/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005/2006, Anthony Minessale II <anthmct@yahoo.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthmct@yahoo.com>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Brian K. West <brian.west@mac.com>
 * 
 *
 * mod_g726.c -- G726 Codec Module
 *
 */  
#include "switch.h"
#include "g72x.h"

static const char modname[] = "mod_g726";


typedef struct {
	g726_state context;
	uint8_t buf[5];
	uint8_t bits_per_frame;
	uint8_t bits;
} g726_handle_t;

static switch_status_t switch_g726_init(switch_codec_t *codec, switch_codec_flag_t flags,
									  const switch_codec_settings_t *codec_settings) 
{
	int encoding, decoding;
	g726_handle_t *handle;

	encoding = (flags & SWITCH_CODEC_FLAG_ENCODE);
	decoding = (flags & SWITCH_CODEC_FLAG_DECODE);

	if (!(encoding || decoding) || (!(handle = switch_core_alloc(codec->memory_pool, sizeof(*handle))))) {
		return SWITCH_STATUS_FALSE;
	} else {
		g726_init_state(&handle->context);
		codec->private_info = handle;
		handle->bits_per_frame = codec->implementation->bits_per_second / (codec->implementation->samples_per_second);
		return SWITCH_STATUS_SUCCESS;
	}
}


static switch_status_t switch_g726_destroy(switch_codec_t *codec) 
{
	codec->private_info = NULL;
	return SWITCH_STATUS_SUCCESS;
}

typedef int (*encoder_t)(int, int, g726_state *);
typedef int (*decoder_t)(int, int, g726_state *);

static switch_status_t switch_g726_encode(switch_codec_t *codec, 
										switch_codec_t *other_codec, 
										void *decoded_data,

										uint32_t decoded_data_len, 
										uint32_t decoded_rate, 
										void *encoded_data,

										uint32_t *encoded_data_len, 
										uint32_t *encoded_rate, 
										unsigned int *flag) 
{

	g726_handle_t *handle = codec->private_info;
	g726_state *context = &handle->context;
	uint32_t len = codec->implementation->bytes_per_frame;
	uint32_t elen = codec->implementation->encoded_bytes_per_frame;
	encoder_t encoder;

	switch(elen) {
	case 100:
		encoder = g726_40_encoder;
		break;
	case 80:
		encoder = g726_32_encoder;
		break;
	case 60:
		encoder = g726_24_encoder;
		break;
	case 40:
		encoder = g726_16_encoder;
		break;
	default:
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "invalid Encoding Size %d!\n", elen);
		return SWITCH_STATUS_FALSE;
		break;
	}

	if (!context) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error!\n");
		return SWITCH_STATUS_FALSE;
	}

	if (decoded_data_len % len == 0) {
		uint32_t new_len = 0;
		int16_t *ddp = decoded_data;
		//int8_t *edp = encoded_data;
		int x;
		uint32_t loops = decoded_data_len / (sizeof(*ddp));

		for (x = 0; x < loops && new_len < *encoded_data_len; x++) {
#if 0
			if (handle->buf & 0x80) {
				edp[new_len++] = ((handle->buf & 0xf) << handle->bits_per_frame) | encoder(*ddp, AUDIO_ENCODING_LINEAR, context);
				handle->buf = 0;
			} else {
				handle->buf = 0x80 | encoder(*ddp, AUDIO_ENCODING_LINEAR, context);
			}
#endif
			ddp++;
		}

		if (new_len <= *encoded_data_len) {
			*encoded_data_len = new_len;
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "buffer overflow!!! %u >= %u\n", new_len, *encoded_data_len);
			return SWITCH_STATUS_FALSE;
		}
	}

	return SWITCH_STATUS_SUCCESS;
}



static switch_status_t switch_g726_decode(switch_codec_t *codec, 
										switch_codec_t *other_codec, 
										void *encoded_data,

										uint32_t encoded_data_len, 
										uint32_t encoded_rate, 
										void *decoded_data,

										uint32_t *decoded_data_len, 
										uint32_t *decoded_rate, 
										unsigned int *flag) 
{

	g726_state *context = codec->private_info;
	uint32_t len = codec->implementation->bytes_per_frame;
	uint32_t elen = codec->implementation->encoded_bytes_per_frame;
	decoder_t decoder;

	switch(elen) {
	case 40:
		decoder = g726_40_decoder;
		break;
	case 32:
		decoder = g726_32_decoder;
		break;
	case 24:
		decoder = g726_24_decoder;
		break;
	case 16:
		decoder = g726_16_decoder;
		break;
	default:
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "invalid Encoding Size!\n");
		return SWITCH_STATUS_FALSE;
		break;
	}

	if (!context) {
		return SWITCH_STATUS_FALSE;

	}


	if (encoded_data_len % elen == 0) {
		int loops = (int) encoded_data_len / elen;
		char *edp = encoded_data;
		int16_t *ddp = decoded_data;
		int x;
		uint32_t new_len = 0;

		for (x = 0; x < loops && new_len < *decoded_data_len; x++) {
			*(int16_t *)ddp = decoder(*(int *)edp, AUDIO_ENCODING_LINEAR, context);
			ddp += len;
			edp += elen;
			new_len += len;
		}

		if (new_len <= *decoded_data_len) {
			*decoded_data_len = new_len;
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "buffer overflow!!!\n");
			return SWITCH_STATUS_FALSE;
		}
	}

	return SWITCH_STATUS_SUCCESS;

}



/* Registration */ 

static const switch_codec_implementation_t g726_16k_implementation = { 
	/*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, 
	/*.ianacode */ 127, 
	/*.iananame */ "G726-16", 
	/*.samples_per_second */ 8000, 
	/*.bits_per_second */ 16000, 
	/*.microseconds_per_frame */ 20000, 
	/*.samples_per_frame */ 160, 
	/*.bytes_per_frame */ 320, 
	/*.encoded_bytes_per_frame */ 40, 
	/*.number_of_channels */ 1, 
	/*.pref_frames_per_packet */ 1, 
	/*.max_frames_per_packet */ 1, 
	/*.init */ switch_g726_init, 
	/*.encode */ switch_g726_encode, 
	/*.decode */ switch_g726_decode, 
	/*.destroy */ switch_g726_destroy, 
};


static const switch_codec_implementation_t g726_24k_implementation = { 
	/*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, 
	/*.ianacode */ 2, 
	/*.iananame */ "G726-24", 
	/*.samples_per_second */ 8000, 
	/*.bits_per_second */ 24000, 
	/*.microseconds_per_frame */ 20000, 
	/*.samples_per_frame */ 160, 
	/*.bytes_per_frame */ 320, 
	/*.encoded_bytes_per_frame */ 60, 
	/*.number_of_channels */ 1, 
	/*.pref_frames_per_packet */ 1, 
	/*.max_frames_per_packet */ 1, 
	/*.init */ switch_g726_init, 
	/*.encode */ switch_g726_encode, 
	/*.decode */ switch_g726_decode, 
	/*.destroy */ switch_g726_destroy, 
};

static const switch_codec_implementation_t g726_32k_implementation = { 
	/*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, 
	/*.ianacode */ 2, 
	/*.iananame */ "G726-32", 
	/*.samples_per_second */ 8000, 
	/*.bits_per_second */ 32000, 
	/*.microseconds_per_frame */ 20000, 
	/*.samples_per_frame */ 160, 
	/*.bytes_per_frame */ 320, 
	/*.encoded_bytes_per_frame */ 80, 
	/*.number_of_channels */ 1, 
	/*.pref_frames_per_packet */ 1, 
	/*.max_frames_per_packet */ 1, 
	/*.init */ switch_g726_init, 
	/*.encode */ switch_g726_encode, 
	/*.decode */ switch_g726_decode, 
	/*.destroy */ switch_g726_destroy, 
};

static const switch_codec_implementation_t g726_40k_implementation = { 
	/*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, 
	/*.ianacode */ 2, 
	/*.iananame */ "G726-40", 
	/*.samples_per_second */ 8000,
	/*.bits_per_second */ 40000, 
	/*.microseconds_per_frame */ 20000, 
	/*.samples_per_frame */ 160, 
	/*.bytes_per_frame */ 320, 
	/*.encoded_bytes_per_frame */ 100, 
	/*.number_of_channels */ 1, 
	/*.pref_frames_per_packet */ 1, 
	/*.max_frames_per_packet */ 1, 
	/*.init */ switch_g726_init, 
	/*.encode */ switch_g726_encode, 
	/*.decode */ switch_g726_decode, 
	/*.destroy */ switch_g726_destroy, 
};

const switch_codec_interface_t g726_16k_codec_interface = { 
	/*.interface_name */ "G.726 16k", 
	/*.implementations */ &g726_16k_implementation, 
};
const switch_codec_interface_t g726_24k_codec_interface = { 
	/*.interface_name */ "G.726 24k", 
	/*.implementations */ &g726_24k_implementation, 
	/*.next */ &g726_16k_codec_interface
};
const switch_codec_interface_t g726_32k_codec_interface = { 
	/*.interface_name */ "G.726 32k", 
	/*.implementations */ &g726_32k_implementation, 
	/*.next */ &g726_24k_codec_interface
};
const switch_codec_interface_t g726_40k_codec_interface = { 
	/*.interface_name */ "G.726 40k", 
	/*.implementations */ &g726_40k_implementation, 
	/*.next */ &g726_32k_codec_interface
};

static switch_loadable_module_interface_t g726_module_interface = { 
	/*.module_name */ modname, 
	/*.endpoint_interface */ NULL, 
	/*.timer_interface */ NULL, 
	/*.dialplan_interface */ NULL, 
	/*.codec_interface */ &g726_40k_codec_interface, 
	/*.application_interface */ NULL 
};

SWITCH_MOD_DECLARE(switch_status_t) switch_module_load(const switch_loadable_module_interface_t **module_interface,
													 char *filename)
{
	/* connect my internal structure to the blank pointer passed to me */ 
	*module_interface = &g726_module_interface;

	/* indicate that the module should continue to be loaded */ 
	return SWITCH_STATUS_SUCCESS;
}
