
9æäžæ¬ãIntelã¯çµç¹Alliance for Open Mediaãžã®åå ãçºè¡šããŸããã ãã®ã¹ãããã§ã¯ããªãŒãã³ãã©ãŒãããã®ãµããŒãã匷調ããæ°äžä»£ã®ãããªãšã³ã³ãŒãã£ã³ã°ããŒã«ã®äœæã«åããŠåªåãåããŠããŸãã Alliance for Open Media Consortiumã¯ãAmazonãCiscoãGoogleãIntelãMicrosoftãMozillaãNetflixã®äŒæ¥ãå«ã¿ãæ°äžä»£ã®ãããªãã©ãŒããããå ±åã§éçºããæ°äžä»£ã®ããã»ããµåãã«æé©åããããšã§ãšã³ããŠãŒã¶ãŒã®ãããªé ä¿¡ã³ã¹ããåæžããããšãç®çã«äœæãããŸããã
ãã®æçš¿ã§ã¯ããããªåœ¢åŒã®åéã«ãããçŸç¶ãåæãããã®éçºã®èŠéããæ€èšããŸãã ãã®èšäºã¯ãIntel Media Development Directorã®Mark Buxtonã«ãã£ãŠæžãããŸããã
ãããªæŸéã«äœ¿çšããã圢åŒã®æè¿ã®æŽå²ãããããç解ããããã«ããããªæŸéãå®éã«äœã§ããããæãåºããŸãããã éå»20幎ã«ããã£ãŠããããªæŸéã¯åºå®ãã£ã³ãã«ãããã£ã³ãã«å€éåããã³ãã±ãããããªã¹ããªãŒã ïŒãã«ãã¬ãã«ãããã¯ãŒã¯çµç±ã§éä¿¡ãããããšãå€ãïŒã«ç§»è¡ããŸããã ãããã®ã¢ãã«ã¯ãã¹ãŠåæã«ååšããŸãã æåŸã®2ã€ã®ã¢ãã«ã¯ãæåã¯ã¹ã±ãŒã©ãã«ãããªã䜿çšããŠããŸããããçŸåšãäžéšã®åžå Žã§ã¯ãªã¢ã«ã¿ã€ã ãšã³ã³ãŒãã£ã³ã°ããããã¯ãŒã¯å¢çã®è¿ãã§äœ¿çšãããŠããŸãïŒããšãã°ããã£ãã«æ¡ä»¶ãã¯ã©ã€ã¢ã³ãããã€ã¹ã®æ©èœã«é©å¿ããããïŒã ãããã®ãã¹ãŠã®ã³ãŒãã£ã³ã°ã¢ãã«ã«ã¯ãããŒã¿ãããŒã¬ãŒããšãããªå質ã®ãã©ã³ã¹ãåãããã«ãç°ãªãå質ã¬ãã«ãšç°ãªãã¢ã«ãŽãªãºã ãå¿ èŠã§ãã
ãã®ãã©ã¹ããã€ã«ãã®æŸéã«å ããŠããããªã®æ®åœ±ã転éãç·šéæã«ã³ãŒãã£ã³ã°ãè¡ãããŸãã å¯èœãªéãæé«ã®ãããªå質ãéæããããšãã欲æ±ã¯ãçæçãªåé¡ã§ã¯ãããŸãããç»é¢ã®è§£å床ãæãããã³ã³ãã©ã¹ãã¯åžžã«å¢å ããŠããŸãã ããã«ã解å床ãšè²æ·±åºŠã®å¢å ã¯éåžžãå§çž®ã®å¿ èŠæ§ãšé¢é£ããŠããŸãã HEVCãªã©ã®æ°ãã圢åŒã«åãæ¿ãããšããããã¯ãŒã¯ããã³ã¹ãã¬ãŒãžã·ã¹ãã ã®ããã«ããã¯ãåé¿ããé«å質ã®ãããŒããã£ã¹ããããªãäœæããŠèŠèŽè ã«éä¿¡ããããšãã§ããŸãã
