//=============================================================================
//
//   File : DccVoiceGsmCodec.cpp
//   Creation date : Wed Aug 22 19:12:55 2001 GMT by Szymon Stefanek
//
//   This file is part of the KVIrc irc client distribution
//   Copyright (C) 2001-2010 Szymon Stefanek (pragma at kvirc dot net)
//
//   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 opinion) 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.
//
//=============================================================================

#define _GSMCODEC_CPP_

#include "DccVoiceGsmCodec.h"

#ifdef COMPILE_USE_GSM
	#include <dlfcn.h>

	#define GSM_PACKED_FRAME_SIZE_IN_BYTES 33
	#define GSM_UNPACKED_FRAME_SIZE_IN_BYTES 320
	#define GSM_UNPACKED_FRAME_SIZE_IN_SHORTS 160

	void * (*gsm_session_create)() = 0;
	void   (*gsm_session_destroy)(void *) = 0;
	void   (*gsm_session_encode)(void *,short *,unsigned char *) = 0;
	int    (*gsm_session_decode)(void *,unsigned char *,short *) = 0;

	void * g_pGSMCodecLibraryHandle = 0;

	bool kvi_gsm_codec_init()
	{
		if(g_pGSMCodecLibraryHandle)return true; // Already initialized

		g_pGSMCodecLibraryHandle = dlopen("libgsm.so",RTLD_NOW | RTLD_GLOBAL);
		if(!g_pGSMCodecLibraryHandle)return false; // no way to open it

		gsm_session_create = (void * (*)()) dlsym(g_pGSMCodecLibraryHandle,"gsm_create");
		gsm_session_destroy = (void (*)(void *))  dlsym(g_pGSMCodecLibraryHandle,"gsm_destroy");
		gsm_session_encode = (void (*)(void *,short *,unsigned char *)) dlsym(g_pGSMCodecLibraryHandle,"gsm_encode");
		gsm_session_decode = (int (*)(void *,unsigned char *,short *)) dlsym(g_pGSMCodecLibraryHandle,"gsm_decode");

		if(! (gsm_session_create && gsm_session_destroy && gsm_session_encode && gsm_session_decode))
		{
			dlclose(g_pGSMCodecLibraryHandle);
			g_pGSMCodecLibraryHandle = 0;
			return false;
		}
		return true;
	}

	void kvi_gsm_codec_done()
	{
		if(g_pGSMCodecLibraryHandle)
		{
			dlclose(g_pGSMCodecLibraryHandle);
			g_pGSMCodecLibraryHandle = 0;
		}
	}


	DccVoiceGsmCodec::DccVoiceGsmCodec()
	: DccVoiceCodec()
	{
		m_pEncodeState = gsm_session_create();
		m_pDecodeState = gsm_session_create();
		m_szName = "gsm (compression 33:320)";
	}

	DccVoiceGsmCodec::~DccVoiceGsmCodec()
	{
		gsm_session_destroy(m_pEncodeState);
		gsm_session_destroy(m_pDecodeState);
	}

	void DccVoiceGsmCodec::encode(KviDataBuffer * signal,KviDataBuffer * stream)
	{
		if(signal->size() < GSM_UNPACKED_FRAME_SIZE_IN_BYTES)return; // nothing to encode

		unsigned char * ptr = signal->data();

		int uFrames = signal->size() / GSM_UNPACKED_FRAME_SIZE_IN_BYTES;
		int uTotalDataCompressed = uFrames * GSM_UNPACKED_FRAME_SIZE_IN_BYTES;
		int uFrameOffset = stream->size();
		unsigned char * endPtr = ptr + uTotalDataCompressed;

		stream->addSize(GSM_PACKED_FRAME_SIZE_IN_BYTES * uFrames);

		while(ptr != endPtr)
		{
			gsm_session_encode(m_pEncodeState,(short *)ptr,stream->data() + uFrameOffset);
			ptr += GSM_UNPACKED_FRAME_SIZE_IN_BYTES;
			uFrameOffset += GSM_PACKED_FRAME_SIZE_IN_BYTES;
		}
		signal->remove(uTotalDataCompressed);
	}

	void DccVoiceGsmCodec::decode(KviDataBuffer * stream,KviDataBuffer * signal)
	{
		if(stream->size() < GSM_PACKED_FRAME_SIZE_IN_BYTES)return; // nothing to decode

		unsigned char * ptr = stream->data();

		// Gsm codec
		int uFrames = stream->size() / GSM_PACKED_FRAME_SIZE_IN_BYTES;
		int uTotalDataDecompressed = uFrames * GSM_PACKED_FRAME_SIZE_IN_BYTES;
		int uSignalOffset = signal->size();
		unsigned char * endPtr = ptr + (uTotalDataDecompressed);

		signal->addSize(GSM_UNPACKED_FRAME_SIZE_IN_BYTES * uFrames);

		while(ptr != endPtr)
		{
			// We don't check the return value here
			// Well..it is either an unrecoverable internal error
			// or a broken frame...
			// but if we receive broken frames over DCC...well....better
			// check the hardware...or the remote codec as well...
			gsm_session_decode(m_pDecodeState,ptr,(short *)(signal->data() + uSignalOffset));
			ptr += GSM_PACKED_FRAME_SIZE_IN_BYTES;
			uSignalOffset += GSM_UNPACKED_FRAME_SIZE_IN_BYTES;
		}
		stream->remove(uTotalDataDecompressed);
	}

	int DccVoiceGsmCodec::encodedFrameSize()
	{
		return GSM_PACKED_FRAME_SIZE_IN_BYTES;
	}

	int DccVoiceGsmCodec::decodedFrameSize()
	{
		return GSM_UNPACKED_FRAME_SIZE_IN_BYTES;
	}

#endif // COMPILE_USE_GSM
