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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/*
* SMPTE 302M decoder
* Copyright (c) 2008 Laurent Aimar <fenrir@videolan.org>
* Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
*
* 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 "libavutil/channel_layout.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "libavutil/log.h"
#include "libavutil/reverse.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#define AES3_HEADER_LEN 4
typedef struct S302Context {
AVClass *class;
int non_pcm_mode;
} S302Context;
static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
int buf_size)
{
uint32_t h;
int frame_size, channels, bits;
if (buf_size <= AES3_HEADER_LEN) {
av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
return AVERROR_INVALIDDATA;
}
/*
* AES3 header :
* size: 16
* number channels 2
* channel_id 8
* bits per samples 2
* alignments 4
*/
h = AV_RB32(buf);
frame_size = (h >> 16) & 0xffff;
channels = ((h >> 14) & 0x0003) * 2 + 2;
bits = ((h >> 4) & 0x0003) * 4 + 16;
if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
return AVERROR_INVALIDDATA;
}
/* Set output properties */
avctx->bits_per_raw_sample = bits;
if (bits > 16)
avctx->sample_fmt = AV_SAMPLE_FMT_S32;
else
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
av_channel_layout_uninit(&avctx->ch_layout);
switch(channels) {
case 2:
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
break;
case 4:
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD;
break;
case 6:
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1_BACK;
break;
case 8:
av_channel_layout_from_mask(&avctx->ch_layout,
AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX);
break;
default:
avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
avctx->ch_layout.nb_channels = channels;
break;
}
return frame_size;
}
static int s302m_decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *avpkt)
{
S302Context *s = avctx->priv_data;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int block_size, ret, channels;
int i;
int non_pcm_data_type = -1;
int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
if (frame_size < 0)
return frame_size;
buf_size -= AES3_HEADER_LEN;
buf += AES3_HEADER_LEN;
/* get output buffer */
block_size = (avctx->bits_per_raw_sample + 4) / 4;
channels = avctx->ch_layout.nb_channels;
frame->nb_samples = 2 * (buf_size / block_size) / channels;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
avctx->bit_rate = 48000 * channels * (avctx->bits_per_raw_sample + 4) +
32 * 48000 / frame->nb_samples;
buf_size = (frame->nb_samples * channels / 2) * block_size;
if (avctx->bits_per_raw_sample == 24) {
uint32_t *o = (uint32_t *)frame->data[0];
for (; buf_size > 6; buf_size -= 7) {
*o++ = ((unsigned)ff_reverse[buf[2]] << 24) |
(ff_reverse[buf[1]] << 16) |
(ff_reverse[buf[0]] << 8);
*o++ = ((unsigned)ff_reverse[buf[6] & 0xf0] << 28) |
(ff_reverse[buf[5]] << 20) |
(ff_reverse[buf[4]] << 12) |
(ff_reverse[buf[3] & 0x0f] << 4);
buf += 7;
}
o = (uint32_t *)frame->data[0];
if (channels == 2)
for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
if (o[i] || o[i+1] || o[i+2] || o[i+3])
break;
if (o[i+4] == 0x96F87200U && o[i+5] == 0xA54E1F00) {
non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
break;
}
}
} else if (avctx->bits_per_raw_sample == 20) {
uint32_t *o = (uint32_t *)frame->data[0];
for (; buf_size > 5; buf_size -= 6) {
*o++ = ((unsigned)ff_reverse[buf[2] & 0xf0] << 28) |
(ff_reverse[buf[1]] << 20) |
(ff_reverse[buf[0]] << 12);
*o++ = ((unsigned)ff_reverse[buf[5] & 0xf0] << 28) |
(ff_reverse[buf[4]] << 20) |
(ff_reverse[buf[3]] << 12);
buf += 6;
}
o = (uint32_t *)frame->data[0];
if (channels == 2)
for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
if (o[i] || o[i+1] || o[i+2] || o[i+3])
break;
if (o[i+4] == 0x6F872000U && o[i+5] == 0x54E1F000) {
non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
break;
}
}
} else {
uint16_t *o = (uint16_t *)frame->data[0];
for (; buf_size > 4; buf_size -= 5) {
*o++ = (ff_reverse[buf[1]] << 8) |
ff_reverse[buf[0]];
*o++ = (ff_reverse[buf[4] & 0xf0] << 12) |
(ff_reverse[buf[3]] << 4) |
(ff_reverse[buf[2]] >> 4);
buf += 5;
}
o = (uint16_t *)frame->data[0];
if (channels == 2)
for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
if (o[i] || o[i+1] || o[i+2] || o[i+3])
break;
if (o[i+4] == 0xF872U && o[i+5] == 0x4E1F) {
non_pcm_data_type = (o[i+6] & 0x1F);
break;
}
}
}
if (non_pcm_data_type != -1) {
if (s->non_pcm_mode == 3) {
av_log(avctx, AV_LOG_ERROR,
"S302 non PCM mode with data type %d not supported\n",
non_pcm_data_type);
return AVERROR_PATCHWELCOME;
}
if (s->non_pcm_mode & 1) {
return avpkt->size;
}
}
avctx->sample_rate = 48000;
*got_frame_ptr = 1;
return avpkt->size;
}
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_DECODING_PARAM
static const AVOption s302m_options[] = {
{"non_pcm_mode", "Chooses what to do with NON-PCM", offsetof(S302Context, non_pcm_mode), AV_OPT_TYPE_INT, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
{"copy" , "Pass NON-PCM through unchanged" , 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 3, FLAGS, "non_pcm_mode"},
{"drop" , "Drop NON-PCM" , 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 3, FLAGS, "non_pcm_mode"},
{"decode_copy" , "Decode if possible else passthrough", 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 3, FLAGS, "non_pcm_mode"},
{"decode_drop" , "Decode if possible else drop" , 0, AV_OPT_TYPE_CONST, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
{NULL}
};
static const AVClass s302m_class = {
.class_name = "SMPTE 302M Decoder",
.item_name = av_default_item_name,
.option = s302m_options,
.version = LIBAVUTIL_VERSION_INT,
};
const FFCodec ff_s302m_decoder = {
.p.name = "s302m",
CODEC_LONG_NAME("SMPTE 302M"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_S302M,
.p.priv_class = &s302m_class,
.priv_data_size = sizeof(S302Context),
FF_CODEC_DECODE_CB(s302m_decode_frame),
.p.capabilities = AV_CODEC_CAP_CHANNEL_CONF |
AV_CODEC_CAP_DR1,
};
|
