Read from disk in larger chunks.

Timeline/Disk_Stream.C

@@ -37,25 +37,24 @@
    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;
+float Disk_Stream::seconds_to_buffer = 5.0f;
+//float Disk_Stream::seconds_to_buffer = 2.0f;
+/* this is really only a rough estimate. The actual amount of data
+ read depends on many factors.  Overlapping regions, for example, will
+ require more data to be read from disk, as will varying channel
+ counts.*/
+size_t Disk_Stream::disk_io_kbytes = 256;
 
 Disk_Stream::Disk_Stream ( Track *th, float frame_rate, nframes_t nframes, int channels ) : _th( th )
 {
+
+    assert( channels );
+
     _frame = 0;
     _thread = 0;
     _terminate = false;
@@ -69,6 +68,10 @@ Disk_Stream::Disk_Stream ( Track *th, float frame_rate, nframes_t nframes, int c
 
     size_t bufsize = _total_blocks * nframes * sizeof( sample_t );
 
+    _disk_io_blocks = ( bufsize * channels ) / ( disk_io_kbytes * 1024 );
+
+    assert( _disk_io_blocks );
+
     for ( int i = channels; i--; )
         _rb.push_back( jack_ringbuffer_create( bufsize ) );
 

Timeline/Disk_Stream.H

@@ -53,6 +53,7 @@ protected:
     sem_t _blocks;          /* semaphore to wake the IO thread with */
 
     int _total_blocks; /* total number of blocks that we can  buffer */
+    int _disk_io_blocks; /* the number of blocks to read/write to/from disk at once */
 
     volatile nframes_t _pending_seek; /* absolute transport position to seek to */
     volatile int _terminate;
@@ -83,6 +84,7 @@ public:
 
     /* must be set before any Disk_Streams are created */
     static float seconds_to_buffer;
+    static size_t disk_io_kbytes;
 
     Disk_Stream ( Track *th, float frame_rate, nframes_t nframes, int channels );
 

Timeline/Playback_DS.C

@@ -109,9 +109,10 @@ Playback_DS::disk_thread ( void )
     printf( "IO thread running...\n" );
 
     /* buffer to hold the interleaved data returned by the track reader */
-    sample_t *buf = new sample_t[ _nframes * channels() ];
+    sample_t *buf = new sample_t[ _nframes * channels() * _disk_io_blocks ];
 
-    const size_t block_size = _nframes * sizeof( sample_t );
+//    const size_t block_size = _nframes * sizeof( sample_t );
+    int blocks_ready = 1;
 
     while ( wait_for_block() )
     {
@@ -126,6 +127,7 @@ Playback_DS::disk_thread ( void )
             printf( "performing seek\n" );
             _frame = _pending_seek;
             _pending_seek = -1;
+            blocks_ready = 1;
             /* finish flushing the buffer */
 
 /*             for ( int i = channels(); i-- ) */
@@ -133,8 +135,20 @@ Playback_DS::disk_thread ( void )
 
         }
 
+        if ( blocks_ready < _disk_io_blocks )
+        {
+            ++blocks_ready;
+            /* wait for more space */
+            continue;
+        }
+
+        /* reset */
+        blocks_ready = 1;
+
+        const nframes_t nframes = _nframes * _disk_io_blocks;
+
         /* FIXME: should we not read from disk in larger-than-JACK-buffer blocks? */
-        read_block( buf, _nframes );
+        read_block( buf, nframes );
 
 //        unlock(); // for seeking
 
@@ -157,22 +171,22 @@ Playback_DS::disk_thread ( void )
 
             jack_ringbuffer_get_write_vector( _rb[ i ], rbd );
 
-            if ( rbd[ 0 ].len >= _nframes )
+            if ( rbd[ 0 ].len >= nframes )
                 /* it'll all fit in one go */
-                buffer_deinterleave_one_channel( (sample_t*)rbd[ 0 ].buf, buf, i, channels(), _nframes );
+                buffer_deinterleave_one_channel( (sample_t*)rbd[ 0 ].buf, buf, i, channels(), nframes );
             else if ( rbd[ 1 ].len )
             {
                 /* there's enough space in the ringbuffer, but it's not contiguous */
 
                 /* do the first half */
-                const nframes_t f = rbd[ 1 ].len / sizeof( sample_t );
+                const nframes_t f = rbd[ 0 ].len / sizeof( sample_t );
 
                 buffer_deinterleave_one_channel( (sample_t*)rbd[ 0 ].buf, buf, i, channels(), f );
 
