1/*
2 * Creative Voice File demuxer.
3 * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
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#include "libavutil/intreadwrite.h"
23#include "voc.h"
24#include "internal.h"
25
26
27static int voc_probe(AVProbeData *p)
28{
29    int version, check;
30
31    if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
32        return 0;
33    version = AV_RL16(p->buf + 22);
34    check = AV_RL16(p->buf + 24);
35    if (~version + 0x1234 != check)
36        return 10;
37
38    return AVPROBE_SCORE_MAX;
39}
40
41static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
42{
43    VocDecContext *voc = s->priv_data;
44    AVIOContext *pb = s->pb;
45    int header_size;
46    AVStream *st;
47
48    avio_skip(pb, 20);
49    header_size = avio_rl16(pb) - 22;
50    if (header_size != 4) {
51        av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
52        return AVERROR(ENOSYS);
53    }
54    avio_skip(pb, header_size);
55    st = avformat_new_stream(s, NULL);
56    if (!st)
57        return AVERROR(ENOMEM);
58    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
59
60    voc->remaining_size = 0;
61    return 0;
62}
63
64int
65voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
66{
67    VocDecContext *voc = s->priv_data;
68    AVCodecContext *dec = st->codec;
69    AVIOContext *pb = s->pb;
70    VocType type;
71    int size, tmp_codec=-1;
72    int sample_rate = 0;
73    int channels = 1;
74
75    while (!voc->remaining_size) {
76        type = avio_r8(pb);
77        if (type == VOC_TYPE_EOF)
78            return AVERROR(EIO);
79        voc->remaining_size = avio_rl24(pb);
80        if (!voc->remaining_size) {
81            if (!s->pb->seekable)
82                return AVERROR(EIO);
83            voc->remaining_size = avio_size(pb) - avio_tell(pb);
84        }
85        max_size -= 4;
86
87        switch (type) {
88        case VOC_TYPE_VOICE_DATA:
89            dec->sample_rate = 1000000 / (256 - avio_r8(pb));
90            if (sample_rate)
91                dec->sample_rate = sample_rate;
92            dec->channels = channels;
93            tmp_codec = avio_r8(pb);
94            dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
95            voc->remaining_size -= 2;
96            max_size -= 2;
97            channels = 1;
98            break;
99
100        case VOC_TYPE_VOICE_DATA_CONT:
101            break;
102
103        case VOC_TYPE_EXTENDED:
104            sample_rate = avio_rl16(pb);
105            avio_r8(pb);
106            channels = avio_r8(pb) + 1;
107            sample_rate = 256000000 / (channels * (65536 - sample_rate));
108            voc->remaining_size = 0;
109            max_size -= 4;
110            break;
111
112        case VOC_TYPE_NEW_VOICE_DATA:
113            dec->sample_rate = avio_rl32(pb);
114            dec->bits_per_coded_sample = avio_r8(pb);
115            dec->channels = avio_r8(pb);
116            tmp_codec = avio_rl16(pb);
117            avio_skip(pb, 4);
118            voc->remaining_size -= 12;
119            max_size -= 12;
120            break;
121
122        default:
123            avio_skip(pb, voc->remaining_size);
124            max_size -= voc->remaining_size;
125            voc->remaining_size = 0;
126            break;
127        }
128    }
129
130    if (tmp_codec >= 0) {
131        tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
132        if (dec->codec_id == CODEC_ID_NONE)
133            dec->codec_id = tmp_codec;
134        else if (dec->codec_id != tmp_codec)
135            av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
136        if (dec->codec_id == CODEC_ID_NONE) {
137            if (s->audio_codec_id == CODEC_ID_NONE) {
138                av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
139                return AVERROR(EINVAL);
140            }
141            av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
142        }
143    }
144
145    dec->bit_rate = dec->sample_rate * dec->bits_per_coded_sample;
146
147    if (max_size <= 0)
148        max_size = 2048;
149    size = FFMIN(voc->remaining_size, max_size);
150    voc->remaining_size -= size;
151    return av_get_packet(pb, pkt, size);
152}
153
154static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
155{
156    return voc_get_packet(s, pkt, s->streams[0], 0);
157}
158
159AVInputFormat ff_voc_demuxer = {
160    .name           = "voc",
161    .long_name      = NULL_IF_CONFIG_SMALL("Creative Voice file format"),
162    .priv_data_size = sizeof(VocDecContext),
163    .read_probe     = voc_probe,
164    .read_header    = voc_read_header,
165    .read_packet    = voc_read_packet,
166    .codec_tag=(const AVCodecTag* const []){ff_voc_codec_tags, 0},
167};
168