FFmpeg
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 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  * @see http://wiki.multimedia.cx/index.php?title=FunCom_ISS
27  */
28 
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 IssDemuxContext {
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(const 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  if (sscanf(token, "%d", &iss->packet_size) != 1) {
80  av_log(s, AV_LOG_ERROR, "Failed parsing packet size\n");
81  return AVERROR_INVALIDDATA;
82  }
83  get_token(pb, token, sizeof(token)); //File ID
84  get_token(pb, token, sizeof(token)); //out size
85  get_token(pb, token, sizeof(token)); //stereo
86  if (sscanf(token, "%d", &stereo) != 1) {
87  av_log(s, AV_LOG_ERROR, "Failed parsing stereo flag\n");
88  return AVERROR_INVALIDDATA;
89  }
90  get_token(pb, token, sizeof(token)); //Unknown1
91  get_token(pb, token, sizeof(token)); //RateDivisor
92  if (sscanf(token, "%d", &rate_divisor) != 1) {
93  av_log(s, AV_LOG_ERROR, "Failed parsing rate_divisor\n");
94  return AVERROR_INVALIDDATA;
95  }
96  get_token(pb, token, sizeof(token)); //Unknown2
97  get_token(pb, token, sizeof(token)); //Version ID
98  get_token(pb, token, sizeof(token)); //Size
99 
100  if (iss->packet_size <= 0) {
101  av_log(s, AV_LOG_ERROR, "packet_size %d is invalid\n", iss->packet_size);
102  return AVERROR_INVALIDDATA;
103  }
104 
105  iss->sample_start_pos = avio_tell(pb);
106 
107  st = avformat_new_stream(s, NULL);
108  if (!st)
109  return AVERROR(ENOMEM);
112  if (stereo) {
113  st->codecpar->channels = 2;
115  } else {
116  st->codecpar->channels = 1;
118  }
119  st->codecpar->sample_rate = 44100;
120  if(rate_divisor > 0)
121  st->codecpar->sample_rate /= rate_divisor;
125  st->codecpar->block_align = iss->packet_size;
126  avpriv_set_pts_info(st, 32, 1, st->codecpar->sample_rate);
127 
128  return 0;
129 }
130 
132 {
133  IssDemuxContext *iss = s->priv_data;
134  int ret = av_get_packet(s->pb, pkt, iss->packet_size);
135 
136  if(ret != iss->packet_size)
137  return AVERROR(EIO);
138 
139  pkt->stream_index = 0;
140  pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
141  if(s->streams[0]->codecpar->channels > 0)
142  pkt->pts /= s->streams[0]->codecpar->channels*2;
143  return 0;
144 }
145 
147  .name = "iss",
148  .long_name = NULL_IF_CONFIG_SMALL("Funcom ISS"),
149  .priv_data_size = sizeof(IssDemuxContext),
153 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AVInputFormat ff_iss_demuxer
Definition: iss.c:146
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:4929
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
Format I/O context.
Definition: avformat.h:1358
#define av_cold
Definition: attributes.h:82
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4502
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
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:310
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4070
#define av_log(a,...)
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3997
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
static av_cold int iss_read_header(AVFormatContext *s)
Definition: iss.c:69
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:641
#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:448
#define ISS_SIG
Definition: iss.c:34
int block_align
Audio only.
Definition: avcodec.h:4085
audio channel layout utility functions
#define s(width, name)
Definition: cbs_vp9.c:257
#define ISS_SIG_LEN
Definition: iss.c:35
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void * buf
Definition: avisynth_c.h:766
int packet_size
Definition: iss.c:39
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int sample_start_pos
Definition: iss.c:40
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
int sample_rate
Audio only.
Definition: avcodec.h:4078
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
static int iss_probe(const AVProbeData *p)
Definition: iss.c:61
void * priv_data
Format private data.
Definition: avformat.h:1386
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4010
int channels
Audio only.
Definition: avcodec.h:4074
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int stream_index
Definition: avcodec.h:1482
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: iss.c:131
This structure stores compressed data.
Definition: avcodec.h:1457
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1473