-                assert( rbd[ 1 ].len >= (_nframes - f) * sizeof( sample_t ) );
+                assert( rbd[ 1 ].len >= (nframes - f) * sizeof( sample_t ) );
 
                 /* do the second half */
-                buffer_deinterleave_one_channel( (sample_t*)rbd[ 1 ].buf, buf + f, i, channels(), _nframes - f );
+                buffer_deinterleave_one_channel( (sample_t*)rbd[ 1 ].buf, buf + f, i, channels(), nframes - f );
             }
             else
                 printf( "programming error: expected more space in ringbuffer\n" );
@@ -180,7 +194,7 @@ Playback_DS::disk_thread ( void )
 /*             buffer_deinterleave_one_channel( (sample_t*)rbd.buf, buf, i, channels(), _nframes ); */
 /*             jack_ringbuffer_write( _rb[ i ], (char*)cbuf, block_size ); */
 
-            jack_ringbuffer_write_advance( _rb[ i ], _nframes * sizeof( sample_t ) );
+            jack_ringbuffer_write_advance( _rb[ i ], nframes * sizeof( sample_t ) );
 
 
 

Timeline/Record_DS.C

@@ -55,16 +55,29 @@ Record_DS::disk_thread ( void )
 
     printf( "IO thread running...\n" );
 
+    const nframes_t nframes = _nframes * _disk_io_blocks;
+
     /* buffer to hold the interleaved data returned by the track reader */
-    sample_t *buf = new sample_t[ _nframes * channels() ];
-    sample_t *cbuf = new sample_t[ _nframes ];
+    sample_t *buf = new sample_t[ nframes * channels() ];
+    sample_t *cbuf = new sample_t[ nframes  ];
+
+    const size_t block_size = nframes * sizeof( sample_t );
 
-    const size_t block_size = _nframes * sizeof( sample_t );
+    int blocks_ready = 1;
 
     while ( wait_for_block() )
     {
-        /* pull data from the per-channel ringbuffers and interlace it */
 
+        if ( blocks_ready < _disk_io_blocks )
+        {
+            ++blocks_ready;
+            continue;
+        }
+
+        blocks_ready = 1;
+
+
+        /* pull data from the per-channel ringbuffers and interlace it */
         for ( int i = channels(); i--; )
         {
 
@@ -79,7 +92,7 @@ Record_DS::disk_thread ( void )
 
             jack_ringbuffer_read( _rb[ i ], (char*)cbuf, block_size );
 
-            buffer_interleave_one_channel( buf, cbuf, i, channels(), _nframes );
+            buffer_interleave_one_channel( buf, cbuf, i, channels(), nframes );
 
 
 /*             /\* deinterleave direcectly into the ringbuffer to avoid */
@@ -118,7 +131,7 @@ Record_DS::disk_thread ( void )
 
         }
 
-        write_block( buf, _nframes );
+        write_block( buf, nframes );
 
     }
 

Timeline/Track.C

@@ -119,6 +119,9 @@ Track::init ( void )
     _show_all_takes = false;
     _size = 1;
 
+    record_ds = NULL;
+    playback_ds = NULL;
+
     labeltype( FL_NO_LABEL );
 
     Fl_Group::size( timeline->w(), height() );
@@ -215,8 +218,6 @@ Track::init ( void )
     }
     end();
 
-    playback_ds = new Playback_DS( this, engine->frame_rate(), engine->nframes(), output.size() );
-    record_ds = new Record_DS( this, engine->frame_rate(), engine->nframes(), input.size() );
 }
 
 
@@ -561,11 +562,14 @@ Track::configure_outputs ( int n )
 
 //    engine->lock();
 
-    Playback_DS *ds = playback_ds;
-    playback_ds = NULL;
+    if ( playback_ds )
+    {
+        Playback_DS *ds = playback_ds;
+        playback_ds = NULL;
 
-    ds->shutdown();
-    delete ds;
+        ds->shutdown();
+        delete ds;
+    }
 
     if ( n > on )
     {
@@ -606,11 +610,14 @@ Track::configure_inputs ( int n )
 
 //    engine->lock();
 
-    Record_DS *ds = record_ds;
-    record_ds = NULL;
+    if ( record_ds )
+    {
+        Record_DS *ds = record_ds;
+        record_ds = NULL;
 
-    ds->shutdown();
-    delete ds;
+        ds->shutdown();
+        delete ds;
+    }
 
     if ( n > on )
     {