¬Û«H±M·~¡Aµ¹§A«~½è
±MÀç«Ø¿vª«¨¾¤ô¡B§ìº|¡B°£¾ÀÀù¡B©î°£¤uµ{
§N®ðª½±µ´£¨Ñ«È¤áµ¹±z¡A¨C¤Ñ´£¨Ñµ¹±z·s«È¤á±a¨Ó·s°Ó¾÷
¤£¥Î¦Aªá°ªÃBªº¼s§i¶O°µ¨Ç¨S®ÄªGªº¼s§i

­º­¶  ¡E  j2h ½×¾Â ¡E µ{¦¡³]­p°Q½×     ¡E 

[°Q½×]§Q¥Î Linux «Øºc Video Streaming Se

©ÐªF¡G¹F¤H
µoªí®É¶¡¡G2007-07-01
[ÀËÁ|]


Video Streaming ªº§Þ³N¤w¸g¥X²{¦h¦~¡A¦b Internet ¤WªºÀ³¥Î¤]¤w¸g¬Û·í¼sªx¡A¦Ó§Q¥Î Linux «Øºc Video Streaming Server ¤]¬O¬Û·í¼öªùªº¸ÜÃD¡C¦pªG±z·QÁA¸Ñ¤°»ò¬O Video Streaming¡A¥»¤å¹ï Video Streaming ªºÆ[©À»P§Þ³N±N°µ¤F²M·¡¦Ó°ò¥»ªº¤¶²Ð¡C


Video Streaming ¨Óªº¥¿¬O®É­Ô


¬Ý¨ì "Video" Streaming ´Nª¾¹D³o­Ó§Þ³N»P¼v­µ¦³Ãö¡CVideo Streaming ¬O¤@ºØ¸g¥Ñºô¸ô¨Ó¼·©ñ¼v­µÀɮתº§Þ³N¡AVideo "Streaming" ªº°ò¥»·§©À¬°¡u¤@Ãä¤U¸ü¤@Ãä¼·©ñ¡v¡A§Ú­ÌºÙ¤§¬°¡uPlay as received¡v¡C


¸g¥Ñ Internet ¦pªG­n¦¬¬Ý»·ºÝ¦øªA¾¹ªº¹qµøÀɮסA³Ì­ì©lªº°µ¬°¬O¡u¤U¸ü«á¦A¼·©ñ¡v¡A¤]´N¬O¸g¥Ñ FTP ©Î HTTP ±N¾ã­ÓÀɮפU¸ü¦Ü¥»¦aºÝ«á¦A§Q¥Î¼·©ñµ{¦¡¨Ó¼·©ñ¡A§Ú­ÌºÙ¤§¬°¡uPlay after download¡v¡C


¥H³Ì±`¨£ªº¨Ò¤l¨ÓÁ¿¡A§Ú­Ì¥i¥H¸g¥Ñºô¸ô±N MP3 §¹¾ã¤U¸ü«á¦A¼·©ñ¡A¤]´N¬O Play after download¡A©ÎªÌ§Ú­Ì¤]¥i¥H¤@Ãä¤U¸ü MP3 ¤@ÃäÅ¥­µ¼Ö¡A³oºØ¤è¦¡«hºÙ¬° Play as received¡C¨ä¥LªºÀ³¥Î½d¨ÒÁ٫ܦh¡A¨Ò¦p§Q¥Î RealPlayer¡u§Y®ÉÆ[¬Ý¼v¤ù©Î¬OÅ¥­µ¼Ö¡v¡A³oºØ§Y®É¼·©ñªº¤è¦¡§Y¬O Play as received¡A§Ú­ÌºÙ³o¼Ëªº§Þ³N¬° Video Streaming Technology¡C


