rockbox/apps/tdspeed.c

335 lines
11 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Nicolas Pitre <nico@cam.org>
* Copyright (C) 2006-2007 by Stéphane Doyon <s.doyon@videotron.ca>
*
* 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 option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <inttypes.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "sound.h"
#include "buffer.h"
#include "system.h"
#include "tdspeed.h"
#include "settings.h"
#define assert(cond)
#define MIN_RATE 8000
#define MAX_RATE 48000 /* double buffer for double rate */
#define MINFREQ 100
#define FIXED_BUFSIZE 3072 /* 48KHz factor 3.0 */
struct tdspeed_state_s
{
bool stereo;
int32_t shift_max; /* maximum displacement on a frame */
int32_t src_step; /* source window pace */
int32_t dst_step; /* destination window pace */
int32_t dst_order; /* power of two for dst_step */
int32_t ovl_shift; /* overlap buffer frame shift */
int32_t ovl_size; /* overlap buffer used size */
int32_t ovl_space; /* overlap buffer size */
int32_t *ovl_buff[2]; /* overlap buffer */
};
static struct tdspeed_state_s tdspeed_state;
static int32_t *overlap_buffer[2] = { NULL, NULL };
static int32_t *outbuf[2] = { NULL, NULL };
void tdspeed_init()
{
if (global_settings.timestretch_enabled)
{
/* Allocate buffers */
if (overlap_buffer[0] == NULL)
overlap_buffer[0] = (int32_t *) buffer_alloc(FIXED_BUFSIZE * sizeof(int32_t));
if (overlap_buffer[1] == NULL)
overlap_buffer[1] = (int32_t *) buffer_alloc(FIXED_BUFSIZE * sizeof(int32_t));
if (outbuf[0] == NULL)
outbuf[0] = (int32_t *) buffer_alloc(TDSPEED_OUTBUFSIZE * sizeof(int32_t));
if (outbuf[1] == NULL)
outbuf[1] = (int32_t *) buffer_alloc(TDSPEED_OUTBUFSIZE * sizeof(int32_t));
}
}
bool tdspeed_config(int samplerate, bool stereo, int32_t factor)
{
struct tdspeed_state_s *st = &tdspeed_state;
int src_frame_sz;
/* Check buffers were allocated ok */
if (overlap_buffer[0] == NULL || overlap_buffer[1] == NULL)
return false;
if (outbuf[0] == NULL || outbuf[1] == NULL)
return false;
/* Check parameters */
if (factor == PITCH_SPEED_100)
return false;
if (samplerate < MIN_RATE || samplerate > MAX_RATE)
return false;
if (factor < STRETCH_MIN || factor > STRETCH_MAX)
return false;
st->stereo = stereo;
st->dst_step = samplerate / MINFREQ;
if (factor > PITCH_SPEED_100)
st->dst_step = st->dst_step * PITCH_SPEED_100 / factor;
st->dst_order = 1;
while (st->dst_step >>= 1)
st->dst_order++;
st->dst_step = (1 << st->dst_order);
st->src_step = st->dst_step * factor / PITCH_SPEED_100;
st->shift_max = (st->dst_step > st->src_step) ? st->dst_step : st->src_step;
src_frame_sz = st->shift_max + st->dst_step;
if (st->dst_step > st->src_step)
src_frame_sz += st->dst_step - st->src_step;
st->ovl_space = ((src_frame_sz - 2)/st->src_step) * st->src_step
+ src_frame_sz;
if (st->src_step > st->dst_step)
st->ovl_space += 2*st->src_step - st->dst_step;
if (st->ovl_space > FIXED_BUFSIZE)
st->ovl_space = FIXED_BUFSIZE;
st->ovl_size = 0;
st->ovl_shift = 0;
st->ovl_buff[0] = overlap_buffer[0];
if (stereo)
st->ovl_buff[1] = overlap_buffer[1];
else
st->ovl_buff[1] = st->ovl_buff[0];
return true;
}
static int tdspeed_apply(int32_t *buf_out[2], int32_t *buf_in[2],
int data_len, int last, int out_size)
/* data_len in samples */
{
struct tdspeed_state_s *st = &tdspeed_state;
int32_t *curr, *prev, *dest[2], *d;
int32_t i, j, next_frame, prev_frame, shift, src_frame_sz;
bool stereo = buf_in[0] != buf_in[1];
assert(stereo == st->stereo);
src_frame_sz = st->shift_max + st->dst_step;
if (st->dst_step > st->src_step)
src_frame_sz += st->dst_step - st->src_step;
/* deal with overlap data first, if any */
if (st->ovl_size)
{
int32_t have, copy, steps;
have = st->ovl_size;
if (st->ovl_shift > 0)
have -= st->ovl_shift;
/* append just enough data to have all of the overlap buffer consumed */
steps = (have - 1) / st->src_step;
copy = steps * st->src_step + src_frame_sz - have;
if (copy < src_frame_sz - st->dst_step)
copy += st->src_step; /* one more step to allow for pregap data */
if (copy > data_len) copy = data_len;
assert(st->ovl_size +copy <= FIXED_BUFSIZE);
memcpy(st->ovl_buff[0] + st->ovl_size, buf_in[0],
copy * sizeof(int32_t));
if (stereo)
memcpy(st->ovl_buff[1] + st->ovl_size, buf_in[1],
copy * sizeof(int32_t));
if (!last && have + copy < src_frame_sz)
