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/* amrdecode.c
 * AMR 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>
#include <string.h>
#include "amrdecode.h"
#include "ws_attributes.h"

#include <opencore-amrnb/interf_dec.h>

void *
codec_amr_init(void)
{
    void *state;
    state = Decoder_Interface_init();

    return state;
}

void
codec_amr_release(void *state)
{
    Decoder_Interface_exit(state);
}

unsigned
codec_amr_get_channels(void *ctx _U_)
{
    return 1;
}

unsigned
codec_amr_get_frequency(void *ctx _U_)
{
    return 8000;
}

size_t
codec_amr_decode(void *state, const void *input, size_t inputSizeBytes, void *output,
        size_t *outputSizeBytes)
{
    int mode;
    unsigned packet_size;
    static const uint8_t block_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};

    /* First byte is CMR, second is the Payload TOC */
    mode = (((uint8_t *)input)[1] >> 3) & 0x0F;
    packet_size = block_size[mode] + 2;

    if (!output || !outputSizeBytes)
	    return 160*2;

    *outputSizeBytes = 160 * 2; /* 160 frames, two byte per frame, 20ms */

    /* If the size is screwed up, insert silence */
    if (packet_size > inputSizeBytes) {
	    memset(output, 0, *outputSizeBytes);
	    return *outputSizeBytes;
    }

    Decoder_Interface_Decode(state, (const unsigned char *)input+1, (short *)output, 0);
    return *outputSizeBytes;
}

/*
 * 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:
 */