mpeg_demux.h

linux下实现视频播放的播放器

/*
 *  Copyright (C) 2005-2007  gulikoza
 *
 *  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.
 */

/* $Id$ */

#ifndef MPEGDEMUX_H
#define MPEGDEMUX_H

#define TS_PACKET_SIZE 188
#define MAX_PAT_ENTRIES 5

#define MODULE "mpeg_reader"

class mpeg_reader {
private:

    unsigned char * buffer;
    int size, offset;
public:
    mpeg_reader():buffer(NULL),size(0),offset(0) { }
    unsigned char * GetPacket() {

	unsigned char * buf = buffer + offset;
	if(!buffer) return NULL;
	while(offset+TS_PACKET_SIZE <= size) {
	    if(*buf == 0x47) {
		DEBUG_MSG("Found sync @%d", offset);
		offset += TS_PACKET_SIZE;
		return buf;
	    } else if(buf[12] == 0x47) {
		// Skip RTP header when present
		offset += 12; buf += 12;
		continue;
	    }
	    buf++;
	    offset++;
	}

	if(size != offset) {
	    LOG_MSG("No valid sync points found, %d bytes unused", size-offset);
	}

	return NULL;
    }

    void SetBuffer(unsigned char * b, int s) {
	buffer = b; size = s; offset = 0;
    }

    int LeftBytes(void) { return size-offset; }

    ~mpeg_reader() { }
};

#undef MODULE
#define MODULE "mpeg_demux"

class mpeg_demux : public Splitter {
private:
    // PAT/PMT tables
    PAT_entry pat_entries[MAX_PAT_ENTRIES];

    unsigned int num_pat_entries;
    unsigned int num_valid_pmts;

    bool first_pat, valid_pat;
    bool m_audio, m_video;
    bool wait;
    int pcr_count;

    // PIDs to decode
    unsigned int MPEG2_Transport_VideoPID;
    unsigned int MPEG2_Transport_AudioPID;

    // TS reader & current packet being processed
    mpeg_reader rdr;
    unsigned char * pkt;

    int   ProcessHeader(bool);
    bool  ParsePAT();
    bool  ParsePMT(unsigned int);
    void  ProcessVideoPacket();
    void  ProcessAudioPacket();

    bool (*SeqHeader)(unsigned char *);
    static bool MpegHDR(unsigned char * p) {
	if((p[3] == 0xB3) && (p[0] == 0x0) && (p[1] == 0x0) && (p[2] == 0x1))
	    return true;
	return false;
    }

    static bool defaultHDR(unsigned char * p) {
	return true;
    }

public:
    mpeg_demux(bool w):num_pat_entries(0),num_valid_pmts(0),
		    first_pat(true),valid_pat(false),
		    m_audio(false),m_video(false),
		    wait(w),pcr_count(0),pkt(NULL),SeqHeader(defaultHDR) { }

    int ProcessData(unsigned char*, int);

    ~mpeg_demux() {
	timer->Reset();
    }
};

#undef MODULE

#endif // MPEGDEMUX_H