ã ãŒã¢ã®æ³åãšãã€ã¯ãããã»ããµã®äœæãµã€ã¯ã«ã«é²ã¿ãŸãã ãããªãã©ãŒãããã®èšç®ã®è€éãã¯ãäžä»£ããäžä»£ãžã®ç§»è¡äžã«å¥è·¡çã«å®å®ããã¬ãã«ã§ç¶æãããŸãã ããããããã¯å®éãå¶ç¶ã«å€æããŸãããHEVC圢åŒã¯AVCãšæ¯èŒããŠã¯ããã«è€éã§ãããããã€ãã®å¹ææé©åã¢ã«ãŽãªãºã ãæäŸããŸãã
ãããªãšã³ã³ãŒãã£ã³ã°ãã©ãŒãããã®æåŸã®2ã€ã®ã¹ãããïŒAVC-> HEVCïŒã®éã§çµéããéã«ãåãäŸ¡æ Œã§å©çšå¯èœãªããã»ããµã³ã¢ã®æ°ãå€§å¹ ã«å¢å ããŸããã ææ°ã®Intel Xeon E5ããã»ããµãââã¡ããªã«ã¯ãããã€ã¹ããšã«æ倧18ã³ã¢ãå«ãŸããŠããŸãïŒ2003幎ã«AVCãç»å ŽãããšããIntel Xeonããã»ããµã¯ã·ã³ã°ã«ã³ã¢ã§ããïŒã ãããªã³ãŒãã£ã³ã°ã®ãå¯åºŠãã¯ããããŒããã£ã¹ãã«å¿ èŠãªå質ãæäŸã§ããIntel Xeon E3ããã»ããµãââã¡ããªãšãããªã³ãŒãã£ã³ã°ããŒããŠã§ã¢ã³ã³ããŒãã³ãã®åºçŸã«ãããããã«é£èºããŸããã ã¯ã©ã€ã¢ã³ãããã»ããµã§äœ¿çšãããããŒããŠã§ã¢ã¢ã¯ã»ã©ã¬ãŒã¿ãšãœãããŠã§ã¢ãœãªã¥ãŒã·ã§ã³ã®éçºã¯ã Intel Media Server Studioããå©çšå¯èœãªIntel Quick Sync VideoããŒããŠã§ã¢ãŠãããã«ãªããŸããã ãããã䜿çšããå ŽåãQSVã䜿çšããIntel Core i7-5850ããã»ããµãŒãšx264ãœãããŠã§ã¢å®è£ ã䜿çšããåãããã»ããµãŒãæ¯èŒãããšããã©ã³ã¹ã³ãŒãã£ã³ã°ã¬ãŒãã¯3åã«ãªããå質ãåäžããŸãã åœç€Ÿãšã¡ãã£ã¢ããã³æŸéæ¥çã®ã¯ã©ã€ã¢ã³ãã¯ãåŸæ¥ã®ã»ãããããããã¯ã¹ã«äœ¿çšãããŠããå€ãMPEG-2ãããæ§äžä»£ã®AVCãææ°äžä»£ã®TVãã¿ãã¬ãããé»è©±ããšã³ã¿ãŒãã€ã¡ã³ãããã€ã¹çšã®ææ°ã®VP9ããã³HEVCãŸã§ããŸããŸãå€ãã®ãã©ãŒãããã䜿çšããŠããŸãã

Intel Core i7-4770ããã»ããµïŒ2ã€ã®ãããªã³ãŒããã¯ãã¡ããªã®ããã©ãŒãã³ã¹ãšå質ã®æ¯èŒ
ã³ãŒãã£ã³ã°ããåã«ããšã³ã·ã¹ãã ã§æãå€ãã®ãªãœãŒã¹ãè²»ãããããšãããããŸãã ãã ããã³ãŒãã£ã³ã°ã®å€§å¹ ãªæ¹åã«ãããããžãã¹ã¢ãã«ãå€ããå¯èœæ§ããããŸãã æãæãããªå©ç¹ã¯ãã客æ§ãããå®äŸ¡ãªã³ãŒãã£ã³ã°ã掻çšããå¹çãé«ããããå€ãã®çŽ æããšã³ã³ãŒãã§ããããšã§ãã
ãããªãšã³ã³ãŒã圢åŒã®éçº
