Mon Aug 31 12:30:36 2015

Asterisk developer's documentation


format_wav_gsm.c File Reference

Save GSM in the proprietary Microsoft format. More...

#include "asterisk.h"
#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
#include "msgsm.h"

Go to the source code of this file.

Data Structures

struct  wavg_desc

Defines

#define GSM_FRAME_SIZE   33
#define GSM_SAMPLES   160
#define htoll(b)   (b)
#define htols(b)   (b)
#define ltohl(b)   (b)
#define ltohs(b)   (b)
#define MSGSM_DATA_OFFSET   60
#define MSGSM_FRAME_SIZE   65
#define MSGSM_SAMPLES   (2*GSM_SAMPLES)

Functions

 AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER,"Microsoft WAV format (Proprietary GSM)",.load=load_module,.unload=unload_module,.load_pri=AST_MODPRI_APP_DEPEND)
static int check_header (FILE *f)
static int load_module (void)
static int unload_module (void)
static int update_header (FILE *f)
static int wav_open (struct ast_filestream *s)
static struct ast_framewav_read (struct ast_filestream *s, int *whennext)
static int wav_rewrite (struct ast_filestream *s, const char *comment)
static int wav_seek (struct ast_filestream *fs, off_t sample_offset, int whence)
static off_t wav_tell (struct ast_filestream *fs)
static int wav_trunc (struct ast_filestream *fs)
static int wav_write (struct ast_filestream *s, struct ast_frame *f)
static int write_header (FILE *f)

Variables

static char msgsm_silence []
static struct ast_format wav49_f

Detailed Description

Save GSM in the proprietary Microsoft format.

Microsoft WAV format (Proprietary GSM)

Definition in file format_wav_gsm.c.


Define Documentation

#define GSM_FRAME_SIZE   33

Definition at line 48 of file format_wav_gsm.c.

#define GSM_SAMPLES   160

Definition at line 51 of file format_wav_gsm.c.

#define htoll (  )     (b)

Definition at line 70 of file format_wav_gsm.c.

#define htols (  )     (b)

Definition at line 71 of file format_wav_gsm.c.

#define ltohl (  )     (b)

Definition at line 72 of file format_wav_gsm.c.

#define ltohs (  )     (b)

Definition at line 73 of file format_wav_gsm.c.

#define MSGSM_DATA_OFFSET   60

Definition at line 50 of file format_wav_gsm.c.

Referenced by update_header(), wav_seek(), and wav_tell().

#define MSGSM_FRAME_SIZE   65

Definition at line 49 of file format_wav_gsm.c.

Referenced by update_header(), wav_read(), wav_seek(), wav_tell(), wav_write(), and write_header().

#define MSGSM_SAMPLES   (2*GSM_SAMPLES)

Definition at line 52 of file format_wav_gsm.c.

Referenced by update_header(), wav_seek(), wav_tell(), and write_header().


Function Documentation

AST_MODULE_INFO ( ASTERISK_GPL_KEY  ,
AST_MODFLAG_LOAD_ORDER  ,
"Microsoft WAV format (Proprietary GSM)"  ,
load = load_module,
unload = unload_module,
load_pri = AST_MODPRI_APP_DEPEND 
)
static int check_header ( FILE *  f  )  [static]

Definition at line 92 of file format_wav_gsm.c.

References ast_log(), DEFAULT_SAMPLE_RATE, format, LOG_WARNING, ltohl, ltohs, and type.

Referenced by wav_open().

