demux_mpg.c

自己移植的linux下的流媒体播放器原代码,支持mms协议,支持ftp和http协议.

//  MPG/VOB file parser for DEMUXER v2.5  by A'rpi/ESP-team

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "config.h"
#include "mp_msg.h"
#include "help_mp.h"

#include "stream.h"
#include "demuxer.h"
#include "parse_es.h"
#include "stheader.h"
#include "mp3_hdr.h"

//#define MAX_PS_PACKETSIZE 2048
#define MAX_PS_PACKETSIZE (224*1024)

#define UNKNOWN         0
#define VIDEO_MPEG1     0x10000001
#define VIDEO_MPEG2     0x10000002
#define VIDEO_MPEG4     0x10000004
#define VIDEO_H264      0x10000005
#define AUDIO_MP2       0x50
#define AUDIO_A52       0x2000
#define AUDIO_LPCM_BE   0x10001
#define AUDIO_AAC       mmioFOURCC('M', 'P', '4', 'A')

typedef struct mpg_demuxer {
  float last_pts;
  float final_pts;
  int has_valid_timestamps;
  unsigned int es_map[0x40];	//es map of stream types (associated to the pes id) from 0xb0 to 0xef
  int num_a_streams;
  int a_stream_ids[MAX_A_STREAMS];
} mpg_demuxer_t;

static int mpeg_pts_error=0;

static int parse_psm(demuxer_t *demux, int len) {
  unsigned char c, id, type;
  unsigned int plen, prog_len, es_map_len;
  mpg_demuxer_t *priv = (mpg_demuxer_t *) demux->priv;
  
  mp_dbg(MSGT_DEMUX,MSGL_V, "PARSE_PSM, len=%d\n", len);
  if(! len)
    return 0;
  
  c = stream_read_char(demux->stream);
  if(! (c & 0x80)) {
    stream_skip(demux->stream, len - 1);  //not yet valid, discard
    return 0;
  }
  stream_skip(demux->stream, 1);
  prog_len = stream_read_word(demux->stream);		//length of program descriptors
  stream_skip(demux->stream, prog_len);			//.. that we ignore
  es_map_len = stream_read_word(demux->stream);		//length of elementary streams map
  es_map_len = min(es_map_len, len - prog_len - 8);	//sanity check
  while(es_map_len > 0) {
    type = stream_read_char(demux->stream);
    id = stream_read_char(demux->stream);
    if(id >= 0xB0 && id <= 0xEF && priv) {
      int idoffset = id - 0xB0;
      switch(type) {
        case 0x1:
          priv->es_map[idoffset] = VIDEO_MPEG1;
          break;
        case 0x2:
          priv->es_map[idoffset] = VIDEO_MPEG2;
          break;
        case 0x3:
        case 0x4:
          priv->es_map[idoffset] = AUDIO_MP2;
          break;
        case 0x0f:
        case 0x11:
          priv->es_map[idoffset] = AUDIO_AAC;
          break;
        case 0x10:
          priv->es_map[idoffset] = VIDEO_MPEG4;
          break;
        case 0x1b:
          priv->es_map[idoffset] = VIDEO_H264;
          break;
        case 0x81:
          priv->es_map[idoffset] = AUDIO_A52;
          break;
      }
      mp_dbg(MSGT_DEMUX,MSGL_V, "PSM ES, id=0x%x, type=%x, stype: %x\n", id, type, priv->es_map[idoffset]);
    }
    plen = stream_read_word(demux->stream);		//length of elementary stream descriptors
    plen = min(plen, es_map_len);			//sanity check
    stream_skip(demux->stream, plen);			//skip descriptors for now
    es_map_len -= 4 + plen;
  }
  stream_skip(demux->stream, 4);			//skip crc32
  return 1;
}

/// Open an mpg physical stream
int demux_mpg_open(demuxer_t* demuxer) {
  stream_t *s = demuxer->stream;
  off_t pos = stream_tell(s);
  off_t end_seq_start = demuxer->movi_end-500000; // 500000 is a wild guess
  float half_pts = 0.0;
  mpg_demuxer_t* mpg_d;

