1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "h264_levels.h"
// H.264 table A-1.
static const H264LevelDescriptor h264_levels[] = {
// Name MaxMBPS MaxBR MinCR
// | level_idc | MaxFS | MaxCPB | MaxMvsPer2Mb
// | | cs3f | | MaxDpbMbs | | MaxVmvR | |
{ "1", 10, 0, 1485, 99, 396, 64, 175, 64, 2, 0 },
{ "1b", 10, 1, 1485, 99, 396, 128, 350, 64, 2, 0 },
{ "1b", 9, 0, 1485, 99, 396, 128, 350, 64, 2, 0 },
{ "1.1", 11, 0, 3000, 396, 900, 192, 500, 128, 2, 0 },
{ "1.2", 12, 0, 6000, 396, 2376, 384, 1000, 128, 2, 0 },
{ "1.3", 13, 0, 11880, 396, 2376, 768, 2000, 128, 2, 0 },
{ "2", 20, 0, 11880, 396, 2376, 2000, 2000, 128, 2, 0 },
{ "2.1", 21, 0, 19800, 792, 4752, 4000, 4000, 256, 2, 0 },
{ "2.2", 22, 0, 20250, 1620, 8100, 4000, 4000, 256, 2, 0 },
{ "3", 30, 0, 40500, 1620, 8100, 10000, 10000, 256, 2, 32 },
{ "3.1", 31, 0, 108000, 3600, 18000, 14000, 14000, 512, 4, 16 },
{ "3.2", 32, 0, 216000, 5120, 20480, 20000, 20000, 512, 4, 16 },
{ "4", 40, 0, 245760, 8192, 32768, 20000, 25000, 512, 4, 16 },
{ "4.1", 41, 0, 245760, 8192, 32768, 50000, 62500, 512, 2, 16 },
{ "4.2", 42, 0, 522240, 8704, 34816, 50000, 62500, 512, 2, 16 },
{ "5", 50, 0, 589824, 22080, 110400, 135000, 135000, 512, 2, 16 },
{ "5.1", 51, 0, 983040, 36864, 184320, 240000, 240000, 512, 2, 16 },
{ "5.2", 52, 0, 2073600, 36864, 184320, 240000, 240000, 512, 2, 16 },
{ "6", 60, 0, 4177920, 139264, 696320, 240000, 240000, 8192, 2, 16 },
{ "6.1", 61, 0, 8355840, 139264, 696320, 480000, 480000, 8192, 2, 16 },
{ "6.2", 62, 0, 16711680, 139264, 696320, 800000, 800000, 8192, 2, 16 },
};
// H.264 table A-2 plus values from A-1.
static const struct {
int profile_idc;
int cpb_br_vcl_factor;
int cpb_br_nal_factor;
} h264_br_factors[] = {
{ 66, 1000, 1200 },
{ 77, 1000, 1200 },
{ 88, 1000, 1200 },
{ 100, 1250, 1500 },
{ 110, 3000, 3600 },
{ 122, 4000, 4800 },
{ 244, 4000, 4800 },
{ 44, 4000, 4800 },
};
// We are only ever interested in the NAL bitrate factor.
static int h264_get_br_factor(int profile_idc)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(h264_br_factors); i++) {
if (h264_br_factors[i].profile_idc == profile_idc)
return h264_br_factors[i].cpb_br_nal_factor;
}
// Default to the non-high profile value if not specified.
return 1200;
}
const H264LevelDescriptor *ff_h264_get_level(int level_idc,
int constraint_set3_flag)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(h264_levels); i++) {
if (h264_levels[i].level_idc == level_idc &&
h264_levels[i].constraint_set3_flag == constraint_set3_flag)
return &h264_levels[i];
}
return NULL;
}
const H264LevelDescriptor *ff_h264_guess_level(int profile_idc,
int64_t bitrate,
int width, int height,
int max_dec_frame_buffering)
{
int width_mbs = (width + 15) / 16;
int height_mbs = (height + 15) / 16;
int no_cs3f = !(profile_idc == 66 ||
profile_idc == 77 ||
profile_idc == 88);
int i;
for (i = 0; i < FF_ARRAY_ELEMS(h264_levels); i++) {
const H264LevelDescriptor *level = &h264_levels[i];
if (level->constraint_set3_flag && no_cs3f)
continue;
if (bitrate > level->max_br * h264_get_br_factor(profile_idc))
continue;
if (width_mbs * height_mbs > level->max_fs)
continue;
if (width_mbs * width_mbs > 8 * level->max_fs)
continue;
if (height_mbs * height_mbs > 8 * level->max_fs)
continue;
if (width_mbs && height_mbs) {
int max_dpb_frames =
FFMIN(level->max_dpb_mbs / (width_mbs * height_mbs), 16);
if (max_dec_frame_buffering > max_dpb_frames)
continue;
}
return level;
}
// No usable levels found - frame is too big or bitrate is too high.
return NULL;
}
|
