iso1394dataflowsource.h

从 IEEE 1394总线接收传输流

/*
 * MPEG2-TS over IEEE 1394 decoder - receive and decode MPEG-2 transport
 *                                   streams according to IEC 61883-4
 *
 * Copyright (C) 2000-2007, Manfred Weihs <[e-mail]>
 *
 * This program 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 Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef ISO1394DATAFLOWSOURCE_INLINE_H
#define ISO1394DATAFLOWSOURCE_INLINE_H

#define TS_BUFFER_ELEMENTS 500 /* number of transport stream packets in buffer */
#define MPEG2_TS_PACKET_SIZE  188

unsigned char buffer[TS_BUFFER_ELEMENTS][MPEG2_TS_PACKET_SIZE+4]; /* buffer for TS packets */
int current; /* last is in iso1394dataflowsource.c (not externally available) */
int bytecount; /* position in current TS packet */



int iso_init(int channel);
void iso_done();

/** returns the next byte of the data flow and consumes it. */
static inline unsigned int getbits8() {
	return buffer[current][bytecount++ +4];
}

static inline unsigned int getbits16(){
	return ((getbits8() << 8) | getbits8());
}

/**  returns the next three bytes of the data flow and consumes them. */
static inline unsigned int getbits24(){
	return ((getbits8() << 16) | (getbits8() << 8) | getbits8());
}

/** returns the next quadlet of the dataflow and consumes it. */
static inline unsigned int getbits32(){
	return ((getbits8() << 24) | (getbits8() << 16) | (getbits8() << 8) | getbits8());
}

/** returns the next quadlet of the data flow without consuming it. */
static inline unsigned int nextbits32(){
	return (buffer[current][bytecount+4] << 24) | (buffer[current][bytecount+5] << 16) |  (buffer[current][bytecount+6] << 8) | buffer[current][bytecount+7];
}

/** returns the next three bytes of the data flow without consuming them. */
static inline unsigned int nextbits24(){
	return (buffer[current][bytecount+4] << 16) | (buffer[current][bytecount+5] << 8) | buffer[current][bytecount+6];
}

/** returns the next word of the data flow without consuming it. */
static inline unsigned int nextbits16(){
	return (buffer[current][bytecount+4] << 8) | buffer[current][bytecount+5];
}

/** returns the next byte of the data flow without consuming it. */
static inline unsigned int nextbits8(){
	return buffer[current][bytecount+4];
}

/** returns the number of remaining bytes in the current TS packet. */
static inline int rest_of_ts_packet() {
	return MPEG2_TS_PACKET_SIZE-bytecount;
}

/** copies length bytes of databytes to output (consuming them). */
int copybytes(unsigned char *output, int length);

/** advances to next TS packet. */

int nextpacket();

/** skips length bytes. */
int skipbytes(int length);


#endif