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authormarkster <markster@f38db490-d61c-443f-a65b-d21fe96a405b>2001-03-22 22:25:06 +0000
committermarkster <markster@f38db490-d61c-443f-a65b-d21fe96a405b>2001-03-22 22:25:06 +0000
commitf7f902ae13273469d523bb80c3f1e107ca0f1789 (patch)
treec967274e7368f940e08151d1815e6cf9d10a37ab /codecs
parentec2340452e7bf4f3a20cf964758b3e035606adbb (diff)
Version 0.1.7 from FTP
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@254 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs')
-rwxr-xr-xcodecs/codec_adpcm.c545
1 files changed, 545 insertions, 0 deletions
diff --git a/codecs/codec_adpcm.c b/codecs/codec_adpcm.c
new file mode 100755
index 000000000..cd1dfe83d
--- /dev/null
+++ b/codecs/codec_adpcm.c
@@ -0,0 +1,545 @@
+/* codec_adpcm.c - translate between signed linear and Dialogic ADPCM
+ *
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * Based on frompcm.c and topcm.c from the Emiliano MIPL browser/
+ * interpreter. See http://www.bsdtelephony.com.mx
+ *
+ * Copyright (c) 2001 Linux Support Services, Inc. All rights reserved.
+ *
+ * Karl Sackett <krs@linux-support.net>, 2001-3-21
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#include <asterisk/logger.h>
+#include <asterisk/module.h>
+#include <asterisk/translate.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define BUFFER_SIZE 8096 /* size for the translation buffers */
+
+static pthread_mutex_t localuser_lock = PTHREAD_MUTEX_INITIALIZER;
+static int localusecnt = 0;
+
+static char *tdesc = "Adaptive Differential PCM Coder/Decoder";
+
+/* Sample frame data */
+
+#include "slin_adpcm_ex.h"
+#include "adpcm_slin_ex.h"
+
+/*
+ * 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 short
+decode (unsigned char encoded, short *ssindex)
+{
+ 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));
+ *ssindex = *ssindex + indsft[(encoded & 7)];
+ if (*ssindex < 0)
+ *ssindex = 0;
+ else if (*ssindex > 48)
+ *ssindex = 48;
+ return (diff);
+}
+
+/*
+ * 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;
+ 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;
+
+ *signal += decode (encoded, ssindex);
+ return (encoded);
+}
+
+/*
+ * Private workspace for translating signed linear signals to ADPCM.
+ */
+
+struct adpcm_encoder_pvt
+{
+ struct ast_frame f;
+ char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
+ short inbuf[BUFFER_SIZE]; /* Unencoded signed linear values */
+ unsigned char outbuf[BUFFER_SIZE]; /* Encoded ADPCM, two nibbles to a word */
+ short ssindex;
+ short signal;
+ int tail;
+};
+
+/*
+ * Private workspace for translating ADPCM signals to signed linear.
+ */
+
+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 */
+ int tail;
+};
+
+/*
+ * AdpcmToLin_New
+ * Create a new instance of adpcm_decoder_pvt.
+ *
+ * Results:
+ * Returns a pointer to the new instance.
+ *
+ * Side effects:
+ * None.
+ */
+
+static struct ast_translator_pvt *
+adpcmtolin_new ()
+{
+ struct adpcm_decoder_pvt *tmp;
+ tmp = malloc (sizeof (struct adpcm_decoder_pvt));
+ if (tmp)
+ {
+ memset(tmp, 0, sizeof(*tmp));
+ tmp->tail = 0;
+ localusecnt++;
+ ast_update_use_count ();
+ }
+ return (struct ast_translator_pvt *) tmp;
+}
+
+/*
+ * LinToAdpcm_New
+ * Create a new instance of adpcm_encoder_pvt.
+ *
+ * Results:
+ * Returns a pointer to the new instance.
+ *
+ * Side effects:
+ * None.
+ */
+
+static struct ast_translator_pvt *
+lintoadpcm_new ()
+{
+ struct adpcm_encoder_pvt *tmp;
+ tmp = malloc (sizeof (struct adpcm_encoder_pvt));
+ if (tmp)
+ {
+ memset(tmp, 0, sizeof(*tmp));
+ localusecnt++;
+ ast_update_use_count ();
+ tmp->tail = 0;
+ }
+ return (struct ast_translator_pvt *) tmp;
+}
+
+/*
+ * AdpcmToLin_FrameIn
+ * Fill an input buffer with packed 4-bit ADPCM values if there is room
+ * left.
