libavformat/xmd.c

   1 /*
   2  * XMD demuxer
   3  * Copyright (c) 2023 Paul B Mahol
   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/channel_layout.h"
  23 #include "libavutil/intreadwrite.h"
  24 #include "avformat.h"
  25 #include "demux.h"
  26 #include "internal.h"
  27 #include "pcm.h"
  28
  29 static int xmd_probe(const AVProbeData *p)
  30 {
  31     if ((AV_RL32(p->buf) & 0xFFFFFF) != MKTAG('x','m','d',0))
  32         return 0;
  33     if (p->buf[3] == 0 || p->buf[3] > 2 ||
  34         AV_RL16(p->buf+4) == 0 ||
  35         AV_RL32(p->buf+6) == 0)
  36         return 0;
  37
  38     return AVPROBE_SCORE_MAX / 3;
  39 }
  40
  41 static int xmd_read_header(AVFormatContext *s)
  42 {
  43     AVIOContext *pb = s->pb;
  44     AVCodecParameters *par;
  45     int channels;
  46     AVStream *st;
  47
  48     avio_skip(pb, 3);
  49
  50     st = avformat_new_stream(s, NULL);
  51     if (!st)
  52         return AVERROR(ENOMEM);
  53
  54     par              = st->codecpar;
  55     par->codec_type  = AVMEDIA_TYPE_AUDIO;
  56     par->codec_id    = AV_CODEC_ID_ADPCM_XMD;
  57     channels         = avio_r8(pb);
  58     if (channels == 0)
  59         return AVERROR_INVALIDDATA;
  60     av_channel_layout_default(&par->ch_layout, channels);
  61     par->sample_rate = avio_rl16(pb);
  62     if (par->sample_rate <= 0)
  63         return AVERROR_INVALIDDATA;
  64     par->block_align = 21 * channels;
  65     st->duration = (avio_rl32(pb) / par->block_align) * 32LL;
  66     avpriv_set_pts_info(st, 64, 1, par->sample_rate);
  67     avio_skip(pb, 7);
  68
  69     return 0;
  70 }
  71
  72 const FFInputFormat ff_xmd_demuxer = {
  73     .p.name         = "xmd",
  74     .p.long_name    = NULL_IF_CONFIG_SMALL("Konami XMD"),
  75     .p.flags        = AVFMT_GENERIC_INDEX,
  76     .p.extensions   = "xmd",
  77     .read_probe     = xmd_probe,
  78     .read_header    = xmd_read_header,
  79     .read_packet    = ff_pcm_read_packet,
  80 };