non/Timeline/Disk_Stream.C

151 lines
4.6 KiB
C

/*******************************************************************************/
/* Copyright (C) 2008 Jonathan Moore Liles */
/* */
/* 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; see the file COPYING. If not,write to the Free Software */
/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/*******************************************************************************/
#include "Disk_Stream.H"
#include "Track.H"
#include "Audio_Sequence.H"
#include "Port.H"
#include "Engine.H" // for locking.
#include "dsp.h"
/**********/
/* Engine */
/**********/
/* A Disk_Stream uses a separate I/O thread to stream a track's
regions from disk into a ringbuffer to be processed by the RT
thread (or vice-versa). The I/O thread syncronizes access with the
user thread via the Timeline mutex. The size of the buffer (in
seconds) must be set before any Disk_Stream objects are created;
that is, at startup time. The default is 5 seconds, which may or
may not be excessive depending on various external factors. */
/* FIXME: handle termination of IO thread in destructor */
/* FIXME: deal with (jack) buffer size changes */
/* FIXME: needs error handling everywhere! */
/* TODO: handle capture too. For this to work with some kind of
* punch-in/out system, I believe we'll have to always keep at least
* one buffer's worth of input. We would need this anyway in order to
* pass input through to output (software monitoring). What about
* looped recording? */
/* TODO: latency compensation? Does this really apply to us? (we're
* not hosting plugins here) */
/* TODO: read/write data from/to disk in larger chunks to avoid
* excessive seeking. 256k is supposedly the sweetspot. */
// float Disk_Stream::seconds_to_buffer = 5.0f;
float Disk_Stream::seconds_to_buffer = 2.0f;
// size_t Disk_Stream::disk_block_frames = 2048;
Disk_Stream::Disk_Stream ( Track *th, float frame_rate, nframes_t nframes, int channels ) : _th( th )
{
_frame = 0;
_thread = 0;
_terminate = false;
_pending_seek = -1;
printf( "nframes %lu\n", nframes );
_total_blocks = frame_rate * seconds_to_buffer / nframes;
_nframes = nframes;
size_t bufsize = _total_blocks * nframes * sizeof( sample_t );
for ( int i = channels; i--; )
_rb.push_back( jack_ringbuffer_create( bufsize ) );
sem_init( &_blocks, 0, _total_blocks );
// run();
}
Disk_Stream::~Disk_Stream ( )
{
/* it isn't safe to do all this with the RT thread running */
engine->lock();
_th = NULL;
sem_destroy( &_blocks );
for ( int i = channels(); i--; )
jack_ringbuffer_free( _rb[ i ] );
engine->unlock();
}
/** stop the IO thread, block until it finishes. */
void
Disk_Stream::shutdown ( void )
{
_terminate = true;
/* try to wake the thread so it'll see that it's time to die */
block_processed();
if ( _thread )
pthread_join( _thread, NULL );
_terminate = false;
}
Audio_Sequence *
Disk_Stream::track ( void )
{
return (Audio_Sequence*)_th->track();
}
/** start Disk_Stream thread */
void
Disk_Stream::run ( void )
{
if ( pthread_create( &_thread, NULL, &Disk_Stream::disk_thread, this ) != 0 )
/* error */;
}
/* to be called when the JACK buffer size changes. */
void
Disk_Stream::resize ( nframes_t nframes )
{
if ( nframes != _nframes )
/* FIXME: to something here! */;
}
/* static wrapper */
void *
Disk_Stream::disk_thread ( void *arg )
{
((Disk_Stream*)arg)->disk_thread();
return NULL;
}
int
Disk_Stream::buffer_percent ( void )
{
int n;
sem_getvalue( &_blocks, &n );
return 100 - (n * 100 / _total_blocks);
}