  if (!ds_fill_buffer(demuxer->video)) return 0;
  mpg_d = (mpg_demuxer_t*)calloc(1,sizeof(mpg_demuxer_t));
  demuxer->priv = mpg_d;
  mpg_d->final_pts = 0.0;
  mpg_d->has_valid_timestamps = 1;
  mpg_d->num_a_streams = 0;
  if (demuxer->seekable && stream_tell(demuxer->stream) < end_seq_start) {
    stream_seek(s,(pos + end_seq_start / 2));
    while ((!s->eof) && ds_fill_buffer(demuxer->video) && half_pts == 0.0) {
      half_pts = mpg_d->last_pts;
    }
    stream_seek(s,end_seq_start);
    while ((!s->eof) && ds_fill_buffer(demuxer->video)) {
      if (mpg_d->final_pts < mpg_d->last_pts) mpg_d->final_pts = mpg_d->last_pts;
    }
    // educated guess about validity of timestamps
    if (mpg_d->final_pts > 3 * half_pts || mpg_d->final_pts < 1.5 * half_pts) {
      mpg_d->has_valid_timestamps = 0;
    }
    ds_free_packs(demuxer->audio);
    ds_free_packs(demuxer->video);
    demuxer->stream->eof=0; // clear eof flag
    demuxer->video->eof=0;
    demuxer->audio->eof=0;
    
    stream_seek(s,pos);
    ds_fill_buffer(demuxer->video);
  }
  return 1;
}

void demux_close_mpg(demuxer_t* demuxer) {
  mpg_demuxer_t* mpg_d = demuxer->priv;
  if (mpg_d) free(mpg_d);
}


static unsigned int read_mpeg_timestamp(stream_t *s,int c){
  int d,e;
  unsigned int pts;
  d=stream_read_word(s);
  e=stream_read_word(s);
  if( ((c&1)!=1) || ((d&1)!=1) || ((e&1)!=1) ){
    ++mpeg_pts_error;
    return 0; // invalid pts
  }
  pts=(((c>>1)&7)<<30)|((d>>1)<<15)|(e>>1);
  mp_dbg(MSGT_DEMUX,MSGL_DBG3,"{%d}",pts);
  return pts;
}

static void new_audio_stream(demuxer_t *demux, int aid){
  if(!demux->a_streams[aid]){
    mpg_demuxer_t *mpg_d=(mpg_demuxer_t*)demux->priv;
    sh_audio_t* sh_a;
    new_sh_audio(demux,aid);
    sh_a = (sh_audio_t*)demux->a_streams[aid];
    switch(aid & 0xE0){  // 1110 0000 b  (high 3 bit: type  low 5: id)
      case 0x00: sh_a->format=0x50;break; // mpeg
      case 0xA0: sh_a->format=0x10001;break;  // dvd pcm
      case 0x80: if((aid & 0xF8) == 0x88) sh_a->format=0x2001;//dts
                  else sh_a->format=0x2000;break; // ac3
    }
    if (mpg_d) mpg_d->a_stream_ids[mpg_d->num_a_streams++] = aid;
  }
  if(demux->audio->id==-1) demux->audio->id=aid;
}

static int demux_mpg_read_packet(demuxer_t *demux,int id){
  int d;
  int len;
  unsigned char c=0;
  unsigned int pts=0;
  unsigned int dts=0;
  demux_stream_t *ds=NULL;
  mpg_demuxer_t *priv = (mpg_demuxer_t *) demux->priv;
  
  mp_dbg(MSGT_DEMUX,MSGL_DBG3,"demux_read_packet: %X\n",id);

//  if(id==0x1F0){
//    demux->synced=0; // force resync after 0x1F0
//    return -1;
//}

//  if(id==0x1BA) packet_start_pos=stream_tell(demux->stream);
  if(id<0x1BC || id>=0x1F0) return -1;
  if(id==0x1BE) return -1; // padding stream
  if(id==0x1BF) return -1; // private2

  len=stream_read_word(demux->stream);
  mp_dbg(MSGT_DEMUX,MSGL_DBG3,"PACKET len=%d",len);
//  if(len==62480){ demux->synced=0;return -1;} /* :) */
  if(len==0 || len>MAX_PS_PACKETSIZE){
    mp_dbg(MSGT_DEMUX,MSGL_DBG2,"Invalid PS packet len: %d\n",len);
    return -2;  // invalid packet !!!!!!
  }

  mpeg_pts_error=0;