¬°¤°»ò»¡ Video Streaming ªº§Þ³N¨Óªº¥¿¬O®É­Ô©O¡HÁ|­Ó³Ì²³æªº±¡ªp¡A§A¥i¯à¦b¤U¸ü MP3 ¤§«e·Q­n¸ÕÅ¥¤@¤U­µ¼Öªº¤º®e¡A¦Ó¤U¸ü­µ¼Ö¤ù¬qªº¤è¦¡¤SÅã±o¤£°÷¤Íµ½¡A³o®É¦pªG§Q¥Î Video Streaming ªº§Þ³N¨ÓÅýºô¤ÍµøÅ¥¡A¤£¦ý¤è«K¡A¦Ó¥B¤£¥²®ö¶O®É¶¡¨Ó¤U¸ü¤£³ßÅwªº­µ¼Öªº¡C


ÀHµÛºô¸ôÀW¼eªº§ï¶i»P IPv6 ªº¥X²{¡AVideo Streaming ªºÀ³¥Î±N¶V¨Ó¶V¼sªx¡A§Q¥Î Video Streaming ¨Ó³]­pªº¸ê°T®a¹q¤]·|¶V¨Ó¶V¦h¡A¨Ò¦p¸û±`³Q´£¤Îªººô¸ô¹q¸Ü (InterPhone)¡C


°£¤F¼eÀWºô¸ôªº´¶¤Î¥~¡AÀx¦s³]³Æªº¤j¶i¨B¤]¬O¥[³t Video Streaming ¶i¥Î´¶¤Îªº³Ì¤j°Ê¤O¡A¨Ò¦p§Q¥Î Linux ³]­pªº NAS ¥i¥H³Q¥Î¨Ó·í°µ¤j«¬ªº¼v­µ¦øªA¾¹©Î¬O°ÊºA¹q¼v¸ê®Æ®w (DMD)¡C


VCD & MPEG-1


­n´£¨ì¼·©ñ°ÊºA¼v­µªº¥ýÂß¡Aµ´¹ï­n¥ý±q VCD »¡°_¡A¦]¬°³o¬O¦b¹q¸£¥X²{«á¡A³Ì¯à²`¤J®ø¶OªÌ¥«³õªº²£«~¡C


·Q·í¦~¡A­n¼·©ñ VCD °£¤F­n¦³¤@¥x·í®Éºâ¬O°ª¾×³fªº 1x CD-ROM ¥~¡AÁÙ­n¦A¥t¥~¥[¸Ë¤]¬O°ª¾×³fªº MPEG ¥d¡C¼·©ñ VCD ¨ä¹ê´N¬O Video Streaming ªº§Þ³N¡A¦]¬° VCD ªº¸ê®Æ¬O¤@ÃäŪ¨ú¤@Ãä¼·©ñ¡A¨º¬°¤°»ò­n¦³ MPEG Card ©O¡H²z©Ò·íµMªº¡A³o¬O¦]¬°MPEG-1 ªº¼Ð·Ç¡C


MPEG-1 ³Q³]­p¦b 1x CD-ROM ¤W¼·©ñ VCD¡A¦Ó VCD ¤Wªº¸ê®Æ¥²¶·¸g¥Ñ MPEG Card ¸Ñ½X (decode) «á¤~¯à¼·©ñ¡C¦ý¬OÀHµÛµwÅ骺¶i¨B¡A²{¦b¥i¥H¸g¥Ñ³nÅé¨Ó°µ MPEG-1 ¸Ñ½Xªº¤u§@¡C§Ú­Ì±N¦b«á¤å¤¶²Ð MPEG-1 ªº³]­p·§©À¡C


DVD & MPEG-2


MPEG-2 ±`³Q´£¨ì«h¬O¥Ñ©ó DVD ªº¬y¦æ¡C¤£ºÞ¬O MPEG-1 ©Î¬O MPEG-2¡A¨ä¹ê¬O¤@ºØ½s½Xªº§Þ³N¡A¦Ó DVD-ROM «h¬O¿ï¾Ü¤F MPEG-2 ¨Ó·í°µ¥¦ªºÀ£ÁY¼Ð·Ç¡C


