1 /*
2 * Xiph CELT parser for Ogg
3 * Copyright (c) 2011 Nicolas George
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 <string.h>
23
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "internal.h"
27 #include "oggdec.h"
28
29 struct oggcelt_private {
30 int extra_headers_left;
31 };
32
celt_header(AVFormatContext * s,int idx)33 static int celt_header(AVFormatContext *s, int idx)
34 {
35 struct ogg *ogg = s->priv_data;
36 struct ogg_stream *os = ogg->streams + idx;
37 AVStream *st = s->streams[idx];
38 struct oggcelt_private *priv = os->private;
39 uint8_t *p = os->buf + os->pstart;
40 int ret;
41
42 if (os->psize == 60 &&
43 !memcmp(p, ff_celt_codec.magic, ff_celt_codec.magicsize)) {
44 /* Main header */
45
46 uint32_t version, sample_rate, nb_channels;
47 uint32_t overlap, extra_headers;
48
49 priv = av_malloc(sizeof(struct oggcelt_private));
50 if (!priv)
51 return AVERROR(ENOMEM);
52 ret = ff_alloc_extradata(st->codecpar, 2 * sizeof(uint32_t));
53 if (ret < 0) {
54 av_free(priv);
55 return ret;
56 }
57 version = AV_RL32(p + 28);
58 /* unused header size field skipped */
59 sample_rate = AV_RL32(p + 36);
60 nb_channels = AV_RL32(p + 40);
61 overlap = AV_RL32(p + 48);
62 /* unused bytes per packet field skipped */
63 extra_headers = AV_RL32(p + 56);
64 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
65 st->codecpar->codec_id = AV_CODEC_ID_CELT;
66 st->codecpar->sample_rate = sample_rate;
67 st->codecpar->channels = nb_channels;
68 if (sample_rate)
69 avpriv_set_pts_info(st, 64, 1, sample_rate);
70
71 if (os->private) {
72 av_free(priv);
73 priv = os->private;
74 }
75 os->private = priv;
76 priv->extra_headers_left = 1 + extra_headers;
77
78 AV_WL32(st->codecpar->extradata + 0, overlap);
79 AV_WL32(st->codecpar->extradata + 4, version);
80 return 1;
81 } else if (priv && priv->extra_headers_left) {
82 /* Extra headers (vorbiscomment) */
83
84 ff_vorbis_stream_comment(s, st, p, os->psize);
85 priv->extra_headers_left--;
86 return 1;
87 } else {
88 return 0;
89 }
90 }
91
92 const struct ogg_codec ff_celt_codec = {
93 .magic = "CELT ",
94 .magicsize = 8,
95 .header = celt_header,
96 .nb_header = 2,
97 };
98