00093 {
00094    int type, size, formtype;
00095    int fmt, hsize, fact;
00096    short format, chans;
00097    int freq;
00098    int data;
00099    if (fread(&type, 1, 4, f) != 4) {
00100       ast_log(LOG_WARNING, "Read failed (type)\n");
00101       return -1;
00102    }
00103    if (fread(&size, 1, 4, f) != 4) {
00104       ast_log(LOG_WARNING, "Read failed (size)\n");
00105       return -1;
00106    }
00107    size = ltohl(size);
00108    if (fread(&formtype, 1, 4, f) != 4) {
00109       ast_log(LOG_WARNING, "Read failed (formtype)\n");
00110       return -1;
00111    }
00112    if (memcmp(&type, "RIFF", 4)) {
00113       ast_log(LOG_WARNING, "Does not begin with RIFF\n");
00114       return -1;
00115    }
00116    if (memcmp(&formtype, "WAVE", 4)) {
00117       ast_log(LOG_WARNING, "Does not contain WAVE\n");
00118       return -1;
00119    }
00120    if (fread(&fmt, 1, 4, f) != 4) {
00121       ast_log(LOG_WARNING, "Read failed (fmt)\n");
00122       return -1;
00123    }
00124    if (memcmp(&fmt, "fmt ", 4)) {
00125       ast_log(LOG_WARNING, "Does not say fmt\n");
00126       return -1;
00127    }
00128    if (fread(&hsize, 1, 4, f) != 4) {
00129       ast_log(LOG_WARNING, "Read failed (formtype)\n");
00130       return -1;
00131    }
00132    if (ltohl(hsize) != 20) {
00133       ast_log(LOG_WARNING, "Unexpected header size %d\n", ltohl(hsize));
00134       return -1;
00135    }
00136    if (fread(&format, 1, 2, f) != 2) {
00137       ast_log(LOG_WARNING, "Read failed (format)\n");
00138       return -1;
00139    }
00140    if (ltohs(format) != 49) {
00141       ast_log(LOG_WARNING, "Not a GSM file %d\n", ltohs(format));
00142       return -1;
00143    }
00144    if (fread(&chans, 1, 2, f) != 2) {
00145       ast_log(LOG_WARNING, "Read failed (format)\n");
00146       return -1;
00147    }
00148    if (ltohs(chans) != 1) {
00149       ast_log(LOG_WARNING, "Not in mono %d\n", ltohs(chans));
00150       return -1;
00151    }
00152    if (fread(&freq, 1, 4, f) != 4) {
00153       ast_log(LOG_WARNING, "Read failed (freq)\n");
00154       return -1;
00155    }
00156    if (ltohl(freq) != DEFAULT_SAMPLE_RATE) {
00157       ast_log(LOG_WARNING, "Unexpected frequency %d\n", ltohl(freq));
00158       return -1;
00159    }
00160    /* Ignore the byte frequency */
00161    if (fread(&freq, 1, 4, f) != 4) {
00162       ast_log(LOG_WARNING, "Read failed (X_1)\n");
00163       return -1;
00164    }
00165    /* Ignore the two weird fields */
00166    if (fread(&freq, 1, 4, f) != 4) {
00167       ast_log(LOG_WARNING, "Read failed (X_2/X_3)\n");
00168       return -1;
00169    }
00170    /* Ignore the byte frequency */
00171    if (fread(&freq, 1, 4, f) != 4) {
00172       ast_log(LOG_WARNING, "Read failed (Y_1)\n");
00173       return -1;
00174    }
00175    /* Check for the word fact */
00176    if (fread(&fact, 1, 4, f) != 4) {
00177       ast_log(LOG_WARNING, "Read failed (fact)\n");
00178       return -1;
00179    }
00180    if (memcmp(&fact, "fact", 4)) {
00181       ast_log(LOG_WARNING, "Does not say fact\n");
00182       return -1;
00183    }
00184    /* Ignore the "fact value" */
00185    if (fread(&fact, 1, 4, f) != 4) {
00186       ast_log(LOG_WARNING, "Read failed (fact header)\n");
00187       return -1;
00188    }
00189    if (fread(&fact, 1, 4, f) != 4) {
00190       ast_log(LOG_WARNING, "Read failed (fact value)\n");
00191       return -1;
00192    }
00193    /* Check for the word data */
00194    if (fread(&data, 1, 4, f) != 4) {
00195       ast_log(LOG_WARNING, "Read failed (data)\n");
00196       return -1;
00197    }
00198    if (memcmp(&data, "data", 4)) {
00199       ast_log(LOG_WARNING, "Does not say data\n");
00200       return -1;
00201    }
00202    /* Ignore the data length */
00203    if (fread(&data, 1, 4, f) != 4) {
00204       ast_log(LOG_WARNING, "Read failed (data)\n");
00205       return -1;
00206    }
00207    return 0;
00208 }

static int load_module ( void   )  [static]

Definition at line 568 of file format_wav_gsm.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, and AST_MODULE_LOAD_SUCCESS.

00569 {
00570    if (ast_format_register(&wav49_f))
00571       return AST_MODULE_LOAD_FAILURE;
00572    return AST_MODULE_LOAD_SUCCESS;
00573 }

static int unload_module ( void   )  [static]

Definition at line 575 of file format_wav_gsm.c.

References ast_format_unregister(), and ast_format::name.

00576 {
00577    return ast_format_unregister(wav49_f.name);
00578 }

static int update_header ( FILE *  f  )  [static]

Definition at line 210 of file format_wav_gsm.c.