¦Ó DVD ¤§©Ò¥HµLªk¹³ VCD ¤@¼Ë¯à³Q¡u³Æ¥÷¨ìµwºÐ¡v¡A«h¬O¥Ñ©ó¨ä¤¤¤S¥[¶i¤F¤T¹Dªº«OÅ@¡A²Ä¤G¹D«OÅ@´N¬Oª±®a­Ì¦Õ¼ô¯à¸Ôªº CSS¡C¦b Linux ¤U¤§©Ò¥HµLªk¦³¡u¦Xªk¡vªº DVD Player¡A´N¬O¨ü¨î©ó CSS ªºÃö«Y¡C


§Q¥Î NAS ¨Ó³]­p Video Server¡A­nÀx¦s¨Ã¼s¼· VCD ¤w¸g¨S¦³§Þ³N¤Wªº»Ùê¡A¦ý¬O­nÀx¦s¨ÃÂX¼· DVD¡A«h¦³ªk«ß¤Wªº°ÝÃD¡A³oÂI¬O­È±o§Ú­Ì²`«äªº¤@­Ó°ÝÃD¡C¦]¬°¥Ø«e CSS ªº§Þ³N´x´¤¦b¤é¥»¤H¤âùØ¡A­n¨ú±o³o¶µ§Þ³N¥²¶·Ã±¸p NDA¡A¤£¹L CSS ¨Ã«D¤£¥i¯}¸Ñ·Q¥²¤j®a³£ª¾¹D¡A¦ý¬O´N¬O¦³ª©Åv¤Wªº°ÝÃD¡C


¼v¹³½s½X§Þ³N¤¶²Ð


¥Ø«e¾Ç³N¬É¤w¸gµo®i¥X³\\¦h³B²z¼v¹³°T¸¹À£ÁY¤Î½s½Xªº§Þ³N (codecs)¡A½Í¨ì³o¨Ç§Þ³N¡AÀ³¥Î³Ì¼sªxªº½s½X¼Ð·Ç©³¤U¥|ºØ¡G



  1. ) H.261

  2. ) H.263

  3. ) JPEG, MJPEG

  4. ) MPEG


©³¤U±N¤À§O²³æ¤¶²Ð³o¥|ºØ½s½X§Þ³N¡C


H.261 ¼Ð·Ç


H.261 ªº¼v¹³½s½X¼Ð·Ç¥X²{¦b 1990 ¦~ªº ITU¡C¤@¶}©lªº¥Î³~¥D­n¬O¤ä´©¼v¹³¹q¸Ü (video phone) »Pµø°T·|ij (video conferencing)¡CH.261 ªº®æ¦¡¦³¤GºØ¡A¤À§O¦³¤£¦Pªº¸ÑªR«×¡G



  1. ) QCIF¡G176x144

  2. ) CIF¡G352x288


H.261 ªº fps (frames per second) ¥i¥H¹F¨ì 7.5, 10, 15 »P 30 fps¡C¥Ñ©ó H.261 ¤@¶}©l¬O¬[ºc¦b ISDN B ¤W­±¡A¦Ó ISDN B ªº¶Ç¿é³t«×¬° 64 Kbps¡A©Ò¥H H.261 ¤]³QºÙ¬° Px64 (x = 1 to 30)¡C


CIF ¥þ¦W¬° (Common Intermediate Format)¡A¥D­n¬O¬°¤F­n¤ä´©¦UºØ¤£¦P¸ÑªR«×ªº¹q¼v¦Ó³Q©w¸q¥X¨Ó¡A¨Ò¦p NTSC, PAL, SECAM ¹qµø¨t²Î¡C¦Ó QCIF «h¬O Quarter-CIF ¤]´N¬O CIF ¸ÑªR«×ªº¤@¥b¡C


°£¦¹¤§¥~¡AH.261 ¤]¥i¥H»¡¬O MPEG-1 ¼Ð·Çªº«e½ú¡C


H.263 ¼Ð·Ç


H.263 ¬O H.261 ªº¥[±jª©¡A½Ï¥Í©ó 1994 ¦~ (ITU)¡CH.263 ¶}©l¤ä´© PSTN¡A¤£¹L­n¯S§O»¡©ú¤@ÂI¡AH.263 ¤ñ MPEG-1 ÁÙ­n±ß¥X²{¡A¦Ó¥B H.263 ÁÙ¬O°ò©ó MPEG-1 ¦Óµo®i¡C


