Mon May 14 04:42:56 2007

Asterisk developer's documentation


format_wav.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Work with WAV in the proprietary Microsoft format.
00022  * Microsoft WAV format (8000hz Signed Linear)
00023  * \arg File name extension: wav (lower case)
00024  * \ingroup formats
00025  */
00026  
00027 #include "asterisk.h"
00028 
00029 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
00030 
00031 #include <unistd.h>
00032 #include <netinet/in.h>
00033 #include <arpa/inet.h>
00034 #include <stdlib.h>
00035 #include <sys/time.h>
00036 #include <stdio.h>
00037 #include <errno.h>
00038 #include <string.h>
00039 
00040 #include "asterisk/lock.h"
00041 #include "asterisk/channel.h"
00042 #include "asterisk/file.h"
00043 #include "asterisk/logger.h"
00044 #include "asterisk/sched.h"
00045 #include "asterisk/module.h"
00046 #include "asterisk/endian.h"
00047 
00048 /* Some Ideas for this code came from makewave.c by Jeffrey Chilton */
00049 
00050 /* Portions of the conversion code are by guido@sienanet.it */
00051 
00052 #define  WAV_BUF_SIZE   320
00053 
00054 struct wav_desc { /* format-specific parameters */
00055    int bytes;
00056    int lasttimeout;
00057    int maxlen;
00058    struct timeval last;
00059 };
00060 
00061 #define BLOCKSIZE 160
00062 
00063 #define GAIN 0    /* 2^GAIN is the multiple to increase the volume by.  The original value of GAIN was 2, or 4x (12 dB),
00064           * but there were many reports of the clipping of loud signal peaks (issue 5823 for example). */
00065 
00066 #if __BYTE_ORDER == __LITTLE_ENDIAN
00067 #define htoll(b) (b)
00068 #define htols(b) (b)
00069 #define ltohl(b) (b)
00070 #define ltohs(b) (b)
00071 #else
00072 #if __BYTE_ORDER == __BIG_ENDIAN
00073 #define htoll(b)  \
00074           (((((b)      ) & 0xFF) << 24) | \
00075           ((((b) >>  8) & 0xFF) << 16) | \
00076          ((((b) >> 16) & 0xFF) <<  8) | \
00077          ((((b) >> 24) & 0xFF)      ))
00078 #define htols(b) \
00079           (((((b)      ) & 0xFF) << 8) | \
00080          ((((b) >> 8) & 0xFF)      ))
00081 #define ltohl(b) htoll(b)
00082 #define ltohs(b) htols(b)
00083 #else
00084 #error "Endianess not defined"
00085 #endif
00086 #endif
00087 
00088 
00089 static int check_header(FILE *f)
00090 {
00091    int type, size, formtype;
00092    int fmt, hsize;
00093    short format, chans, bysam, bisam;
00094    int bysec;
00095    int freq;
00096    int data;
00097    if (fread(&type, 1, 4, f) != 4) {
00098       ast_log(LOG_WARNING, "Read failed (type)\n");
00099       return -1;
00100    }
00101    if (fread(&size, 1, 4, f) != 4) {
00102       ast_log(LOG_WARNING, "Read failed (size)\n");
00103       return -1;
00104    }
00105    size = ltohl(size);
00106    if (fread(&formtype, 1, 4, f) != 4) {
00107       ast_log(LOG_WARNING, "Read failed (formtype)\n");
00108       return -1;
00109    }
00110    if (memcmp(&type, "RIFF", 4)) {
00111       ast_log(LOG_WARNING, "Does not begin with RIFF\n");
00112       return -1;
00113    }
00114    if (memcmp(&formtype, "WAVE", 4)) {
00115       ast_log(LOG_WARNING, "Does not contain WAVE\n");
00116       return -1;
00117    }
00118    if (fread(&fmt, 1, 4, f) != 4) {
00119       ast_log(LOG_WARNING, "Read failed (fmt)\n");
00120       return -1;
00121    }
00122    if (memcmp(&fmt, "fmt ", 4)) {
00123       ast_log(LOG_WARNING, "Does not say fmt\n");
00124       return -1;
00125    }
00126    if (fread(&hsize, 1, 4, f) != 4) {
00127       ast_log(LOG_WARNING, "Read failed (formtype)\n");
00128       return -1;
00129    }
00130    if (ltohl(hsize) < 16) {
00131       ast_log(LOG_WARNING, "Unexpected header size %d\n", ltohl(hsize));
00132       return -1;
00133    }
00134    if (fread(&format, 1, 2, f) != 2) {
00135       ast_log(LOG_WARNING, "Read failed (format)\n");
00136       return -1;
00137    }
00138    if (ltohs(format) != 1) {
00139       ast_log(LOG_WARNING, "Not a wav file %d\n", ltohs(format));
00140       return -1;
00141    }
