xref: /third_party/ffmpeg/libavformat/adp.c (revision cabdff1a)
1/*
2 * ADP demuxer
3 * Copyright (c) 2013 James Almer
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 "internal.h"
26
27static int adp_probe(const AVProbeData *p)
28{
29    int i, changes = 0;
30    uint8_t last = 0;
31
32    if (p->buf_size < 32)
33        return 0;
34
35    for (i = 0; i < p->buf_size - 3; i+=32) {
36        if (p->buf[i] != p->buf[i+2] || p->buf[i+1] != p->buf[i+3])
37            return 0;
38        if (p->buf[i] != last)
39            changes++;
40        last = p->buf[i];
41    }
42    if (changes <= 1)
43        return 0;
44
45    return p->buf_size < 260 ? 1 : AVPROBE_SCORE_MAX / 4;
46}
47
48static int adp_read_header(AVFormatContext *s)
49{
50    AVStream *st;
51
52    st = avformat_new_stream(s, NULL);
53    if (!st)
54        return AVERROR(ENOMEM);
55
56    st->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
57    st->codecpar->codec_id       = AV_CODEC_ID_ADPCM_DTK;
58    st->codecpar->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
59    st->codecpar->sample_rate    = 48000;
60    st->start_time            = 0;
61    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
62        st->duration          = av_get_audio_frame_duration2(st->codecpar, avio_size(s->pb));
63
64    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
65
66    return 0;
67}
68
69static int adp_read_packet(AVFormatContext *s, AVPacket *pkt)
70{
71    int ret, size = 1024;
72
73    if (avio_feof(s->pb))
74        return AVERROR_EOF;
75
76    ret = av_get_packet(s->pb, pkt, size);
77    if (ret < 0)
78        return ret;
79
80    pkt->stream_index = 0;
81
82    return ret;
83}
84
85const AVInputFormat ff_adp_demuxer = {
86    .name           = "adp",
87    .long_name      = NULL_IF_CONFIG_SMALL("ADP"),
88    .read_probe     = adp_probe,
89    .read_header    = adp_read_header,
90    .read_packet    = adp_read_packet,
91    .extensions     = "adp,dtk",
92};
93