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/*****************************************************************************
* cyclic_buffer.h cyclic buffer helper class for vlc's audio visualizations
*****************************************************************************
* Copyright © 2012 Vovoid Media Technologies
*
* Authors: Jonatan "jaw" Wallmander
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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.
*****************************************************************************/
#ifndef CYCLIC_BUFFER_H
#define CYCLIC_BUFFER_H
class block_holder
{
public:
float data[512]; // data holder
vlc_tick_t pts; // machine time when this is to be played
block_holder()
{
pts = 0; // max_int 64-bit
}
};
#define CYCLIC_BUFFER_SIZE 128
class cyclic_block_queue
{
block_holder cycl_buffer[CYCLIC_BUFFER_SIZE];
size_t consumer_pos;
size_t insertion_pos;
public:
cyclic_block_queue()
{
consumer_pos = 0;
insertion_pos = 0;
}
block_holder* consume()
{
vlc_tick_t cur_machine_time = mdate();
size_t steps = 0;
while (
(cycl_buffer[consumer_pos].pts < cur_machine_time)
&&
(steps++ < CYCLIC_BUFFER_SIZE)
)
{
consumer_pos++;
if (consumer_pos == CYCLIC_BUFFER_SIZE)
{
consumer_pos = 0;
}
}
return &cycl_buffer[consumer_pos];
}
block_holder* get_insertion_object()
{
insertion_pos++;
if ( insertion_pos == CYCLIC_BUFFER_SIZE )
{
insertion_pos = 0;
}
return &cycl_buffer[insertion_pos];
}
void reset()
{
for (size_t i = 0; i < CYCLIC_BUFFER_SIZE; i++)
{
cycl_buffer[i].pts = 0;
consumer_pos = 0;
insertion_pos = 0;
}
}
};
#undef CYCLIC_BUFFER_SIZE
#endif // CYCLIC_BUFFER_H
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