• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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
40 static 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  */
59 typedef 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 
69 typedef 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 
82 typedef 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 
95 int 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  */
104 int 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  */
111 int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
112                                   int left_samples_available,
113                                   int mode, int is_chroma);
114 
115 int 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 
119 int 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 
123 int 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 
pack16to32(unsigned a,unsigned b)127 static 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