ãããŸã§ã§æãå¹æçãªãããªãšã³ã³ãŒãã£ã³ã°åœ¢åŒã¯HEVCã§ãã ãããªã³ãŒãã£ã³ã°å¹çã枬å®ããæ¹æ³ã¯å€æ°ãããŸãã äžèšã®ãã£ãŒãã®çžŠè»žã§äœ¿çšãããŠããBD-RATEã¡ãœããã¯åºã䜿çšãããŠããŸãã ããŒã¿ã®å質ãšé床ã«ãã£ãŠåœ¢æãããæ²ç·ãããŽãŒã«ãã圢åŒãšæ¯èŒããããšã«ããã1ã€ã®ã¡ããªãã¯ã§ããŒã¿ãããŒã¬ãŒããšãããªå質ãäžããããšãã§ããŸãïŒãããã®2ã€ã®ç¹æ§ã¯ããçšåºŠäŸåããããïŒïŒåç §ãšã³ã³ãŒãã£ã³ã°ãšããŠWG11 HM14ãââ䜿çšãããŸãïŒ ã
ãã®æ¯èŒã§ã¯ãY-PSNRã¡ããªãã¯ã䜿çšããŠå質ãè©äŸ¡ããŸãã Y-PSNRã¯é·ãéãããªã®è©äŸ¡ã«é©ããŠãããšèããããŠããŸããããææ°äžä»£ã®ãããªãšã³ã³ãŒã圢åŒã®åºçŸã«ãããY-PSNRã¯ããŸã圹ã«ç«ããªããªããŸããã ããã«ãããããããããã¯éåžžã«è¯ããã©ãŒãããã§ãã 倧ããªãããã¯ã®åé¡ã解決ããã°ãã客芳çãªãçµæã«è¿ãéåžžã«é«å質ã®ãããªãå®çŸã§ããŸãã ããã¯ãæè²æ©é¢ãåœå®¶æ©é¢ãæ°éäŒæ¥ãªã©ãããŸããŸãªåœã®ä»£è¡šè ãåå ãããªãŒãã³ããã»ã¹ã®äžéšãšããŠéçºãããŸããã
WebMã«ã¯ä»£æ¿ã¢ãã«ããããŸãã VP8ã³ãŒããã¯ïŒWebMã³ãŒããã¯ã®äžã§æåã®ãã®ïŒã¯ãå ã ç¬èªæè¡ãšããŠéçºãããŸããã Googleã«è²·åããããªãŒãã³ã«ãªãããããªã®ã¹ããªãŒãã³ã°ã«ããã«é©å¿ããŸããã Googleã¯ãç¡æã®äœ¿çšã©ã€ã»ã³ã¹ãç¡æã®ãªãŒãã³ãœãŒã¹ãœãããŠã§ã¢ãããã«ã¯ç¡æã®ããŒããŠã§ã¢ãªãœãŒã¹ãããæ¥çã«æäŸããŠããŸãã VP8ã³ãŒããã¯ã¯ãæŸéçšã®ãããªãšã³ã³ãŒãã£ã³ã°å¹çã®ç¹ã§ã¯ãAVCããã³HEVCã®ç«¶åçžæã§ã¯ãããŸããã§ããããããããªã©ã€ã»ã³ã¹å¶éã®ããå€æ°ã®é¡§å®¢ã«ãã£ãŠå±éãããŸããã ãã®åœ¢åŒã¯ããããªäŒè°ã«æããã䜿çšãããŸãã
VP9圢åŒã¯ãæè¿ãåæ§ã®ïŒç¡æã®ïŒã©ã€ã»ã³ã¹ã¢ãã«ãæã€VP8ã®ä»£æ¿ãšããŠéçºãããŸããã VP9ã¯ãHEVCãšåæ§ã«ãåªããææ°ã®ãããªã³ãŒããã¯ã§ãã å³ã®éæ¢ãã¬ãŒã ãæ¯èŒããŸãã 以äžã®1ã2ã3ã å€ãå質ã¡ããªã¯ã¹ã䜿çšããããšã®æ¬ ç¹ã瀺ãããã£ãã®ã§ãHEVCã§æãé£ãããããªã®1ã€ã§ããcrowd_runã䜿çšããŸãã ããã¯è€éãªã·ãŒã±ã³ã¹ã§ããããã¯ã倧ããªãããã¯ã«è©°ã蟌ããªãå€ãã®çš®é¡ã®åãã倧éã®æ å ±ãããã³ãã¯ã¹ãã£ãŒãæ··åšããŠããããã§ãã éåžžãå¹³åããŠã倧éã®ææã«å¯ŸããŠãHEVCã¯VP9ãããé«ãå質ãçæããŸããããã®å Žåã¯ããã§ã¯ãããŸããã ãã®å ŽåãVP9ã®å©ç¹ã¯èçŒã§ãèŠãããããšã§ãã