H.263 ªº¼Ð·Ç¦@¤ä´©¤­ºØ¤£¦Pªº¸ÑªR«×¡A¤À§O¬°¡G



  1. ) Sub-QCIF¡G128x96

  2. ) QCIF¡G176x144

  3. ) CIF¡G352x288

  4. ) 4CIF¡G704x576

  5. ) 16CIF¡G1408x1152


¶Ç¿é³t«×¬° 8 Kbps ~ 1.5 Mbps¡C°£¦¹¤§¥~¡AH.263 ¤]¬O MPEG-4 ¼Ð·Çªº°ò¦¡C


JPEG


´£¨ì JPEG ªº¼Ð·Ç¡A¤j®a¥i´N¤£²ö¥Í¤F¡A¥Ñ¨ä¬O¦b GIF µo¥X¸T¥O«á¡AJPEG §ó¬O³Q¼sªxÀ³¥Î¡CJPEG ªº¥þ¦W¤j®a¤@©w¤£²ö¥Í¡A¥L¥i¬O»®»®¦³¦Wªº¤@¸s§Þ³N¹Î¶¤ªºÁY¼g - Joint Photographic Experts Group¡C


JPEG ¬O 24-bit ªº "true-color" ¼v¹³¼Ð·Ç¡AJPEG ªº¤u§@¬O±N RGB ®æ¦¡ªº¼v¹³Âà´«¦¨ YCrCB ®æ¦¡¡A¥Øªº¬O¬°¤F´î¤ÖÀɮפj¤p¡A¤@¯ë¬ù¥i´î¤Ö 1/3 ~ 1/2 ¥ª¥k¡C


¤£¹L MJPEG ¤~¬O§Ú­Ìªº¥D¨¤¡AMJPEG ¥þ¦W¬° "Motion" JPEG¡A¤]´N¬O·|°Êªº JPEG ¹ÏÀÉ¡C³\\¦h Video Streaming ªº³õ¦X¡A¹³¬O²³æªºµø°T·|ij³nÅé³£·|¨Ï¥Î MJPEG ¨Ó¨ú¥N MPEG¡A­ì¦]µL¥¦¡A¦]¬° MJPEG ®æ¦¡Â²³æ¡A¦ý¯ÊÂI¬O¤£¤ä´©Án­µ¡C


MPEG-1 ¼Ð·Ç


MPEG ªº¼Ð·Ç¥Ñ ISO (International Standards Organization) ©Ò¨î©w¡A¥þ¦W¬° Moving Pictures Experts Group (MPEG ¬° ISO ¤u§@)¡A³o¨Ç¹Î¶¤¨î©w¤F¥]¬A MPEG-1¡BMPEG-2¡BMPEG-4 µ¥¼Ð·Ç¡C


MPEG-1 ªº¼Ð·Ç¤ñ H.263 ¦­¥X²{¡AMPEG-1 ¨î©w©ó 1992 ¦~¡A¥D­n¥Î³~¬°¡Gµø°T·|ij¡B¼v¹³¹q¸Ü¡B¹q¸£¹CÀ¸»P¤ä´©²Ä¤@¥Nªº CD-ROM¡CMPEG-1 ³Q³]­p¨Ó¤ä´©¤j³¡¥÷ªº¼v¹³»P CD-ROM ªº­µ®Ä¡A¶Ç¿é³t«×¬° 1.5 Mbps (30 fps)¡C


°£¦¹¤§¥~¡AMPEG-1 ¤]¤ä´© playback¡A¨Ò¦p§ÖÂà¡B­Ë±a©Î¬O¸õÅD¡A³o¤]¬O MPEG-1 ¦n¥Îªº¦a¤è¡Cµy«á§Ú­Ì·|²³æ¤¶²Ð¤@¤U MPEG-1 ªº­ì¦]¡A¥H©ú¥Õ MPEG-1 ¦p¦ó°µ¨ì³o¨Ç¥\\¯à¡C