{
/* still not enough to process at least one frame */
st->ovl_size += copy;
return 0;
}
/* recursively call ourselves to process the overlap buffer */
have = st->ovl_size;
st->ovl_size = 0;
if (copy == data_len)
{
assert( (have+copy) <= FIXED_BUFSIZE);
return tdspeed_apply(buf_out, st->ovl_buff, have+copy, last,
out_size);
}
assert( (have+copy) <= FIXED_BUFSIZE);
i = tdspeed_apply(buf_out, st->ovl_buff, have+copy, -1, out_size);
dest[0] = buf_out[0] + i;
dest[1] = buf_out[1] + i;
/* readjust pointers to account for data already consumed */
next_frame = copy - src_frame_sz + st->src_step;
prev_frame = next_frame - st->ovl_shift;
}
else
{
dest[0] = buf_out[0];
dest[1] = buf_out[1];
next_frame = prev_frame = 0;
if (st->ovl_shift > 0)
next_frame += st->ovl_shift;
else
prev_frame += -st->ovl_shift;
}
st->ovl_shift = 0;
/* process all complete frames */
while (data_len - next_frame >= src_frame_sz)
{
/* find frame overlap by autocorelation */
int64_t min_delta = ~(1ll << 63); /* most positive */
shift = 0;
#define INC1 8
#define INC2 32
/* Power of 2 of a 28bit number requires 56bits, can accumulate
256times in a 64bit variable. */
assert(st->dst_step / INC2 <= 256);
assert(next_frame + st->shift_max - 1 + st->dst_step-1 < data_len);
assert(prev_frame + st->dst_step - 1 < data_len);
for (i = 0; i < st->shift_max; i += INC1)
{
int64_t delta = 0;
curr = buf_in[0] + next_frame + i;
prev = buf_in[0] + prev_frame;
for (j = 0; j < st->dst_step; j += INC2, curr += INC2, prev += INC2)
{
int32_t diff = *curr - *prev;
delta += (int64_t)diff * diff;
if (delta >= min_delta)
goto skip;
}
if (stereo)
{
curr = buf_in[1] +next_frame + i;
prev = buf_in[1] +prev_frame;
for (j = 0; j < st->dst_step; j += INC2, curr += INC2, prev += INC2)
{
int32_t diff = *curr - *prev;
delta += (int64_t)diff * diff;
if (delta >= min_delta)
goto skip;
}
}
min_delta = delta;
shift = i;
skip:;
}
/* overlap fading-out previous frame with fading-in current frame */
curr = buf_in[0] + next_frame + shift;
prev = buf_in[0] + prev_frame;
d = dest[0];
assert(next_frame + shift + st->dst_step - 1 < data_len);
assert(prev_frame + st->dst_step - 1 < data_len);
assert(dest[0] - buf_out[0] + st->dst_step - 1 < out_size);
for (i = 0, j = st->dst_step; j; i++, j--)
{
*d++ = (*curr++ * (int64_t)i
+ *prev++ * (int64_t)j) >> st->dst_order;
}
dest[0] = d;
if (stereo)
{
curr = buf_in[1] +next_frame + shift;
prev = buf_in[1] +prev_frame;
d = dest[1];
for (i = 0, j = st->dst_step; j; i++, j--)
{
assert(d < buf_out[1] +out_size);
*d++ = (*curr++ * (int64_t) i
+ *prev++ * (int64_t) j) >> st->dst_order;
}
dest[1] = d;
}
/* adjust pointers for next frame */
prev_frame = next_frame + shift + st->dst_step;
next_frame += st->src_step;
/* here next_frame - prev_frame = src_step - dst_step - shift */
assert(next_frame - prev_frame == st->src_step - st->dst_step - shift);
}
/* now deal with remaining partial frames */
if (last == -1)
{
/* special overlap buffer processing: remember frame shift only */
st->ovl_shift = next_frame - prev_frame;
}
else if (last != 0)
{
/* last call: purge all remaining data to output buffer */
i = data_len -prev_frame;
assert(dest[0] +i <= buf_out[0] +out_size);
memcpy(dest[0], buf_in[0] +prev_frame, i * sizeof(int32_t));
dest[0] += i;
if (stereo)
{
assert(dest[1] +i <= buf_out[1] +out_size);
memcpy(dest[1], buf_in[1] +prev_frame, i * sizeof(int32_t));
dest[1] += i;
}
}
else
{
/* preserve remaining data + needed overlap data for next call */
st->ovl_shift = next_frame - prev_frame;
i = (st->ovl_shift < 0) ? next_frame : prev_frame;
st->ovl_size = data_len - i;
assert(st->ovl_size <= FIXED_BUFSIZE);
memcpy(st->ovl_buff[0], buf_in[0]+i, st->ovl_size * sizeof(int32_t));
if (stereo)
memcpy(st->ovl_buff[1], buf_in[1]+i, st->ovl_size * sizeof(int32_t));
}
return dest[0] - buf_out[0];
}
long tdspeed_est_output_size()
{
return TDSPEED_OUTBUFSIZE;
}
long tdspeed_est_input_size(long size)
{
struct tdspeed_state_s *st = &tdspeed_state;
size = (size -st->ovl_size) *st->src_step / st->dst_step;
if (size < 0)
size = 0;
return size;
}
int tdspeed_doit(int32_t *src[], int count)
{
count = tdspeed_apply( (int32_t *[2]) { outbuf[0], outbuf[1] },
src, count, 0, TDSPEED_OUTBUFSIZE);
src[0] = outbuf[0];
src[1] = outbuf[1];
return count;
}