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-rw-r--r--trunk/codecs/codec_resample.c237
1 files changed, 237 insertions, 0 deletions
diff --git a/trunk/codecs/codec_resample.c b/trunk/codecs/codec_resample.c
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+++ b/trunk/codecs/codec_resample.c
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+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007, Digium, Inc.
+ *
+ * Russell Bryant <russell@digium.com>
+ *
+ * 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 Resample slinear audio
+ *
+ * \ingroup codecs
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+/* These are for SHRT_MAX and FLT_MAX -- { */
+#if defined(__Darwin__) || defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__CYGWIN__)
+#include <float.h>
+#else
+#include <values.h>
+#endif
+#include <limits.h>
+/* } */
+
+#include "asterisk/module.h"
+#include "asterisk/translate.h"
+#include "asterisk/libresample.h"
+
+#include "slin_resample_ex.h"
+
+#define RESAMPLER_QUALITY 0
+
+#define OUTBUF_SIZE 8096
+
+struct slin16_to_slin8_pvt {
+ void *resampler;
+ float resample_factor;
+};
+
+struct slin8_to_slin16_pvt {
+ void *resampler;
+ float resample_factor;
+};
+
+static int slin16_to_slin8_new(struct ast_trans_pvt *pvt)
+{
+ struct slin16_to_slin8_pvt *resamp_pvt = pvt->pvt;
+
+ resamp_pvt->resample_factor = 0.5;
+
+ if (!(resamp_pvt->resampler = resample_open(RESAMPLER_QUALITY, 0.5, 0.5)))
+ return -1;
+
+ return 0;
+}
+
+static int slin8_to_slin16_new(struct ast_trans_pvt *pvt)
+{
+ struct slin8_to_slin16_pvt *resamp_pvt = pvt->pvt;
+
+ resamp_pvt->resample_factor = 2.0;
+
+ if (!(resamp_pvt->resampler = resample_open(RESAMPLER_QUALITY, 2.0, 2.0)))
+ return -1;
+
+ return 0;
+}
+
+static void slin16_to_slin8_destroy(struct ast_trans_pvt *pvt)
+{
+ struct slin16_to_slin8_pvt *resamp_pvt = pvt->pvt;
+
+ if (resamp_pvt->resampler)
+ resample_close(resamp_pvt->resampler);
+}
+
+static void slin8_to_slin16_destroy(struct ast_trans_pvt *pvt)
+{
+ struct slin8_to_slin16_pvt *resamp_pvt = pvt->pvt;
+
+ if (resamp_pvt->resampler)
+ resample_close(resamp_pvt->resampler);
+}
+
+static int resample_frame(struct ast_trans_pvt *pvt,
+ void *resampler, float resample_factor, struct ast_frame *f)
+{
+ int total_in_buf_used = 0;
+ int total_out_buf_used = 0;
+ int16_t *in_buf = (int16_t *) f->data;
+ int16_t *out_buf = (int16_t *) pvt->outbuf + pvt->samples;
+ float in_buf_f[f->samples];
+ float out_buf_f[2048];
+ int res = 0;
+ int i;
+
+ for (i = 0; i < f->samples; i++)
+ in_buf_f[i] = in_buf[i] * (FLT_MAX / SHRT_MAX);
+
+ while (total_in_buf_used < f->samples) {
+ int in_buf_used, out_buf_used;
+
+ out_buf_used = resample_process(resampler, resample_factor,
+ &in_buf_f[total_in_buf_used], f->samples - total_in_buf_used,
+ 0, &in_buf_used,
+ &out_buf_f[total_out_buf_used], ARRAY_LEN(out_buf_f) - total_out_buf_used);
+
+ if (out_buf_used < 0)
+ break;
+
+ total_out_buf_used += out_buf_used;
