424 lines
9.7 KiB
C
Executable File
424 lines
9.7 KiB
C
Executable File
/*
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* Asterisk -- A telephony toolkit for Linux.
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*
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* Flat, binary, ADPCM vox file format.
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*
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* Copyright (C) 1999, Mark Spencer
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*
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* Mark Spencer <markster@linux-support.net>
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License
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*/
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#include <asterisk/lock.h>
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#include <asterisk/channel.h>
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#include <asterisk/file.h>
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#include <asterisk/logger.h>
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#include <asterisk/sched.h>
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#include <asterisk/module.h>
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#include <arpa/inet.h>
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#include <stdlib.h>
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#include <sys/time.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <pthread.h>
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#include <endian.h>
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#define BUF_SIZE 80 /* 160 samples */
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struct ast_filestream {
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void *reserved[AST_RESERVED_POINTERS];
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/* Believe it or not, we must decode/recode to account for the
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weird MS format */
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/* This is what a filestream means to us */
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int fd; /* Descriptor */
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struct ast_channel *owner;
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struct ast_frame fr; /* Frame information */
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char waste[AST_FRIENDLY_OFFSET]; /* Buffer for sending frames, etc */
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char empty; /* Empty character */
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unsigned char buf[BUF_SIZE + 3]; /* Output Buffer */
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int lasttimeout;
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struct timeval last;
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int adj;
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short signal; /* Signal level (file side) */
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short ssindex; /* Signal ssindex (file side) */
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struct ast_filestream *next;
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};
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static struct ast_filestream *glist = NULL;
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static pthread_mutex_t vox_lock = AST_MUTEX_INITIALIZER;
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static int glistcnt = 0;
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static char *name = "vox";
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static char *desc = "Dialogic VOX (ADPCM) File Format";
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static char *exts = "vox";
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/*
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* Step size index shift table
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*/
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static short indsft[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
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/*
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* Step size table, where stpsz[i]=floor[16*(11/10)^i]
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*/
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static short stpsz[49] = {
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16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73,
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80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279,
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307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963,
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1060, 1166, 1282, 1411, 1552
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};
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/*
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* Nibble to bit map
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*/
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static short nbl2bit[16][4] = {
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{1, 0, 0, 0}, {1, 0, 0, 1}, {1, 0, 1, 0}, {1, 0, 1, 1},
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{1, 1, 0, 0}, {1, 1, 0, 1}, {1, 1, 1, 0}, {1, 1, 1, 1},
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{-1, 0, 0, 0}, {-1, 0, 0, 1}, {-1, 0, 1, 0}, {-1, 0, 1, 1},
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{-1, 1, 0, 0}, {-1, 1, 0, 1}, {-1, 1, 1, 0}, {-1, 1, 1, 1}
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};
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/*
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* Decode(encoded)
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* Decodes the encoded nibble from the adpcm file.
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*
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* Results:
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* Returns the encoded difference.
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*
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* Side effects:
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* Sets the index to the step size table for the next encode.
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*/
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static inline short
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decode (unsigned char encoded, short *ssindex)
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{
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short diff, step;
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step = stpsz[*ssindex];
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diff = nbl2bit[encoded][0] * (step * nbl2bit[encoded][1] +
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(step >> 1) * nbl2bit[encoded][2] +
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(step >> 2) * nbl2bit[encoded][3] +
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(step >> 3));
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*ssindex = *ssindex + indsft[(encoded & 7)];
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if (*ssindex < 0)
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*ssindex = 0;
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else if (*ssindex > 48)
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*ssindex = 48;
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return (diff);
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}
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/*
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* Adpcm
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* Takes a signed linear signal and encodes it as ADPCM
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* For more information see http://support.dialogic.com/appnotes/adpcm.pdf
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*
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* Results:
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* Foo.
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*
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* Side effects:
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* signal gets updated with each pass.
