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291 Izvedba video aplikacija na Microsoft PocketPC platformama

291 Izvedba video aplikacija na Microsoft PocketPC platformama. Mr.sc. Hrvoje Mlinarić Prof. Dr.sc. Mario Kovač FER - Zagreb. 300. Što i Kako ?. Uvod Problematika Dekodiranje Video Datoteka Sinkronizacija ??? Zaslon Game API Zaključak. Što želimo postići ? Kome to treba ?

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291 Izvedba video aplikacija na Microsoft PocketPC platformama

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  1. 291Izvedba video aplikacija na Microsoft PocketPC platformama Mr.sc. Hrvoje Mlinarić Prof. Dr.sc. Mario Kovač FER - Zagreb 300

  2. Što i Kako ? • Uvod • Problematika • Dekodiranje Video Datoteka • Sinkronizacija ??? • Zaslon • Game API • Zaključak

  3. Što želimo postići ? • Kome to treba ? • Kako to realizirati ?

  4. Video Sadržaj • Video kompresija • MPEG-1 • MPEG-2 • MPEG-4 • MJPEG • … • Zapis videa • AVI, QuickTime format, MPEG System file

  5. Dekodiranje Video Sadržaja • Trenutno Microsoft ne nudi rješenje… • Direct Show, Direct Play, Direct Draw ??? • Zašto ??? • Vjerujem da ubrzano rade na tome ! • Video dekodiranje je vrlo zahtjevno • Sinkronizacija audija i videa komplicirana • Snaga PDA uređaja ograničena (400MHz) • Rješenje • Koristiti druga komercijalna rješenja ...

  6. PlayMediaSystems- 4Play • Skup alata za rad s video i audio sadržajem • dekodiranje videa MPEG1,MPEG2, MPEG4, MJPEG, … • dekodiranje audia MP3 • Parsiranje video datoteka AVI, VCD, MPEG4 System datoteka. • Enkodiranje MPEG4 • Skup alata za YUV-RGB konverziju • …

  7. buffer_size = 32768; stream.full_decode = TRUE; stream.postprocess = POST_NONE; stream.output_type = OUTPUT_RGB_16; stream.data_buffer = (unsigned char *) malloc(buffer_size); stream.data_buffer_size = 0; stream.use_external_yuv_buffers = 0; mp4_init_decoder(&stream); • Primjer inicijalizacije MPEG4 dekodera

  8. memcpy(stream.data_buffer,buffer,size); stream.data_buffer_size = size; mp4_reload_decoder(&stream); result=mp4_get_frame(&stream); • Primjer dekodiranja MPEG4 okvira AVI datoteka… AVIStream_Init(c_file,&aFile) // Init AVI parser AVIStream_ReadVideoData(&aFile,&size,&buffer); AVIStream_ReadAudioData(&aFile,&size,&buffer);

  9. Zaslon • Većina video formata zasniva se na YUV formatu zapisa boja • YUV format podržan je na PC grafičkim karticama • Niti jedan PDA uređaj nema zaslon koji podržava YUV format. • Moramo koristiti YUV-RGB konverziju • Veliki problem:: slika 320*244 troši 40% CPU-a

  10. CDC *pDC; pDC=GetDC(); bitmapinfo.bmiHeader.biSize=sizeof(BITMAPINFOHEADER); bitmapinfo.bmiHeader.biWidth=100; . . . . . . bitmapinfo.bmiHeader.biClrImportant=256; hTargetBitmap = CreateDIBSection(pDC->m_hDC, &bitmapinfo, DIB_RGB_COLORS, &pBuffer,NULL,0); hDC_C=CreateCompatibleDC(pDC->m_hDC); HBITMAP old=(HBITMAP)SelectObject(hDC_C,hTargetBitmap); t=(int*)pBuffer; for(i=0;i<100*100;i++) t[i]=i; BOOL c= BitBlt(pDC->m_hDC,0, 0, 100, 100, hDC_C,0, 0, SRCCOPY); ReleaseDC(pDC);

  11. Problematika navedenog rješenja • Video dekodiranje vrlo zahtjevno • 45fps (320 x 240) • + YUV-RBG :: 32 – 36 fps • audio dekodiranje MP3 sadržaja 20% • Video + RGB + YUV :: ~26 fps… • Svi podatci navedeni za X-SCALE na 400MHz • Najveći problem memorija • CPU radi na 400 MHz • Sabirnica prema memoriji 50MHz • usko grlo !!!

  12. Problematika navedenog rješenja • U navedenom rješenju imamo tri kopiranja blokova • sliku u blok memorije • iz memorije u DC • iz DC u Video memoriju • Nameće se pitanje kako pisati direktno u Video memoriju • Microsoft nam nudi pomoć • GAME API

  13. Game API • Omogućava direktan pristup Video uređaju • Dozvoljava crtanje po zaslonu zaobilazeći PocketPC system • Preteča budućeg Pocket DirectX-a

  14. Funkcije GAPI-a • GXBeginDraw • GXCloseDisplay • GXCloseInputGXEndDraw • GXGetDefaultKeys • GXGetDisplayProperties • GXIsDisplayDRAMBuffer • GXOpenDisplay • GXOpenInput • GXResume • GXSetViewport • GXSuspend

  15. GXBeginDraw GXDLL_API void * GXBeginDraw (); Parameters • None. Return Values • Pointer to start of display memory, or NULL if the display cannot be locked.

  16. GXEndDraw GXDLL_API int GXEndDraw (); Parameters • None. Return Values • Returns 1 if the call was successful, or 0 if there was an error. Call GetLastError to retrieve extended error information.

  17. GXGetDisplayProperties GXDLL_API GXDisplayProperties GXGetDisplayProperties (); Parameters • None. Return Values • Returns a populated GXDisplayProperties structure.

  18. GXDisplayProperties struct GXDisplayProperties { DWORD cxWidth; DWORD cyHeight; long cbxPitch; long cbyPitch; long cBPP; DWORD ffFormat; };

  19. unsigned short * pusLine; pusLine = (unsigned short *)GXBeginDraw(); pms_yuv2rgb_dev(stream.y_resize, stream.output_width+64, stream.u_resize, stream.v_resize,stream.output_width/2+32, (unsigned short *) pusLine,stream.output_width, stream.output_height, gx_displayprop.cbxPitch,gx_displayprop.cbyPitch,3,0,0,stream.mb_coded); GXEndDraw();

  20. Problem različitih zaslona • Dimenzije zaslona • 320 x 244 • 244 x 320 • Orijentacija • Od lijeva na desno ili od desna na lijevo • Odozgo prema dolje ili obrnuto • Broje boja • 32bpp, 24 bpp, 16 bpp • RGB:: 444, 555, 565

  21. Zaključak • Video dekodiranje • Ispis na zaslon • GAME API • Neriješeni problemi • Zvuk • Sinkronizacija videa i zvuka • GUI

  22. Q & A

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