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/*
* FILE: codec_lpc.c
* AUTHORS: Orion Hodson
*
* Copyright (c) 1998-2001 University College London
* All rights reserved.
*/
#ifndef HIDE_SOURCE_STRINGS
static const char cvsid[] =
"$Id: codec_lpc.c,v 1.14 2001/01/08 20:29:57 ucaccsp Exp $";
#endif /* HIDE_SOURCE_STRINGS */
#include "config_unix.h"
#include "config_win32.h"
#include "memory.h"
#include "util.h"
#include "debug.h"
#include "audio_types.h"
#include "codec_types.h"
#include "codec_lpc.h"
#include "cx_lpc.h"
static codec_format_t cs[] = {
{"LPC", "LPC-8K-Mono",
"Pitch excited linear prediction codec (C) R. Zuckerman. Contributed by R. Frederick.",
7, 0, LPCTXSIZE,
{DEV_S16, 8000, 16, 1, 160 * BYTES_PER_SAMPLE}}
};
#define LPC_NUM_FORMATS (sizeof(cs)/sizeof(codec_format_t))
uint16_t
lpc_get_formats_count()
{
return LPC_NUM_FORMATS;
}
const codec_format_t*
lpc_get_format(uint16_t idx)
{
assert(idx < LPC_NUM_FORMATS);
return &cs[idx];
}
void
lpc_setup(void)
{
lpc_init();
}
int
lpc_encoder_state_create(uint16_t idx, u_char **state)
{
assert(idx < LPC_NUM_FORMATS);
UNUSED(idx);
*state = (u_char*) xmalloc(sizeof(lpc_encstate_t));
lpc_enc_init((lpc_encstate_t*) *state);
return sizeof(lpc_encstate_t);
}
void
lpc_encoder_state_destroy(uint16_t idx, u_char **state)
{
assert(idx < LPC_NUM_FORMATS);
UNUSED(idx);
xfree(*state);
*state = (u_char*)NULL;
}
int
lpc_decoder_state_create(uint16_t idx, u_char **state)
{
assert(idx < LPC_NUM_FORMATS);
UNUSED(idx);
*state = (u_char*) xmalloc(sizeof(lpc_intstate_t));
lpc_dec_init((lpc_intstate_t*) *state);
return sizeof(lpc_intstate_t);
}
void
lpc_decoder_state_destroy(uint16_t idx, u_char **state)
{
assert(idx < LPC_NUM_FORMATS);
UNUSED(idx);
xfree(*state);
*state = (u_char*)NULL;
}
int
lpc_encoder (uint16_t idx, u_char *state, sample *in, coded_unit *out)
{
assert(idx < LPC_NUM_FORMATS);
assert(in);
assert(out);
UNUSED(idx);
UNUSED(state);
out->state = NULL;
out->state_len = 0;
out->data = (u_char*)block_alloc(LPCTXSIZE);
out->data_len = LPCTXSIZE;
lpc_analyze((const short*)in,
(lpc_encstate_t*)state,
(lpc_txstate_t*)out->data);
return out->data_len;
}
int
lpc_decoder (uint16_t idx, u_char *state, coded_unit *in, sample *out)
{
assert(idx < LPC_NUM_FORMATS);
assert(state);
assert(in && in->data);
assert(out);
UNUSED(idx);
lpc_synthesize((short*)out,
(lpc_txstate_t*)in->data,
(lpc_intstate_t*)state);
return cs[idx].format.bytes_per_block / BYTES_PER_SAMPLE;
}
int
lpc_repair (uint16_t idx, u_char *state, uint16_t consec_lost,
coded_unit *prev, coded_unit *missing, coded_unit *next)
{
lpc_txstate_t *lps;
assert(prev);
assert(missing);
if (missing->data) {
debug_msg("lpc_repair: missing unit had data!\n");
block_free(missing->data, missing->data_len);
}
missing->data = (u_char*)block_alloc(LPCTXSIZE);
missing->data_len = LPCTXSIZE;
assert(prev->data);
assert(prev->data_len == LPCTXSIZE);
memcpy(missing->data, prev->data, LPCTXSIZE);
lps = (lpc_txstate_t*)missing->data;
lps->gain = (u_char)((float)lps->gain * 0.8f);
UNUSED(next);
UNUSED(consec_lost);
UNUSED(state);
UNUSED(idx);
return TRUE;
}
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