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 #include "internal.h"
25
voc_probe(const AVProbeData *p)26 static int voc_probe(const 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
voc_read_header(AVFormatContext *s)40 static int voc_read_header(AVFormatContext *s)
41 {
42 VocDecContext *voc = s->priv_data;
43 AVIOContext *pb = s->pb;
44 int header_size;
45
46 avio_skip(pb, 20);
47 header_size = avio_rl16(pb) - 22;
48 if (header_size != 4) {
49 av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
50 return AVERROR(ENOSYS);
51 }
52 avio_skip(pb, header_size);
53
54 s->ctx_flags |= AVFMTCTX_NOHEADER;
55
56 voc->remaining_size = 0;
57 return 0;
58 }
59
voc_read_packet(AVFormatContext *s, AVPacket *pkt)60 static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
61 {
62 if (!s->nb_streams) {
63 AVStream *st = avformat_new_stream(s, NULL);
64 if (!st)
65 return AVERROR(ENOMEM);
66 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
67 }
68 return ff_voc_get_packet(s, pkt, s->streams[0], 0);
69 }
70
voc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)71 static int voc_read_seek(AVFormatContext *s, int stream_index,
72 int64_t timestamp, int flags)
73 {
74 VocDecContext *voc = s->priv_data;
75 AVStream *st;
76 FFStream *sti;
77 int index;
78
79 if (s->nb_streams < 1) {
80 av_log(s, AV_LOG_ERROR, "cannot seek while no stream was found yet\n");
81 return AVERROR(EINVAL);
82 }
83
84 st = s->streams[stream_index];
85 sti = ffstream(st);
86 index = av_index_search_timestamp(st, timestamp, flags);
87
88 if (index >= 0 && index < sti->nb_index_entries - 1) {
89 const AVIndexEntry *const e = &sti->index_entries[index];
90 avio_seek(s->pb, e->pos, SEEK_SET);
91 voc->pts = e->timestamp;
92 voc->remaining_size = e->size;
93 return 0;
94 } else if (sti->nb_index_entries && sti->index_entries[0].timestamp <= timestamp) {
95 const AVIndexEntry *const e = &sti->index_entries[sti->nb_index_entries - 1];
96 // prepare context for seek_frame_generic()
97 voc->pts = e->timestamp;
98 voc->remaining_size = e->size;
99 }
100 return -1;
101 }
102
103 const AVInputFormat ff_voc_demuxer = {
104 .name = "voc",
105 .long_name = NULL_IF_CONFIG_SMALL("Creative Voice"),
106 .priv_data_size = sizeof(VocDecContext),
107 .read_probe = voc_probe,
108 .read_header = voc_read_header,
109 .read_packet = voc_read_packet,
110 .read_seek = voc_read_seek,
111 .codec_tag = ff_voc_codec_tags_list,
112 };
113