Statistics
| Branch: | Revision:

ffmpeg / libavformat / vocdec.c @ 0a5790d1

History | View | Annotate | Download (4.12 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 e5a389a1 Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 ea395e8c Aurelien Jacobs
 */
21
22
#include "voc.h"
23
24
25
static int voc_probe(AVProbeData *p)
26
{
27
    int version, check;
28
29
    if (memcmp(p->buf, voc_magic, sizeof(voc_magic) - 1))
30
        return 0;
31 6bca498d Aurelien Jacobs
    version = AV_RL16(p->buf + 22);
32
    check = AV_RL16(p->buf + 24);
33 ea395e8c Aurelien Jacobs
    if (~version + 0x1234 != check)
34
        return 10;
35
36
    return AVPROBE_SCORE_MAX;
37
}
38
39
static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
40
{
41
    voc_dec_context_t *voc = s->priv_data;
42
    ByteIOContext *pb = &s->pb;
43
    int header_size;
44
    AVStream *st;
45
46
    url_fskip(pb, 20);
47
    header_size = get_le16(pb) - 22;
48
    if (header_size != 4) {
49 cbc09a7d Alex Beregszaszi
        av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
50 85565db0 Panagiotis Issaris
        return AVERROR(ENOSYS);
51 ea395e8c Aurelien Jacobs
    }
52
    url_fskip(pb, header_size);
53
    st = av_new_stream(s, 0);
54
    if (!st)
55 769e10f0 Panagiotis Issaris
        return AVERROR(ENOMEM);
56 ea395e8c Aurelien Jacobs
    st->codec->codec_type = CODEC_TYPE_AUDIO;
57
58
    voc->remaining_size = 0;
59
    return 0;
60
}
61
62
int
63
voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
64
{
65
    voc_dec_context_t *voc = s->priv_data;
66
    AVCodecContext *dec = st->codec;
67
    ByteIOContext *pb = &s->pb;
68
    voc_type_t type;
69
    int size;
70
    int sample_rate = 0;
71
    int channels = 1;
72
73
    while (!voc->remaining_size) {
74
        type = get_byte(pb);
75
        if (type == VOC_TYPE_EOF)
76 6f3e0b21 Panagiotis Issaris
            return AVERROR(EIO);
77 ea395e8c Aurelien Jacobs
        voc->remaining_size = get_le24(pb);
78
        max_size -= 4;
79
80
        switch (type) {
81
        case VOC_TYPE_VOICE_DATA:
82
            dec->sample_rate = 1000000 / (256 - get_byte(pb));
83
            if (sample_rate)
84
                dec->sample_rate = sample_rate;
85
            dec->channels = channels;
86
            dec->codec_id = codec_get_id(voc_codec_tags, get_byte(pb));
87 5da71469 Aurelien Jacobs
            dec->bits_per_sample = av_get_bits_per_sample(dec->codec_id);
88 ea395e8c Aurelien Jacobs
            voc->remaining_size -= 2;
89
            max_size -= 2;
90
            channels = 1;
91
            break;
92
93
        case VOC_TYPE_VOICE_DATA_CONT:
94
            break;
95
96
        case VOC_TYPE_EXTENDED:
97
            sample_rate = get_le16(pb);
98
            get_byte(pb);
99
            channels = get_byte(pb) + 1;
100
            sample_rate = 256000000 / (channels * (65536 - sample_rate));
101
            voc->remaining_size = 0;
102
            max_size -= 4;
103
            break;
104
105
        case VOC_TYPE_NEW_VOICE_DATA:
106
            dec->sample_rate = get_le32(pb);
107
            dec->bits_per_sample = get_byte(pb);
108
            dec->channels = get_byte(pb);
109
            dec->codec_id = codec_get_id(voc_codec_tags, get_le16(pb));
110
            url_fskip(pb, 4);
111
            voc->remaining_size -= 12;
112
            max_size -= 12;
113
            break;
114
115
        default:
116
            url_fskip(pb, voc->remaining_size);
117
            max_size -= voc->remaining_size;
118
            voc->remaining_size = 0;
119
            break;
120
        }
121
    }
122
123
    dec->bit_rate = dec->sample_rate * dec->bits_per_sample;
124
125
    if (max_size <= 0)
126 fd9a71ac Alex Beregszaszi
        max_size = 2048;
127 ea395e8c Aurelien Jacobs
    size = FFMIN(voc->remaining_size, max_size);
128
    voc->remaining_size -= size;
129
    return av_get_packet(pb, pkt, size);
130
}
131
132
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
133
{
134
    return voc_get_packet(s, pkt, s->streams[0], 0);
135
}
136
137 ff70e601 Måns Rullgård
AVInputFormat voc_demuxer = {
138 ea395e8c Aurelien Jacobs
    "voc",
139
    "Creative Voice File format",
140
    sizeof(voc_dec_context_t),
141
    voc_probe,
142
    voc_read_header,
143
    voc_read_packet,
144 6c77805f Michael Niedermayer
    .codec_tag=(const AVCodecTag*[]){voc_codec_tags, 0},
145 ea395e8c Aurelien Jacobs
};