From ccb009fa09d2f1eb359c08185d1df6ea61377519 Mon Sep 17 00:00:00 2001 From: markster Date: Thu, 11 Mar 2004 19:57:10 +0000 Subject: Make ADPCM frames standard git-svn-id: http://svn.digium.com/svn/asterisk/trunk@2400 f38db490-d61c-443f-a65b-d21fe96a405b --- formats/format_vox.c | 162 ++------------------------------------------------- 1 file changed, 4 insertions(+), 158 deletions(-) (limited to 'formats') diff --git a/formats/format_vox.c b/formats/format_vox.c index 4fd7ffd94..20021fb73 100755 --- a/formats/format_vox.c +++ b/formats/format_vox.c @@ -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;xbuf[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; } -- cgit v1.2.3