MPEG-2 ¼Ð·Ç


MPEG-2 ªº¼Ð·Ç¥X²{©ó 1994 ¦~¡AMPEG-2 ¬Û®e©ó MPEG-1¡CMPEG-2 ªº¥X²{¨Ã¤£¬O¬°¤F­n¨ú¥N MPEG-1 ªºÂ¼зǡA¦Ó¬O­n¥[±j MPEG-1 ¤£¨¬ªº¦a¤è¡C¦]¦¹ MPEG-2 §ó¯àª@¥ô¨ä¥¦¤u§@Àô¹Ò¡A¨Ò¦p HDTV¡Bµø°T¼s¼½¡C


¦P®É¡AMPEG-2 ªº¸ÑªR«×¤]¤ä´©¨ì HDTV 1280x720¡C¦b­µ®Ä¤è­±¡AMPEG-2 ¤]¤ä´©¨ì 6 ­ÓÀW¹D (MPEG-1 ¥u¤ä´© 2 ­ÓÀW¹D)¡CMPEG-2 ªº¶Ç¿é³t«×¤]´£ª@¦Ü 2Mbps ~ 10 Mbps¡A¦]¦¹»Ý­n 4x ªº CD-ROM¡A¦ý¤]¦]¦¹ 4x CD-ROM ¥u¯àÀx¦s 18 ¤ÀºØªº¼v¹³¡A©Ò¥H§Ú­Ì§Q¥Î DVD-ROM ¨ÓÀx¦s MPEG-2 ®æ¦¡ªº¼v¹³¡A¦Ó¥B DVD-ROM ¤]¤ä´© Dolby ­µ®Ä¡C


MPEG-4 ¼Ð·Ç


MPEG-4 ªº¼Ð·Ç¦b 1993 ¦~³Q´£¥X¡A¥D­nªºÀ³¥Î¥Î³~¤ñ¸û¼s¡A¥]¬A¡Gµø°T·|ij¡B¼v­µ¶l¥ó¡BµL½u¸Ë¸mµ¥µ¥¡A¤ä´©ªº¶Ç¿é³t«×¬° 8Kbps ~ 35Mbps¡C


MPEG-4 ¥i¥H¶Ç°e¼v¹³ªºª«¥ó¡A¦Ó¤£¬O¥u¦³¼v¹³ªº "frame"¡A¨Ò¦p¤@³s¦êªº°Ê§@«ü¥O¡C¦]¦¹¡AMPEG-1 »P MPEG-2 ¬Ò¬O "frame-based" ªº¼Ð·Ç¡A¦Ó MPEG-4 «h¬O "object-based" ªº¼Ð·Ç¡A¥¼¨Ó¦bºô¸ô»P¦h´CÅ骺À³·|¤]·|§ó´¶¹M¡C


MPEG-4 ¥Ø«e¦b Linux ¤W¤w¸g¦³ OpenMPEG ªº±M®×­pµe¡Aµo°_¥»­pµeªº¥Ø¦a¦b§Æ±æ¥i¥H¦b Linux ¤Wµo®i§¹¾ãªº MPEG-4 ¤ä´©Àô¹Ò¡C


Video Streaming ªººô¸ô§Þ³N


­n«Ø¸m¤@­Ó§¹¾ãªº Video Streaming Àô¹Ò¡A¦b¾ãÅé¨Ó¬Ý¡A­n·Ç³ÆªºµwÅé¥]¬A¡G¦øªA¾¹¡BCCD¡B¼v¹³¸É®»¥dµ¥µ¥¡A¦Ó¦b©³¼hªº§Þ³N­±¤è­±¡A°£¤F«e­±´£¨ìªº¼v¹³½s½X§Þ³N¥~¡A¤]­n°t¦X³q°T¨ó©w¤~¯à¹ê§@¥X Video Streaming ªºÀ³¥Îµ{¦¡¡C


