FFmpeg
h264.h
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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 common definitions
22  */
23 
24 #ifndef AVCODEC_H264_H
25 #define AVCODEC_H264_H
26 
27 #define QP_MAX_NUM (51 + 6*6) // The maximum supported qp
28 
29 /*
30  * Table 7-1 – NAL unit type codes, syntax element categories, and NAL unit type classes in
31  * T-REC-H.264-201704
32  */
33 enum {
66 };
67 
68 
69 enum {
70  // 7.4.2.1.1: seq_parameter_set_id is in [0, 31].
72  // 7.4.2.2: pic_parameter_set_id is in [0, 255].
74 
75  // A.3: MaxDpbFrames is bounded above by 16.
77  // 7.4.2.1.1: max_num_ref_frames is in [0, MaxDpbFrames], and
78  // each reference frame can have two fields.
80 
81  // 7.4.3.1: modification_of_pic_nums_idc is not equal to 3 at most
82  // num_ref_idx_lN_active_minus1 + 1 times (that is, once for each
83  // possible reference), then equal to 3 once.
85 
86  // 7.4.3.3: in the worst case, we begin with a full short-term
87  // reference picture list. Each picture in turn is moved to the
88  // long-term list (type 3) and then discarded from there (type 2).
89  // Then, we set the length of the long-term list (type 4), mark
90  // the current picture as long-term (type 6) and terminate the
91  // process (type 0).
93 
94  // A.2.1, A.2.3: profiles supporting FMO constrain
95  // num_slice_groups_minus1 to be in [0, 7].
97 
98  // E.2.2: cpb_cnt_minus1 is in [0, 31].
100 
101  // A.3: in table A-1 the highest level allows a MaxFS of 139264.
103  // A.3.1, A.3.2: PicWidthInMbs and PicHeightInMbs are constrained
104  // to be not greater than sqrt(MaxFS * 8). Hence height/width are
105  // bounded above by sqrt(139264 * 8) = 1055.5 macroblocks.
110 };
111 
112 
113 #endif /* AVCODEC_H264_H */