References ast_log(), htoll, LOG_WARNING, MSGSM_DATA_OFFSET, MSGSM_FRAME_SIZE, and MSGSM_SAMPLES.

Referenced by wav_trunc(), and wav_write().

00211 {
00212    off_t cur,end,bytes;
00213    int datalen, filelen, samples;
00214 
00215    cur = ftello(f);
00216    fseek(f, 0, SEEK_END);
00217    end = ftello(f);
00218    /* in a gsm WAV, data starts 60 bytes in */
00219    bytes = end - MSGSM_DATA_OFFSET;
00220    samples = htoll(bytes / MSGSM_FRAME_SIZE * MSGSM_SAMPLES);
00221    datalen = htoll(bytes);
00222    filelen = htoll(MSGSM_DATA_OFFSET - 8 + bytes);
00223    if (cur < 0) {
00224       ast_log(LOG_WARNING, "Unable to find our position\n");
00225       return -1;
00226    }
00227    if (fseek(f, 4, SEEK_SET)) {
00228       ast_log(LOG_WARNING, "Unable to set our position\n");
00229       return -1;
00230    }
00231    if (fwrite(&filelen, 1, 4, f) != 4) {
00232       ast_log(LOG_WARNING, "Unable to write file size\n");
00233       return -1;
00234    }
00235    if (fseek(f, 48, SEEK_SET)) {
00236       ast_log(LOG_WARNING, "Unable to set our position\n");
00237       return -1;
00238    }
00239    if (fwrite(&samples, 1, 4, f) != 4) {
00240       ast_log(LOG_WARNING, "Unable to write samples\n");
00241       return -1;
00242    }
00243    if (fseek(f, 56, SEEK_SET)) {
00244       ast_log(LOG_WARNING, "Unable to set our position\n");
00245       return -1;
00246    }
00247    if (fwrite(&datalen, 1, 4, f) != 4) {
00248       ast_log(LOG_WARNING, "Unable to write datalen\n");
00249       return -1;
00250    }
00251    if (fseeko(f, cur, SEEK_SET)) {
00252       ast_log(LOG_WARNING, "Unable to return to position\n");
00253       return -1;
00254    }
00255    return 0;
00256 }

static int wav_open ( struct ast_filestream s  )  [static]

Definition at line 372 of file format_wav_gsm.c.

References ast_filestream::_private, check_header(), ast_filestream::f, and wavg_desc::secondhalf.

00373 {
00374    /* We don't have any header to read or anything really, but
00375       if we did, it would go here.  We also might want to check
00376       and be sure it's a valid file.  */
00377    struct wavg_desc *fs = (struct wavg_desc *)s->_private;
00378 
00379    if (check_header(s->f))
00380       return -1;
00381    fs->secondhalf = 0;  /* not strictly necessary */
00382    return 0;
00383 }

static struct ast_frame* wav_read ( struct ast_filestream s,
int *  whennext 
) [static, read]

Definition at line 396 of file format_wav_gsm.c.

References ast_filestream::_private, AST_FORMAT_GSM, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), ast_filestream::buf, ast_frame_subclass::codec, conv65(), ast_frame::data, errno, ast_filestream::f, ast_filestream::fr, ast_frame::frametype, GSM_FRAME_SIZE, GSM_SAMPLES, LOG_WARNING, ast_frame::mallocd, MSGSM_FRAME_SIZE, ast_frame::offset, ast_frame::ptr, ast_frame::samples, wavg_desc::secondhalf, and ast_frame::subclass.

00397 {
00398    /* Send a frame from the file to the appropriate channel */
00399    struct wavg_desc *fs = (struct wavg_desc *)s->_private;
00400 
00401    s->fr.frametype = AST_FRAME_VOICE;
00402    s->fr.subclass.codec = AST_FORMAT_GSM;
00403    s->fr.offset = AST_FRIENDLY_OFFSET;
00404    s->fr.samples = GSM_SAMPLES;
00405    s->fr.mallocd = 0;
00406    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE);
00407    if (fs->secondhalf) {
00408       /* Just return a frame based on the second GSM frame */
00409       s->fr.data.ptr = (char *)s->fr.data.ptr + GSM_FRAME_SIZE;
00410       s->fr.offset += GSM_FRAME_SIZE;
00411    } else {
00412       /* read and convert */
00413       unsigned char msdata[MSGSM_FRAME_SIZE];
00414       int res;
00415       
00416       if ((res = fread(msdata, 1, MSGSM_FRAME_SIZE, s->f)) != MSGSM_FRAME_SIZE) {
00417          if (res && (res != 1))
00418             ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00419          return NULL;
00420       }
00421       /* Convert from MS format to two real GSM frames */
00422       conv65(msdata, s->fr.data.ptr);
00423    }
00424    fs->secondhalf = !fs->secondhalf;
00425    *whennext = GSM_SAMPLES;
00426    return &s->fr;
00427 }

static int wav_rewrite ( struct ast_filestream s,
const char *  comment 
) [static]

Definition at line 385 of file format_wav_gsm.c.

