diff options
Diffstat (limited to 'trunk/formats/format_gsm.c')
| -rw-r--r-- | trunk/formats/format_gsm.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/trunk/formats/format_gsm.c b/trunk/formats/format_gsm.c new file mode 100644 index 000000000..d43844e64 --- /dev/null +++ b/trunk/formats/format_gsm.c @@ -0,0 +1,170 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 1999 - 2005, Digium, Inc. + * + * Mark Spencer <markster@digium.com> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/*! \file + * + * \brief Save to raw, headerless GSM data. + * \arg File name extension: gsm + * \ingroup formats + */ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/mod_format.h" +#include "asterisk/module.h" +#include "asterisk/endian.h" + +#include "msgsm.h" + +/* Some Ideas for this code came from makegsme.c by Jeffrey Chilton */ + +/* Portions of the conversion code are by guido@sienanet.it */ + +#define GSM_FRAME_SIZE 33 +#define GSM_SAMPLES 160 + +/* silent gsm frame */ +/* begin binary data: */ +char gsm_silence[] = /* 33 */ +{0xD8,0x20,0xA2,0xE1,0x5A,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49 +,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24 +,0x92,0x49,0x24}; +/* end binary data. size = 33 bytes */ + +static struct ast_frame *gsm_read(struct ast_filestream *s, int *whennext) +{ + int res; + + s->fr.frametype = AST_FRAME_VOICE; + s->fr.subclass = AST_FORMAT_GSM; + AST_FRAME_SET_BUFFER(&(s->fr), s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE) + s->fr.mallocd = 0; + if ((res = fread(s->fr.data, 1, GSM_FRAME_SIZE, s->f)) != GSM_FRAME_SIZE) { + if (res) + ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno)); + return NULL; + } + *whennext = s->fr.samples = GSM_SAMPLES; + return &s->fr; +} + +static int gsm_write(struct ast_filestream *fs, struct ast_frame *f) +{ + int res; + unsigned char gsm[2*GSM_FRAME_SIZE]; + + if (f->frametype != AST_FRAME_VOICE) { + ast_log(LOG_WARNING, "Asked to write non-voice frame!\n"); + return -1; + } + if (f->subclass != AST_FORMAT_GSM) { + ast_log(LOG_WARNING, "Asked to write non-GSM frame (%d)!\n", f->subclass); + return -1; + } + if (!(f->datalen % 65)) { + /* This is in MSGSM format, need to be converted */ + int len=0; + while(len < f->datalen) { + conv65(f->data + len, gsm); + if ((res = fwrite(gsm, 1, 2*GSM_FRAME_SIZE, fs->f)) != 2*GSM_FRAME_SIZE) { + ast_log(LOG_WARNING, "Bad write (%d/66): %s\n", res, strerror(errno)); + return -1; + } + len += 65; + } + } else { + if (f->datalen % GSM_FRAME_SIZE) { + ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 33\n", f->datalen); + return -1; + } + if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) { + ast_log(LOG_WARNING, "Bad write (%d/33): %s\n", res, strerror(errno)); + return -1; + } + } + return 0; +} + +static int gsm_seek(struct ast_filestream *fs, off_t sample_offset, int whence) +{ + off_t offset=0,min,cur,max,distance; + + min = 0; + cur = ftello(fs->f); + fseeko(fs->f, 0, SEEK_END); + max = ftello(fs->f); + /* have to fudge to frame here, so not fully to sample */ + distance = (sample_offset/GSM_SAMPLES) * GSM_FRAME_SIZE; + if(whence == SEEK_SET) + offset = distance; + else if(whence == SEEK_CUR || whence == SEEK_FORCECUR) + offset = distance + cur; + else if(whence == SEEK_END) + offset = max - distance; + /* Always protect against seeking past the begining. */ + offset = (offset < min)?min:offset; + if (whence != SEEK_FORCECUR) { + offset = (offset > max)?max:offset; + } else if (offset > max) { + int i; + fseeko(fs->f, 0, SEEK_END); + for (i=0; i< (offset - max) / GSM_FRAME_SIZE; i++) { + fwrite(gsm_silence, 1, GSM_FRAME_SIZE, fs->f); + } + } + return fseeko(fs->f, offset, SEEK_SET); +} + +static int gsm_trunc(struct ast_filestream *fs) +{ + return ftruncate(fileno(fs->f), ftello(fs->f)); +} + +static off_t gsm_tell(struct ast_filestream *fs) +{ + off_t offset = ftello(fs->f); + return (offset/GSM_FRAME_SIZE)*GSM_SAMPLES; +} + +static const struct ast_format gsm_f = { + .name = "gsm", + .exts = "gsm", + .format = AST_FORMAT_GSM, + .write = gsm_write, + .seek = gsm_seek, + .trunc = gsm_trunc, + .tell = gsm_tell, + .read = gsm_read, + .buf_size = 2*GSM_FRAME_SIZE + AST_FRIENDLY_OFFSET, /* 2 gsm frames */ +}; + +static int load_module(void) +{ + if (ast_format_register(&gsm_f)) + return AST_MODULE_LOAD_FAILURE; + return AST_MODULE_LOAD_SUCCESS; +} + +static int unload_module(void) +{ + return ast_format_unregister(gsm_f.name); +} + +AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw GSM data"); |