1/*
2 * ISS (.iss) file demuxer
3 * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
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
24 * Funcom ISS file demuxer
25 * @author Jaikrishnan Menon
26 * for more information on the .iss file format, visit:
27 * http://wiki.multimedia.cx/index.php?title=FunCom_ISS
28 */
29
30#include "avformat.h"
31#include "libavutil/avstring.h"
32
33#define ISS_SIG "IMA_ADPCM_Sound"
34#define ISS_SIG_LEN 15
35#define MAX_TOKEN_SIZE 20
36
37typedef struct {
38    int packet_size;
39    int sample_start_pos;
40} IssDemuxContext;
41
42static void get_token(ByteIOContext *s, char *buf, int maxlen)
43{
44    int i = 0;
45    char c;
46
47    while ((c = get_byte(s))) {
48        if(c == ' ')
49            break;
50        if (i < maxlen-1)
51            buf[i++] = c;
52    }
53
54    if(!c)
55        get_byte(s);
56
57    buf[i] = 0; /* Ensure null terminated, but may be truncated */
58}
59
60static int iss_probe(AVProbeData *p)
61{
62    if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
63        return 0;
64
65    return AVPROBE_SCORE_MAX;
66}
67
68static av_cold int iss_read_header(AVFormatContext *s, AVFormatParameters *ap)
69{
70    IssDemuxContext *iss = s->priv_data;
71    ByteIOContext *pb = s->pb;
72    AVStream *st;
73    char token[MAX_TOKEN_SIZE];
74    int stereo, rate_divisor;
75
76    get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound"
77    get_token(pb, token, sizeof(token)); //packet size
78    sscanf(token, "%d", &iss->packet_size);
79    get_token(pb, token, sizeof(token)); //File ID
80    get_token(pb, token, sizeof(token)); //out size
81    get_token(pb, token, sizeof(token)); //stereo
82    sscanf(token, "%d", &stereo);
83    get_token(pb, token, sizeof(token)); //Unknown1
84    get_token(pb, token, sizeof(token)); //RateDivisor
85    sscanf(token, "%d", &rate_divisor);
86    get_token(pb, token, sizeof(token)); //Unknown2
87    get_token(pb, token, sizeof(token)); //Version ID
88    get_token(pb, token, sizeof(token)); //Size
89
90    iss->sample_start_pos = url_ftell(pb);
91
92    st = av_new_stream(s, 0);
93    if (!st)
94        return AVERROR(ENOMEM);
95    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
96    st->codec->codec_id = CODEC_ID_ADPCM_IMA_ISS;
97    st->codec->channels = stereo ? 2 : 1;
98    st->codec->sample_rate = 44100;
99    if(rate_divisor > 0)
100         st->codec->sample_rate /= rate_divisor;
101    st->codec->bits_per_coded_sample = 4;
102    st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
103                                      * st->codec->bits_per_coded_sample;
104    st->codec->block_align = iss->packet_size;
105    av_set_pts_info(st, 32, 1, st->codec->sample_rate);
106
107    return 0;
108}
109
110static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
111{
112    IssDemuxContext *iss = s->priv_data;
113    int ret = av_get_packet(s->pb, pkt, iss->packet_size);
114
115    if(ret != iss->packet_size)
116        return AVERROR(EIO);
117
118    pkt->stream_index = 0;
119    pkt->pts = url_ftell(s->pb) - iss->sample_start_pos;
120    if(s->streams[0]->codec->channels > 0)
121        pkt->pts /= s->streams[0]->codec->channels*2;
122    return 0;
123}
124
125AVInputFormat iss_demuxer = {
126    "ISS",
127    NULL_IF_CONFIG_SMALL("Funcom ISS format"),
128    sizeof(IssDemuxContext),
129    iss_probe,
130    iss_read_header,
131    iss_read_packet,
132};
133
134