the top & left blocks are available if needed & change the
109 * dc mode so it only uses the available blocks.
110 */
111int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
112                                  int left_samples_available,
113                                  int mode, int is_chroma);
114
115int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
116                            GetBitContext *gb, const PPS *pps,
117                            int slice_type_nos, int picture_structure, void *logctx);
118
119int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
120                     const SPS *sps, H264POCContext *poc,
121                     int picture_structure, int nal_ref_idc);
122
123int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
124                             int *is_avc, int *nal_length_size,
125                             int err_recognition, void *logctx);
126
127static av_always_inline uint32_t pack16to32(unsigned a, unsigned b)
128{
129#if HAVE_BIGENDIAN
130    return (b & 0xFFFF) + (a << 16);
131#else
132    return (a & 0xFFFF) + (b << 16);
133#endif
134}
135
136#endif /* AVCODEC_H264_PARSE_H */
137