References ast_filestream::f, and write_header().

00386 {
00387    /* We don't have any header to read or anything really, but
00388       if we did, it would go here.  We also might want to check
00389       and be sure it's a valid file.  */
00390 
00391    if (write_header(s->f))
00392       return -1;
00393    return 0;
00394 }

static int wav_seek ( struct ast_filestream fs,
off_t  sample_offset,
int  whence 
) [static]

Definition at line 476 of file format_wav_gsm.c.

References ast_filestream::_private, ast_log(), AST_LOG_WARNING, errno, ast_filestream::f, LOG_WARNING, MSGSM_DATA_OFFSET, MSGSM_FRAME_SIZE, MSGSM_SAMPLES, wavg_desc::secondhalf, and SEEK_FORCECUR.

00477 {
00478    off_t offset = 0, min = MSGSM_DATA_OFFSET, distance, max, cur;
00479    struct wavg_desc *s = (struct wavg_desc *)fs->_private;
00480 
00481    if ((cur = ftello(fs->f)) < 0) {
00482       ast_log(AST_LOG_WARNING, "Unable to determine current position in WAV filestream %p: %s\n", fs, strerror(errno));
00483       return -1;
00484    }
00485 
00486    if (fseeko(fs->f, 0, SEEK_END) < 0) {
00487       ast_log(AST_LOG_WARNING, "Unable to seek to end of WAV filestream %p: %s\n", fs, strerror(errno));
00488       return -1;
00489    }
00490 
00491    /* XXX ideally, should round correctly */
00492    if ((max = ftello(fs->f)) < 0) {
00493       ast_log(AST_LOG_WARNING, "Unable to determine max position in WAV filestream %p: %s\n", fs, strerror(errno));
00494       return -1;
00495    }
00496 
00497    /* Compute the distance in bytes, rounded to the block size */
00498    distance = (sample_offset/MSGSM_SAMPLES) * MSGSM_FRAME_SIZE;
00499    if (whence == SEEK_SET)
00500       offset = distance + min;
00501    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00502       offset = distance + cur;
00503    else if (whence == SEEK_END)
00504       offset = max - distance;
00505    /* always protect against seeking past end of header */
00506    if (offset < min)
00507       offset = min;
00508    if (whence != SEEK_FORCECUR) {
00509       if (offset > max)
00510          offset = max;
00511    } else if (offset > max) {
00512       int i;
00513       fseek(fs->f, 0, SEEK_END);
00514       for (i=0; i< (offset - max) / MSGSM_FRAME_SIZE; i++) {
00515          if (!fwrite(msgsm_silence, 1, MSGSM_FRAME_SIZE, fs->f)) {
00516             ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00517          }
00518       }
00519    }
00520    s->secondhalf = 0;
00521    return fseeko(fs->f, offset, SEEK_SET);
00522 }

static off_t wav_tell ( struct ast_filestream fs  )  [static]

Definition at line 544 of file format_wav_gsm.c.

References ast_filestream::f, MSGSM_DATA_OFFSET, MSGSM_FRAME_SIZE, and MSGSM_SAMPLES.

00545 {
00546    off_t offset;
00547    offset = ftello(fs->f);
00548    /* since this will most likely be used later in play or record, lets stick
00549     * to that level of resolution, just even frames boundaries */
00550    return (offset - MSGSM_DATA_OFFSET)/MSGSM_FRAME_SIZE*MSGSM_SAMPLES;
00551 }

static int wav_trunc ( struct ast_filestream fs  )  [static]

Definition at line 524 of file format_wav_gsm.c.

References ast_log(), AST_LOG_WARNING, errno, ast_filestream::f, and update_header().