00142    if (fread(&chans, 1, 2, f) != 2) {
00143       ast_log(LOG_WARNING, "Read failed (format)\n");
00144       return -1;
00145    }
00146    if (ltohs(chans) != 1) {
00147       ast_log(LOG_WARNING, "Not in mono %d\n", ltohs(chans));
00148       return -1;
00149    }
00150    if (fread(&freq, 1, 4, f) != 4) {
00151       ast_log(LOG_WARNING, "Read failed (freq)\n");
00152       return -1;
00153    }
00154    if (ltohl(freq) != DEFAULT_SAMPLE_RATE) {
00155       ast_log(LOG_WARNING, "Unexpected freqency %d\n", ltohl(freq));
00156       return -1;
00157    }
00158    /* Ignore the byte frequency */
00159    if (fread(&bysec, 1, 4, f) != 4) {
00160       ast_log(LOG_WARNING, "Read failed (BYTES_PER_SECOND)\n");
00161       return -1;
00162    }
00163    /* Check bytes per sample */
00164    if (fread(&bysam, 1, 2, f) != 2) {
00165       ast_log(LOG_WARNING, "Read failed (BYTES_PER_SAMPLE)\n");
00166       return -1;
00167    }
00168    if (ltohs(bysam) != 2) {
00169       ast_log(LOG_WARNING, "Can only handle 16bits per sample: %d\n", ltohs(bysam));
00170       return -1;
00171    }
00172    if (fread(&bisam, 1, 2, f) != 2) {
00173       ast_log(LOG_WARNING, "Read failed (Bits Per Sample): %d\n", ltohs(bisam));
00174       return -1;
00175    }
00176    /* Skip any additional header */
00177    if (fseek(f,ltohl(hsize)-16,SEEK_CUR) == -1 ) {
00178       ast_log(LOG_WARNING, "Failed to skip remaining header bytes: %d\n", ltohl(hsize)-16 );
00179       return -1;
00180    }
00181    /* Skip any facts and get the first data block */
00182    for(;;)
00183    { 
00184       char buf[4];
00185        
00186        /* Begin data chunk */
00187        if (fread(&buf, 1, 4, f) != 4) {
00188          ast_log(LOG_WARNING, "Read failed (data)\n");
00189          return -1;
00190        }
00191        /* Data has the actual length of data in it */
00192        if (fread(&data, 1, 4, f) != 4) {
00193          ast_log(LOG_WARNING, "Read failed (data)\n");
00194          return -1;
00195        }
00196        data = ltohl(data);
00197        if(memcmp(buf, "data", 4) == 0 ) 
00198          break;
00199        if(memcmp(buf, "fact", 4) != 0 ) {
00200          ast_log(LOG_WARNING, "Unknown block - not fact or data\n");
00201          return -1;
00202        }
00203        if (fseek(f,data,SEEK_CUR) == -1 ) {
00204          ast_log(LOG_WARNING, "Failed to skip fact block: %d\n", data );
00205          return -1;
00206        }
00207    }
00208 #if 0
00209    curpos = lseek(fd, 0, SEEK_CUR);
00210    truelength = lseek(fd, 0, SEEK_END);
00211    lseek(fd, curpos, SEEK_SET);
00212    truelength -= curpos;
00213 #endif   
00214    return data;
00215 }
00216 
00217 static int update_header(FILE *f)
00218 {
00219    off_t cur,end;
00220    int datalen,filelen,bytes;
00221    
00222    cur = ftello(f);
00223    fseek(f, 0, SEEK_END);
00224    end = ftello(f);
00225    /* data starts 44 bytes in */
00226    bytes = end - 44;
00227    datalen = htoll(bytes);
00228    /* chunk size is bytes of data plus 36 bytes of header */
00229    filelen = htoll(36 + bytes);
00230    
00231    if (cur < 0) {
00232       ast_log(LOG_WARNING, "Unable to find our position\n");
00233       return -1;
00234    }
00235    if (fseek(f, 4, SEEK_SET)) {
00236       ast_log(LOG_WARNING, "Unable to set our position\n");
00237       return -1;
00238    }
00239    if (fwrite(&filelen, 1, 4, f) != 4) {
00240       ast_log(LOG_WARNING, "Unable to set write file size\n");
00241       return -1;
00242    }
00243    if (fseek(f, 40, 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 set 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 }
00257 
00258 static int write_header(FILE *f)
00259 {
00260    unsigned int hz=htoll(8000);
00261    unsigned int bhz = htoll(16000);
00262    unsigned int hs = htoll(16);
00263    unsigned short fmt = htols(1);
00264    unsigned short chans = htols(1);
00265    unsigned short bysam = htols(2);
00266    unsigned short bisam = htols(16);
