forked from osmocom/wireshark
98 lines
2.4 KiB
C
98 lines
2.4 KiB
C
/* G729decode.c
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* G.729 codec
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "config.h"
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#include <glib.h>
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#include "bcg729/decoder.h"
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#include "wsutil/codecs.h"
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#include "ws_attributes.h"
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static void *
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codec_g729_init(void)
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{
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return initBcg729DecoderChannel();
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}
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static void
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codec_g729_release(void *ctx)
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{
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closeBcg729DecoderChannel((bcg729DecoderChannelContextStruct *)ctx);
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}
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static unsigned
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codec_g729_get_channels(void *ctx _U_)
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{
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return 1;
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}
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static unsigned
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codec_g729_get_frequency(void *ctx _U_)
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{
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return 8000;
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}
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static size_t
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codec_g729_decode(void *ctx, const void *inputBytes, size_t inputBytesSize,
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void *outputSamples, size_t *outputSamplesSize)
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{
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bcg729DecoderChannelContextStruct *state = (bcg729DecoderChannelContextStruct *)ctx;
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const guint8 *dataIn = (const guint8 *) inputBytes;
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gint16 *dataOut = (gint16 *) outputSamples;
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size_t i;
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if (!ctx) {
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return 0;
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}
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if (!outputSamples || !outputSamplesSize) {
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return 80*2*(inputBytesSize/10);
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}
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/* The G729 algorithm encodes 10ms of voice into 80bit (10 bytes).
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Based on the RTP packetization period (usually 20ms), we need to
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pass to the bcg729 decoder chunks of 10ms (10 bytes)
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*/
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for (i = 0; i < (inputBytesSize/10); i++) {
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/* The bcg729 decoder library fails to declare the second
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argument to bcg729Decoder() to be a const pointer. If you
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fix it, and some other functions, to use const, the library
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compiles, so presumably it doesn't modify its input and
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therefore can safely be passed a const pointer. Cast away
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the problem for now; a patch will be sent to the maintainers
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of the library.
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*/
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bcg729Decoder(state, (guint8 *)dataIn + i*10, 10, 0, 0, 0, dataOut + i*80);
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}
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*outputSamplesSize = 80*2*(inputBytesSize/10);
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return *outputSamplesSize;
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}
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void
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codec_register_g729(void)
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{
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register_codec("g729", codec_g729_init, codec_g729_release,
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codec_g729_get_channels, codec_g729_get_frequency, codec_g729_decode);
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}
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/*
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* Editor modelines - https://www.wireshark.org/tools/modelines.html
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*
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* Local variables:
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* c-basic-offset: 4
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* vi: set shiftwidth=4 tabstop=8 expandtab:
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* :indentSize=4:tabSize=8:noTabs=true:
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*/
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