[Asterisk-cvs] asterisk/formats format_vox.c,1.7,1.8
markster at lists.digium.com
markster at lists.digium.com
Thu Oct 2 18:16:21 CDT 2003
Update of /usr/cvsroot/asterisk/formats
In directory mongoose.digium.com:/tmp/cvs-serv4193/formats
Modified Files:
format_vox.c
Log Message:
Minor ADPCM quality enhancements
Index: format_vox.c
===================================================================
RCS file: /usr/cvsroot/asterisk/formats/format_vox.c,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -d -r1.7 -r1.8
--- format_vox.c 21 Sep 2003 02:59:26 -0000 1.7
+++ format_vox.c 2 Oct 2003 23:17:32 -0000 1.8
@@ -33,6 +33,7 @@
#endif
#define BUF_SIZE 80 /* 160 samples */
+#define BUF_SHIFT 5
struct ast_filestream {
void *reserved[AST_RESERVED_POINTERS];
@@ -41,11 +42,13 @@
struct ast_frame fr; /* Frame information */
char waste[AST_FRIENDLY_OFFSET]; /* Buffer for sending frames, etc */
char empty; /* Empty character */
- unsigned char buf[BUF_SIZE + 3]; /* Output Buffer */
+ unsigned char buf[BUF_SIZE + BUF_SHIFT]; /* Output Buffer */
int lasttimeout;
struct timeval last;
short signal; /* Signal level (file side) */
short ssindex; /* Signal ssindex (file side) */
+ unsigned char zero_count; /* counter of consecutive zero samples */
+ unsigned char next_flag;
};
@@ -95,21 +98,48 @@
* Sets the index to the step size table for the next encode.
*/
-static inline short
-decode (unsigned char encoded, short *ssindex)
+static inline void
+decode (unsigned char encoded, short *ssindex, short *signal, unsigned char *rkey, unsigned char *next)
{
short diff, step;
step = stpsz[*ssindex];
- diff = nbl2bit[encoded][0] * (step * nbl2bit[encoded][1] +
- (step >> 1) * nbl2bit[encoded][2] +
- (step >> 2) * nbl2bit[encoded][3] +
- (step >> 3));
+
+ diff = step * nbl2bit[encoded][1] +
+ (step >> 1) * nbl2bit[encoded][2] +
+ (step >> 2) * nbl2bit[encoded][3] +
+ (step >> 3);
+ if (nbl2bit[encoded][2] && (step & 0x1))
+ diff++;
+ diff *= nbl2bit[encoded][0];
+
+ if ( *next & 0x1 )
+ *signal -= 8;
+ else if ( *next & 0x2 )
+ *signal += 8;
+
+ *signal += diff;
+
+ if (*signal > 2047)
+ *signal = 2047;
+ else if (*signal < -2047)
+ *signal = -2047;
+
+ *next = 0;
+ if( encoded & 0x7 )
+ *rkey = 0;
+ else if ( ++(*rkey) == 24 ) {
+ *rkey = 0;
+ if (*signal > 0)
+ *next = 0x1;
+ else if (*signal < 0)
+ *next = 0x2;
+ }
+
*ssindex = *ssindex + indsft[(encoded & 7)];
if (*ssindex < 0)
*ssindex = 0;
else if (*ssindex > 48)
*ssindex = 48;
- return (diff);
}
/*
@@ -129,6 +159,7 @@
{
short diff, step;
unsigned char encoded;
+ unsigned char zero_count, next_flag;
step = stpsz[*ssindex];
/*
* Clip csig if too large or too small
@@ -160,7 +191,8 @@
if (diff >= step)
encoded |= 1;
- *signal += decode (encoded, ssindex);
+ decode (encoded, ssindex, signal, &zero_count, &next_flag);
+
return (encoded);
}
@@ -233,13 +265,12 @@
int res;
int x;
/* Send a frame from the file to the appropriate channel */
-
s->fr.frametype = AST_FRAME_VOICE;
s->fr.subclass = AST_FORMAT_ADPCM;
s->fr.offset = AST_FRIENDLY_OFFSET;
s->fr.mallocd = 0;
s->fr.data = s->buf;
- if ((res = read(s->fd, s->buf + 3, BUF_SIZE)) < 1) {
+ if ((res = read(s->fd, s->buf + BUF_SHIFT, BUF_SIZE)) < 1) {
if (res)
ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
return NULL;
@@ -248,13 +279,15 @@
s->buf[0] = s->ssindex & 0xff;
s->buf[1] = (s->signal >> 8) & 0xff;
s->buf[2] = s->signal & 0xff;
+ s->buf[3] = s->zero_count;
+ s->buf[4] = s->next_flag;
/* Do the decoder to be sure we get the right stuff in the signal and index fields. */
- for (x=3;x<res+3;x++) {
- s->signal += decode(s->buf[x] >> 4, &s->ssindex);
- s->signal += decode(s->buf[x] & 0xf, &s->ssindex);
+ for (x=BUF_SHIFT;x<res+BUF_SHIFT;x++) {
+ decode (s->buf[x] >> 4, &s->ssindex, &s->signal, &s->zero_count, &s->next_flag);
+ decode (s->buf[x] & 0xf, &s->ssindex, &s->signal, &s->zero_count, &s->next_flag);
}
s->fr.samples = res * 2;
- s->fr.datalen = res + 3;
+ s->fr.datalen = res + BUF_SHIFT;
*whennext = s->fr.samples;
return &s->fr;
}
@@ -270,11 +303,11 @@
ast_log(LOG_WARNING, "Asked to write non-ADPCM frame (%d)!\n", f->subclass);
return -1;
}
- if (f->datalen < 3) {
- ast_log(LOG_WARNING, "Invalid frame of data (< 3 bytes long) from %s\n", f->src);
+ if (f->datalen < BUF_SHIFT) {
+ ast_log(LOG_WARNING, "Invalid frame of data (< %d bytes long) from %s\n", BUF_SHIFT, f->src);
return -1;
}
- if ((res = write(fs->fd, f->data + 3, f->datalen - 3)) != f->datalen - 3) {
+ if ((res = write(fs->fd, f->data + BUF_SHIFT, f->datalen - BUF_SHIFT)) != f->datalen - BUF_SHIFT) {
ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
return -1;
}
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