HEVCãšåæ§ã«ãVP9ã¯è²æ·±åºŠã®åŒ·åãè²åã®åŒ·åãé«è§£å床ãå¹ åºãã¢ããªã±ãŒã·ã§ã³ããµããŒãããŠããŸãã VP9ã®å質ã¯ãVP8ããAVCãããHEVCã«ã¯ããã«è¿ããïŒVP9圢åŒã¯ãŸã æ¯èŒçæ°ããããïŒå°æ¥ããã®å質ã®ã©ã°ã¯ããã«å°ãããªããšæšæž¬ã§ããŸãã

ãã©ã¡ãŒã¿ãŒâgood âcpu-used = 0ã䜿çšããã8.5 Mbpsã®æµéã§ã®VP9ãšã³ã³ãŒãã æ¡å€§ç»åé åã®ã¯ã©ãŠãã©ã³ã æšã®è©³çŽ°ã«æ³šæããŠãã ããã éåžžã«è€éãªãã¬ãŒã ã·ãŒã±ã³ã¹ã«å¯ŸããŠéåžžã«è¯ãçµæïŒæ®å¿µãªããããã®ã¬ãã«ã®å質ã§ã¯ãã³ãŒããã¯ã¯ä»ã®ã³ãŒããã¯ããã2æ¡é ããªããŸãïŒ

-veryslowãã©ã¡ãŒã¿ãŒã䜿çšãã12 Mbpsãããã¬ãŒãã§ã®AVCãšã³ã³ãŒãã£ã³ã°ã æšæºã®ã¯ã©ãŠãå®è¡ç»åãã¹ãã·ãŒã±ã³ã¹ã®æ¡å€§é åã æšãã©ãã»ã©ãã¿ãã¿ããŠãããã«æ³šç®ããŠãã ããã ããã«ãããããããAVCã®PSNRã¡ããªãã¯ã¯2 dBé«ããªããŸãïŒïŒïŒ

7.6 Mbpsãããã¬ãŒãã§-TU4ã䜿çšããHEVCãšã³ã³ãŒãã£ã³ã°ã æ¡å€§ç»åé åã®ã¯ã©ãŠãã©ã³ã ã¯ããã«äœãããŒã¿ã¬ãŒãã§ãx264ãããæãããªã³ãŒãã£ã³ã°ã¢ãŒãã£ãã¡ã¯ãã¯å°ãªãã§ãããå質ã¯VP9ãããäœããªã£ãŠããŸãã ïŒãã®å Žåã客芳çãªææšã«ãããšãåãY-PSNRã§VP9ã䜿çšããå ŽåãããããŒã¿ãããŒã¬ãŒãã10ïŒ äœããªããŸããïŒèå³æ·±ãããšã«ããœãããŠã§ã¢ããŒãžã§ã³ã¯AVCã®2åé«éã§ãã
ãã ããGoogleã¯ãã®åéã§åç¬ã§è¡åããããã§ã¯ãããŸããã ãã€ã€ãªãã£ãæ¯æãããšãªããããªããšã³ã³ãŒãããå¿ èŠãããä»ã®äŒæ¥ã¯ãæ°ãããããªåœ¢åŒãäœæããŸããã æãæåãªã®ã¯ãäžåœã®AVS圢åŒïŒv1ããã³v2ïŒã䜿çšããŠããCisco Corporationã®ããŒã«ã§ããXiph / Mozillaã®Daalaã§ãã
ã©ã¡ãã®ã¢ãã«ããåçã®æè¡å質ã®ãããªãšã³ã³ãŒã圢åŒãäœæã§ããŸãã ã§ã¯ããªãOpen Media for Allianceã«åå ããã®ã§ããïŒ
ãã®ã³ã³ãœãŒã·ã¢ã ã®ä»ã®åµèšè ãšåæ§ã«ãHEVCããã³VP9ã«ç¶ãæ°ãã圢åŒã¯ããããªãšã³ã³ãŒãã£ã³ã°å¹çã®åäžã«åããŠããã«é²ãã¹ãã§ã¯ãªããšèããŠããŸãã ç§ãã¡ã¯ãäžçäžã®ãã¹ãŠã®ãŠãŒã¶ãŒåãã«ãããããçš®é¡ã®ããã€ã¹ãžã®é«å質ã®ãããªããµãŠã³ããç»åãã¹ããªãŒãã³ã°ã¡ãã£ã¢ã«å¯Ÿããã€ã³ã¿ãŒãããã®å¢å€§ããããŒãºãæºããããšãã§ãããã¯ãããžãŒã®äœæã«åªããŠããŸãã ã¢ã©ã€ã¢ã³ã¹ã®äžç°ãšããŠãThorãDaalaãVP10ãåäžã®åçš®ã®æ°äžä»£ãããªåœ¢åŒã«çµ±åããæ©äŒãåŸãŠãããŸããŸãªãã«ãã¡ãã£ã¢ãœãªã¥ãŒã·ã§ã³ãå®è£ ããæ©äŒãåµåºããŸããã