Video Streaming ªº¤è¦¡


Video ¦b°µ Streaming ®É¡A¦³¤TºØ¤è¦¡¥i¥HÀ³¥Î¡Gbroadcasting¡Bunicasting¡Bmulticasting¡C


broadcasting ªº¤è¦¡¤ñ¸û³æ¯Â¡A¥L¬O¦b LAN ¤Wª½±µ±N¤@­Ó­Óªº¼v¹³«Ê¥]¥á¨ìºô¸ô¤W (server ºÝ)¡A¦A¥Ñ client ªºÀ³¥Îµ{¦¡¦Ûºô¸ô¤W¨ú¦^«Ê¥]¼½©ñ¡C¦ýºô¸ôµwÅé¼h¤W¡A¤´¦³³\\¦h»Ý­n¦Ò¼{ªº°ÝÃD¡A¨Ò¦p¦b Shared Non-Switched Enthernet ¤W®É¡A´N·|µo¥Í¤@¨Ç¤p°ÝÃD¡C


unicasting »P multicasting ³£¬OÄÝ©ó IP ªº¶Ç¿é¤è¦¡¡Cunicasting ±Ä¨ú 1 ¹ï 1 ªº¤è¦V¶Ç¼v¹³µ¹»·ºÝ¡AºÙ¬° Video-on-Demand (VoD)¡Amulticasting «h¬O 1 ¹ï¦hªº¶Ç¿é¤è¦¡¡AºÙ¬° Near-Video-on-Demand (NVoD)¡C¥¼¨Ó IPv6 ±N¤ä´© IP Multicasting¡A¦]¦¹ Video Streaming ªºÀ³¥Î±N§ó¬°¼sªx¡C


IPv6


IPv6 ¥þ¦W¬° IP version 6¡A¥¼¨Ó±N¨ú¥N¥Ø«e©Ò¨Ï¥Îªº IPv4¡CIPv6 ·s¼W³\\¦h¹ï¦h´CÅé¶Ç¿éªº¤ä´©¡A¨Ò¦p multicasting¡Bauthentication/encryptionµ¥¡C¤£¹L¥Ø«e©|¤´¥¼¥þ­±¤É¯Å¡A©Ò¥HÀ³¥Î¤´¨ü­­¡C


UDP ³q°T¨ó©w


UDP ¥þ¦W¬O Universal Datagram Protocol¡AUDP ³q°T¨ó©w¬O Video Streaming ªº°ò¥Û¡CUDP »P TCP ¤£¦Pªº¬O¡AUDP ¨Ã¨S¦³¿ù»~Àˬd¡A¤£¹L³o¦b Video Streaming ªºÀ³¥Î¬O¼vÂQ¤£¤Óªº¡C


RTP ³q°T¨ó©w


RTP ¥þ¦W¬° Real-Time Protocol¡ARTP ¬O¦b UDP «Ê¥]¤§«e¦h¥[ 10 bytes ªºÀÉÀY¡A¸Ì­±°O¸ü¦³®É¶¡¡B§Ç¸¹¡BÀ£ÁY«¬ºAµ¥¸ê°T¡CRTP ¬O¥Ø«e¤j¦h¼Æ Video Streaming ³nÅé©Ò¨Ï¥Îªº³q°T¨ó©w¡C


RTP ¥i¥Î¨Ó°w¹ï¦UºØ¤£¦Pªº¦h´CÅé®æ¦¡°µ Streaming ªº¤u§@¡A¦]¬°§Ú­Ì±N¼v¹³¤À¸Ñ¦¨¼Æ­Ó RTP «Ê¥]¦A¶Ç°e¥X¥h¡A¦]¦¹·|¹J¨ì³\\¦hºô¸ô§Þ³N±`·|¹J¨ìªº°ÝÃD¡C¨Ò¦p¡A¦]¬°«Ê¥]°e¹Fªº®É¶¡¤£¤@¡A³y¦¨¼½©ñ®É·|µe­±¤£¬yºZªº²{¹³¡A¦]¦¹¡A¦b¼½µo®É´N¥²¶·¨Ï¥Î¤@­Ó½w½Ä°Ï (playout buffer) ¨Ó¼È®É¦s©ñ¨Ã³B²zºô¸ô¤W±µ¨ü¨ìªº«Ê¥]¡C