+ *
+ * Results:
+ * Foo
+ *
+ * Side effects:
+ * tmp->tail is the number of packed values in the buffer.
+ */
+
+static int
+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;
+
+ if (f->datalen < 3) {
+ ast_log(LOG_WARNING, "Didn't have at least three bytes of input\n");
+ return -1;
+ }
+
+ if ((f->datalen - 3) * 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=3;x<f->datalen;x++) {
+ signal += decode(b[x] >> 4, &ssindex);
+ if (signal > 2047)
+ signal = 2047;
+ if (signal < -2048)
+ signal = -2048;
+ tmp->outbuf[tmp->tail++] = signal << 4;
+ signal += decode(b[x] & 0x0f, &ssindex);
+ if (signal > 2047)
+ signal = 2047;
+ if (signal < -2048)
+ signal = -2048;
+ tmp->outbuf[tmp->tail++] = signal << 4;
+ }
+
+ return 0;
+}
+
+/*
+ * AdpcmToLin_FrameOut
+ * Convert 4-bit ADPCM encoded signals to 16-bit signed linear.
+ *
+ * Results:
+ * Converted signals are placed in tmp->f.data, tmp->f.datalen
+ * and tmp->f.timelen are calculated.
+ *
+ * Side effects:
+ * None.
+ */
+
+static struct ast_frame *
+adpcmtolin_frameout (struct ast_translator_pvt *pvt)
+{
+ struct adpcm_decoder_pvt *tmp = (struct adpcm_decoder_pvt *) pvt;
+
+ if (!tmp->tail)
+ return NULL;
+
+ tmp->f.frametype = AST_FRAME_VOICE;
+ tmp->f.subclass = AST_FORMAT_SLINEAR;
+ tmp->f.datalen = tmp->tail *2;
+ tmp->f.timelen = tmp->tail / 8;
+ tmp->f.mallocd = 0;
+ tmp->f.offset = AST_FRIENDLY_OFFSET;
+ tmp->f.src = __PRETTY_FUNCTION__;
+ tmp->f.data = tmp->outbuf;
+ tmp->tail = 0;
+ return &tmp->f;
+}
+
+/*
+ * LinToAdpcm_FrameIn
+ * Fill an input buffer with 16-bit signed linear PCM values.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * tmp->tail is number of signal values in the input buffer.
+ */
+
+static int
+lintoadpcm_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
+{
+ struct adpcm_encoder_pvt *tmp = (struct adpcm_encoder_pvt *) pvt;
+
+ if ((tmp->tail + f->datalen / 2) < (sizeof (tmp->inbuf) / 2))
+ {
+ memcpy (&tmp->inbuf[tmp->tail], f->data, f->datalen);
+ tmp->tail += f->datalen / 2;
+ }
+ else
+ {
+ ast_log (LOG_WARNING, "Out of buffer space\n");
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * LinToAdpcm_FrameOut
+ * Convert a buffer of raw 16-bit signed linear PCM to a buffer
+ * of 4-bit ADPCM packed two to a byte (Big Endian).
+ *
+ * Results:
+ * Foo
+ *
+ * Side effects:
+ * Leftover inbuf data gets packed, tail gets updated.
+ */
+
+static struct ast_frame *
+lintoadpcm_frameout (struct ast_translator_pvt *pvt)
+{
+ struct adpcm_encoder_pvt *tmp = (struct adpcm_encoder_pvt *) pvt;
+ unsigned char adpcm0, adpcm1;
+ int i_max, i;
+
+ if (tmp->tail < 2) return NULL;
+
+
+ i_max = (tmp->tail / 2) * 2;
+
+ tmp->outbuf[0] = tmp->ssindex & 0xff;
+ tmp->outbuf[1] = (tmp->signal >> 8) & 0xff;
+ tmp->outbuf[2] = (tmp->signal & 0xff);
+
+ for (i = 0; i < i_max; i+=2)
+ {
+ adpcm0 = adpcm(tmp->inbuf[i], &tmp->ssindex, &tmp->signal);
+ adpcm1 = adpcm(tmp->inbuf[i+1], &tmp->ssindex, &tmp->signal);
+ tmp->outbuf[i/2 + 3] = (adpcm0 << 4) | adpcm1;
+ };
+
+
+ tmp->f.frametype = AST_FRAME_VOICE;
+ tmp->f.subclass = AST_FORMAT_ADPCM;
+ tmp->f.timelen = i_max / 8;
+ tmp->f.mallocd = 0;
+ tmp->f.offset = AST_FRIENDLY_OFFSET;
+ tmp->f.src = __PRETTY_FUNCTION__;
+ tmp->f.data = tmp->outbuf;
+ tmp->f.datalen = i_max / 2 + 3;
+
+ /*
+ * If there is a signal left over (there should be no more than
+ * one) move it to the beginning of the input buffer.
