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
154
155
156
157
158
159
160
161
162
163
164
165
|
/*
* Common AAC and AC-3 parser
* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2003 Michael Niedermayer
*
* 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 "config_components.h"
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "parser.h"
#include "aac_ac3_parser.h"
#include "ac3_parser_internal.h"
#include "adts_header.h"
int ff_aac_ac3_parse(AVCodecParserContext *s1,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
AACAC3ParseContext *s = s1->priv_data;
ParseContext *pc = &s->pc;
int len, i;
int new_frame_start;
int got_frame = 0;
if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
i = buf_size;
got_frame = 1;
} else {
get_next:
i=END_NOT_FOUND;
if(s->remaining_size <= buf_size){
if(s->remaining_size && !s->need_next_header){
i= s->remaining_size;
s->remaining_size = 0;
}else{ //we need a header first
len=0;
for(i=s->remaining_size; i<buf_size; i++){
s->state = (s->state<<8) + buf[i];
if((len=s->sync(s->state, &s->need_next_header, &new_frame_start)))
break;
}
if(len<=0){
i=END_NOT_FOUND;
}else{
got_frame = 1;
s->state=0;
i-= s->header_size -1;
s->remaining_size = len;
if(!new_frame_start || pc->index+i<=0){
s->remaining_size += i;
goto get_next;
}
else if (i < 0) {
s->remaining_size += i;
}
}
}
}
if(ff_combine_frame(pc, i, &buf, &buf_size)<0){
s->remaining_size -= FFMIN(s->remaining_size, buf_size);
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
if (got_frame) {
int bit_rate;
/* Due to backwards compatible HE-AAC the sample rate, channel count,
and total number of samples found in an AAC ADTS header are not
reliable. Bit rate is still accurate because the total frame
duration in seconds is still correct (as is the number of bits in
the frame). */
if (avctx->codec_id != AV_CODEC_ID_AAC) {
#if CONFIG_AC3_PARSER
AC3HeaderInfo hdr, *phrd = &hdr;
int offset = ff_ac3_find_syncword(buf, buf_size);
if (offset < 0)
return i;
buf += offset;
buf_size -= offset;
while (buf_size > 0) {
int ret = avpriv_ac3_parse_header(&phrd, buf, buf_size);
if (ret < 0 || hdr.frame_size > buf_size)
return i;
if (buf_size > hdr.frame_size) {
buf += hdr.frame_size;
buf_size -= hdr.frame_size;
continue;
}
/* Check for false positives since the syncword is not enough.
See section 6.1.2 of A/52. */
if (av_crc(s->crc_ctx, 0, buf + 2, hdr.frame_size - 2))
return i;
break;
}
avctx->sample_rate = hdr.sample_rate;
if (hdr.bitstream_id > 10)
avctx->codec_id = AV_CODEC_ID_EAC3;
if (!CONFIG_EAC3_DECODER || avctx->codec_id != AV_CODEC_ID_EAC3) {
av_channel_layout_uninit(&avctx->ch_layout);
if (hdr.channel_layout) {
av_channel_layout_from_mask(&avctx->ch_layout, hdr.channel_layout);
} else {
avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
avctx->ch_layout.nb_channels = hdr.channels;
}
}
s1->duration = hdr.num_blocks * 256;
avctx->audio_service_type = hdr.bitstream_mode;
if (hdr.bitstream_mode == 0x7 && hdr.channels > 1)
avctx->audio_service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE;
bit_rate = hdr.bit_rate;
#endif
} else {
#if CONFIG_AAC_PARSER
AACADTSHeaderInfo hdr;
if (buf_size < AV_AAC_ADTS_HEADER_SIZE ||
ff_adts_header_parse_buf(buf, &hdr) < 0)
return i;
bit_rate = hdr.bit_rate;
#endif
}
/* Calculate the average bit rate */
s->frame_number++;
if (!CONFIG_EAC3_DECODER || avctx->codec_id != AV_CODEC_ID_EAC3) {
avctx->bit_rate +=
(bit_rate - avctx->bit_rate) / s->frame_number;
}
}
return i;
}
|