00525 {
00526    int fd;
00527    off_t cur;
00528 
00529    if ((fd = fileno(fs->f)) < 0) {
00530       ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for WAV filestream %p: %s\n", fs, strerror(errno));
00531       return -1;
00532    }
00533    if ((cur = ftello(fs->f)) < 0) {
00534       ast_log(AST_LOG_WARNING, "Unable to determine current position in WAV filestream %p: %s\n", fs, strerror(errno));
00535       return -1;
00536    }
00537    /* Truncate file to current length */
00538    if (ftruncate(fd, cur)) {
00539       return -1;
00540    }
00541    return update_header(fs->f);
00542 }

static int wav_write ( struct ast_filestream s,
struct ast_frame f 
) [static]

Definition at line 429 of file format_wav_gsm.c.

References ast_filestream::_private, AST_FORMAT_GSM, AST_FRAME_VOICE, ast_getformatname(), ast_log(), ast_filestream::buf, ast_frame_subclass::codec, conv66(), ast_frame::data, ast_frame::datalen, errno, ast_filestream::f, ast_frame::frametype, GSM_FRAME_SIZE, len(), LOG_WARNING, MSGSM_FRAME_SIZE, ast_frame::ptr, wavg_desc::secondhalf, ast_frame::subclass, and update_header().

00430 {
00431    int len;
00432    int size;
00433    struct wavg_desc *fs = (struct wavg_desc *)s->_private;
00434 
00435    if (f->frametype != AST_FRAME_VOICE) {
00436       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00437       return -1;
00438    }
00439    if (f->subclass.codec != AST_FORMAT_GSM) {
00440       ast_log(LOG_WARNING, "Asked to write non-GSM frame (%s)!\n", ast_getformatname(f->subclass.codec));
00441       return -1;
00442    }
00443    /* XXX this might fail... if the input is a multiple of MSGSM_FRAME_SIZE
00444     * we assume it is already in the correct format.
00445     */
00446    if (!(f->datalen % MSGSM_FRAME_SIZE)) {
00447       size = MSGSM_FRAME_SIZE;
00448       fs->secondhalf = 0;
00449    } else {
00450       size = GSM_FRAME_SIZE;
00451    }
00452    for (len = 0; len < f->datalen ; len += size) {
00453       int res;
00454       unsigned char *src, msdata[MSGSM_FRAME_SIZE];
00455       if (fs->secondhalf) {   /* second half of raw gsm to be converted */
00456          memcpy(s->buf + GSM_FRAME_SIZE, f->data.ptr + len, GSM_FRAME_SIZE);
00457          conv66((unsigned char *) s->buf, msdata);
00458          src = msdata;
00459          fs->secondhalf = 0;
00460       } else if (size == GSM_FRAME_SIZE) {   /* first half of raw gsm */
00461          memcpy(s->buf, f->data.ptr + len, GSM_FRAME_SIZE);
00462          src = NULL; /* nothing to write */
00463          fs->secondhalf = 1;
00464       } else { /* raw msgsm data */
00465          src = f->data.ptr + len;
00466       }
00467       if (src && (res = fwrite(src, 1, MSGSM_FRAME_SIZE, s->f)) != MSGSM_FRAME_SIZE) {
00468          ast_log(LOG_WARNING, "Bad write (%d/65): %s\n", res, strerror(errno));
00469          return -1;
00470       }
00471       update_header(s->f); /* XXX inefficient! */
00472    }
00473    return 0;
00474 }

static int write_header ( FILE *  f  )  [static]

Definition at line 258 of file format_wav_gsm.c.

References ast_log(), htoll, htols, LOG_WARNING, MSGSM_FRAME_SIZE, and MSGSM_SAMPLES.

Referenced by wav_rewrite().