00267    unsigned int size = htoll(0);
00268    /* Write a wav header, ignoring sizes which will be filled in later */
00269    fseek(f,0,SEEK_SET);
00270    if (fwrite("RIFF", 1, 4, f) != 4) {
00271       ast_log(LOG_WARNING, "Unable to write header\n");
00272       return -1;
00273    }
00274    if (fwrite(&size, 1, 4, f) != 4) {
00275       ast_log(LOG_WARNING, "Unable to write header\n");
00276       return -1;
00277    }
00278    if (fwrite("WAVEfmt ", 1, 8, f) != 8) {
00279       ast_log(LOG_WARNING, "Unable to write header\n");
00280       return -1;
00281    }
00282    if (fwrite(&hs, 1, 4, f) != 4) {
00283       ast_log(LOG_WARNING, "Unable to write header\n");
00284       return -1;
00285    }
00286    if (fwrite(&fmt, 1, 2, f) != 2) {
00287       ast_log(LOG_WARNING, "Unable to write header\n");
00288       return -1;
00289    }
00290    if (fwrite(&chans, 1, 2, f) != 2) {
00291       ast_log(LOG_WARNING, "Unable to write header\n");
00292       return -1;
00293    }
00294    if (fwrite(&hz, 1, 4, f) != 4) {
00295       ast_log(LOG_WARNING, "Unable to write header\n");
00296       return -1;
00297    }
00298    if (fwrite(&bhz, 1, 4, f) != 4) {
00299       ast_log(LOG_WARNING, "Unable to write header\n");
00300       return -1;
00301    }
00302    if (fwrite(&bysam, 1, 2, f) != 2) {
00303       ast_log(LOG_WARNING, "Unable to write header\n");
00304       return -1;
00305    }
00306    if (fwrite(&bisam, 1, 2, f) != 2) {
00307       ast_log(LOG_WARNING, "Unable to write header\n");
00308       return -1;
00309    }
00310    if (fwrite("data", 1, 4, f) != 4) {
00311       ast_log(LOG_WARNING, "Unable to write header\n");
00312       return -1;
00313    }
00314    if (fwrite(&size, 1, 4, f) != 4) {
00315       ast_log(LOG_WARNING, "Unable to write header\n");
00316       return -1;
00317    }
00318    return 0;
00319 }
00320 
00321 static int wav_open(struct ast_filestream *s)
00322 {
00323    /* We don't have any header to read or anything really, but
00324       if we did, it would go here.  We also might want to check
00325       and be sure it's a valid file.  */
00326    struct wav_desc *tmp = (struct wav_desc *)s->private;
00327    if ((tmp->maxlen = check_header(s->f)) < 0)
00328       return -1;
00329    return 0;
00330 }
00331 
00332 static int wav_rewrite(struct ast_filestream *s, const char *comment)
00333 {
00334    /* We don't have any header to read or anything really, but
00335       if we did, it would go here.  We also might want to check
00336       and be sure it's a valid file.  */
00337 
00338    if (write_header(s->f))
00339       return -1;
00340    return 0;
00341 }
00342 
00343 static void wav_close(struct ast_filestream *s)
00344 {
00345    char zero = 0;
00346    struct wav_desc *fs = (struct wav_desc *)s->private;
00347    /* Pad to even length */
00348    if (fs->bytes & 0x1)
00349       fwrite(&zero, 1, 1, s->f);
00350 }
00351 
00352 static struct ast_frame *wav_read(struct ast_filestream *s, int *whennext)
00353 {
00354    int res;
00355    int samples;   /* actual samples read */
00356    short *tmp;
00357    int bytes = WAV_BUF_SIZE;  /* in bytes */
00358    off_t here;
00359    /* Send a frame from the file to the appropriate channel */
00360    struct wav_desc *fs = (struct wav_desc *)s->private;
00361 
00362    here = ftello(s->f);
00363    if (fs->maxlen - here < bytes)      /* truncate if necessary */
00364       bytes = fs->maxlen - here;
00365    if (bytes < 0)
00366       bytes = 0;
00367 /*    ast_log(LOG_DEBUG, "here: %d, maxlen: %d, bytes: %d\n", here, s->maxlen, bytes); */
00368    s->fr.frametype = AST_FRAME_VOICE;
00369    s->fr.subclass = AST_FORMAT_SLINEAR;
00370    s->fr.mallocd = 0;
00371    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, bytes);
00372    
00373    if ( (res = fread(s->fr.data, 1, s->fr.datalen, s->f)) <= 0 ) {
00374       if (res)
00375          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00376       return NULL;
00377    }
