Statistics
| Branch: | Revision:

ffmpeg / libavformat / au.c @ 2912e87a

History | View | Annotate | Download (5.27 KB)

1
/*
2
 * AU muxer and demuxer
3
 * Copyright (c) 2001 Fabrice Bellard
4
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * Libav is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with Libav; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
/*
23
 * First version by Francois Revol revol@free.fr
24
 *
25
 * Reference documents:
26
 * http://www.opengroup.org/public/pubs/external/auformat.html
27
 * http://www.goice.co.jp/member/mo/formats/au.html
28
 */
29

    
30
#include "avformat.h"
31
#include "avio_internal.h"
32
#include "pcm.h"
33
#include "riff.h"
34

    
35
/* if we don't know the size in advance */
36
#define AU_UNKNOWN_SIZE ((uint32_t)(~0))
37

    
38
/* The ffmpeg codecs we support, and the IDs they have in the file */
39
static const AVCodecTag codec_au_tags[] = {
40
    { CODEC_ID_PCM_MULAW, 1 },
41
    { CODEC_ID_PCM_S8, 2 },
42
    { CODEC_ID_PCM_S16BE, 3 },
43
    { CODEC_ID_PCM_S24BE, 4 },
44
    { CODEC_ID_PCM_S32BE, 5 },
45
    { CODEC_ID_PCM_F32BE, 6 },
46
    { CODEC_ID_PCM_F64BE, 7 },
47
    { CODEC_ID_PCM_ALAW, 27 },
48
    { CODEC_ID_NONE, 0 },
49
};
50

    
51
#if CONFIG_AU_MUXER
52
/* AUDIO_FILE header */
53
static int put_au_header(AVIOContext *pb, AVCodecContext *enc)
54
{
55
    if(!enc->codec_tag)
56
        return -1;
57
    ffio_wfourcc(pb, ".snd");    /* magic number */
58
    avio_wb32(pb, 24);           /* header size */
59
    avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
60
    avio_wb32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
61
    avio_wb32(pb, enc->sample_rate);
62
    avio_wb32(pb, (uint32_t)enc->channels);
63
    return 0;
64
}
65

    
66
static int au_write_header(AVFormatContext *s)
67
{
68
    AVIOContext *pb = s->pb;
69

    
70
    s->priv_data = NULL;
71

    
72
    /* format header */
73
    if (put_au_header(pb, s->streams[0]->codec) < 0) {
74
        return -1;
75
    }
76

    
77
    avio_flush(pb);
78

    
79
    return 0;
80
}
81

    
82
static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
83
{
84
    AVIOContext *pb = s->pb;
85
    avio_write(pb, pkt->data, pkt->size);
86
    return 0;
87
}
88

    
89
static int au_write_trailer(AVFormatContext *s)
90
{
91
    AVIOContext *pb = s->pb;
92
    int64_t file_size;
93

    
94
    if (!url_is_streamed(s->pb)) {
95

    
96
        /* update file size */
97
        file_size = avio_tell(pb);
98
        avio_seek(pb, 8, SEEK_SET);
99
        avio_wb32(pb, (uint32_t)(file_size - 24));
100
        avio_seek(pb, file_size, SEEK_SET);
101

    
102
        avio_flush(pb);
103
    }
104

    
105
    return 0;
106
}
107
#endif /* CONFIG_AU_MUXER */
108

    
109
static int au_probe(AVProbeData *p)
110
{
111
    /* check file header */
112
    if (p->buf[0] == '.' && p->buf[1] == 's' &&
113
        p->buf[2] == 'n' && p->buf[3] == 'd')
114
        return AVPROBE_SCORE_MAX;
115
    else
116
        return 0;
117
}
118

    
119
/* au input */
120
static int au_read_header(AVFormatContext *s,
121
                          AVFormatParameters *ap)
122
{
123
    int size;
124
    unsigned int tag;
125
    AVIOContext *pb = s->pb;
126
    unsigned int id, channels, rate;
127
    enum CodecID codec;
128
    AVStream *st;
129

    
130
    /* check ".snd" header */
131
    tag = avio_rl32(pb);
132
    if (tag != MKTAG('.', 's', 'n', 'd'))
133
        return -1;
134
    size = avio_rb32(pb); /* header size */
135
    avio_rb32(pb); /* data size */
136

    
137
    id = avio_rb32(pb);
138
    rate = avio_rb32(pb);
139
    channels = avio_rb32(pb);
140

    
141
    codec = ff_codec_get_id(codec_au_tags, id);
142

    
143
    if (!av_get_bits_per_sample(codec)) {
144
        av_log_ask_for_sample(s, "could not determine bits per sample\n");
145
        return AVERROR_INVALIDDATA;
146
    }
147

    
148
    if (size >= 24) {
149
        /* skip unused data */
150
        avio_skip(pb, size - 24);
151
    }
152

    
153
    /* now we are ready: build format streams */
154
    st = av_new_stream(s, 0);
155
    if (!st)
156
        return -1;
157
    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
158
    st->codec->codec_tag = id;
159
    st->codec->codec_id = codec;
160
    st->codec->channels = channels;
161
    st->codec->sample_rate = rate;
162
    av_set_pts_info(st, 64, 1, rate);
163
    return 0;
164
}
165

    
166
#define BLOCK_SIZE 1024
167

    
168
static int au_read_packet(AVFormatContext *s,
169
                          AVPacket *pkt)
170
{
171
    int ret;
172

    
173
    ret= av_get_packet(s->pb, pkt, BLOCK_SIZE *
174
                       s->streams[0]->codec->channels *
175
                       av_get_bits_per_sample(s->streams[0]->codec->codec_id) >> 3);
176
    if (ret < 0)
177
        return ret;
178
    pkt->stream_index = 0;
179

    
180
    /* note: we need to modify the packet size here to handle the last
181
       packet */
182
    pkt->size = ret;
183
    return 0;
184
}
185

    
186
#if CONFIG_AU_DEMUXER
187
AVInputFormat ff_au_demuxer = {
188
    "au",
189
    NULL_IF_CONFIG_SMALL("SUN AU format"),
190
    0,
191
    au_probe,
192
    au_read_header,
193
    au_read_packet,
194
    NULL,
195
    pcm_read_seek,
196
    .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
197
};
198
#endif
199

    
200
#if CONFIG_AU_MUXER
201
AVOutputFormat ff_au_muxer = {
202
    "au",
203
    NULL_IF_CONFIG_SMALL("SUN AU format"),
204
    "audio/basic",
205
    "au",
206
    0,
207
    CODEC_ID_PCM_S16BE,
208
    CODEC_ID_NONE,
209
    au_write_header,
210
    au_write_packet,
211
    au_write_trailer,
212
    .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
213
};
214
#endif //CONFIG_AU_MUXER