+ */
+
+ if (tmp->tail == i_max)
+ tmp->tail = 0;
+ else
+ {
+ tmp->inbuf[0] = tmp->inbuf[tmp->tail];
+ tmp->tail = 1;
+ }
+ return &tmp->f;
+}
+
+
+/*
+ * AdpcmToLin_Sample
+ */
+
+static struct ast_frame *
+adpcmtolin_sample ()
+{
+ static struct ast_frame f;
+ f.frametype = AST_FRAME_VOICE;
+ f.subclass = AST_FORMAT_ADPCM;
+ f.datalen = sizeof (adpcm_slin_ex);
+ f.timelen = sizeof(adpcm_slin_ex) / 4;
+ f.mallocd = 0;
+ f.offset = 0;
+ f.src = __PRETTY_FUNCTION__;
+ f.data = adpcm_slin_ex;
+ return &f;
+}
+
+/*
+ * LinToAdpcm_Sample
+ */
+
+static struct ast_frame *
+lintoadpcm_sample ()
+{
+ static struct ast_frame f;
+ f.frametype = AST_FRAME_VOICE;
+ f.subclass = AST_FORMAT_SLINEAR;
+ f.datalen = sizeof (slin_adpcm_ex);
+ /* Assume 8000 Hz */
+ f.timelen = sizeof (slin_adpcm_ex) / 16;
+ f.mallocd = 0;
+ f.offset = 0;
+ f.src = __PRETTY_FUNCTION__;
+ f.data = slin_adpcm_ex;
+ return &f;
+}
+
+/*
+ * Adpcm_Destroy
+ * Destroys a private workspace.
+ *
+ * Results:
+ * It's gone!
+ *
+ * Side effects:
+ * None.
+ */
+
+static void
+adpcm_destroy (struct ast_translator_pvt *pvt)
+{
+ free (pvt);
+ localusecnt--;
+ ast_update_use_count ();
+}
+
+/*
+ * The complete translator for ADPCMToLin.
+ */
+
+static struct ast_translator adpcmtolin = {
+ "adpcmtolin",
+ AST_FORMAT_ADPCM,
+ AST_FORMAT_SLINEAR,
+ adpcmtolin_new,
+ adpcmtolin_framein,
+ adpcmtolin_frameout,
+ adpcm_destroy,
+ /* NULL */
+ adpcmtolin_sample
+};
+
+/*
+ * The complete translator for LinToADPCM.
+ */
+
+static struct ast_translator lintoadpcm = {
+ "lintoadpcm",
+ AST_FORMAT_SLINEAR,
+ AST_FORMAT_ADPCM,
+ lintoadpcm_new,
+ lintoadpcm_framein,
+ lintoadpcm_frameout,
+ adpcm_destroy,
+ /* NULL */
+ lintoadpcm_sample
+};
+
+int
+unload_module (void)
+{
+ int res;
+ pthread_mutex_lock (&localuser_lock);
+ res = ast_unregister_translator (&lintoadpcm);
+ if (!res)
+ res = ast_unregister_translator (&adpcmtolin);
+ if (localusecnt)
+ res = -1;
+ pthread_mutex_unlock (&localuser_lock);
+ return res;
+}
+
+int
+load_module (void)
+{
+ int res;
+ res = ast_register_translator (&adpcmtolin);
+ if (!res)
+ res = ast_register_translator (&lintoadpcm);
+ else
+ ast_unregister_translator (&adpcmtolin);
+ return res;
+}
+
+/*
+ * Return a description of this module.
+ */
+
+char *
+description (void)
+{
+ return tdesc;
+}
+
+int
+usecount (void)
+{
+ int res;
+ STANDARD_USECOUNT (res);
+ return res;
+}
+
+char *
+key ()
+{
+ return ASTERISK_GPL_KEY;
+}