Statistics
| Branch: | Revision:

ffmpeg / libavformat / vocdec.c @ e19fbbec

History | View | Annotate | Download (4.26 KB)

1 ea395e8c Aurelien Jacobs
/*
2
 * Creative Voice File demuxer.
3
 * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
4
 *
5 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8 ea395e8c Aurelien Jacobs
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
11 ea395e8c Aurelien Jacobs
 *
12 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
13 ea395e8c Aurelien Jacobs
 * 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 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
19 ea395e8c Aurelien Jacobs
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
20
 */
21
22
#include "voc.h"
23
24
25
26
27
static int voc_probe(AVProbeData *p)
28
{
29
    int version, check;
30
31
    if (p->buf_size < 26)
32
        return 0;
33
    if (memcmp(p->buf, voc_magic, sizeof(voc_magic) - 1))
34
        return 0;
35
    version = p->buf[22] | (p->buf[23] << 8);
36
    check = p->buf[24] | (p->buf[25] << 8);
37
    if (~version + 0x1234 != check)
38
        return 10;
39
40
    return AVPROBE_SCORE_MAX;
41
}
42
43
static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
44
{
45
    voc_dec_context_t *voc = s->priv_data;
46
    ByteIOContext *pb = &s->pb;
47
    int header_size;
48
    AVStream *st;
49
50
    url_fskip(pb, 20);
51
    header_size = get_le16(pb) - 22;
52
    if (header_size != 4) {
53 cbc09a7d Alex Beregszaszi
        av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
54 ea395e8c Aurelien Jacobs
        return AVERROR_NOTSUPP;
55
    }
56
    url_fskip(pb, header_size);
57
    st = av_new_stream(s, 0);
58
    if (!st)
59
        return AVERROR_NOMEM;
60
    st->codec->codec_type = CODEC_TYPE_AUDIO;
61
62
    voc->remaining_size = 0;
63
    return 0;
64
}
65
66
int
67
voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
68
{
69
    voc_dec_context_t *voc = s->priv_data;
70
    AVCodecContext *dec = st->codec;
71
    ByteIOContext *pb = &s->pb;
72
    voc_type_t type;
73
    int size;
74
    int sample_rate = 0;
75
    int channels = 1;
76
77
    while (!voc->remaining_size) {
78
        type = get_byte(pb);
79
        if (type == VOC_TYPE_EOF)
80
            return AVERROR_IO;
81
        voc->remaining_size = get_le24(pb);
82
        max_size -= 4;
83
84
        switch (type) {
85
        case VOC_TYPE_VOICE_DATA:
86
            dec->sample_rate = 1000000 / (256 - get_byte(pb));
87
            if (sample_rate)
88
                dec->sample_rate = sample_rate;
89
            dec->channels = channels;
90
            dec->codec_id = codec_get_id(voc_codec_tags, get_byte(pb));
91 5da71469 Aurelien Jacobs
            dec->bits_per_sample = av_get_bits_per_sample(dec->codec_id);
92 ea395e8c Aurelien Jacobs
            voc->remaining_size -= 2;
93
            max_size -= 2;
94
            channels = 1;
95
            break;
96
97
        case VOC_TYPE_VOICE_DATA_CONT:
98
            break;
99
100
        case VOC_TYPE_EXTENDED:
101
            sample_rate = get_le16(pb);
102
            get_byte(pb);
103
            channels = get_byte(pb) + 1;
104
            sample_rate = 256000000 / (channels * (65536 - sample_rate));
105
            voc->remaining_size = 0;
106
            max_size -= 4;
107
            break;
108
109
        case VOC_TYPE_NEW_VOICE_DATA:
110
            dec->sample_rate = get_le32(pb);
111
            dec->bits_per_sample = get_byte(pb);
112
            dec->channels = get_byte(pb);
113
            dec->codec_id = codec_get_id(voc_codec_tags, get_le16(pb));
114
            url_fskip(pb, 4);
115
            voc->remaining_size -= 12;
116
            max_size -= 12;
117
            break;
118
119
        default:
120
            url_fskip(pb, voc->remaining_size);
121
            max_size -= voc->remaining_size;
122
            voc->remaining_size = 0;
123
            break;
124
        }
125
    }
126
127
    dec->bit_rate = dec->sample_rate * dec->bits_per_sample;
128
129
    if (max_size <= 0)
130 fd9a71ac Alex Beregszaszi
        max_size = 2048;
131 ea395e8c Aurelien Jacobs
    size = FFMIN(voc->remaining_size, max_size);
132
    voc->remaining_size -= size;
133
    return av_get_packet(pb, pkt, size);
134
}
135
136
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
137
{
138
    return voc_get_packet(s, pkt, s->streams[0], 0);
139
}
140
141
static int voc_read_close(AVFormatContext *s)
142
{
143
    return 0;
144
}
145
146 ff70e601 Måns Rullgård
AVInputFormat voc_demuxer = {
147 ea395e8c Aurelien Jacobs
    "voc",
148
    "Creative Voice File format",
149
    sizeof(voc_dec_context_t),
150
    voc_probe,
151
    voc_read_header,
152
    voc_read_packet,
153
    voc_read_close,
154 6c77805f Michael Niedermayer
    .codec_tag=(const AVCodecTag*[]){voc_codec_tags, 0},
155 ea395e8c Aurelien Jacobs
};