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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 "get_bits.h"
28 #include "h264_ps.h"
29 
30 typedef struct H264PredWeightTable {
31     int use_weight;
32     int use_weight_chroma;
33     int luma_log2_weight_denom;
34     int chroma_log2_weight_denom;
35     int luma_weight_flag[2];    ///< 7.4.3.2 luma_weight_lX_flag
36     int chroma_weight_flag[2];  ///< 7.4.3.2 chroma_weight_lX_flag
37     // The following 2 can be changed to int8_t but that causes a 10 CPU cycles speed loss
38     int luma_weight[48][2][2];
39     int chroma_weight[48][2][2][2];
40     int implicit_weight[48][48][2];
41 } H264PredWeightTable;
42 
43 typedef struct H264POCContext {
44     int poc_lsb;
45     int poc_msb;
46     int delta_poc_bottom;
47     int delta_poc[2];
48     int frame_num;
49     int prev_poc_msb;           ///< poc_msb of the last reference pic for POC type 0
50     int prev_poc_lsb;           ///< poc_lsb of the last reference pic for POC type 0
51     int frame_num_offset;       ///< for POC type 2
52     int prev_frame_num_offset;  ///< for POC type 2
53     int prev_frame_num;         ///< frame_num of the last pic for POC type 1/2
54 } H264POCContext;
55 
56 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
57                               const int *ref_count, int slice_type_nos,
58                               H264PredWeightTable *pwt,
59                               int picture_structure, void *logctx);
60 
61 /**
62  * Check if the top & left blocks are available if needed & change the
63  * dc mode so it only uses the available blocks.
64  */
65 int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
66                                      int top_samples_available, int left_samples_available);
67 
68 /**
69  * Check if the top & left blocks are available if needed & change the
70  * dc mode so it only uses the available blocks.
71  */
72 int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
73                                   int left_samples_available,
74                                   int mode, int is_chroma);
75 
76 int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
77                             GetBitContext *gb, const PPS *pps,
78                             int slice_type_nos, int picture_structure, void *logctx);
79 
80 int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
81                      const SPS *sps, H264POCContext *poc,
82                      int picture_structure, int nal_ref_idc);
83 
84 int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
85                              int *is_avc, int *nal_length_size,
86                              int err_recognition, void *logctx);
87 
88 /**
89  * compute profile from sps
90  */
91 int ff_h264_get_profile(const SPS *sps);
92 
93 #endif /* AVCODEC_H264_PARSE_H */
94