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
|
/*
* IFF (.iff) file demuxer
* Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
*
* 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
*/
/**
* @file iff.c
* IFF file demuxer
* by Jaikrishnan Menon
* for more information on the .iff file format, visit:
* http://wiki.multimedia.cx/index.php?title=IFF
*/
#include "avformat.h"
#define ID_8SVX MKTAG('8','S','V','X')
#define ID_VHDR MKTAG('V','H','D','R')
#define ID_ATAK MKTAG('A','T','A','K')
#define ID_RLSE MKTAG('R','L','S','E')
#define ID_CHAN MKTAG('C','H','A','N')
#define ID_FORM MKTAG('F','O','R','M')
#define ID_ANNO MKTAG('A','N','N','O')
#define ID_AUTH MKTAG('A','U','T','H')
#define ID_CHRS MKTAG('C','H','R','S')
#define ID_COPYRIGHT MKTAG('(','c',')',' ')
#define ID_CSET MKTAG('C','S','E','T')
#define ID_FVER MKTAG('F','V','E','R')
#define ID_NAME MKTAG('N','A','M','E')
#define ID_TEXT MKTAG('T','E','X','T')
#define ID_BODY MKTAG('B','O','D','Y')
#define LEFT 2
#define RIGHT 4
#define STEREO 6
#define PACKET_SIZE 1024
typedef enum {COMP_NONE, COMP_FIB, COMP_EXP} svx8_compression_t;
typedef struct {
uint32_t body_size;
uint32_t sent_bytes;
uint32_t audio_frame_count;
} IffDemuxContext;
static void interleave_stereo(const uint8_t *src, uint8_t *dest, int size)
{
uint8_t *end = dest + size;
size = size>>1;
while(dest < end) {
*dest++ = *src;
*dest++ = *(src+size);
src++;
}
}
static int iff_probe(AVProbeData *p)
{
const uint8_t *d = p->buf;
if ( AV_RL32(d) == ID_FORM &&
AV_RL32(d+8) == ID_8SVX)
return AVPROBE_SCORE_MAX;
return 0;
}
static int iff_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
IffDemuxContext *iff = s->priv_data;
ByteIOContext *pb = s->pb;
AVStream *st;
uint32_t chunk_id, data_size;
int padding, done = 0;
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->channels = 1;
url_fskip(pb, 12);
while(!done && !url_feof(pb)) {
chunk_id = get_le32(pb);
data_size = get_be32(pb);
padding = data_size & 1;
switch(chunk_id) {
case ID_VHDR:
url_fskip(pb, 12);
st->codec->sample_rate = get_be16(pb);
url_fskip(pb, 1);
st->codec->codec_tag = get_byte(pb);
url_fskip(pb, 4);
break;
case ID_BODY:
iff->body_size = data_size;
done = 1;
break;
case ID_CHAN:
st->codec->channels = (get_be32(pb) < 6) ? 1 : 2;
break;
default:
url_fseek(pb, data_size + padding, SEEK_CUR);
break;
}
}
if(!st->codec->sample_rate)
return AVERROR_INVALIDDATA;
av_set_pts_info(st, 32, 1, st->codec->sample_rate);
st->codec->codec_type = CODEC_TYPE_AUDIO;
switch(st->codec->codec_tag) {
case COMP_NONE:
st->codec->codec_id = CODEC_ID_PCM_S8;
break;
case COMP_FIB:
st->codec->codec_id = CODEC_ID_8SVX_FIB;
break;
case COMP_EXP:
st->codec->codec_id = CODEC_ID_8SVX_EXP;
break;
default:
av_log(s, AV_LOG_ERROR, "iff: unknown compression method\n");
return -1;
}
st->codec->bits_per_sample = 8;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_sample;
st->codec->block_align = st->codec->channels * st->codec->bits_per_sample;
return 0;
}
static int iff_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
IffDemuxContext *iff = s->priv_data;
ByteIOContext *pb = s->pb;
int ret;
if(iff->sent_bytes > iff->body_size)
return AVERROR(EIO);
if(s->streams[0]->codec->channels == 2) {
uint8_t sample_buffer[PACKET_SIZE];
ret = get_buffer(pb, sample_buffer, PACKET_SIZE);
if(av_new_packet(pkt, PACKET_SIZE) < 0) {
av_log(s, AV_LOG_ERROR, "iff: cannot allocate packet \n");
return AVERROR(ENOMEM);
}
interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
}
else {
ret = av_get_packet(pb, pkt, PACKET_SIZE);
}
if(iff->sent_bytes == 0)
pkt->flags |= PKT_FLAG_KEY;
iff->sent_bytes += PACKET_SIZE;
pkt->stream_index = 0;
pkt->pts = iff->audio_frame_count;
iff->audio_frame_count += ret / s->streams[0]->codec->channels;
return ret;
}
AVInputFormat iff_demuxer = {
"IFF",
NULL_IF_CONFIG_SMALL("IFF format"),
sizeof(IffDemuxContext),
iff_probe,
iff_read_header,
iff_read_packet,
};
|
