1/*
2 * Creative Voice File demuxer.
3 * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "libavutil/intreadwrite.h"
23#include "voc.h"
24
25
26static int voc_probe(AVProbeData *p)
27{
28    int version, check;
29
30    if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
31        return 0;
32    version = AV_RL16(p->buf + 22);
33    check = AV_RL16(p->buf + 24);
34    if (~version + 0x1234 != check)
35        return 10;
36
37    return AVPROBE_SCORE_MAX;
38}
39
40static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
41{
42    VocDecContext *voc = s->priv_data;
43    ByteIOContext *pb = s->pb;
44    int header_size;
45    AVStream *st;
46
47    url_fskip(pb, 20);
48    header_size = get_le16(pb) - 22;
49    if (header_size != 4) {
50        av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
51        return AVERROR(ENOSYS);
52    }
53    url_fskip(pb, header_size);
54    st = av_new_stream(s, 0);
55    if (!st)
56        return AVERROR(ENOMEM);
57    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
58
59    voc->remaining_size = 0;
60    return 0;
61}
62
63int
64voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
65{
66    VocDecContext *voc = s->priv_data;
67    AVCodecContext *dec = st->codec;
68    ByteIOContext *pb = s->pb;
69    VocType type;
70    int size;
71    int sample_rate = 0;
72    int channels = 1;
73
74    while (!voc->remaining_size) {
75        type = get_byte(pb);
76        if (type == VOC_TYPE_EOF)
77            return AVERROR(EIO);
78        voc->remaining_size = get_le24(pb);
79        if (!voc->remaining_size) {
80            if (url_is_streamed(s->pb))
81                return AVERROR(EIO);
82            voc->remaining_size = url_fsize(pb) - url_ftell(pb);
83        }
84        max_size -= 4;
85
86        switch (type) {
87        case VOC_TYPE_VOICE_DATA:
88            dec->sample_rate = 1000000 / (256 - get_byte(pb));
89            if (sample_rate)
90                dec->sample_rate = sample_rate;
91            dec->channels = channels;
92            dec->codec_id = ff_codec_get_id(ff_voc_codec_tags, get_byte(pb));
93            dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
94            voc->remaining_size -= 2;
95            max_size -= 2;
96            channels = 1;
97            break;
98
99        case VOC_TYPE_VOICE_DATA_CONT:
100            break;
101
102        case VOC_TYPE_EXTENDED:
103            sample_rate = get_le16(pb);
104            get_byte(pb);
105            channels = get_byte(pb) + 1;
106            sample_rate = 256000000 / (channels * (65536 - sample_rate));
107            voc->remaining_size = 0;
108            max_size -= 4;
109            break;
110
111        case VOC_TYPE_NEW_VOICE_DATA:
112            dec->sample_rate = get_le32(pb);
113            dec->bits_per_coded_sample = get_byte(pb);
114            dec->channels = get_byte(pb);
115            dec->codec_id = ff_codec_get_id(ff_voc_codec_tags, get_le16(pb));
116            url_fskip(pb, 4);
117            voc->remaining_size -= 12;
118            max_size -= 12;
119            break;
120
121        default:
122            url_fskip(pb, voc->remaining_size);
123            max_size -= voc->remaining_size;
124            voc->remaining_size = 0;
125            break;
126        }
127    }
128
129    dec->bit_rate = dec->sample_rate * dec->bits_per_coded_sample;
130
131    if (max_size <= 0)
132        max_size = 2048;
133    size = FFMIN(voc->remaining_size, max_size);
134    voc->remaining_size -= size;
135    return av_get_packet(pb, pkt, size);
136}
137
138static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
139{
140    return voc_get_packet(s, pkt, s->streams[0], 0);
141}
142
143AVInputFormat voc_demuxer = {
144    "voc",
145    NULL_IF_CONFIG_SMALL("Creative Voice file format"),
146    sizeof(VocDecContext),
147    voc_probe,
148    voc_read_header,
149    voc_read_packet,
150    .codec_tag=(const AVCodecTag* const []){ff_voc_codec_tags, 0},
151};
152