Commit 3c5f3a24 authored by Rov Juvano's avatar Rov Juvano Committed by Rémi Denis-Courmont

Add Scaletempo audio filter

Scaletempo maintains the audio pitch when playback rate != 1.0 (i.e.
no chipmunk effect).  This fixes the pitch scaling caused by using the
resampler to handle playback rate.

Ported from GStreamer.  Inspired by SoundTouch library by Olli Parviainen.
Signed-off-by: default avatarRémi Denis-Courmont <rdenis@simphalempin.com>
parent 10eab32c
......@@ -1216,6 +1216,7 @@ if test "${SYS}" != "mingwce"; then
VLC_ADD_PLUGIN([normvol])
VLC_ADD_PLUGIN([equalizer])
VLC_ADD_PLUGIN([param_eq])
VLC_ADD_PLUGIN([scaletempo])
VLC_ADD_PLUGIN([converter_float])
VLC_ADD_PLUGIN([a52tospdif])
VLC_ADD_PLUGIN([dtstospdif])
......
......@@ -3,3 +3,4 @@ SOURCES_equalizer = equalizer.c equalizer_presets.h
SOURCES_normvol = normvol.c
SOURCES_audio_format = format.c
SOURCES_param_eq = param_eq.c
SOURCES_scaletempo = scaletempo.c
/*****************************************************************************
* scaletempo.c: Scale audio tempo while maintaining pitch
*****************************************************************************
* Copyright © 2008 the VideoLAN team
* $Id$
*
* Authors: Rov Juvano <rovjuvano@users.sourceforge.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 option) 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.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_aout.h>
#include <string.h> /* for memset */
#include <limits.h> /* form INT_MIN */
/*****************************************************************************
* Module descriptor
*****************************************************************************/
static int Open( vlc_object_t * );
static void Close( vlc_object_t * );
static void DoWork( aout_instance_t *, aout_filter_t *,
aout_buffer_t *, aout_buffer_t * );
vlc_module_begin();
set_description( N_("Scale audio tempo in sync with playback rate") );
set_shortname( N_("Scaletempo") );
set_capability( "audio filter", 0 );
set_category( CAT_AUDIO );
set_subcategory( SUBCAT_AUDIO_AFILTER );
add_integer_with_range( "scaletempo-stride", 30, 1, 2000, NULL,
N_("Stride Length"), N_("Length in milliseconds to output each stride"), true );
add_float_with_range( "scaletempo-overlap", .20, 0.0, 1.0, NULL,
N_("Overlap Length"), N_("Percentage of stride to overlap"), true );
add_integer_with_range( "scaletempo-search", 14, 0, 200, NULL,
N_("Search Length"), N_("Length in milliseconds to search for best overlap position"), true );
set_callbacks( Open, Close );
vlc_module_end();
/*
* Scaletempo works by producing audio in constant sized chunks (a "stride") but
* consuming chunks proportional to the playback rate.
*
* Scaletempo then smooths the output by blending the end of one stride with
* the next ("overlap").
*
* Scaletempo smooths the overlap further by searching within the input buffer
* for the best overlap position. Scaletempo uses a statistical cross correlation
* (roughly a dot-product). Scaletempo consumes most of its CPU cycles here.
*
* NOTE:
* sample: a single audio sample for one channel
* frame: a single set of samples, one for each channel
* VLC uses these terms differently
*/
typedef struct aout_filter_sys_t
{
/* Filter static config */
double scale;
/* parameters */
uint ms_stride;
double percent_overlap;
uint ms_search;
/* audio format */
uint samples_per_frame; /* AKA number of channels */
uint bytes_per_sample;
uint bytes_per_frame;
uint sample_rate;
/* stride */
double frames_stride_scaled;
double frames_stride_error;
uint bytes_stride;
double bytes_stride_scaled;
uint bytes_queue_max;
uint bytes_queued;
uint bytes_to_slide;
uint8_t *buf_queue;
/* overlap */
uint samples_overlap;
uint samples_standing;
uint bytes_overlap;
uint bytes_standing;
void *buf_overlap;
void *table_blend;
void (*output_overlap)( aout_filter_t *p_filter, void *p_out_buf, uint bytes_off );
/* best overlap */
uint frames_search;
void *buf_pre_corr;
void *table_window;
uint (*best_overlap_offset)( aout_filter_t *p_filter );
/* for "audio filter" only, manage own buffers */
