libavformat/eacdata.c

   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 libavformat/eacdata.c
  24  * Electronic Arts cdata Format Demuxer
  25  * by Peter Ross (suxen_drol at hotmail dot com)
  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
  33 typedef struct {
  34   unsigned int channels;
  35   unsigned int audio_pts;
  36 } CdataDemuxContext;
  37
  38 static int cdata_probe(AVProbeData *p)
  39 {
  40     const uint8_t *b = p->buf;
  41
  42     if (b[0] == 0x04 && (b[1] == 0x00 || b[1] == 0x04 || b[1] == 0x0C))
  43         return AVPROBE_SCORE_MAX/8;
  44     return 0;
  45 }
  46
  47 static int cdata_read_header(AVFormatContext *s, AVFormatParameters *ap)
  48 {
  49     CdataDemuxContext *cdata = s->priv_data;
  50     ByteIOContext *pb = s->pb;
  51     unsigned int sample_rate, header;
  52     AVStream *st;
  53
  54     header = get_be16(pb);
  55     switch (header) {
  56         case 0x0400: cdata->channels = 1; break;
  57         case 0x0404: cdata->channels = 2; break;
  58         case 0x040C: cdata->channels = 4; break;
  59         default:
  60             av_log(s, AV_LOG_INFO, "unknown header 0x%04x\n", header);
  61             return -1;
  62     };
  63
  64     sample_rate = get_be16(pb);
  65     url_fskip(pb, 12);
  66
  67     st = av_new_stream(s, 0);
  68     if (!st)
  69         return AVERROR(ENOMEM);
  70     st->codec->codec_type = CODEC_TYPE_AUDIO;
  71     st->codec->codec_tag = 0; /* no fourcc */
  72     st->codec->codec_id = CODEC_ID_ADPCM_EA_XAS;
  73     st->codec->channels = cdata->channels;
  74     st->codec->sample_rate = sample_rate;
  75     av_set_pts_info(st, 64, 1, sample_rate);
  76
  77     cdata->audio_pts = 0;
  78     return 0;
  79 }
  80
  81 static int cdata_read_packet(AVFormatContext *s, AVPacket *pkt)
  82 {
  83     CdataDemuxContext *cdata = s->priv_data;
  84     int packet_size = 76*cdata->channels;
  85
  86     if (av_get_packet(s->pb, pkt, packet_size) != packet_size)
  87         return AVERROR(EIO);
  88     pkt->pts = cdata->audio_pts++;
  89     return 1;
  90 }
  91
  92 AVInputFormat ea_cdata_demuxer = {
  93     "ea_cdata",
  94     NULL_IF_CONFIG_SMALL("Electronic Arts cdata"),
  95     sizeof(CdataDemuxContext),
  96     cdata_probe,
  97     cdata_read_header,
  98     cdata_read_packet,
  99     .extensions = "cdata",
 100 };