1 files changed, 311 insertions, 0 deletions
diff --git a/trunk/codecs/codec_lpc10.c b/trunk/codecs/codec_lpc10.c
new file mode 100644
index 000000000..1e4ec37f3
--- /dev/null
+++ b/trunk/codecs/codec_lpc10.c
@@ -0,0 +1,311 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 1999 - 2005, Digium, Inc.
+ *
+ * Mark Spencer <markster@digium.com>
+ *
+ * The lpc10 code is from a library used by nautilus, modified to be a bit
+ * nicer to the compiler.
+ * See http://www.arl.wustl.edu/~jaf/ 
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Translate between signed linear and LPC10 (Linear Predictor Code)
+ *
+ * \ingroup codecs
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/translate.h"
+#include "asterisk/config.h"
+#include "asterisk/module.h"
+#include "asterisk/utils.h"
+
+#include "lpc10/lpc10.h"
+
+/* Sample frame data */
+#include "slin_lpc10_ex.h"
+#include "lpc10_slin_ex.h"
+
+/* We use a very strange format here...  I have no idea why...  The frames are 180
+   samples long, which isn't even an even number of milliseconds...  Not only that
+   but we hvae to waste two bits of each frame to keep them ending on a byte boundary
+   because the frames are 54 bits long */
+
+#define LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8
+
+#define	BUFFER_SAMPLES	8000
+
+struct lpc10_coder_pvt {
+	union {
+		struct lpc10_encoder_state *enc;
+		struct lpc10_decoder_state *dec;
+	} lpc10;
+	/* Enough to store a full second */
+	short buf[BUFFER_SAMPLES];
+	int longer;
+};
+
+static int lpc10_enc_new(struct ast_trans_pvt *pvt)
+{
+	struct lpc10_coder_pvt *tmp = pvt->pvt;
+
+	return (tmp->lpc10.enc = create_lpc10_encoder_state()) ? 0 : -1;
+}
+
+static int lpc10_dec_new(struct ast_trans_pvt *pvt)
+{
+	struct lpc10_coder_pvt *tmp = pvt->pvt;
+
+	return (tmp->lpc10.dec = create_lpc10_decoder_state()) ? 0 : -1;
+}
+
+static struct ast_frame *lintolpc10_sample(void)
+{
+	static struct ast_frame f;
+	f.frametype = AST_FRAME_VOICE;
+	f.subclass = AST_FORMAT_SLINEAR;
+	f.datalen = sizeof(slin_lpc10_ex);
+	/* Assume 8000 Hz */
+	f.samples = LPC10_SAMPLES_PER_FRAME;
+	f.mallocd = 0;
+	f.offset = 0;
+	f.src = __PRETTY_FUNCTION__;
+	f.data = slin_lpc10_ex;
+	return &f;
+}
+
+static struct ast_frame *lpc10tolin_sample(void)
+{
+	static struct ast_frame f;
+	f.frametype = AST_FRAME_VOICE;
+	f.subclass = AST_FORMAT_LPC10;
+	f.datalen = sizeof(lpc10_slin_ex);
+	/* All frames are 22 ms long (maybe a little more -- why did he choose
+	   LPC10_SAMPLES_PER_FRAME sample frames anyway?? */
+	f.samples = LPC10_SAMPLES_PER_FRAME;
+	f.mallocd = 0;
+	f.offset = 0;
+	f.src = __PRETTY_FUNCTION__;
+	f.data = lpc10_slin_ex;
+	return &f;
+}
+
+static void extract_bits(INT32 *bits, unsigned char *c)
+{
+	int x;
+	for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
+		if (*c & (0x80 >> (x & 7)))
+			bits[x] = 1;
+		else
+			bits[x] = 0;
+		if ((x & 7) == 7)
+			c++;
+	}
+}
+
+/* XXX note lpc10_encode() produces one bit per word in bits[] */
+static void build_bits(unsigned char *c, INT32 *bits)
+{
+	unsigned char mask=0x80;
+	int x;
+	*c = 0;
+	for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
+		if (bits[x])
+			*c |= mask;
+		mask = mask >> 1;
+		if ((x % 8)==7) {
+			c++;
+			*c = 0;
+			mask = 0x80;
+		}
+	}
+}
+
+static int lpc10tolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
+{
+	struct lpc10_coder_pvt *tmp = pvt->pvt;
+	int16_t *dst = (int16_t *)pvt->outbuf;
+	int len = 0;
+
+	while (len + LPC10_BYTES_IN_COMPRESSED_FRAME <= f->datalen) {
+		int x;
+		float tmpbuf[LPC10_SAMPLES_PER_FRAME];
+		INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX see note */
+		if (pvt->samples + LPC10_SAMPLES_PER_FRAME > BUFFER_SAMPLES) {
+			ast_log(LOG_WARNING, "Out of buffer space\n");
+			return -1;
+		}
+		extract_bits(bits, f->data + len);
+		if (lpc10_decode(bits, tmpbuf, tmp->lpc10.dec)) {
+			ast_log(LOG_WARNING, "Invalid lpc10 data\n");
+			return -1;
+		}
+		for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++) {
+			/* Convert to a short between -1.0 and 1.0 */
+			dst[pvt->samples + x] = (int16_t)(32768.0 * tmpbuf[x]);
+		}
+
+		pvt->samples += LPC10_SAMPLES_PER_FRAME;
+		pvt->datalen += 2*LPC10_SAMPLES_PER_FRAME;