int i_buf;
uint8_t *p_buffers[2];
} aout_filter_sys_t;
/*****************************************************************************
* best_overlap_offset: calculate best offset for overlap
*****************************************************************************/
static uint best_overlap_offset_float( aout_filter_t *p_filter )
{
aout_filter_sys_t *p = p_filter->p_sys;
float *pw, *po, *ppc, *search_start;
float best_corr = INT_MIN;
uint best_off = 0;
uint i, off;
pw = p->table_window;
po = p->buf_overlap;
po += p->samples_per_frame;
ppc = p->buf_pre_corr;
for( i = p->samples_per_frame; i < p->samples_overlap; i++ ) {
*ppc++ = *pw++ * *po++;
}
search_start = (float *)p->buf_queue + p->samples_per_frame;
for( off = 0; off < p->frames_search; off++ ) {
float corr = 0;
float *ps = search_start;
ppc = p->buf_pre_corr;
for( i = p->samples_per_frame; i < p->samples_overlap; i++ ) {
corr += *ppc++ * *ps++;
}
if( corr > best_corr ) {
best_corr = corr;
best_off = off;
}
search_start += p->samples_per_frame;
}
return best_off * p->bytes_per_frame;
}
/*****************************************************************************
* output_overlap: blend end of previous stride with beginning of current stride
*****************************************************************************/
static void output_overlap_float( aout_filter_t *p_filter,
void *buf_out,
uint bytes_off )
{
aout_filter_sys_t *p = p_filter->p_sys;
float *pout = buf_out;
float *pb = p->table_blend;
float *po = p->buf_overlap;
float *pin = (float *)( p->buf_queue + bytes_off );
uint i;
for( i = 0; i < p->samples_overlap; i++ ) {
*pout++ = *po - *pb++ * ( *po - *pin++ ); po++;
}
}
/*****************************************************************************
* fill_queue: fill p_sys->buf_queue as much possible, skipping samples as needed
*****************************************************************************/
static size_t fill_queue( aout_filter_t *p_filter,
uint8_t *p_buffer,
size_t i_buffer,
size_t offset )
{
aout_filter_sys_t *p = p_filter->p_sys;
uint bytes_in = i_buffer - offset;
size_t offset_unchanged = offset;
if( p->bytes_to_slide > 0 ) {
if( p->bytes_to_slide < p->bytes_queued ) {
uint bytes_in_move = p->bytes_queued - p->bytes_to_slide;
memmove( p->buf_queue,
p->buf_queue + p->bytes_to_slide,
bytes_in_move );
p->bytes_to_slide = 0;
p->bytes_queued = bytes_in_move;
} else {
uint bytes_in_skip;
p->bytes_to_slide -= p->bytes_queued;
bytes_in_skip = __MIN( p->bytes_to_slide, bytes_in );
p->bytes_queued = 0;
p->bytes_to_slide -= bytes_in_skip;
offset += bytes_in_skip;
bytes_in -= bytes_in_skip;
}
}
if( bytes_in > 0 ) {
uint bytes_in_copy = __MIN( p->bytes_queue_max - p->bytes_queued, bytes_in );
memcpy( p->buf_queue + p->bytes_queued,
p_buffer + offset,
bytes_in_copy );
p->bytes_queued += bytes_in_copy;
offset += bytes_in_copy;
}
return offset - offset_unchanged;
}
/*****************************************************************************
* transform_buffer: main filter loop
*****************************************************************************/
static size_t transform_buffer( aout_filter_t *p_filter,
uint8_t *p_buffer,
size_t i_buffer,
uint8_t *pout )
{
aout_filter_sys_t *p = p_filter->p_sys;
size_t offset_in = fill_queue( p_filter, p_buffer, i_buffer, 0 );
uint bytes_out = 0;
while( p->bytes_queued >= p->bytes_queue_max ) {
uint bytes_off = 0;
// output stride
if( p->output_overlap ) {
if( p->best_overlap_offset ) {
bytes_off = p->best_overlap_offset( p_filter );
}
p->output_overlap( p_filter, pout, bytes_off );
}
memcpy( pout + p->bytes_overlap,
p->buf_queue + bytes_off + p->bytes_overlap,
p->bytes_standing );
pout += p->bytes_stride;
bytes_out += p->bytes_stride;
// input stride
memcpy( p->buf_overlap,
p->buf_queue + bytes_off + p->bytes_stride,
p->bytes_overlap );
double frames_to_slide = p->frames_stride_scaled + p->frames_stride_error;
uint frames_to_stride_whole = (int)frames_to_slide;
p->bytes_to_slide = frames_to_stride_whole * p->bytes_per_frame;
p->frames_stride_error = frames_to_slide - frames_to_stride_whole;
