Wed Jan 8 2020 09:49:47

Asterisk developer's documentation


format_g719.c
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1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2010, Anthony Minessale and Digium, Inc.
5  * Anthony Minessale (anthmct@yahoo.com)
6  * Kevin P. Fleming <kpfleming@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  */
18 
19 /*! \file
20  *
21  * \brief ITU G.719 , 64kbps bitrate only
22  * \arg File name extensions: g719
23  * \ingroup formats
24  */
25 
26 /*** MODULEINFO
27  <support_level>core</support_level>
28  ***/
29 
30 #include "asterisk.h"
31 
32 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 364578 $")
33 
34 #include "asterisk/mod_format.h"
35 #include "asterisk/module.h"
36 #include "asterisk/endian.h"
37 
38 #define BUF_SIZE 160 /* 20 milliseconds == 160 bytes, 960 samples */
39 #define SAMPLES_TO_BYTES(x) ((typeof(x)) x / ((float) 960 / 160))
40 #define BYTES_TO_SAMPLES(x) ((typeof(x)) x * ((float) 960 / 160))
41 
42 static struct ast_frame *g719read(struct ast_filestream *s, int *whennext)
43 {
44  int res;
45  /* Send a frame from the file to the appropriate channel */
46 
49  s->fr.mallocd = 0;
51  if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
52  if (res)
53  ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
54  return NULL;
55  }
56  *whennext = s->fr.samples = BYTES_TO_SAMPLES(res);
57  return &s->fr;
58 }
59 
60 static int g719write(struct ast_filestream *fs, struct ast_frame *f)
61 {
62  int res;
63 
64  if (f->frametype != AST_FRAME_VOICE) {
65  ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
66  return -1;
67  }
68  if (f->subclass.codec != AST_FORMAT_G719) {
69  ast_log(LOG_WARNING, "Asked to write non-G.719 frame (%s)!\n", ast_getformatname(f->subclass.codec));
70  return -1;
71  }
72  if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
73  ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
74  return -1;
75  }
76  return 0;
77 }
78 
79 static int g719seek(struct ast_filestream *fs, off_t sample_offset, int whence)
80 {
81  off_t offset = 0, min = 0, cur, max;
82 
83  sample_offset = SAMPLES_TO_BYTES(sample_offset);
84 
85  if ((cur = ftello(fs->f)) < 0) {
86  ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
87  return -1;
88  }
89 
90  if (fseeko(fs->f, 0, SEEK_END) < 0) {
91  ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
92  return -1;
93  }
94 
95  if ((max = ftello(fs->f)) < 0) {
96  ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
97  return -1;
98  }
99 
100  if (whence == SEEK_SET)
101  offset = sample_offset;
102  else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
103  offset = sample_offset + cur;
104  else if (whence == SEEK_END)
105  offset = max - sample_offset;
106 
107  if (whence != SEEK_FORCECUR)
108  offset = (offset > max) ? max : offset;
109 
110  /* always protect against seeking past begining. */
111  offset = (offset < min) ? min : offset;
112 
113  return fseeko(fs->f, offset, SEEK_SET);
114 }
115 
116 static int g719trunc(struct ast_filestream *fs)
117 {
118  int fd;
119  off_t cur;
120 
121  if ((fd = fileno(fs->f)) < 0) {
122  ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for g719 filestream %p: %s\n", fs, strerror(errno));
123  return -1;
124  }
125  if ((cur = ftello(fs->f)) < 0) {
126  ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
127  return -1;
128  }
129  return ftruncate(fd, cur);
130 }
131 
132 static off_t g719tell(struct ast_filestream *fs)
133 {
134  return BYTES_TO_SAMPLES(ftello(fs->f));
135 }
136 
137 static const struct ast_format g719_f = {
138  .name = "g719",
139  .exts = "g719",
140  .format = AST_FORMAT_G719,
141  .write = g719write,
142  .seek = g719seek,
143  .trunc = g719trunc,
144  .tell = g719tell,
145  .read = g719read,
146  .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
147 };
148 
149 static int load_module(void)
150 {
151  if (ast_format_register(&g719_f))
153 
155 }
156 
157 static int unload_module(void)
158 {
159  return ast_format_unregister(g719_f.name);
160 }
161 
163  .load = load_module,
164  .unload = unload_module,
165  .load_pri = AST_MODPRI_APP_DEPEND
166 );
167 
union ast_frame_subclass subclass
Definition: frame.h:146
#define BUF_SIZE
Definition: format_g719.c:38
Asterisk main include file. File version handling, generic pbx functions.
#define ast_format_register(f)
Definition: mod_format.h:131
int offset
Definition: frame.h:156
static int g719trunc(struct ast_filestream *fs)
Definition: format_g719.c:116
void * ptr
Definition: frame.h:160
#define LOG_WARNING
Definition: logger.h:144
#define AST_LOG_WARNING
Definition: logger.h:149
Each supported file format is described by the following structure.
Definition: mod_format.h:43
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...)
Definition: module.h:374
format_t codec
Definition: frame.h:137
static int g719write(struct ast_filestream *fs, struct ast_frame *f)
Definition: format_g719.c:60
#define AST_FRAME_SET_BUFFER(fr, _base, _ofs, _datalen)
Definition: frame.h:183
static int unload_module(void)
Definition: format_g719.c:157
#define AST_FRIENDLY_OFFSET
Offset into a frame&#39;s data buffer.
Definition: frame.h:204
Asterisk architecture endianess compatibility definitions.
int datalen
Definition: frame.h:148
struct ast_frame fr
Definition: mod_format.h:117
int ast_format_unregister(const char *name)
Unregisters a file format.
Definition: file.c:104
char * ast_getformatname(format_t format)
Get the name of a format.
Definition: frame.c:578
char name[80]
Definition: mod_format.h:44
static int load_module(void)
Definition: format_g719.c:149
static off_t g719tell(struct ast_filestream *fs)
Definition: format_g719.c:132
void ast_log(int level, const char *file, int line, const char *function, const char *fmt,...)
Used for sending a log message This is the standard logger function. Probably the only way you will i...
Definition: logger.c:1207
static struct ast_format g719_f
Definition: format_g719.c:137
int errno
#define SEEK_FORCECUR
Definition: file.h:50
static struct ast_format f[]
Definition: format_g726.c:181
int mallocd
Definition: frame.h:152
This structure is allocated by file.c in one chunk, together with buf_size and desc_size bytes of mem...
Definition: mod_format.h:100
#define AST_FORMAT_G719
Definition: frame.h:299
Data structure associated with a single frame of data.
Definition: frame.h:142
enum ast_frame_type frametype
Definition: frame.h:144
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:38
Asterisk module definitions.
union ast_frame::@172 data
static int g719seek(struct ast_filestream *fs, off_t sample_offset, int whence)
Definition: format_g719.c:79
#define BYTES_TO_SAMPLES(x)
Definition: format_g719.c:40
static struct ast_frame * g719read(struct ast_filestream *s, int *whennext)
Definition: format_g719.c:42
#define SAMPLES_TO_BYTES(x)
Definition: format_g719.c:39
#define ASTERISK_FILE_VERSION(file, version)
Register/unregister a source code file with the core.
Definition: asterisk.h:180
int samples
Definition: frame.h:150