+		len += LPC10_BYTES_IN_COMPRESSED_FRAME;
+	}
+	if (len != f->datalen) 
+		printf("Decoded %d, expected %d\n", len, f->datalen);
+	return 0;
+}
+
+static int lintolpc10_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
+{
+	struct lpc10_coder_pvt *tmp = pvt->pvt;
+
+	/* Just add the frames to our stream */
+	if (pvt->samples + f->samples > BUFFER_SAMPLES) {
+		ast_log(LOG_WARNING, "Out of buffer space\n");
+		return -1;
+	}
+	memcpy(tmp->buf + pvt->samples, f->data, f->datalen);
+	pvt->samples += f->samples;
+	return 0;
+}
+
+static struct ast_frame *lintolpc10_frameout(struct ast_trans_pvt *pvt)
+{
+	struct lpc10_coder_pvt *tmp = pvt->pvt;
+	int x;
+	int datalen = 0;	/* output frame */
+	int samples = 0;	/* output samples */
+	float tmpbuf[LPC10_SAMPLES_PER_FRAME];
+	INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME];	/* XXX what ??? */
+	/* We can't work on anything less than a frame in size */
+	if (pvt->samples < LPC10_SAMPLES_PER_FRAME)
+		return NULL;
+	while (pvt->samples >=  LPC10_SAMPLES_PER_FRAME) {
+		/* Encode a frame of data */
+		for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++)
+			tmpbuf[x] = (float)tmp->buf[x + samples] / 32768.0;
+		lpc10_encode(tmpbuf, bits, tmp->lpc10.enc);
+		build_bits((unsigned char *) pvt->outbuf + datalen, bits);
+		datalen += LPC10_BYTES_IN_COMPRESSED_FRAME;
+		samples += LPC10_SAMPLES_PER_FRAME;
+		pvt->samples -= LPC10_SAMPLES_PER_FRAME;
+		/* Use one of the two left over bits to record if this is a 22 or 23 ms frame...
+		   important for IAX use */
+		tmp->longer = 1 - tmp->longer;
+	}
+	/* Move the data at the end of the buffer to the front */
+	if (pvt->samples)
+		memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
+	return ast_trans_frameout(pvt, datalen, samples);
+}
+
+
+static void lpc10_destroy(struct ast_trans_pvt *arg)
+{
+	struct lpc10_coder_pvt *pvt = arg->pvt;
+	/* Enc and DEC are both just allocated, so they can be freed */
+	ast_free(pvt->lpc10.enc);
+}
+
+static struct ast_translator lpc10tolin = {
+	.name = "lpc10tolin", 
+	.srcfmt = AST_FORMAT_LPC10,
+	.dstfmt = AST_FORMAT_SLINEAR,
+	.newpvt = lpc10_dec_new,
+	.framein = lpc10tolin_framein,
+	.destroy = lpc10_destroy,
+	.sample = lpc10tolin_sample,
+	.desc_size = sizeof(struct lpc10_coder_pvt),
+	.buffer_samples = BUFFER_SAMPLES,
+	.plc_samples = LPC10_SAMPLES_PER_FRAME,
+	.buf_size = BUFFER_SAMPLES * 2,
+};
+
+static struct ast_translator lintolpc10 = {
+	.name = "lintolpc10", 
+	.srcfmt = AST_FORMAT_SLINEAR,
+	.dstfmt = AST_FORMAT_LPC10,
+	.newpvt = lpc10_enc_new,
+	.framein = lintolpc10_framein,
+	.frameout = lintolpc10_frameout,
+	.destroy = lpc10_destroy,
+	.sample = lintolpc10_sample,
+	.desc_size = sizeof(struct lpc10_coder_pvt),
+	.buffer_samples = BUFFER_SAMPLES,
+	.buf_size = LPC10_BYTES_IN_COMPRESSED_FRAME * (1 + BUFFER_SAMPLES / LPC10_SAMPLES_PER_FRAME),
+};
+
+static int parse_config(int reload)
+{
+	struct ast_variable *var;
+	struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
+	struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
+	if (cfg == NULL)
+		return 0;
+	if (cfg == CONFIG_STATUS_FILEUNCHANGED)
+		return 0;
+	for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
+		if (!strcasecmp(var->name, "genericplc")) {
+			lpc10tolin.useplc = ast_true(var->value) ? 1 : 0;
+			ast_verb(3, "codec_lpc10: %susing generic PLC\n",
+					lpc10tolin.useplc ? "" : "not ");
+		}
+	}
+	ast_config_destroy(cfg);
+	return 0;
+}
+
+static int reload(void)
+{
+	if (parse_config(1))
+		return AST_MODULE_LOAD_DECLINE;
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+
+static int unload_module(void)
+{
+	int res;
+
+	res = ast_unregister_translator(&lintolpc10);
+	res |= ast_unregister_translator(&lpc10tolin);
+
+	return res;
+}
+
+static int load_module(void)
+{
+	int res;
+
+	if (parse_config(0))
+		return AST_MODULE_LOAD_DECLINE;
+	res = ast_register_translator(&lpc10tolin);
+	if (!res) 
+		res = ast_register_translator(&lintolpc10);
+	else
+		ast_unregister_translator(&lpc10tolin);
+	if (res)
+		return AST_MODULE_LOAD_FAILURE;
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "LPC10 2.4kbps Coder/Decoder",
+		.load = load_module,
+		.unload = unload_module,
+		.reload = reload,
+	       );