+ total_in_buf_used += in_buf_used;
+
+ if (total_out_buf_used == ARRAY_LEN(out_buf_f)) {
+ ast_log(LOG_ERROR, "Output buffer filled ... need to increase its size\n");
+ res = -1;
+ break;
+ }
+ }
+
+ for (i = 0; i < total_out_buf_used; i++)
+ out_buf[i] = out_buf_f[i] * (SHRT_MAX / FLT_MAX);
+
+ pvt->samples += total_out_buf_used;
+ pvt->datalen += (total_out_buf_used * sizeof(int16_t));
+
+ return res;
+}
+
+static int slin16_to_slin8_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
+{
+ struct slin16_to_slin8_pvt *resamp_pvt = pvt->pvt;
+ void *resampler = resamp_pvt->resampler;
+ float resample_factor = resamp_pvt->resample_factor;
+
+ return resample_frame(pvt, resampler, resample_factor, f);
+}
+
+static int slin8_to_slin16_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
+{
+ struct slin8_to_slin16_pvt *resamp_pvt = pvt->pvt;
+ void *resampler = resamp_pvt->resampler;
+ float resample_factor = resamp_pvt->resample_factor;
+
+ return resample_frame(pvt, resampler, resample_factor, f);
+}
+
+static struct ast_frame *slin16_to_slin8_sample(void)
+{
+ static struct ast_frame f = {
+ .frametype = AST_FRAME_VOICE,
+ .subclass = AST_FORMAT_SLINEAR16,
+ .datalen = sizeof(slin16_slin8_ex),
+ .samples = sizeof(slin16_slin8_ex) / sizeof(slin16_slin8_ex[0]),
+ .src = __PRETTY_FUNCTION__,
+ .data = slin16_slin8_ex,
+ };
+
+ return &f;
+}
+
+static struct ast_frame *slin8_to_slin16_sample(void)
+{
+ static struct ast_frame f = {
+ .frametype = AST_FRAME_VOICE,
+ .subclass = AST_FORMAT_SLINEAR,
+ .datalen = sizeof(slin8_slin16_ex),
+ .samples = sizeof(slin8_slin16_ex) / sizeof(slin8_slin16_ex[0]),
+ .src = __PRETTY_FUNCTION__,
+ .data = slin8_slin16_ex,
+ };
+
+ return &f;
+}
+
+static struct ast_translator slin16_to_slin8 = {
+ .name = "slin16_to_slin8",
+ .srcfmt = AST_FORMAT_SLINEAR16,
+ .dstfmt = AST_FORMAT_SLINEAR,
+ .newpvt = slin16_to_slin8_new,
+ .destroy = slin16_to_slin8_destroy,
+ .framein = slin16_to_slin8_framein,
+ .sample = slin16_to_slin8_sample,
+ .desc_size = sizeof(struct slin16_to_slin8_pvt),
+ .buffer_samples = (OUTBUF_SIZE / sizeof(int16_t)),
+ .buf_size = OUTBUF_SIZE,
+};
+
+static struct ast_translator slin8_to_slin16 = {
+ .name = "slin8_to_slin16",
+ .srcfmt = AST_FORMAT_SLINEAR,
+ .dstfmt = AST_FORMAT_SLINEAR16,
+ .newpvt = slin8_to_slin16_new,
+ .destroy = slin8_to_slin16_destroy,
+ .framein = slin8_to_slin16_framein,
+ .sample = slin8_to_slin16_sample,
+ .desc_size = sizeof(struct slin8_to_slin16_pvt),
+ .buffer_samples = (OUTBUF_SIZE / sizeof(int16_t)),
+ .buf_size = OUTBUF_SIZE,
+};
+
+static int unload_module(void)
+{
+ int res = 0;
+
+ res |= ast_unregister_translator(&slin16_to_slin8);
+ res |= ast_unregister_translator(&slin8_to_slin16);
+
+ return res;
+}
+
+static int load_module(void)
+{
+ int res = 0;
+
+ res |= ast_register_translator(&slin16_to_slin8);
+ res |= ast_register_translator(&slin8_to_slin16);
+
+ return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "SLIN Resampling Codec");