libavformat/wavarc.c

   1 /*
   2  * WavArc 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 "avio_internal.h"
  26 #include "demux.h"
  27 #include "internal.h"
  28
  29 typedef struct WavArcContext {
  30     int64_t data_end;
  31 } WavArcContext;
  32
  33 static int wavarc_probe(const AVProbeData *p)
  34 {
  35     int len = p->buf[0];
  36     uint32_t id;
  37
  38     if (len == 0 || len + 6 >= p->buf_size)
  39         return 0;
  40
  41     if (p->buf[len + 1] != 0)
  42         return 0;
  43
  44     id = AV_RL32(p->buf + len + 2);
  45     if (id != MKTAG('0','C','P','Y') &&
  46         id != MKTAG('1','D','I','F') &&
  47         id != MKTAG('2','S','L','P') &&
  48         id != MKTAG('3','N','L','P') &&
  49         id != MKTAG('4','A','L','P') &&
  50         id != MKTAG('5','E','L','P'))
  51         return 0;
  52
  53     return AVPROBE_SCORE_MAX / 3 * 2;
  54 }
  55
  56 static int wavarc_read_header(AVFormatContext *s)
  57 {
  58     WavArcContext *w = s->priv_data;
  59     AVIOContext *pb = s->pb;
  60     AVCodecParameters *par;
  61     int filename_len, fmt_len, ret;
  62     uint8_t data[36];
  63     AVStream *st;
  64     uint32_t id;
  65
  66     filename_len = avio_r8(pb);
  67     if (filename_len == 0)
  68         return AVERROR_INVALIDDATA;
  69     avio_skip(pb, filename_len);
  70     if (avio_r8(pb))
  71         return AVERROR_INVALIDDATA;
  72     id = avio_rl32(pb);
  73     w->data_end = avio_tell(pb);
  74     if ((ret = ffio_read_size(pb, data, sizeof(data))) < 0)
  75         return ret;
  76     w->data_end += 16LL + AV_RL32(data + 4);
  77     fmt_len = AV_RL32(data + 32);
  78     if (fmt_len < 12)
  79         return AVERROR_INVALIDDATA;
  80
  81     st = avformat_new_stream(s, NULL);
  82     if (!st)
  83         return AVERROR(ENOMEM);
  84     par = st->codecpar;
  85
  86     ret = ff_alloc_extradata(par, fmt_len + sizeof(data));
  87     if (ret < 0)
  88         return ret;
  89     memcpy(par->extradata, data, sizeof(data));
  90     ret = ffio_read_size(pb, par->extradata + sizeof(data), fmt_len);
  91     if (ret < 0)
  92         return ret;
  93
  94     par->codec_type = AVMEDIA_TYPE_AUDIO;
  95     par->codec_id   = AV_CODEC_ID_WAVARC;
  96     par->codec_tag  = id;
  97
  98     do {
  99         id = avio_rl32(pb);
 100         if (id != MKTAG('d','a','t','a'))
 101             avio_skip(pb, avio_rl32(pb));
 102     } while (id != MKTAG('d','a','t','a') && !avio_feof(pb));
 103     avio_skip(pb, 4);
 104
 105     if (AV_RL32(par->extradata + 16) != MKTAG('R','I','F','F'))
 106         return AVERROR_INVALIDDATA;
 107     if (AV_RL32(par->extradata + 24) != MKTAG('W','A','V','E'))
 108         return AVERROR_INVALIDDATA;
 109     if (AV_RL32(par->extradata + 28) != MKTAG('f','m','t',' '))
 110         return AVERROR_INVALIDDATA;
 111
 112     av_channel_layout_default(&par->ch_layout, AV_RL16(par->extradata + 38));
 113     par->sample_rate = AV_RL32(par->extradata + 40);
 114     avpriv_set_pts_info(st, 64, 1, par->sample_rate);
 115     st->start_time = 0;
 116
 117     return 0;
 118 }
 119
 120 static int wavarc_read_packet(AVFormatContext *s, AVPacket *pkt)
 121 {
 122     WavArcContext *w = s->priv_data;
 123     AVIOContext *pb = s->pb;
 124     int64_t size, left = w->data_end - avio_tell(pb);
 125     int ret;
 126
 127     size = FFMIN(left, 1024);
 128     if (size <= 0)
 129         return AVERROR_EOF;
 130
 131     ret = av_get_packet(pb, pkt, size);
 132     pkt->stream_index = 0;
 133     return ret;
 134 }
 135
 136 const FFInputFormat ff_wavarc_demuxer = {
 137     .p.name         = "wavarc",
 138     .p.long_name    = NULL_IF_CONFIG_SMALL("Waveform Archiver"),
 139     .p.flags        = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
 140     .p.extensions   = "wa",
 141     .priv_data_size = sizeof(WavArcContext),
 142     .read_probe     = wavarc_probe,
 143     .read_packet    = wavarc_read_packet,
 144     .read_header    = wavarc_read_header,
 145     .raw_codec_id   = AV_CODEC_ID_WAVARC,
 146 };