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BufferedMPGStreamReader Class Reference

#include <BufferedMPGStreamReader.hpp>

Inheritance diagram for BufferedMPGStreamReader:

MPGStreamIO IO VThread List of all members.

Public Member Functions

 BufferedMPGStreamReader (ESInfo *es, const char *file, bool writeOnly, bool omitHeader=false, int bufferSize=STREAMREADER_DEF_BUFFER_SIZE, int maxFrameSize=MAX_FRAME_SIZE)
bool testFileopen ()
Frame * getFrame ()
 returns a frame if one complete frame is available, otherwise null is returned.

Static Public Member Functions

int getDefaultBufferSize ()

Detailed Description

Author:
Klaus Schoeffmann

Definition at line 62 of file BufferedMPGStreamReader.hpp.

Member Function Documentation

Frame * BufferedMPGStreamReader::getFrame (   )  [virtual]
 

returns a frame if one complete frame is available, otherwise null is returned.

This function is typically blocking. Don't use a NULL return value to conclude STREAMEOF, always check with getState()!

Reimplemented from MPGStreamIO.

Definition at line 180 of file BufferedMPGStreamReader.cpp.

References MPGStreamIO::close(), ESInfo::getVOPTimeIncrement(), ESInfo::isAudioStream(), ESInfo::isVisualStream(), Frame::setAU(), and Frame::setMediaTimeScale().

00180                                          {
00181         if (writeOnly || state != OPEN)
00182                 return NULL;
00183  
00184         if (( (this->currentFrameNumber > this->endFrameNumber) && (endFrameNumber!=0) )) { // || feof(io)) {
00185                 close(true);
00186                 state=STREAMEOF;
00187                 return NULL;
00188         }
00189 
00190         // now read the frame
00191         AU *au = new AU();
00192         Frame *frm = NULL;
00193         Frame::FrameType type = Frame::NN_VOP;
00194 
00195         // parse MPGFile for VOB_Code if it is a visual stream
00196 
00197         if(es->isVisualStream()) {
00198                 // 00 00 01 182 dec -> 0x1B6 (=438 dec)
00199                 u32 code = 2000;        // don't init to 0, we want the code from the 2nd frame, not the first
00200                 int i = 0;
00201 
00202                 u8 *data = new u8[MAX_FRAME_SIZE];
00203 
00204                 do {
00205                         data[i] = buffered_getc();
00206                         code = (code << 8) | data[i]; //(u8)buffered_getc();
00207                         i++;
00208                         if ((i==4) && code == VOP_START_CODE) code = 0;
00209                 } while ((code != VOP_START_CODE) && (i < maxFrameSize) && state != CLOSED);
00210                 
00211                 if (code == VOP_START_CODE) {
00212                         goBack(4);
00213                         i -= 4;
00214                         au->size = i;
00215                         au->payload = new u8[i];
00216                         memcpy(au->payload, data, i);
00217                         delete [] data;
00218                         dprintf_full("BufferedMPGStreamReader::getFrame() read %d bytes of video frame\n", i);
00219                 }
00220 
00221                 if (au->size == 0) {
00222                         state = STREAMEOF;
00223                         delete au;
00224                         return NULL;
00225                 }
00226 
00227                 au->prio = IO_NETWORK_HIGHEST_PRIORITY;
00228                 au->duration = es->getVOPTimeIncrement();
00229                 au->cts = currentFrameNumber * es->getVOPTimeIncrement();
00230                 au->dts = currentFrameNumber * es->getVOPTimeIncrement();
00231                 au->sampleFlags = 0;
00232                 if (code != VOP_START_CODE)
00233                 au->err = SA_EOF;
00234                 else
00235                 au->err = SA_OK;
00236 
00237         }
00238         
00239         if(es->isAudioStream()) { //XXX not sure if it works properly
00240                 // start code for MP3 frame is 11111111 111 (first 11 bits set) 
00241                 u32 code = 2000;        // don't init to 0, we want the code from the 2nd frame, not the first
00242                 int i = 0;
00243 
00244                 //special handling for first frame
00245                 if (framesSeen == 0) {
00246                         int ch = 0;
00247                         au->payload = new u8[1024];
00248                         do {
00249                                 ch = buffered_getc();
00250                                 au->payload[i] = ch;
00251                                 i++;
00252                                 code = (code << 8) | ch;
00253                         }
00254                         while ((code>>21) != 0x000007FF /*VOP_START_CODE for audio(actually MP3)*/);
00255                         au->size = i;
00256                 } else {
00257                         au->payload = new u8[MAX_FRAME_SIZE];
00258                         au->size = buffered_copy(au->payload, maxFrameSize);
00259                 }
00260 
00261                 dprintf_full("BufferedMPGStreamReader::getFrame() read %d bytes of audio frame\n", au->size);
00262         
00263                 au->cts = DTS;
00264                 au->dts = DTS;
00265                 au->duration = 0;
00266                 au->sampleFlags = 0;
00267                 au->err = SA_OK;
00268         
00269                 DTS += es->getVOPTimeIncrement();
00270         }
00271 
00272         // frame types will be detected in frm->setAU()!
00273         if(es->isVisualStream())
00274                 frm = new CompressedVideoFrame(type, ((VideoESInfo*)es)->getWidth(), ((VideoESInfo*)es)->getHeight());
00275         else if(es->isAudioStream())
00276                 frm=new CompressedAudioFrame(type);
00277         else
00278                 frm = new CompressedVideoFrame(type, 0, 0);
00279         frm->setAU(au);
00280         frm->setMediaTimeScale(es->getMediaTimeScale());
00281         framesSeen++;
00282         currentFrameNumber++;
00283 
00284 
00285 #ifdef _POSIX_PRIORITY_SCHEDULING
00286         sched_yield();
00287 #else
00288         // for windows pthread lib!
00289 #ifdef WIN32
00290 #ifndef WINCE
00291         sched_yield();
00292 #else
00293         Sleep(1);
00294 #endif
00295 #endif
00296 #endif
00297 
00298   return frm;
00299 }

The documentation for this class was generated from the following files: