3 * Copyright (c) 2019 Paul B Mahol
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/intreadwrite.h"
23 #include "libavcodec/internal.h"
28 static int hcom_probe(AVProbeData *p)
30 if (!memcmp(p->buf+65, "FSSD", 4) &&
31 !memcmp(p->buf+128, "HCOM", 4))
32 return AVPROBE_SCORE_MAX;
36 static int hcom_read_header(AVFormatContext *s)
39 unsigned data_size, rsrc_size, huffcount;
40 unsigned compresstype, divisor;
41 unsigned dict_entries;
45 data_size = avio_rb32(s->pb);
46 rsrc_size = avio_rb32(s->pb);
47 avio_skip(s->pb, 128-91+4);
48 huffcount = avio_rb32(s->pb);
50 compresstype = avio_rb32(s->pb);
52 return AVERROR_INVALIDDATA;
53 divisor = avio_rb32(s->pb);
54 if (divisor == 0 || divisor > 4)
55 return AVERROR_INVALIDDATA;
56 dict_entries = avio_rb16(s->pb);
58 st = avformat_new_stream(s, NULL);
60 return AVERROR(ENOMEM);
62 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
63 st->codecpar->channels = 1;
64 st->codecpar->sample_rate = 22050 / divisor;
65 st->codecpar->codec_id = AV_CODEC_ID_HCOM;
66 st->codecpar->bits_per_coded_sample = 8;
67 st->codecpar->block_align = 4;
69 ret = ff_alloc_extradata(st->codecpar, dict_entries * 4 + 7);
72 AV_WB16(st->codecpar->extradata, dict_entries);
73 AV_WB32(st->codecpar->extradata + 2, compresstype);
74 avio_read(s->pb, st->codecpar->extradata + 6, dict_entries * 4);
76 st->codecpar->extradata[dict_entries * 4 + 6] = avio_r8(s->pb);
78 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
83 AVInputFormat ff_hcom_demuxer = {
85 .long_name = NULL_IF_CONFIG_SMALL("Macintosh HCOM"),
86 .read_probe = hcom_probe,
87 .read_header = hcom_read_header,
88 .read_packet = ff_pcm_read_packet,