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Make ADPCM frames standard 

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2400 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Mark Spencer 2004-03-11 19:57:10 +00:00
parent f12928f700
commit 39c60235f8
2 changed files with 16 additions and 187 deletions
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41
codecs/codec_adpcm.c
View File

@ -27,7 +27,6 @@
#include <unistd.h>
#define BUFFER_SIZE 8096 /* size for the translation buffers */
#define BUF_SHIFT 5
static ast_mutex_t localuser_lock = AST_MUTEX_INITIALIZER;
static int localusecnt = 0;
@ -200,6 +199,10 @@ struct adpcm_decoder_pvt
struct ast_frame f;
char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
short outbuf[BUFFER_SIZE]; /* Decoded signed linear values */
short ssindex;
short signal;
unsigned char zero_count;
unsigned char next_flag;
int tail;
};
@ -272,41 +275,21 @@ adpcmtolin_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
{
struct adpcm_decoder_pvt *tmp = (struct adpcm_decoder_pvt *) pvt;
int x;
short signal;
short ssindex;
unsigned char *b;
unsigned char zero_count;
unsigned char next_flag;
if (f->datalen < BUF_SHIFT) {
ast_log(LOG_WARNING, "Didn't have at least %d bytes of input\n", BUF_SHIFT);
return -1;
}
if ((f->datalen - BUF_SHIFT) * 4 > sizeof(tmp->outbuf)) {
if (f->datalen * 4 > sizeof(tmp->outbuf)) {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
/* Reset ssindex and signal to frame's specified values */
b = f->data;
ssindex = b[0];
if (ssindex < 0)
ssindex = 0;
if (ssindex > 48)
ssindex = 48;
signal = (b[1] << 8) | b[2];
for (x=0;x<f->datalen;x++) {
decode((b[x] >> 4) & 0xf, &tmp->ssindex, &tmp->signal, &tmp->zero_count, &tmp->next_flag);
tmp->outbuf[tmp->tail++] = tmp->signal << 4;
zero_count = b[3];
next_flag = b[4];
for (x=BUF_SHIFT;x<f->datalen;x++) {
decode((b[x] >> 4) & 0xf, &ssindex, &signal, &zero_count, &next_flag);
tmp->outbuf[tmp->tail++] = signal << 4;
decode(b[x] & 0x0f, &ssindex, &signal, &zero_count, &next_flag);
tmp->outbuf[tmp->tail++] = signal << 4;
decode(b[x] & 0x0f, &tmp->ssindex, &tmp->signal, &tmp->zero_count, &tmp->next_flag);
tmp->outbuf[tmp->tail++] = tmp->signal << 4;
}
return 0;
@ -408,7 +391,7 @@ lintoadpcm_frameout (struct ast_translator_pvt *pvt)
adpcm0 = adpcm (tmp->inbuf[i], &tmp->ssindex, &tmp->signal, &tmp->zero_count, &tmp->next_flag);
adpcm1 = adpcm (tmp->inbuf[i+1], &tmp->ssindex, &tmp->signal, &tmp->zero_count, &tmp->next_flag);
tmp->outbuf[i/2 + BUF_SHIFT] = (adpcm0 << 4) | adpcm1;
tmp->outbuf[i/2] = (adpcm0 << 4) | adpcm1;
};
@ -419,7 +402,7 @@ lintoadpcm_frameout (struct ast_translator_pvt *pvt)
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->outbuf;
tmp->f.datalen = i_max / 2 + BUF_SHIFT;
tmp->f.datalen = i_max / 2;
/*
* If there is a signal left over (there should be no more than

162
formats/format_vox.c
View File

@ -33,7 +33,6 @@
#endif
#define BUF_SIZE 80 /* 160 samples */
#define BUF_SHIFT 5
struct ast_filestream {
void *reserved[AST_RESERVED_POINTERS];
@ -42,7 +41,7 @@ struct ast_filestream {
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 + BUF_SHIFT]; /* Output Buffer */
unsigned char buf[BUF_SIZE]; /* Output Buffer */
int lasttimeout;
struct timeval last;
short signal; /* Signal level (file side) */
@ -59,143 +58,6 @@ static char *name = "vox";
static char *desc = "Dialogic VOX (ADPCM) File Format";
static char *exts = "vox";
/*
* Step size index shift table
*/
static short indsft[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
/*
* Step size table, where stpsz[i]=floor[16*(11/10)^i]
*/
static short stpsz[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73,
80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279,
307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963,
1060, 1166, 1282, 1411, 1552
};
/*
* Nibble to bit map
*/
static short nbl2bit[16][4] = {
{1, 0, 0, 0}, {1, 0, 0, 1}, {1, 0, 1, 0}, {1, 0, 1, 1},
{1, 1, 0, 0}, {1, 1, 0, 1}, {1, 1, 1, 0}, {1, 1, 1, 1},
{-1, 0, 0, 0}, {-1, 0, 0, 1}, {-1, 0, 1, 0}, {-1, 0, 1, 1},
{-1, 1, 0, 0}, {-1, 1, 0, 1}, {-1, 1, 1, 0}, {-1, 1, 1, 1}
};
/*
* Decode(encoded)
* Decodes the encoded nibble from the adpcm file.
*
* Results:
* Returns the encoded difference.
*
* Side effects:
* Sets the index to the step size table for the next encode.
*/
static inline void
decode (unsigned char encoded, short *ssindex, short *signal, unsigned char *rkey, unsigned char *next)
{
short diff, step;
step = stpsz[*ssindex];
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;
}
/*
* Adpcm
* Takes a signed linear signal and encodes it as ADPCM
* For more information see http://support.dialogic.com/appnotes/adpcm.pdf
*
* Results:
* Foo.
*
* Side effects:
* signal gets updated with each pass.
*/
static inline unsigned char
adpcm (short csig, short *ssindex, short *signal)
{
short diff, step;
unsigned char encoded;
unsigned char zero_count, next_flag;
step = stpsz[*ssindex];
/*
* Clip csig if too large or too small
*/
csig >>= 4;
diff = csig - *signal;
if (diff < 0)
{
encoded = 8;
diff = -diff;
}
else
encoded = 0;
if (diff >= step)
{
encoded |= 4;
diff -= step;
}
step >>= 1;
if (diff >= step)
{
encoded |= 2;
diff -= step;
}
step >>= 1;
if (diff >= step)
encoded |= 1;
decode (encoded, ssindex, signal, &zero_count, &next_flag);
return (encoded);
}
static struct ast_filestream *vox_open(int fd)
{
/* We don't have any header to read or anything really, but
@ -263,31 +125,19 @@ static void vox_close(struct ast_filestream *s)
static struct ast_frame *vox_read(struct ast_filestream *s, int *whennext)
{
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 + BUF_SHIFT, BUF_SIZE)) < 1) {
if ((res = read(s->fd, s->buf, BUF_SIZE)) < 1) {
if (res)
ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
return NULL;
}
/* Store index, then signal */
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=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 + BUF_SHIFT;
s->fr.datalen = res;
*whennext = s->fr.samples;
return &s->fr;
}
@ -303,11 +153,7 @@ static int vox_write(struct ast_filestream *fs, struct ast_frame *f)
ast_log(LOG_WARNING, "Asked to write non-ADPCM frame (%d)!\n", f->subclass);
return -1;
}
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 + BUF_SHIFT, f->datalen - BUF_SHIFT)) != f->datalen - BUF_SHIFT) {
if ((res = write(fs->fd, f->data, f->datalen)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
return -1;
}