00259 {
00260    /* Samples per second (always 8000 for this format). */
00261    unsigned int sample_rate = htoll(8000);
00262    /* Bytes per second (always 1625 for this format). */
00263    unsigned int byte_sample_rate = htoll(1625);
00264    /* This is the size of the "fmt " subchunk */
00265    unsigned int fmtsize = htoll(20);
00266    /* WAV #49 */
00267    unsigned short fmt = htols(49);
00268    /* Mono = 1 channel */
00269    unsigned short chans = htols(1);
00270    /* Each block of data is exactly 65 bytes in size. */
00271    unsigned int block_align = htoll(MSGSM_FRAME_SIZE);
00272    /* Not actually 2, but rounded up to the nearest bit */
00273    unsigned short bits_per_sample = htols(2);
00274    /* Needed for compressed formats */
00275    unsigned short extra_format = htols(MSGSM_SAMPLES);
00276    /* This is the size of the "fact" subchunk */
00277    unsigned int factsize = htoll(4);
00278    /* Number of samples in the data chunk */
00279    unsigned int num_samples = htoll(0);
00280    /* Number of bytes in the data chunk */
00281    unsigned int size = htoll(0);
00282    /* Write a GSM header, ignoring sizes which will be filled in later */
00283 
00284    /*  0: Chunk ID */
00285    if (fwrite("RIFF", 1, 4, f) != 4) {
00286       ast_log(LOG_WARNING, "Unable to write header\n");
00287       return -1;
00288    }
00289    /*  4: Chunk Size */
00290    if (fwrite(&size, 1, 4, f) != 4) {
00291       ast_log(LOG_WARNING, "Unable to write header\n");
00292       return -1;
00293    }
00294    /*  8: Chunk Format */
00295    if (fwrite("WAVE", 1, 4, f) != 4) {
00296       ast_log(LOG_WARNING, "Unable to write header\n");
00297       return -1;
00298    }
00299    /* 12: Subchunk 1: ID */
00300    if (fwrite("fmt ", 1, 4, f) != 4) {
00301       ast_log(LOG_WARNING, "Unable to write header\n");
00302       return -1;
00303    }
00304    /* 16: Subchunk 1: Size (minus 8) */
00305    if (fwrite(&fmtsize, 1, 4, f) != 4) {
00306       ast_log(LOG_WARNING, "Unable to write header\n");
00307       return -1;
00308    }
00309    /* 20: Subchunk 1: Audio format (49) */
00310    if (fwrite(&fmt, 1, 2, f) != 2) {
00311       ast_log(LOG_WARNING, "Unable to write header\n");
00312       return -1;
00313    }
00314    /* 22: Subchunk 1: Number of channels */
00315    if (fwrite(&chans, 1, 2, f) != 2) {
00316       ast_log(LOG_WARNING, "Unable to write header\n");
00317       return -1;
00318    }
00319    /* 24: Subchunk 1: Sample rate */
00320    if (fwrite(&sample_rate, 1, 4, f) != 4) {
00321       ast_log(LOG_WARNING, "Unable to write header\n");
00322       return -1;
00323    }
00324    /* 28: Subchunk 1: Byte rate */
00325    if (fwrite(&byte_sample_rate, 1, 4, f) != 4) {
00326       ast_log(LOG_WARNING, "Unable to write header\n");
00327       return -1;
00328    }
00329    /* 32: Subchunk 1: Block align */
00330    if (fwrite(&block_align, 1, 4, f) != 4) {
00331       ast_log(LOG_WARNING, "Unable to write header\n");
00332       return -1;
00333    }
00334    /* 36: Subchunk 1: Bits per sample */
00335    if (fwrite(&bits_per_sample, 1, 2, f) != 2) {
00336       ast_log(LOG_WARNING, "Unable to write header\n");
00337       return -1;
00338    }
00339    /* 38: Subchunk 1: Extra format bytes */
00340    if (fwrite(&extra_format, 1, 2, f) != 2) {
00341       ast_log(LOG_WARNING, "Unable to write header\n");
00342       return -1;
00343    }
00344    /* 40: Subchunk 2: ID */
00345    if (fwrite("fact", 1, 4, f) != 4) {
00346       ast_log(LOG_WARNING, "Unable to write header\n");
00347       return -1;
00348    }
00349    /* 44: Subchunk 2: Size (minus 8) */
00350    if (fwrite(&factsize, 1, 4, f) != 4) {
00351       ast_log(LOG_WARNING, "Unable to write header\n");
00352       return -1;
00353    }
00354    /* 48: Subchunk 2: Number of samples */
00355    if (fwrite(&num_samples, 1, 4, f) != 4) {
00356       ast_log(LOG_WARNING, "Unable to write header\n");
00357       return -1;
00358    }
00359    /* 52: Subchunk 3: ID */
00360    if (fwrite("data", 1, 4, f) != 4) {
00361       ast_log(LOG_WARNING, "Unable to write header\n");
00362       return -1;
00363    }
00364    /* 56: Subchunk 3: Size */
00365    if (fwrite(&size, 1, 4, f) != 4) {
00366       ast_log(LOG_WARNING, "Unable to write header\n");
00367       return -1;
00368    }
00369    return 0;
00370 }


Variable Documentation

char msgsm_silence[] [static]

Definition at line 55 of file format_wav_gsm.c.

struct ast_format wav49_f [static]

Definition at line 553 of file format_wav_gsm.c.


Generated on 31 Aug 2015 for Asterisk - The Open Source Telephony Project by  doxygen 1.6.1