RetroArch/audio/buffer.c
2011-01-07 15:50:16 +01:00

122 lines
3.0 KiB
C

/* RSound - A PCM audio client/server
* Copyright (C) 2010 - Hans-Kristian Arntzen
*
* RSound 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 Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RSound 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 RSound.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "buffer.h"
struct rsound_fifo_buffer
{
char *buffer;
size_t bufsize;
size_t first;
size_t end;
};
rsound_fifo_buffer_t* rsnd_fifo_new(size_t size)
{
rsound_fifo_buffer_t *buf = calloc(1, sizeof(*buf));
if (buf == NULL)
return NULL;
buf->buffer = calloc(1, size + 1);
if (buf->buffer == NULL)
{
free(buf);
return NULL;
}
buf->bufsize = size + 1;
return buf;
}
void rsnd_fifo_free(rsound_fifo_buffer_t* buffer)
{
assert(buffer);
assert(buffer->buffer);
free(buffer->buffer);
free(buffer);
}
size_t rsnd_fifo_read_avail(rsound_fifo_buffer_t* buffer)
{
assert(buffer);
assert(buffer->buffer);
size_t first = buffer->first;
size_t end = buffer->end;
if (end < first)
end += buffer->bufsize;
return end - first;
}
size_t rsnd_fifo_write_avail(rsound_fifo_buffer_t* buffer)
{
assert(buffer);
assert(buffer->buffer);
size_t first = buffer->first;
size_t end = buffer->end;
if (end < first)
end += buffer->bufsize;
return (buffer->bufsize - 1) - (end - first);
}
void rsnd_fifo_write(rsound_fifo_buffer_t* buffer, const void* in_buf, size_t size)
{
assert(buffer);
assert(buffer->buffer);
assert(in_buf);
assert(rsnd_fifo_write_avail(buffer) >= size);
size_t first_write = size;
size_t rest_write = 0;
if (buffer->end + size > buffer->bufsize)
{
first_write = buffer->bufsize - buffer->end;
rest_write = size - first_write;
}
memcpy(buffer->buffer + buffer->end, in_buf, first_write);
if (rest_write > 0)
memcpy(buffer->buffer, (const char*)in_buf + first_write, rest_write);
buffer->end = (buffer->end + size) % buffer->bufsize;
}
void rsnd_fifo_read(rsound_fifo_buffer_t* buffer, void* in_buf, size_t size)
{
assert(buffer);
assert(buffer->buffer);
assert(in_buf);
assert(rsnd_fifo_read_avail(buffer) >= size);
size_t first_read = size;
size_t rest_read = 0;
if (buffer->first + size > buffer->bufsize)
{
first_read = buffer->bufsize - buffer->first;
rest_read = size - first_read;
}
memcpy(in_buf, (const char*)buffer->buffer + buffer->first, first_read);
if (rest_read > 0)
memcpy((char*)in_buf + first_read, buffer->buffer, rest_read);
buffer->first = (buffer->first + size) % buffer->bufsize;
}