95 lines
2.8 KiB
C++
95 lines
2.8 KiB
C++
/*
|
|
SMPEG - SDL MPEG Player Library
|
|
Copyright (C) 1999 Loki Entertainment Software
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
This library 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with this library; if not, write to the Free
|
|
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
/* A ring-buffer class for multi-threaded applications.
|
|
This assumes a single reader and a single writer, with blocking reads.
|
|
*/
|
|
|
|
#ifndef _MPEGRING_H
|
|
#define _MPEGRING_H
|
|
|
|
#include "SDL_types.h"
|
|
#include "SDL_thread.h"
|
|
|
|
class MPEG_ring {
|
|
public:
|
|
/* Create a ring with 'count' buffers, each 'size' bytes long */
|
|
MPEG_ring(Uint32 size, Uint32 count = 16);
|
|
|
|
/* Release any waiting threads on the ring so they can be cleaned up.
|
|
The ring isn't valid after this call, so when threads are done you
|
|
should call MPRing_sdelete() on the ring.
|
|
*/
|
|
void ReleaseThreads(void);
|
|
|
|
/* Destroy a ring after all threads are no longer using it */
|
|
virtual ~MPEG_ring();
|
|
|
|
/* Returns the maximum size of each buffer */
|
|
Uint32 BufferSize( void ) {
|
|
return(bufSize);
|
|
}
|
|
/* Returns how many buffers have available data */
|
|
int BuffersWritten(void) {
|
|
return(SDL_SemValue(ring->readwait));
|
|
}
|
|
|
|
/* Reserve a buffer for writing in the ring */
|
|
Uint8 *NextWriteBuffer( void );
|
|
|
|
/* Release a buffer, written to in the ring */
|
|
void WriteDone( Uint32 len, double timestamp=-1 );
|
|
|
|
/* Reserve a buffer for reading in the ring */
|
|
Uint32 NextReadBuffer( Uint8** buffer );
|
|
|
|
/* Read the timestamp of the current buffer */
|
|
double ReadTimeStamp(void);
|
|
|
|
/* Release a buffer having read some of it */
|
|
void ReadSome( Uint32 used );
|
|
|
|
/* Release a buffer having read all of it */
|
|
void ReadDone( void );
|
|
|
|
protected:
|
|
MPEG_ring *ring; /* Converted from C code, an alias for 'this' */
|
|
|
|
/* read only */
|
|
Uint32 bufSize;
|
|
|
|
/* private */
|
|
Uint8 *begin;
|
|
Uint8 *end;
|
|
|
|
double *timestamps;
|
|
double *timestamp_read;
|
|
double *timestamp_write;
|
|
|
|
Uint8 *read;
|
|
Uint8 *write;
|
|
|
|
/* For read/write synchronization */
|
|
int active;
|
|
SDL_semaphore *readwait;
|
|
SDL_semaphore *writewait;
|
|
};
|
|
|
|
#endif /* _MPEGRING_H */
|