offset_in += fill_queue( p_filter, p_buffer, i_buffer, offset_in );
}
return bytes_out;
}
/*****************************************************************************
* calculate_output_buffer_size
*****************************************************************************/
static size_t calculate_output_buffer_size( aout_filter_t *p_filter,
size_t bytes_in )
{
aout_filter_sys_t *p = p_filter->p_sys;
size_t bytes_out = 0;
int bytes_to_out = bytes_in + p->bytes_queued - p->bytes_to_slide;
if( bytes_to_out >= (int)p->bytes_queue_max ) {
/* while (total_buffered - stride_length * n >= queue_max) n++ */
bytes_out = p->bytes_stride * ( (uint)(
( bytes_to_out - p->bytes_queue_max + /* rounding protection */ p->bytes_per_frame )
/ p->bytes_stride_scaled ) + 1 );
}
return bytes_out;
}
/*****************************************************************************
* reinit_buffers: reinitializes buffers in p_filter->p_sys
*****************************************************************************/
static int reinit_buffers( aout_filter_t *p_filter )
{
aout_filter_sys_t *p = p_filter->p_sys;
uint i,j;
uint frames_stride = p->ms_stride * p->sample_rate / 1000.0;
p->bytes_stride = frames_stride * p->bytes_per_frame;
/* overlap */
uint frames_overlap = frames_stride * p->percent_overlap;
if( frames_overlap < 1 ) { /* if no overlap */
p->bytes_overlap = 0;
p->bytes_standing = p->bytes_stride;
p->samples_standing = p->bytes_standing / p->bytes_per_sample;
p->output_overlap = NULL;
} else {
uint prev_overlap = p->bytes_overlap;
p->bytes_overlap = frames_overlap * p->bytes_per_frame;
p->samples_overlap = frames_overlap * p->samples_per_frame;
p->bytes_standing = p->bytes_stride - p->bytes_overlap;
p->samples_standing = p->bytes_standing / p->bytes_per_sample;
p->buf_overlap = malloc( p->bytes_overlap );
p->table_blend = malloc( p->samples_overlap * 4 ); /* sizeof (int32|float) */
if( ! p->buf_overlap || ! p->table_blend ) {
return VLC_ENOMEM;
}
if( p->bytes_overlap > prev_overlap ) {
memset( (uint8_t *)p->buf_overlap + prev_overlap, 0, p->bytes_overlap - prev_overlap );
}
float *pb = p->table_blend;
float t = (float)frames_overlap;
for( i = 0; i<frames_overlap; i++ ) {
float v = i / t;
for( j = 0; j < p->samples_per_frame; j++ ) {
*pb++ = v;
}
}
p->output_overlap = output_overlap_float;
}
/* best overlap */
p->frames_search = ( frames_overlap <= 1 ) ? 0 : p->ms_search * p->sample_rate / 1000.0;
if( p->frames_search < 1 ) { /* if no search */
p->best_overlap_offset = NULL;
} else {
uint bytes_pre_corr = ( p->samples_overlap - p->samples_per_frame ) * 4; /* sizeof (int32|float) */
p->buf_pre_corr = malloc( bytes_pre_corr );
p->table_window = malloc( bytes_pre_corr );
if( ! p->buf_pre_corr || ! p->table_window ) {
return VLC_ENOMEM;
}
float *pw = p->table_window;
for( i = 1; i<frames_overlap; i++ ) {
float v = i * ( frames_overlap - i );
for( j = 0; j < p->samples_per_frame; j++ ) {
*pw++ = v;
}
}
p->best_overlap_offset = best_overlap_offset_float;
}
uint new_size = ( p->frames_search + frames_stride + frames_overlap ) * p->bytes_per_frame;
if( p->bytes_queued > new_size ) {
if( p->bytes_to_slide > p->bytes_queued ) {
p->bytes_to_slide -= p->bytes_queued;
p->bytes_queued = 0;
} else {
uint new_queued = __MIN( p->bytes_queued - p->bytes_to_slide, new_size );
memmove( p->buf_queue,
p->buf_queue + p->bytes_queued - new_queued,
new_queued );
p->bytes_to_slide = 0;
p->bytes_queued = new_queued;
}
}
p->bytes_queue_max = new_size;
p->buf_queue = malloc( p->bytes_queue_max );
if( ! p->buf_queue ) {
return VLC_ENOMEM;
}
p->bytes_stride_scaled = p->bytes_stride * p->scale;
p->frames_stride_scaled = p->bytes_stride_scaled / p->bytes_per_frame;
msg_Dbg( VLC_OBJECT(p_filter),
"%.3f scale, %.3f stride_in, %i stride_out, %i standing, %i overlap, %i search, %i queue, %s mode",
p->scale,
p->frames_stride_scaled,
(int)( p->bytes_stride / p->bytes_per_frame ),
(int)( p->bytes_standing / p->bytes_per_frame ),
(int)( p->bytes_overlap / p->bytes_per_frame ),
p->frames_search,
