Libav
iss.c
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1 /*
2  * ISS (.iss) file demuxer
3  * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
30 #include "avformat.h"
31 #include "internal.h"
32 #include "libavutil/avstring.h"
33 
34 #define ISS_SIG "IMA_ADPCM_Sound"
35 #define ISS_SIG_LEN 15
36 #define MAX_TOKEN_SIZE 20
37 
38 typedef struct {
42 
43 static void get_token(AVIOContext *s, char *buf, int maxlen)
44 {
45  int i = 0;
46  char c;
47 
48  while ((c = avio_r8(s))) {
49  if(c == ' ')
50  break;
51  if (i < maxlen-1)
52  buf[i++] = c;
53  }
54 
55  if(!c)
56  avio_r8(s);
57 
58  buf[i] = 0; /* Ensure null terminated, but may be truncated */
59 }
60 
61 static int iss_probe(AVProbeData *p)
62 {
63  if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
64  return 0;
65 
66  return AVPROBE_SCORE_MAX;
67 }
68 
70 {
71  IssDemuxContext *iss = s->priv_data;
72  AVIOContext *pb = s->pb;
73  AVStream *st;
74  char token[MAX_TOKEN_SIZE];
75  int stereo, rate_divisor;
76 
77  get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound"
78  get_token(pb, token, sizeof(token)); //packet size
79  sscanf(token, "%d", &iss->packet_size);
80  get_token(pb, token, sizeof(token)); //File ID
81  get_token(pb, token, sizeof(token)); //out size
82  get_token(pb, token, sizeof(token)); //stereo
83  sscanf(token, "%d", &stereo);
84  get_token(pb, token, sizeof(token)); //Unknown1
85  get_token(pb, token, sizeof(token)); //RateDivisor
86  sscanf(token, "%d", &rate_divisor);
87  get_token(pb, token, sizeof(token)); //Unknown2
88  get_token(pb, token, sizeof(token)); //Version ID
89  get_token(pb, token, sizeof(token)); //Size
90 
91  iss->sample_start_pos = avio_tell(pb);
92 
93  st = avformat_new_stream(s, NULL);
94  if (!st)
95  return AVERROR(ENOMEM);
98  if (stereo) {
99  st->codec->channels = 2;
101  } else {
102  st->codec->channels = 1;
104  }
105  st->codec->sample_rate = 44100;
106  if(rate_divisor > 0)
107  st->codec->sample_rate /= rate_divisor;
108  st->codec->bits_per_coded_sample = 4;
109  st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
111  st->codec->block_align = iss->packet_size;
112  avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate);
113 
114  return 0;
115 }
116 
118 {
119  IssDemuxContext *iss = s->priv_data;
120  int ret = av_get_packet(s->pb, pkt, iss->packet_size);
121 
122  if(ret != iss->packet_size)
123  return AVERROR(EIO);
124 
125  pkt->stream_index = 0;
126  pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
127  if(s->streams[0]->codec->channels > 0)
128  pkt->pts /= s->streams[0]->codec->channels*2;
129  return 0;
130 }
131 
133  .name = "iss",
134  .long_name = NULL_IF_CONFIG_SMALL("Funcom ISS"),
135  .priv_data_size = sizeof(IssDemuxContext),
139 };
Bytestream IO Context.
Definition: avio.h:68
AVInputFormat ff_iss_demuxer
Definition: iss.c:132
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:2829
#define AV_CH_LAYOUT_STEREO
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:1844
Format I/O context.
Definition: avformat.h:922
#define av_cold
Definition: attributes.h:66
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2521
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:990
static void get_token(AVIOContext *s, char *buf, int maxlen)
Definition: iss.c:43
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:117
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:219
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2523
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
static av_cold int iss_read_header(AVFormatContext *s)
Definition: iss.c:69
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1868
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:443
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:718
#define MAX_TOKEN_SIZE
Definition: iss.c:36
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:397
#define ISS_SIG
Definition: iss.c:34
int bit_rate
the average bitrate
Definition: avcodec.h:1114
audio channel layout utility functions
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
#define ISS_SIG_LEN
Definition: iss.c:35
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:544
Stream structure.
Definition: avformat.h:699
NULL
Definition: eval.c:55
enum AVMediaType codec_type
Definition: avcodec.h:1058
enum AVCodecID codec_id
Definition: avcodec.h:1067
int sample_rate
samples per second
Definition: avcodec.h:1807
AVIOContext * pb
I/O context.
Definition: avformat.h:964
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
int packet_size
Definition: iss.c:39
This structure contains the data a format has to probe a file.
Definition: avformat.h:395
static int iss_probe(AVProbeData *p)
Definition: iss.c:61
int sample_start_pos
Definition: iss.c:40
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:404
Main libavformat public API header.
int channels
number of audio channels
Definition: avcodec.h:1808
void * priv_data
Format private data.
Definition: avformat.h:950
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:525
int stream_index
Definition: avcodec.h:975
#define AV_CH_LAYOUT_MONO
static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: iss.c:117
This structure stores compressed data.
Definition: avcodec.h:950
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:966