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
|
/*
* AST muxer
* Copyright (c) 2012 James Almer
*
* 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 "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "ast.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
typedef struct ASTMuxContext {
AVClass *class;
int64_t size;
int64_t samples;
int64_t loopstart;
int64_t loopend;
int fbs;
} ASTMuxContext;
#define CHECK_LOOP(type) \
if (ast->loop ## type > 0) { \
ast->loop ## type = av_rescale_rnd(ast->loop ## type, enc->sample_rate, 1000, AV_ROUND_DOWN); \
if (ast->loop ## type < 0 || ast->loop ## type > UINT_MAX) { \
av_log(s, AV_LOG_ERROR, "Invalid loop" #type " value\n"); \
return AVERROR(EINVAL); \
} \
}
static int ast_write_header(AVFormatContext *s)
{
ASTMuxContext *ast = s->priv_data;
AVIOContext *pb = s->pb;
AVCodecContext *enc;
unsigned int codec_tag;
if (s->nb_streams == 1) {
enc = s->streams[0]->codec;
} else {
av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
return AVERROR(EINVAL);
}
if (enc->codec_id == AV_CODEC_ID_ADPCM_AFC) {
av_log(s, AV_LOG_ERROR, "muxing ADPCM AFC is not implemented\n");
return AVERROR_PATCHWELCOME;
}
codec_tag = ff_codec_get_tag(ff_codec_ast_tags, enc->codec_id);
if (!codec_tag) {
av_log(s, AV_LOG_ERROR, "unsupported codec\n");
return AVERROR(EINVAL);
}
if (ast->loopend > 0 && ast->loopstart >= ast->loopend) {
av_log(s, AV_LOG_ERROR, "loopend can't be less or equal to loopstart\n");
return AVERROR(EINVAL);
}
/* Convert milliseconds to samples */
CHECK_LOOP(start)
CHECK_LOOP(end)
ffio_wfourcc(pb, "STRM");
ast->size = avio_tell(pb);
avio_wb32(pb, 0); /* File size minus header */
avio_wb16(pb, codec_tag);
avio_wb16(pb, 16); /* Bit depth */
avio_wb16(pb, enc->channels);
avio_wb16(pb, 0); /* Loop flag */
avio_wb32(pb, enc->sample_rate);
ast->samples = avio_tell(pb);
avio_wb32(pb, 0); /* Number of samples */
avio_wb32(pb, 0); /* Loopstart */
avio_wb32(pb, 0); /* Loopend */
avio_wb32(pb, 0); /* Size of first block */
/* Unknown */
avio_wb32(pb, 0);
avio_wl32(pb, 0x7F);
avio_wb64(pb, 0);
avio_wb64(pb, 0);
avio_wb32(pb, 0);
avio_flush(pb);
return 0;
}
static int ast_write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
ASTMuxContext *ast = s->priv_data;
AVCodecContext *enc = s->streams[0]->codec;
int size = pkt->size / enc->channels;
if (enc->frame_number == 1)
ast->fbs = size;
ffio_wfourcc(pb, "BLCK");
avio_wb32(pb, size); /* Block size */
/* padding */
avio_wb64(pb, 0);
avio_wb64(pb, 0);
avio_wb64(pb, 0);
avio_write(pb, pkt->data, pkt->size);
return 0;
}
static int ast_write_trailer(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
ASTMuxContext *ast = s->priv_data;
AVCodecContext *enc = s->streams[0]->codec;
int64_t file_size = avio_tell(pb);
int64_t samples = (file_size - 64 - (32 * enc->frame_number)) / enc->block_align; /* PCM_S16BE_PLANAR */
av_log(s, AV_LOG_DEBUG, "total samples: %"PRId64"\n", samples);
if (s->pb->seekable) {
/* Number of samples */
avio_seek(pb, ast->samples, SEEK_SET);
avio_wb32(pb, samples);
/* Loopstart if provided */
if (ast->loopstart > 0) {
if (ast->loopstart >= samples) {
av_log(s, AV_LOG_WARNING, "Loopstart value is out of range and will be ignored\n");
ast->loopstart = -1;
avio_skip(pb, 4);
} else
avio_wb32(pb, ast->loopstart);
} else
avio_skip(pb, 4);
/* Loopend if provided. Otherwise number of samples again */
if (ast->loopend && ast->loopstart >= 0) {
if (ast->loopend > samples) {
av_log(s, AV_LOG_WARNING, "Loopend value is out of range and will be ignored\n");
ast->loopend = samples;
}
avio_wb32(pb, ast->loopend);
} else {
avio_wb32(pb, samples);
}
/* Size of first block */
avio_wb32(pb, ast->fbs);
/* File size minus header */
avio_seek(pb, ast->size, SEEK_SET);
avio_wb32(pb, file_size - 64);
/* Loop flag */
if (ast->loopstart >= 0) {
avio_skip(pb, 6);
avio_wb16(pb, 0xFFFF);
}
avio_seek(pb, file_size, SEEK_SET);
avio_flush(pb);
}
return 0;
}
#define OFFSET(obj) offsetof(ASTMuxContext, obj)
static const AVOption options[] = {
{ "loopstart", "Loopstart position in milliseconds.", OFFSET(loopstart), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "loopend", "Loopend position in milliseconds.", OFFSET(loopend), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL },
};
static const AVClass ast_muxer_class = {
.class_name = "AST muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_ast_muxer = {
.name = "ast",
.long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
.extensions = "ast",
.priv_data_size = sizeof(ASTMuxContext),
.audio_codec = AV_CODEC_ID_PCM_S16BE_PLANAR,
.video_codec = AV_CODEC_ID_NONE,
.write_header = ast_write_header,
.write_packet = ast_write_packet,
.write_trailer = ast_write_trailer,
.priv_class = &ast_muxer_class,
.codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0},
};
|
