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
|
/*
* LPCM codecs for PCM formats found in Video DVD streams
* Copyright (c) 2018 Paul B Mahol
*
* 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 "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "encode.h"
#include "internal.h"
typedef struct PCMDVDContext {
uint8_t header[3]; // Header added to every frame
int block_size; // Size of a block of samples in bytes
int samples_per_block; // Number of samples per channel per block
int groups_per_block; // Number of 20/24-bit sample groups per block
uint8_t *extra_samples; // Pointer to leftover samples from a frame
int extra_sample_count; // Number of leftover samples in the buffer
} PCMDVDContext;
static av_cold int pcm_dvd_encode_init(AVCodecContext *avctx)
{
PCMDVDContext *s = avctx->priv_data;
int quant, freq, frame_size;
switch (avctx->sample_rate) {
case 48000:
freq = 0;
break;
case 96000:
freq = 1;
break;
}
switch (avctx->sample_fmt) {
case AV_SAMPLE_FMT_S16:
avctx->bits_per_coded_sample = 16;
quant = 0;
break;
case AV_SAMPLE_FMT_S32:
avctx->bits_per_coded_sample = 24;
quant = 2;
break;
}
avctx->bits_per_coded_sample = 16 + quant * 4;
avctx->block_align = avctx->ch_layout.nb_channels * avctx->bits_per_coded_sample / 8;
avctx->bit_rate = avctx->block_align * 8LL * avctx->sample_rate;
if (avctx->bit_rate > 9800000) {
av_log(avctx, AV_LOG_ERROR, "Too big bitrate: reduce sample rate, bitdepth or channels.\n");
return AVERROR(EINVAL);
}
if (avctx->sample_fmt == AV_SAMPLE_FMT_S16) {
s->samples_per_block = 1;
s->block_size = avctx->ch_layout.nb_channels * 2;
frame_size = 2008 / s->block_size;
} else {
switch (avctx->ch_layout.nb_channels) {
case 1:
case 2:
case 4:
/* one group has all the samples needed */
s->block_size = 4 * avctx->bits_per_coded_sample / 8;
s->samples_per_block = 4 / avctx->ch_layout.nb_channels;
s->groups_per_block = 1;
break;
case 8:
/* two groups have all the samples needed */
s->block_size = 8 * avctx->bits_per_coded_sample / 8;
s->samples_per_block = 1;
s->groups_per_block = 2;
break;
default:
/* need avctx->ch_layout.nb_channels groups */
s->block_size = 4 * avctx->ch_layout.nb_channels *
avctx->bits_per_coded_sample / 8;
s->samples_per_block = 4;
s->groups_per_block = avctx->ch_layout.nb_channels;
break;
}
frame_size = FFALIGN(2008 / s->block_size, s->samples_per_block);
}
s->header[0] = 0x0c;
s->header[1] = (quant << 6) | (freq << 4) | (avctx->ch_layout.nb_channels - 1);
s->header[2] = 0x80;
if (!avctx->frame_size)
avctx->frame_size = frame_size;
return 0;
}
static int pcm_dvd_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
const AVFrame *frame, int *got_packet_ptr)
{
PCMDVDContext *s = avctx->priv_data;
int samples = frame->nb_samples * avctx->ch_layout.nb_channels;
int64_t pkt_size = (frame->nb_samples / s->samples_per_block) * s->block_size + 3;
int blocks = (pkt_size - 3) / s->block_size;
const int16_t *src16;
const int32_t *src32;
PutByteContext pb;
int ret;
if ((ret = ff_get_encode_buffer(avctx, avpkt, pkt_size, 0)) < 0)
return ret;
memcpy(avpkt->data, s->header, 3);
src16 = (const int16_t *)frame->data[0];
src32 = (const int32_t *)frame->data[0];
bytestream2_init_writer(&pb, avpkt->data + 3, avpkt->size - 3);
switch (avctx->sample_fmt) {
case AV_SAMPLE_FMT_S16:
do {
bytestream2_put_be16(&pb, *src16++);
} while (--samples);
break;
case AV_SAMPLE_FMT_S32:
if (avctx->ch_layout.nb_channels == 1) {
do {
for (int i = 2; i; i--) {
bytestream2_put_be16(&pb, src32[0] >> 16);
bytestream2_put_be16(&pb, src32[1] >> 16);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
}
} while (--blocks);
} else {
do {
for (int i = s->groups_per_block; i; i--) {
bytestream2_put_be16(&pb, src32[0] >> 16);
bytestream2_put_be16(&pb, src32[1] >> 16);
bytestream2_put_be16(&pb, src32[2] >> 16);
bytestream2_put_be16(&pb, src32[3] >> 16);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
}
} while (--blocks);
}
break;
}
avpkt->pts = frame->pts;
avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
*got_packet_ptr = 1;
return 0;
}
const FFCodec ff_pcm_dvd_encoder = {
.p.name = "pcm_dvd",
.p.long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for DVD media"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_PCM_DVD,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SMALL_LAST_FRAME,
.priv_data_size = sizeof(PCMDVDContext),
.init = pcm_dvd_encode_init,
.encode2 = pcm_dvd_encode_frame,
.p.supported_samplerates = (const int[]) { 48000, 96000, 0},
#if FF_API_OLD_CHANNEL_LAYOUT
.p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
AV_CH_LAYOUT_STEREO,
AV_CH_LAYOUT_5POINT1,
AV_CH_LAYOUT_7POINT1,
0 },
#endif
.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO,
AV_CHANNEL_LAYOUT_STEREO,
AV_CHANNEL_LAYOUT_5POINT1,
AV_CHANNEL_LAYOUT_7POINT1,
{ 0 } },
.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_S32,
AV_SAMPLE_FMT_NONE },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};
|