  if(id==0x1BC) {
    parse_psm(demux, len);
    return 0;
  }

  while(len>0){   // Skip stuFFing bytes
    c=stream_read_char(demux->stream);--len;
    if(c!=0xFF)break;
  }
  if((c>>6)==1){  // Read (skip) STD scale & size value
//    printf("  STD_scale=%d",(c>>5)&1);
    d=((c&0x1F)<<8)|stream_read_char(demux->stream);
    len-=2;
//    printf("  STD_size=%d",d);
    c=stream_read_char(demux->stream);
  }
  // Read System-1 stream timestamps:
  if((c>>4)==2){
    pts=read_mpeg_timestamp(demux->stream,c);
    len-=4;
  } else
  if((c>>4)==3){
    pts=read_mpeg_timestamp(demux->stream,c);
    c=stream_read_char(demux->stream);
    if((c>>4)!=1) pts=0; //printf("{ERROR4}");
    dts=read_mpeg_timestamp(demux->stream,c);
    len-=4+1+4;
  } else
  if((c>>6)==2){
    int pts_flags;
    int hdrlen;
    // System-2 (.VOB) stream:
    if((c>>4)&3) {
        mp_msg(MSGT_DEMUX,MSGL_WARN,MSGTR_EncryptedVOB);
    }
    c=stream_read_char(demux->stream); pts_flags=c>>6;
    c=stream_read_char(demux->stream); hdrlen=c;
    len-=2;
    mp_dbg(MSGT_DEMUX,MSGL_DBG3,"  hdrlen=%d  (len=%d)",hdrlen,len);
    if(hdrlen>len){ mp_msg(MSGT_DEMUX,MSGL_V,"demux_mpg: invalid header length  \n"); return -1;}
    if(pts_flags==2 && hdrlen>=5){
      c=stream_read_char(demux->stream);
      pts=read_mpeg_timestamp(demux->stream,c);
      len-=5;hdrlen-=5;
    } else
    if(pts_flags==3 && hdrlen>=10){
      c=stream_read_char(demux->stream);
      pts=read_mpeg_timestamp(demux->stream,c);
      c=stream_read_char(demux->stream);
      dts=read_mpeg_timestamp(demux->stream,c);
      len-=10;hdrlen-=10;
    }
    len-=hdrlen;
    if(hdrlen>0) stream_skip(demux->stream,hdrlen); // skip header bytes
    
    //============== DVD Audio sub-stream ======================
    if(id==0x1BD){
      int aid=stream_read_char(demux->stream);--len;
      if(len<3) return -1; // invalid audio packet
      
      // AID:
      // 0x20..0x3F  subtitle
      // 0x80..0x9F  AC3 audio
      // 0xA0..0xBF  PCM audio
      
      if((aid & 0xE0) == 0x20){
        // subtitle:
        aid&=0x1F;

        if(!demux->s_streams[aid]){
            mp_msg(MSGT_DEMUX,MSGL_V,"==> Found subtitle: %d\n",aid);
            demux->s_streams[aid]=1;
        }

        if(demux->sub->id==aid){
            ds=demux->sub;
        }
          
      } else if((aid & 0xC0) == 0x80 || (aid & 0xE0) == 0x00) {

//        aid=128+(aid&0x7F);
        // aid=0x80..0xBF
        new_audio_stream(demux, aid);
      if(demux->audio->id==aid){
        int type;
        ds=demux->audio;
        if(!ds->sh) ds->sh=demux->a_streams[aid];
        // READ Packet: Skip additional audio header data:
        c=stream_read_char(demux->stream);//num of frames
        type=stream_read_char(demux->stream);//startpos hi
        type=(type<<8)|stream_read_char(demux->stream);//startpos lo
//        printf("\r[%02X][%04X]",c,type);
        len-=3;
        if((aid&0xE0)==0xA0 && len>=3){
	  unsigned char* hdr;
	  // save audio header as codecdata!
	  if(!((sh_audio_t*)(ds->sh))->codecdata_len){
	      ((sh_audio_t*)(ds->sh))->codecdata=malloc(3);
	      ((sh_audio_t*)(ds->sh))->codecdata_len=3;
	  }
	  hdr=((sh_audio_t*)(ds->sh))->codecdata;
          // read LPCM header:
	  // emphasis[1], mute[1], rvd[1], frame number[5]:
          hdr[0]=stream_read_char(demux->stream);
//          printf(" [%01X:%02d]",c>>5,c&31);
	  // quantization[2],freq[2],rvd[1],channels[3]
          hdr[1]=stream_read_char(demux->stream);
//          printf("[%01X:%01X] ",c>>4,c&15);
	  // dynamic range control (0x80=off):
          hdr[2]=stream_read_char(demux->stream);
//          printf("[%02X] ",c);
          len-=3;
          if(len<=0) mp_msg(MSGT_DEMUX,MSGL_V,"End of packet while searching for PCM header\n");
        }
//        printf("  \n");
      } //  if(demux->audio->id==aid)

      } else mp_msg(MSGT_DEMUX,MSGL_V,"Unknown 0x1BD substream: 0x%02X  \n",aid);

    } //if(id==0x1BD)

  } else {
    if(c!=0x0f){
      mp_msg(MSGT_DEMUX,MSGL_V,"  {ERROR5,c=%d}  \n",c);
      return -1;  // invalid packet !!!!!!
    }