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*/
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static inline unsigned char
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adpcm (short csig, short *ssindex, short *signal)
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{
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short diff, step;
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unsigned char encoded;
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step = stpsz[*ssindex];
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/*
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* Clip csig if too large or too small
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*/
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csig >>= 4;
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diff = csig - *signal;
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if (diff < 0)
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{
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encoded = 8;
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diff = -diff;
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}
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else
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encoded = 0;
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if (diff >= step)
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{
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encoded |= 4;
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diff -= step;
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}
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step >>= 1;
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if (diff >= step)
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{
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encoded |= 2;
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diff -= step;
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}
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step >>= 1;
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if (diff >= step)
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encoded |= 1;
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*signal += decode (encoded, ssindex);
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return (encoded);
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}
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static struct ast_filestream *vox_open(int fd)
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{
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/* We don't have any header to read or anything really, but
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if we did, it would go here. We also might want to check
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and be sure it's a valid file. */
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struct ast_filestream *tmp;
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if ((tmp = malloc(sizeof(struct ast_filestream)))) {
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memset(tmp, 0, sizeof(struct ast_filestream));
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if (ast_pthread_mutex_lock(&vox_lock)) {
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ast_log(LOG_WARNING, "Unable to lock vox list\n");
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free(tmp);
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return NULL;
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}
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tmp->next = glist;
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glist = tmp;
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tmp->fd = fd;
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tmp->owner = NULL;
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tmp->fr.data = tmp->buf;
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tmp->fr.frametype = AST_FRAME_VOICE;
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tmp->fr.subclass = AST_FORMAT_ADPCM;
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/* datalen will vary for each frame */
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tmp->fr.src = name;
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tmp->fr.mallocd = 0;
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tmp->lasttimeout = -1;
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glistcnt++;
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ast_pthread_mutex_unlock(&vox_lock);
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ast_update_use_count();
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}
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return tmp;
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}
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static struct ast_filestream *vox_rewrite(int fd, char *comment)
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{
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/* We don't have any header to read or anything really, but
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if we did, it would go here. We also might want to check
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and be sure it's a valid file. */
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struct ast_filestream *tmp;
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if ((tmp = malloc(sizeof(struct ast_filestream)))) {
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memset(tmp, 0, sizeof(struct ast_filestream));
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if (ast_pthread_mutex_lock(&vox_lock)) {
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ast_log(LOG_WARNING, "Unable to lock vox list\n");
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free(tmp);
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return NULL;
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}
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tmp->next = glist;
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glist = tmp;
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tmp->fd = fd;
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tmp->owner = NULL;
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tmp->lasttimeout = -1;
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glistcnt++;
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ast_pthread_mutex_unlock(&vox_lock);
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ast_update_use_count();
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} else
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ast_log(LOG_WARNING, "Out of memory\n");
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return tmp;
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}
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static struct ast_frame *vox_read(struct ast_filestream *s)
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{
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return NULL;
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}
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static void vox_close(struct ast_filestream *s)
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{
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struct ast_filestream *tmp, *tmpl = NULL;
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if (ast_pthread_mutex_lock(&vox_lock)) {
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ast_log(LOG_WARNING, "Unable to lock vox list\n");
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return;
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}
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tmp = glist;
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while(tmp) {
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if (tmp == s) {
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if (tmpl)
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tmpl->next = tmp->next;
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else
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glist = tmp->next;
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break;
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}
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tmpl = tmp;
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tmp = tmp->next;
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}
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glistcnt--;
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if (s->owner) {
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s->owner->stream = NULL;
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if (s->owner->streamid > -1)
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ast_sched_del(s->owner->sched, s->owner->streamid);
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s->owner->streamid = -1;
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}
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ast_pthread_mutex_unlock(&vox_lock);
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ast_update_use_count();
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if (!tmp)
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ast_log(LOG_WARNING, "Freeing a filestream we don't seem to own\n");
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close(s->fd);
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free(s);
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}
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static int ast_read_callback(void *data)
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{
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int retval = 0;
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int res;
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int delay;
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struct ast_filestream *s = data;
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struct timeval tv;
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int x;
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/* Send a frame from the file to the appropriate channel */
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s->fr.frametype = AST_FRAME_VOICE;
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s->fr.subclass = AST_FORMAT_ADPCM;
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s->fr.offset = AST_FRIENDLY_OFFSET;
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s->fr.mallocd = 0;
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s->fr.data = s->buf;
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if ((res = read(s->fd, s->buf + 3, BUF_SIZE)) < 1) {
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if (res)
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ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
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s->owner->streamid = -1;
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return 0;
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}
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/* Store index, then signal */
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s->buf[0] = s->ssindex & 0xff;
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s->buf[1] = (s->signal >> 8) & 0xff;
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s->buf[2] = s->signal & 0xff;
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/* Do the decoder to be sure we get the right stuff in the signal and index fields. */
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for (x=3;x<res+3;x++) {
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s->signal += decode(s->buf[x] >> 4, &s->ssindex);
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s->signal += decode(s->buf[x] & 0xf, &s->ssindex);
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}
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s->fr.timelen = res / 4;
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s->fr.datalen = res + 3;
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delay = s->fr.timelen;
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/* Lastly, process the frame */
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if (ast_write(s->owner, &s->fr)) {
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ast_log(LOG_WARNING, "Failed to write frame\n");
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s->owner->streamid = -1;
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return 0;
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}
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if (s->last.tv_usec || s->last.tv_usec) {
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int ms;
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gettimeofday(&tv, NULL);
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ms = 1000 * (tv.tv_sec - s->last.tv_sec) +
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(tv.tv_usec - s->last.tv_usec) / 1000;
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s->last.tv_sec = tv.tv_sec;
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s->last.tv_usec = tv.tv_usec;
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if ((ms - delay) * (ms - delay) > 4) {
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/* Compensate if we're more than 2 ms off */
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s->adj -= (ms - delay);
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}
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#if 0
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fprintf(stdout, "Delay is %d, adjustment is %d, last was %d\n", delay, s->adj, ms);
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#endif
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delay += s->adj;
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if (delay < 1)
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delay = 1;
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} else
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gettimeofday(&s->last, NULL);
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if (s->lasttimeout != delay) {
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/* We'll install the next timeout now. */
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s->owner->streamid = ast_sched_add(s->owner->sched,
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delay, ast_read_callback, s);
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s->lasttimeout = delay;
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} else {
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/* Just come back again at the same time */
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retval = -1;
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}
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return retval;
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}
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static int vox_apply(struct ast_channel *c, struct ast_filestream *s)
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{
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/* Select our owner for this stream, and get the ball rolling. */
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s->owner = c;
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ast_read_callback(s);
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return 0;
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}
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static int vox_write(struct ast_filestream *fs, struct ast_frame *f)
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{
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int res;
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if (f->frametype != AST_FRAME_VOICE) {
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ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
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return -1;
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}
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if (f->subclass != AST_FORMAT_ADPCM) {
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ast_log(LOG_WARNING, "Asked to write non-ADPCM frame (%d)!\n", f->subclass);
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return -1;
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}
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if (f->datalen < 3) {
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ast_log(LOG_WARNING, "Invalid frame of data (< 3 bytes long) from %s\n", f->src);
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return -1;
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}
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if ((res = write(fs->fd, f->data + 3, f->datalen)) != f->datalen) {
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ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
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return -1;
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}
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return 0;
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}
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static char *vox_getcomment(struct ast_filestream *s)
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{
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return NULL;
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}
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int load_module()
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{
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return ast_format_register(name, exts, AST_FORMAT_ADPCM,
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vox_open,
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vox_rewrite,
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vox_apply,
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vox_write,
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vox_read,
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vox_close,
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vox_getcomment);
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}
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int unload_module()
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{
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struct ast_filestream *tmp, *tmpl;
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if (ast_pthread_mutex_lock(&vox_lock)) {
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ast_log(LOG_WARNING, "Unable to lock vox list\n");
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return -1;
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}
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tmp = glist;
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while(tmp) {
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if (tmp->owner)
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ast_softhangup(tmp->owner);
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tmpl = tmp;
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tmp = tmp->next;
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free(tmpl);
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}
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ast_pthread_mutex_unlock(&vox_lock);
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return ast_format_unregister(name);
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}
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int usecount()
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{
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int res;
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if (ast_pthread_mutex_lock(&vox_lock)) {
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ast_log(LOG_WARNING, "Unable to lock vox list\n");
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return -1;
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}
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res = glistcnt;
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ast_pthread_mutex_unlock(&vox_lock);
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return res;
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}
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char *description()
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{
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return desc;
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}
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char *key()
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{
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return ASTERISK_GPL_KEY;
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}
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