äœãã©ãããã€ïŒ
ä»å¹Žã®çµãããŸã§ã«æ°ãããããªã³ãŒããã¯ãå ¥æãããå Žåã¯ãæ²ããããªãäœæã«æéãããããŸãã è¿ éã«å¯Ÿå¿ããŠããŸãããçŸåšã®äžä»£ã®ãããªåœ¢åŒã§ãã以åã®ãã®ã倧ããäžåã£ãŠãããHEVCïŒããã³VP9ïŒãäœæããã³é åžããããã®æ©åšãããã°ã©ã ãããŒã«ã«å€å€§ãªåŽåãšãéãè²»ãããŠããŸãã HEVCãå®æ§çã«è¿œãè¶ãããšãã§ããæ°ãããããªåœ¢åŒãéçºããã«ã¯ããªãã®æéãããããŸãïŒãããã£ãŠãAVC <<ã§ã³ãŒããã¯ã«åãæ¿ããŠHEVC >>ã®ã¡ãªãããåŸãããã«äœæ¥ã®çµæãåŸ ã€å¿ èŠã¯ãããŸãã...ïŒã
ãã®æ¹åã§ã®å ±åäœæ¥ã«ãããäžè¬ã®äººã ãé¢å¿ãæã€æ°äžä»£ã®ãã«ãã¡ãã£ã¢ãã©ãŒããããã³ãŒããã¯ãããã³ãã¯ãããžãŒãäœæããããã¬ãŒã ã¯ãŒã¯å ã§ããªãŒãã³ãœãŒã¹ãããžã§ã¯ããäœæã§ããããšã¯ééããããŸããã
åå ããŠãã ããïŒ
å©å®³é¢ä¿è ã¯ã圌ããã©ã®ããã«å©ããããšãã§ãããå°ããŸãã ã§ããããAlliance for Open MediaãšçŽæ¥é¢ä¿ãçµã°ãªãããšã«æ±ºãããšããŠããããã«ç§ãããåºãã³ãã¥ããã£ããåããããã®ããããŸãã
- Intelã¯ããªãªãžãã«ã®å§çž®ãããŠããªãç¡æã®æŸéå質ã®ãããªãå¿ èŠãšããŸãïŒå§çž®ã¢ã«ãŽãªãºã ãæ±ãããŒã ã«ããæè¡çãªåé¡ã解決ãããã®æè¡ãå®èšŒããããïŒã
- Intel Corp.ã¯ã次äžä»£ã®ãšã³ã³ãŒãã£ã³ã°ããŒã«ãšé£æºã§ããæ°ãããããªå質åæããŒã«ããµããŒãããŠããŸãã ç¹ã«ãå質åæããŒã«ã¯ãæ¯åãããªãã«ãŒãåãã«ææãªã¢ãŒãã£ãã¡ã¯ãã«ç¹ã«æ³šæãæãå¿ èŠããããŸããããã¯ãç¹ã«é«ãèŒåºŠãšã³ã³ãã©ã¹ãã®ç»é¢ã§ã倧ããªãããã¯ã§ããããããšãã«æãé¡èã«ãªããŸãã Intel Video Quality CaliperïŒ Intel Video Pro Analyzerã®äžéšãšããŠïŒã¯ããã®åéã§æ°ãããœãªã¥ãŒã·ã§ã³ãäœæããããã®ãã©ã°ã€ã³ã§ãã
- ãããŠæãéèŠãªããšã¯ãIntelãããªãã®ãµããŒããå¿ èŠãšããŠããããšã§ãã ãã€ã€ã«ãã£ãå¿ èŠãšããªããªãŒãã³ãããªåœ¢åŒã®ãµããŒã¿ãŒã§ããå Žåã¯ããç¥ãããã ããã