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oggparsecelt.c
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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 
31 };
32 
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 
41  if (os->psize == 60 &&
43  /* Main header */
44 
46  uint32_t overlap, extra_headers;
47  uint8_t *extradata;
48 
49  extradata = av_malloc(2 * sizeof(uint32_t) +
51  priv = av_malloc(sizeof(struct oggcelt_private));
52  if (!extradata || !priv) {
53  av_free(extradata);
54  av_free(priv);
55  return AVERROR(ENOMEM);
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  frame_size = AV_RL32(p + 44);
62  overlap = AV_RL32(p + 48);
63  /* unused bytes per packet field skipped */
64  extra_headers = AV_RL32(p + 56);
68  st->codec->channels = nb_channels;
70  av_free(st->codec->extradata);
71  st->codec->extradata = extradata;
72  st->codec->extradata_size = 2 * sizeof(uint32_t);
73  if (sample_rate)
74  avpriv_set_pts_info(st, 64, 1, sample_rate);
75  priv->extra_headers_left = 1 + extra_headers;
76  av_free(os->private);
77  os->private = priv;
78  AV_WL32(extradata + 0, overlap);
79  AV_WL32(extradata + 4, version);
80  return 1;
81  } else if (priv && priv->extra_headers_left) {
82  /* Extra headers (vorbiscomment) */
83 
84  ff_vorbis_comment(s, &st->metadata, 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 };