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/*
* FILE: codec_vdvi.c
* AUTHORS: Orion Hodson
*
* Copyright (c) 1998-2001 University College London
* All rights reserved.
*/
#ifndef HIDE_SOURCE_STRINGS
static const char cvsid[] =
"$Id: codec_vdvi.c,v 1.13 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_vdvi.h"
#include "cx_dvi.h"
#include "bitstream.h"
#include "cx_vdvi.h"
#define CODEC_PAYLOAD_NO(x) x
static codec_format_t cs[] = {
{"VDVI", "VDVI-8K-Mono",
"Variable Rate IMA ADPCM codec.",
CODEC_PAYLOAD_NO(77), 4, 80,
{DEV_S16, 8000, 16, 1, 160 * BYTES_PER_SAMPLE}}, /* 20 ms */
{"VDVI", "VDVI-16K-Mono",
"Variable Rate IMA ADPCM codec.",
CODEC_PAYLOAD_NO(78), 4, 80,
{DEV_S16, 16000, 16, 1, 160 * BYTES_PER_SAMPLE}}, /* 10 ms */
{"VDVI", "VDVI-32K-Mono",
"Variable Rate IMA ADPCM codec.",
CODEC_PAYLOAD_NO(79), 4, 80,
{DEV_S16, 32000, 16, 1, 160 * BYTES_PER_SAMPLE}}, /* 5 ms */
{"VDVI", "VDVI-48K-Mono",
"Variable Rate IMA ADPCM codec.",
CODEC_PAYLOAD_NO(80), 4, 80,
{DEV_S16, 48000, 16, 1, 160 * BYTES_PER_SAMPLE}} /* 3.3 ms */
};
#define VDVI_NUM_FORMATS sizeof(cs)/sizeof(codec_format_t)
uint16_t
vdvi_get_formats_count()
{
return (uint16_t)VDVI_NUM_FORMATS;
}
const codec_format_t *
vdvi_get_format(uint16_t idx)
{
assert(idx < VDVI_NUM_FORMATS);
return &cs[idx];
}
typedef struct {
struct adpcm_state *as;
bitstream_t *bs;
} vdvi_state_t;
int
vdvi_state_create(uint16_t idx, u_char **s)
{
vdvi_state_t *v;
if (idx < VDVI_NUM_FORMATS) {
v = (vdvi_state_t*)xmalloc(sizeof(vdvi_state_t));
if (v == NULL) {
return FALSE;
}
v->as = (struct adpcm_state*)xmalloc(sizeof(struct adpcm_state));
if (v->as == NULL) {
xfree(v);
return FALSE;
}
memset(v->as, 0, sizeof(struct adpcm_state));
if (bs_create(&v->bs) == FALSE) {
xfree(v->as);
xfree(v);
return FALSE;
}
*s = (unsigned char*)v;
return TRUE;
}
return 0;
}
void
vdvi_state_destroy(uint16_t idx, u_char **s)
{
vdvi_state_t *v;
v = (vdvi_state_t*)*s;
xfree(v->as);
bs_destroy(&v->bs);
xfree(v);
*s = (u_char*)NULL;
UNUSED(idx);
}
/* Buffer of maximum length of vdvi coded data - never know how big
* it needs to be
*/
int
vdvi_encoder(uint16_t idx, u_char *encoder_state, sample *inbuf, coded_unit *c)
{
int samples, len;
u_char dvi_buf[80];
u_char vdvi_buf[160];
vdvi_state_t *v;
assert(encoder_state);
assert(inbuf);
assert(idx < VDVI_NUM_FORMATS);
UNUSED(idx);
v = (vdvi_state_t*)encoder_state;
/* Transfer state and fix ordering */
c->state = (u_char*)block_alloc(sizeof(struct adpcm_state));
c->state_len = sizeof(struct adpcm_state);
memcpy(c->state, v->as, sizeof(struct adpcm_state));
/* Fix coded state for byte ordering */
((struct adpcm_state*)c->state)->valprev = htons(((struct adpcm_state*)c->state)->valprev);
samples = cs[idx].format.bytes_per_block * 8 / cs[idx].format.bits_per_sample;
assert(samples == 160);
adpcm_coder(inbuf, dvi_buf, samples, v->as);
bs_attach(v->bs, vdvi_buf, sizeof(vdvi_buf)/sizeof(vdvi_buf[0]));
memset(vdvi_buf, 0, sizeof(vdvi_buf)/sizeof(vdvi_buf[0]));
len = vdvi_encode(dvi_buf, 160, v->bs);
c->data = (u_char*)block_alloc(len);
c->data_len = len;
memcpy(c->data, vdvi_buf, len);
return len;
}
int
vdvi_decoder(uint16_t idx, u_char *decoder_state, coded_unit *c, sample *data)
{
int samples, len;
u_char dvi_buf[80];
vdvi_state_t *v;
assert(decoder_state);
assert(c);
assert(data);
assert(idx < VDVI_NUM_FORMATS);
v = (vdvi_state_t*)decoder_state;
if (c->state_len > 0) {
assert(c->state_len == sizeof(struct adpcm_state));
memcpy(v->as, c->state, sizeof(struct adpcm_state));
v->as->valprev = ntohs(v->as->valprev);
}
bs_attach(v->bs, c->data, c->data_len);
len = vdvi_decode(v->bs, dvi_buf, 160);
samples = cs[idx].format.bytes_per_block / sizeof(sample);
adpcm_decoder(dvi_buf, data, samples, v->as);
return samples;
}
int
vdvi_peek_frame_size(uint16_t idx, u_char *data, int data_len)
{
bitstream_t *bs;
u_char dvi_buf[80];
int len;
UNUSED(idx);
bs_create(&bs);
bs_attach(bs, data, data_len);
len = vdvi_decode(bs, dvi_buf, 160);
bs_destroy(&bs);
assert(len <= data_len);
return len;
}
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