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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* This bitstream filter splits VP9 superframes into packets containing
* just one frame.
*/
#include <stddef.h>
#include "avcodec.h"
#include "bsf.h"
#include "bitstream.h"
#include "bytestream.h"
typedef struct VP9SFSplitContext {
AVPacket *buffer_pkt;
int nb_frames;
int next_frame;
size_t next_frame_offset;
int sizes[8];
} VP9SFSplitContext;
static int vp9_superframe_split_filter(AVBSFContext *ctx, AVPacket *out)
{
VP9SFSplitContext *s = ctx->priv_data;
AVPacket *in;
int i, j, ret, marker;
int is_superframe = !!s->buffer_pkt;
if (!s->buffer_pkt) {
ret = ff_bsf_get_packet(ctx, &s->buffer_pkt);
if (ret < 0)
return ret;
in = s->buffer_pkt;
marker = in->data[in->size - 1];
if ((marker & 0xe0) == 0xc0) {
int length_size = 1 + ((marker >> 3) & 0x3);
int nb_frames = 1 + (marker & 0x7);
int idx_size = 2 + nb_frames * length_size;
if (in->size >= idx_size && in->data[in->size - idx_size] == marker) {
GetByteContext bc;
int total_size = 0;
bytestream2_init(&bc, in->data + in->size + 1 - idx_size,
nb_frames * length_size);
for (i = 0; i < nb_frames; i++) {
int frame_size = 0;
for (j = 0; j < length_size; j++)
frame_size |= bytestream2_get_byte(&bc) << (j * 8);
total_size += frame_size;
if (total_size > in->size - idx_size) {
av_log(ctx, AV_LOG_ERROR,
"Invalid frame size in a superframe: %d\n", frame_size);
ret = AVERROR(EINVAL);
goto fail;
}
s->sizes[i] = frame_size;
}
s->nb_frames = nb_frames;
s->next_frame = 0;
s->next_frame_offset = 0;
is_superframe = 1;
}
}
}
if (is_superframe) {
BitstreamContext bc;
int profile, invisible = 0;
ret = av_packet_ref(out, s->buffer_pkt);
if (ret < 0)
goto fail;
out->data += s->next_frame_offset;
out->size = s->sizes[s->next_frame];
s->next_frame_offset += out->size;
s->next_frame++;
if (s->next_frame >= s->nb_frames)
av_packet_free(&s->buffer_pkt);
ret = bitstream_init8(&bc, out->data, out->size);
if (ret < 0)
goto fail;
bitstream_read(&bc, 2); // frame_marker
profile = bitstream_read(&bc, 1);
profile |= bitstream_read(&bc, 1) << 1;
if (profile == 3)
bitstream_read(&bc, 1);
if (!bitstream_read(&bc, 1)) {
bitstream_read(&bc, 1);
invisible = !bitstream_read(&bc, 1);
}
if (invisible)
out->pts = AV_NOPTS_VALUE;
} else {
av_packet_move_ref(out, s->buffer_pkt);
av_packet_free(&s->buffer_pkt);
}
return 0;
fail:
av_packet_free(&s->buffer_pkt);
return ret;
}
static void vp9_superframe_split_flush(AVBSFContext *ctx)
{
VP9SFSplitContext *s = ctx->priv_data;
av_packet_free(&s->buffer_pkt);
}
static void vp9_superframe_split_uninit(AVBSFContext *ctx)
{
VP9SFSplitContext *s = ctx->priv_data;
av_packet_free(&s->buffer_pkt);
}
const AVBitStreamFilter ff_vp9_superframe_split_bsf = {
.name = "vp9_superframe_split",
.priv_data_size = sizeof(VP9SFSplitContext),
.flush = vp9_superframe_split_flush,
.close = vp9_superframe_split_uninit,
.filter = vp9_superframe_split_filter,
.codec_ids = (const enum AVCodecID []){ AV_CODEC_ID_VP9, AV_CODEC_ID_NONE },
};
|
