wireshark/codecs/G722/G722decode.c

105 lines
2.6 KiB
C

/* G722decode.c
* G.722 codec
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <glib.h>
#ifdef HAVE_SPANDSP
#include "spandsp.h"
#include "G722decode.h"
void *
codec_g722_init(void)
{
g722_decode_state_t *state;
/* Valid values for bit_rate for G.722 are 48000, 56000, 64000, but RTP/AVP
* profile requires 64kbps, aligned at octets. */
state = g722_decode_init(NULL, 64000, 0);
return state;
}
void
codec_g722_release(void *ctx)
{
g722_decode_state_t *state = (g722_decode_state_t *)ctx;
if (!state) {
return; /* out-of-memory; */
}
/* Note: replaces g722_decode_release since spandsp 20090211 */
g722_decode_free(state);
}
unsigned
codec_g722_get_channels(void *ctx _U_)
{
/* G.722 has only one channel. */
return 1;
}
unsigned
codec_g722_get_frequency(void *ctx _U_)
{
/* Note: RTP Clock rate is 8kHz due to a historic error, but actual sampling
* rate is 16kHz (RFC 3551, section 4.5.2). */
return 16000;
}
size_t
codec_g722_decode(void *ctx, const void *input, size_t inputSizeBytes, void *output,
size_t *outputSizeBytes)
{
g722_decode_state_t *state = (g722_decode_state_t *)ctx;
if (!state) {
return 0; /* out-of-memory; */
}
if (!output || !outputSizeBytes) {
return 4 * inputSizeBytes;
}
/* g722_decode returns the number of 16-bit samples. */
*outputSizeBytes = 2 * g722_decode(state, (int16_t *)output, (const uint8_t *)input, (int)inputSizeBytes);
return *outputSizeBytes;
}
#endif
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/