(int)( p->bytes_queue_max / p->bytes_per_frame ),
"fl32");
return VLC_SUCCESS;
}
/*****************************************************************************
* Open: initialize as "audio filter"
*****************************************************************************/
static int Open( vlc_object_t *p_this )
{
aout_filter_t *p_filter = (aout_filter_t *)p_this;
aout_filter_sys_t *p_sys;
bool b_fit = true;
if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2' ) ||
p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
{
b_fit = false;
p_filter->input.i_format = p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
msg_Warn( p_filter, "bad input or output format" );
}
if( ! AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
{
b_fit = false;
memcpy( &p_filter->output, &p_filter->input, sizeof(audio_sample_format_t) );
msg_Warn( p_filter, "input and output formats are not similar" );
}
if( ! b_fit )
{
return VLC_EGENERIC;
}
p_filter->pf_do_work = DoWork;
p_filter->b_in_place = false;
/* Allocate structure */
p_sys = p_filter->p_sys = malloc( sizeof(aout_filter_sys_t) );
if( ! p_sys )
{
return VLC_ENOMEM;
}
p_sys->scale = 1.0;
p_sys->sample_rate = p_filter->input.i_rate;
p_sys->samples_per_frame = aout_FormatNbChannels( &p_filter->input );
p_sys->bytes_per_sample = 4;
p_sys->bytes_per_frame = p_sys->samples_per_frame * p_sys->bytes_per_sample;
msg_Dbg( p_this, "format: %5i rate, %i nch, %i bps, %s",
p_sys->sample_rate,
p_sys->samples_per_frame,
p_sys->bytes_per_sample,
"fl32" );
p_sys->ms_stride = config_GetInt( p_this, "scaletempo-stride" );
p_sys->percent_overlap = config_GetFloat( p_this, "scaletempo-overlap" );
p_sys->ms_search = config_GetInt( p_this, "scaletempo-search" );
msg_Dbg( p_this, "params: %i stride, %.3f overlap, %i search",
p_sys->ms_stride, p_sys->percent_overlap, p_sys->ms_search );
p_sys->i_buf = 0;
p_sys->p_buffers[0] = NULL;
p_sys->p_buffers[1] = NULL;
p_sys->buf_queue = NULL;
p_sys->buf_overlap = NULL;
p_sys->table_blend = NULL;
p_sys->buf_pre_corr = NULL;
p_sys->table_window = NULL;
p_sys->bytes_overlap = 0;
p_sys->bytes_queued = 0;
p_sys->bytes_to_slide = 0;
p_sys->frames_stride_error = 0;
return reinit_buffers( p_filter );
}
static void Close( vlc_object_t *p_this )
{
aout_filter_t *p_filter = (aout_filter_t *)p_this;
aout_filter_sys_t *p_sys = p_filter->p_sys;
free( p_sys->buf_queue );
free( p_sys->buf_overlap );
free( p_sys->table_blend );
free( p_sys->buf_pre_corr );
free( p_sys->table_window );
free( p_sys->p_buffers[0] );
free( p_sys->p_buffers[1] );
free( p_filter->p_sys );
}
/*****************************************************************************
* DoWork: aout_filter wrapper for transform_buffer
*****************************************************************************/
static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
{
VLC_UNUSED(p_aout);
aout_filter_sys_t *p = p_filter->p_sys;
if( p_filter->input.i_rate == p->sample_rate ) {
memcpy( p_out_buf->p_buffer, p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes;
p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
return;
}
double scale = p_filter->input.i_rate / (double)p->sample_rate;
if( scale != p->scale ) {
p->scale = scale;
p->bytes_stride_scaled = p->bytes_stride * p->scale;
p->frames_stride_scaled = p->bytes_stride_scaled / p->bytes_per_frame;
p->bytes_to_slide = 0;
msg_Dbg( p_filter, "%.3f scale, %.3f stride_in, %i stride_out",
p->scale,
p->frames_stride_scaled,
(int)( p->bytes_stride / p->bytes_per_frame ) );
}
size_t i_outsize = calculate_output_buffer_size ( p_filter, p_in_buf->i_nb_bytes );
if( i_outsize > p_out_buf->i_size ) {
void *temp = realloc( p->p_buffers[ p->i_buf ], i_outsize );
if( temp == NULL )
{
return;
}
p->p_buffers[ p->i_buf ] = temp;
p_out_buf->p_buffer = p->p_buffers[ p->i_buf ];
p->i_buf = ! p->i_buf;
}
size_t bytes_out = transform_buffer( p_filter,
p_in_buf->p_buffer, p_in_buf->i_nb_bytes,
p_out_buf->p_buffer );
p_out_buf->i_nb_bytes = bytes_out;
p_out_buf->i_nb_samples = bytes_out / p->bytes_per_frame;
}
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment