buffer.h

一个两碟控制的VCD的代码,两碟之间的转动及连续播放,已大量生产的CODE.

/* Copyright 1996, ESS Technology, Inc.					*/
/* SCCSID @(#)buffer.h	1.2 12/3/97 */ 


/*
 * $Log$
 */

#ifdef DRIVER

#ifndef __BUFFER_H__
#define __BUFFER_H__

#include "common.h"
#define GBLDEF4 GBLDEF

/******************************************************************************

 Audio and Video bitstream buffer in DRAM. All units in dword.

 ******************************************************************************/

#define MPEG1

#define ADAM		128

#define LOW_RES_VBV_SIZE 	(0x20000/4)
#define HIGH_RES_VBV_SIZE	(8*ADAM)

extern unsigned int VBV_end;

extern int VBV_start;
extern int VBV_size;

#define PCM_size        2048    /* Must be multiple of 441 */
#define PCM_end         (PCM_start + PCM_size)
#define PCM_zero_start  PCM_end
#define PCM_zero_size   128
#define PCM_zero_end    (PCM_zero_start + PCM_zero_size)

/******************************************************************************
 Some pointer advancement macros. These all assume that the buffer size
 is an integer multiple of the xfer size.
 ******************************************************************************/
#define nice_ptr_advance(A, rw, n) do { \
    A##_##rw += n;                      \
    if (A##_##rw == A##_end)            \
        A##_##rw = A##_start;           \
} while (0)

#define VBV_wrptr_advance(n) nice_ptr_advance(VBV, wrptr, n)
#define VBV_rdptr_advance(n) nice_ptr_advance(VBV, rdptr, n)
#define ABV_wrptr_advance(n) nice_ptr_advance(ABV, wrptr, n)
#define ABV_rdptr_advance(n) nice_ptr_advance(ABV, rdptr, n)


/******************************************************************************
 Number of dwords we read/write to the buffer with each DMA. Max 512.
 ******************************************************************************/
#define VBV_read	(2*ADAM)
#define VBV_write	(2*ADAM)
#define ABV_read	ADAM
#define ABV_write	ADAM

/******************************************************************************
 R/W pointers and transfer status flags. "filling" means xport buscon is
 running so buffer is being filled. "draining" means huffdec buscon is
 running so buffer is being drained.
 ******************************************************************************/
extern int VBV_wrptr;
extern int VBV_rdptr;
GBLDEF(int PCM_start,0);
#if 0
GBLDEF (int Y_wrptr, 0);
GBLDEF (int UV_wrptr, 0);
#endif

extern int VBV_filling;

extern int VBV_draining;

extern volatile int PCM_starved;
extern volatile int PCM_wrptr;
extern volatile int PCM_rdptr;


void PCM_init(void);
void PCM_clear_buffer(void);
void PCM_take_out(void);
void PCM_back_track(void);
void BUSCON_interrupt_service1(void);

void PCM_clear_zero_buffer(void);

void Hres_init(void);
void DispYUV(void);
void ntsc_vscale(void);

#undef MPEG1
#endif /* __BUFFER_H__ */
#endif