00378    s->fr.datalen = res;
00379    s->fr.samples = samples = res / 2;
00380 
00381    tmp = (short *)(s->fr.data);
00382 #if __BYTE_ORDER == __BIG_ENDIAN
00383    /* file format is little endian so we need to swap */
00384    for( x = 0; x < samples; x++)
00385       tmp[x] = (tmp[x] << 8) | ((tmp[x] & 0xff00) >> 8);
00386 #endif
00387    *whennext = samples;
00388    return &s->fr;
00389 }
00390 
00391 static int wav_write(struct ast_filestream *fs, struct ast_frame *f)
00392 {
00393    int x;
00394    short tmp[8000], *tmpi;
00395    struct wav_desc *s = (struct wav_desc *)fs->private;
00396    int res;
00397 
00398    if (f->frametype != AST_FRAME_VOICE) {
00399       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00400       return -1;
00401    }
00402    if (f->subclass != AST_FORMAT_SLINEAR) {
00403       ast_log(LOG_WARNING, "Asked to write non-SLINEAR frame (%d)!\n", f->subclass);
00404       return -1;
00405    }
00406    if (f->datalen > sizeof(tmp)) {
00407       ast_log(LOG_WARNING, "Data length is too long\n");
00408       return -1;
00409    }
00410    if (!f->datalen)
00411       return -1;
00412 
00413 #if 0
00414    printf("Data Length: %d\n", f->datalen);
00415 #endif   
00416 
00417    tmpi = f->data;
00418    /* Volume adjust here to accomodate */
00419    for (x=0;x<f->datalen/2;x++) {
00420       tmp[x] = tmpi[x];
00421 #if __BYTE_ORDER == __BIG_ENDIAN
00422       tmp[x] = (tmp[x] << 8) | ((tmp[x] & 0xff00) >> 8);
00423 #endif
00424    }
00425    if ((res = fwrite(tmp, 1, f->datalen, fs->f)) != f->datalen ) {
00426       ast_log(LOG_WARNING, "Bad write (%d): %s\n", res, strerror(errno));
00427       return -1;
00428    }
00429 
00430    s->bytes += f->datalen;
00431    update_header(fs->f);
00432       
00433    return 0;
00434 
00435 }
00436 
00437 static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
00438 {
00439    off_t min, max, cur, offset = 0, samples;
00440 
00441    samples = sample_offset * 2; /* SLINEAR is 16 bits mono, so sample_offset * 2 = bytes */
00442    min = 44; /* wav header is 44 bytes */
00443    cur = ftello(fs->f);
00444    fseeko(fs->f, 0, SEEK_END);
00445    max = ftello(fs->f);
00446    if (whence == SEEK_SET)
00447       offset = samples + min;
00448    else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
00449       offset = samples + cur;
00450    else if (whence == SEEK_END)
00451       offset = max - samples;
00452         if (whence != SEEK_FORCECUR) {
00453       offset = (offset > max)?max:offset;
00454    }
00455    /* always protect the header space. */
00456    offset = (offset < min)?min:offset;
00457    return fseeko(fs->f, offset, SEEK_SET);
00458 }
00459 
00460 static int wav_trunc(struct ast_filestream *fs)
00461 {
00462    if (ftruncate(fileno(fs->f), ftello(fs->f)))
00463       return -1;
00464    return update_header(fs->f);
00465 }
00466 
00467 static off_t wav_tell(struct ast_filestream *fs)
00468 {
00469    off_t offset;
00470    offset = ftello(fs->f);
00471    /* subtract header size to get samples, then divide by 2 for 16 bit samples */
00472    return (offset - 44)/2;
00473 }
00474 
00475 static const struct ast_format wav_f = {
00476    .name = "wav",
00477    .exts = "wav",
00478    .format = AST_FORMAT_SLINEAR,
00479    .open =  wav_open,
00480    .rewrite = wav_rewrite,
00481    .write = wav_write,
00482    .seek = wav_seek,
00483    .trunc = wav_trunc,
00484    .tell =  wav_tell,
00485    .read = wav_read,
00486    .close = wav_close,
00487    .buf_size = WAV_BUF_SIZE + AST_FRIENDLY_OFFSET,
00488    .desc_size = sizeof(struct wav_desc),
00489 };
00490 
00491 static int load_module(void)
00492 {
00493    return ast_format_register(&wav_f);
00494 }
00495 
00496 static int unload_module(void)
00497 {
00498    return ast_format_unregister(wav_f.name);
00499 }  
00500 
00501 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Microsoft WAV format (8000Hz Signed Linear)");

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