FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
eacdata.c
Go to the documentation of this file.
1 /*
2  * Electronic Arts .cdata file Demuxer
3  * Copyright (c) 2007 Peter Ross
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 /**
23  * @file
24  * Electronic Arts cdata Format Demuxer
25  * by Peter Ross (pross@xvid.org)
26  *
27  * Technical details here:
28  * http://wiki.multimedia.cx/index.php?title=EA_Command_And_Conquer_3_Audio_Codec
29  */
30 
31 #include "avformat.h"
32 #include "internal.h"
33 
34 typedef struct CdataDemuxContext {
35  unsigned int channels;
36  unsigned int audio_pts;
38 
39 static int cdata_probe(AVProbeData *p)
40 {
41  const uint8_t *b = p->buf;
42 
43  if (b[0] == 0x04 && (b[1] == 0x00 || b[1] == 0x04 || b[1] == 0x0C || b[1] == 0x14))
44  return AVPROBE_SCORE_MAX/8;
45  return 0;
46 }
47 
49 {
50  CdataDemuxContext *cdata = s->priv_data;
51  AVIOContext *pb = s->pb;
52  unsigned int sample_rate, header;
53  AVStream *st;
54  int64_t channel_layout = 0;
55 
56  header = avio_rb16(pb);
57  switch (header) {
58  case 0x0400: cdata->channels = 1; break;
59  case 0x0404: cdata->channels = 2; break;
60  case 0x040C: cdata->channels = 4; channel_layout = AV_CH_LAYOUT_QUAD; break;
61  case 0x0414: cdata->channels = 6; channel_layout = AV_CH_LAYOUT_5POINT1_BACK; break;
62  default:
63  av_log(s, AV_LOG_INFO, "unknown header 0x%04x\n", header);
64  return -1;
65  };
66 
67  sample_rate = avio_rb16(pb);
68  avio_skip(pb, (avio_r8(pb) & 0x20) ? 15 : 11);
69 
70  st = avformat_new_stream(s, NULL);
71  if (!st)
72  return AVERROR(ENOMEM);
74  st->codec->codec_tag = 0; /* no fourcc */
76  st->codec->channels = cdata->channels;
77  st->codec->channel_layout = channel_layout;
79  avpriv_set_pts_info(st, 64, 1, sample_rate);
80 
81  cdata->audio_pts = 0;
82  return 0;
83 }
84 
86 {
87  CdataDemuxContext *cdata = s->priv_data;
88  int packet_size = 76*cdata->channels;
89 
90  int ret = av_get_packet(s->pb, pkt, packet_size);
91  if (ret < 0)
92  return ret;
93  pkt->pts = cdata->audio_pts++;
94  return 0;
95 }
96 
98  .name = "ea_cdata",
99  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts cdata"),
100  .priv_data_size = sizeof(CdataDemuxContext),
104  .extensions = "cdata",
105 };