¥Ñºô¸ô¤W±µ¦¬ªº¼v¹³«Ê¥]¦]¬°©¼¦¹¤§¶¡¨ì¹Fªº®É¶¡¶¡¹j¤£¦P (Synchronous Data Packets)¡A©Ò¥H¥²¶·§Q¥Î½w½Ä°Ï±N³o¨Ç«Ê¥]°µ½w½Ä¡AÅý©¼¦¹¤§¶¡ªº®É¶¡¶¡¹j¤@¼Ë (Isochronous Data Packets)¡C


MPEG-1 ªº­ì²z


MPEG-1 ªº½s½X­ì²z¤j®a³£À³¸Ó­n»{ÃѤ@¤U¡CMPEG-1 ±N¼v¹³¤À¦¨¤@­Ó Group¡A§Y GOP (Group of Pictures)¡A¨C­Ó GOP ¦³¤@­Ó Entry Point¡AºÙ¬° I-frame¡A¨C­Ó I-frame ªº¤j¤p¬° 15KB¡A¥t¥~ÁÙ¦³ P-frame »P B-frame¡C


I-frame ºÙ¬° Independent-frame¡A¬°¨C­Ó GOP ªº°_ÂI¡Aºò±µµÛªº¬O¤G­Ó B-frame¡AB-frame ºÙ¬° Bi-directional frame¡A¨C­Ó B-frame ¤j¤p¬° 3KB¡A¨C¤G­Ó B-frame ¤§¶¡¦A´¡¤J¤@­Ó P-frame¡A§Y Predictive-frame¡A¨C­Ó B-frame ªº¤j¤p¬° 8KB¡C


GOP ¦@¦³¤TºØ¤£¦Pªº frame¡A¨CºØ frame ¦s©ñªº¼v¹³»P©Ê½è¬Ò¤£¦P¡A³o¦b¥H«á§Ú­Ì¹ê°µµ{¦¡®É·|¦A°µ§ó²M·¡ªº¤¶²Ð¡C¨Ò¦p¡A§Ú­Ì­n±N¼v¤ù§ÖÂà®É¡A¥i¥H©¿²¤±¼©Ò¦³ªº B-frame »P P-frame¡A¥u¼·©ñ I-frame¡A¦p¦¹¤@¨Ó«K¥i¥H¸`¬Ù³\\¦h¶QÄ_ªººô¸ôÀW¼e»P®É¶¡¡A¦ý«e´£¬O¡AI-frame ¥²¶·¦s©ñ¥D­nªº¼v¹³¸ê®Æ¡A¨Æ¹ê¤W¤]¬O¦p¦¹¡C





  • ÃÙ§Uºô¯¸       

    ¼s§Q¤£°Ê²£-·sªO¯S°Ï«ü¦W«×³Ì°ª¡B­È±o±z«H¿àªº¦n©Ð¥ò
    ±zªº¦«¥I,¼s§Q¥Î¤ß¬°±zªA°È
    ¼s§Q¤£°Ê²£-ªO¾ô¦b¦a¥Í®Ú³Ì¹ê¦b--·sªO¯S°Ï«ü¦W«×³Ì°ª¡B­È±o±z«H¿àªº¦n©Ð¥ò
    §¹¾ã©Ð°T¡A©Ð«Î¡B©±­±¼öªùºë¿ïª«¥ó¡A¼s§Q¤£°Ê²£ Àu½è¥ò¤¶¡A©Ð«Î¯²¸î¡B¶R½æ¸ê°T³z©ú¡A¥æ©ö¯u¦w¤ß¡I



  • ¡@¦@ 0 ¤H¦^À³

    ©m¦W¡G
    §G§i¤º®e¡G