summaryrefslogtreecommitdiff
path: root/pjmedia/include
diff options
context:
space:
mode:
authorBenny Prijono <bennylp@teluu.com>2008-03-30 08:58:58 +0000
committerBenny Prijono <bennylp@teluu.com>2008-03-30 08:58:58 +0000
commiteaa4d06187e300b0a6187c6253edf573a3389ad8 (patch)
tree5df3b18c9c56f91b8313dba472d230fb7d30952b /pjmedia/include
parente25862fffb9f06348d6163991daa0ab2ac875620 (diff)
More ticket #504: added missing new files!
git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@1901 74dad513-b988-da41-8d7b-12977e46ad98
Diffstat (limited to 'pjmedia/include')
-rw-r--r--pjmedia/include/pjmedia/stereo.h206
1 files changed, 206 insertions, 0 deletions
diff --git a/pjmedia/include/pjmedia/stereo.h b/pjmedia/include/pjmedia/stereo.h
new file mode 100644
index 00000000..96eb3699
--- /dev/null
+++ b/pjmedia/include/pjmedia/stereo.h
@@ -0,0 +1,206 @@
+/* $Id$ */
+/*
+ * Copyright (C) 2003-2007 Benny Prijono <benny@prijono.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef __PJMEDIA_STEREO_H__
+#define __PJMEDIA_STEREO_H__
+
+/**
+ * @file stereo.h
+ * @brief Monochannel and multichannel converter.
+ */
+
+#include <pjmedia/errno.h>
+#include <pjmedia/port.h>
+#include <pjmedia/types.h>
+#include <pj/assert.h>
+
+
+/**
+ * @defgroup PJMEDIA_STEREO Monochannel and multichannel audio frame converter
+ * @ingroup PJMEDIA_MISC
+ * @brief Interface for converting monochannel audio frame to multichannel
+ * audio frame and vice versa.
+ * @{
+ *
+ */
+
+PJ_BEGIN_DECL
+
+
+/**
+ * Multichannel to monochannel conversion mixes samples from all channels
+ * into the monochannel.
+ */
+#define PJMEDIA_STEREO_MIX PJ_TRUE
+
+
+
+/**
+ * Multichannel to monochannel conversion, it has two operation mode specified
+ * by param options, @see pjmedia_stereo_options. This function can work safely
+ * using the same buffer (in place conversion).
+ *
+ * @param mono Output buffer to store the mono frame extracted
+ * from the multichannels frame.
+ * @param multi Input frame containing multichannels audio.
+ * @param channel_count Number of channels in the input frame.
+ * @param samples_per_frame Number of samples in the input frame.
+ * @param mix If the value is PJ_TRUE then the input channels
+ * will be mixed to produce output frame, otherwise
+ * only frame from channel_src will be copied to the
+ * output frame.
+ * @param channel_src When mixing is disabled, the mono output frame
+ * will be copied from this channel number.
+ *
+ * @return PJ_SUCCESS on success;
+ */
+PJ_INLINE(pj_status_t) pjmedia_convert_channel_nto1(pj_int16_t mono[],
+ const pj_int16_t multi[],
+ unsigned channel_count,
+ unsigned samples_per_frame,
+ pj_bool_t mix,
+ unsigned channel_src)
+{
+ unsigned i;
+
+ PJ_ASSERT_RETURN(mono && multi && channel_count && samples_per_frame &&
+ channel_src < channel_count, PJ_EINVAL);
+
+ if (mix==PJ_FALSE) {
+ for (i = channel_src; i < samples_per_frame; i += channel_count) {
+ *mono = multi[i];
+ ++mono;
+ }
+ } else {
+ unsigned j;
+ for (i = 0; i < samples_per_frame; i += channel_count) {
+ int tmp = 0;
+ for(j = 0; j < channel_count; ++j)
+ tmp += multi[i+j];
+
+ if (tmp > 32767) tmp = 32767;
+ else if (tmp < -32768) tmp = -32768;
+ *mono = (pj_int16_t) tmp;
+ ++mono;
+ }
+ }
+
+ return PJ_SUCCESS;
+}
+
+
+/**
+ * Monochannel to multichannel conversion, it will just duplicate the samples
+ * from monochannel frame to all channels in the multichannel frame.
+ * This function can work safely using the same buffer (in place conversion)
+ * as long as the buffer is big enough for the multichannel samples.
+ *
+ * @param multi Output buffer to store the multichannels frame
+ * mixed from the mono frame.
+ * @param mono The input monochannel audio frame.
+ * @param channel_count Desired number of channels in the output frame.
+ * @param samples_per_frame Number of samples in the input frame.
+ * @param options Options for conversion, currently must be zero.
+ *
+ * @return PJ_SUCCESS on success;
+ */
+PJ_INLINE(pj_status_t) pjmedia_convert_channel_1ton(pj_int16_t multi[],
+ const pj_int16_t mono[],
+ unsigned channel_count,
+ unsigned samples_per_frame,
+ unsigned options)
+{
+ const pj_int16_t *src;
+
+ PJ_ASSERT_RETURN(mono && multi && channel_count && samples_per_frame,
+ PJ_EINVAL);
+ PJ_ASSERT_RETURN(options == 0, PJ_EINVAL);
+
+ PJ_UNUSED_ARG(options);
+
+ src = mono + samples_per_frame - 1;
+ samples_per_frame *= channel_count;
+ while (samples_per_frame) {
+ unsigned i;
+ for (i=1; i<=channel_count; ++i)
+ multi[samples_per_frame-i] = *src;
+ samples_per_frame -= channel_count;
+ --src;
+ }
+
+ return PJ_SUCCESS;
+}
+
+
+/**
+ * Options for channel converter port. The @pjmedia_stereo_options is also
+ * valid for this port options.
+ */
+enum pjmedia_stereo_port_options
+{
+ /**
+ * Specifies whether this port should not destroy downstream port when
+ * this port is destroyed.
+ */
+ PJMEDIA_STEREO_DONT_DESTROY_DN = 4
+};
+
+
+/**
+ * Create a mono-multi channel converter port. This creates a converter session,
+ * which will adjust the samples of audio frame to a different channel count
+ * when the port's get_frame() and put_frame() is called.
+ *
+ * When the port's get_frame() is called, this port will get a frame from
+ * the downstream port and convert the frame to the target channel count before
+ * returning it to the caller.
+ *
+ * When the port's put_frame() is called, this port will convert the frame
+ * to the downstream port's channel count before giving the frame to the
+ * downstream port.
+ *
+ * @param pool Pool to allocate the structure and buffers.
+ * @param dn_port The downstream port, which channel count is to
+ * be converted to the target channel count.
+ * @param channel_count This port channel count.
+ * @param options Bitmask flags from #pjmedia_stereo_port_options
+ * and also application may add PJMEDIA_STEREO_MIX
+ * to mix channels.
+ * When this flag is zero, the default behavior
+ * is to use simple N-to-1 channel converter and
+ * to destroy downstream port when this port is
+ * destroyed.
+ * @param p_port Pointer to receive the stereo port instance.
+ *
+ * @return PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stereo_port_create( pj_pool_t *pool,
+ pjmedia_port *dn_port,
+ unsigned channel_count,
+ unsigned options,
+ pjmedia_port **p_port );
+
+PJ_END_DECL
+
+/**
+ * @}
+ */
+
+
+#endif /* __PJMEDIA_STEREO_H__ */
+