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00026 #include "asterisk.h"
00027
00028 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 233693 $")
00029
00030 #include "asterisk/mod_format.h"
00031 #include "asterisk/module.h"
00032 #include "asterisk/endian.h"
00033
00034 #include "msgsm.h"
00035
00036
00037
00038
00039
00040 #define GSM_FRAME_SIZE 33
00041 #define GSM_SAMPLES 160
00042
00043
00044
00045 char gsm_silence[] =
00046 {0xD8,0x20,0xA2,0xE1,0x5A,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49
00047 ,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24
00048 ,0x92,0x49,0x24};
00049
00050
00051 static struct ast_frame *gsm_read(struct ast_filestream *s, int *whennext)
00052 {
00053 int res;
00054
00055 s->fr.frametype = AST_FRAME_VOICE;
00056 s->fr.subclass = AST_FORMAT_GSM;
00057 AST_FRAME_SET_BUFFER(&(s->fr), s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE)
00058 s->fr.mallocd = 0;
00059 if ((res = fread(s->fr.data.ptr, 1, GSM_FRAME_SIZE, s->f)) != GSM_FRAME_SIZE) {
00060 if (res)
00061 ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00062 return NULL;
00063 }
00064 *whennext = s->fr.samples = GSM_SAMPLES;
00065 return &s->fr;
00066 }
00067
00068 static int gsm_write(struct ast_filestream *fs, struct ast_frame *f)
00069 {
00070 int res;
00071 unsigned char gsm[2*GSM_FRAME_SIZE];
00072
00073 if (f->frametype != AST_FRAME_VOICE) {
00074 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00075 return -1;
00076 }
00077 if (f->subclass != AST_FORMAT_GSM) {
00078 ast_log(LOG_WARNING, "Asked to write non-GSM frame (%d)!\n", f->subclass);
00079 return -1;
00080 }
00081 if (!(f->datalen % 65)) {
00082
00083 int len=0;
00084 while(len < f->datalen) {
00085 conv65(f->data.ptr + len, gsm);
00086 if ((res = fwrite(gsm, 1, 2*GSM_FRAME_SIZE, fs->f)) != 2*GSM_FRAME_SIZE) {
00087 ast_log(LOG_WARNING, "Bad write (%d/66): %s\n", res, strerror(errno));
00088 return -1;
00089 }
00090 len += 65;
00091 }
00092 } else {
00093 if (f->datalen % GSM_FRAME_SIZE) {
00094 ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 33\n", f->datalen);
00095 return -1;
00096 }
00097 if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
00098 ast_log(LOG_WARNING, "Bad write (%d/33): %s\n", res, strerror(errno));
00099 return -1;
00100 }
00101 }
00102 return 0;
00103 }
00104
00105 static int gsm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
00106 {
00107 off_t offset=0,min,cur,max,distance;
00108
00109 min = 0;
00110 cur = ftello(fs->f);
00111 fseeko(fs->f, 0, SEEK_END);
00112 max = ftello(fs->f);
00113
00114 distance = (sample_offset/GSM_SAMPLES) * GSM_FRAME_SIZE;
00115 if(whence == SEEK_SET)
00116 offset = distance;
00117 else if(whence == SEEK_CUR || whence == SEEK_FORCECUR)
00118 offset = distance + cur;
00119 else if(whence == SEEK_END)
00120 offset = max - distance;
00121
00122 offset = (offset < min)?min:offset;
00123 if (whence != SEEK_FORCECUR) {
00124 offset = (offset > max)?max:offset;
00125 } else if (offset > max) {
00126 int i;
00127 fseeko(fs->f, 0, SEEK_END);
00128 for (i=0; i< (offset - max) / GSM_FRAME_SIZE; i++) {
00129 if (!fwrite(gsm_silence, 1, GSM_FRAME_SIZE, fs->f)) {
00130 ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00131 }
00132 }
00133 }
00134 return fseeko(fs->f, offset, SEEK_SET);
00135 }
00136
00137 static int gsm_trunc(struct ast_filestream *fs)
00138 {
00139 return ftruncate(fileno(fs->f), ftello(fs->f));
00140 }
00141
00142 static off_t gsm_tell(struct ast_filestream *fs)
00143 {
00144 off_t offset = ftello(fs->f);
00145 return (offset/GSM_FRAME_SIZE)*GSM_SAMPLES;
00146 }
00147
00148 static const struct ast_format gsm_f = {
00149 .name = "gsm",
00150 .exts = "gsm",
00151 .format = AST_FORMAT_GSM,
00152 .write = gsm_write,
00153 .seek = gsm_seek,
00154 .trunc = gsm_trunc,
00155 .tell = gsm_tell,
00156 .read = gsm_read,
00157 .buf_size = 2*GSM_FRAME_SIZE + AST_FRIENDLY_OFFSET,
00158 };
00159
00160 static int load_module(void)
00161 {
00162 if (ast_format_register(&gsm_f))
00163 return AST_MODULE_LOAD_FAILURE;
00164 return AST_MODULE_LOAD_SUCCESS;
00165 }
00166
00167 static int unload_module(void)
00168 {
00169 return ast_format_unregister(gsm_f.name);
00170 }
00171
00172 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Raw GSM data",
00173 .load = load_module,
00174 .unload = unload_module,
00175 .load_pri = 10,
00176 );