ãã¯ããã«ã
æšå¹Žã®4æã«Hi-Resã¬ã³ãŒãã£ã³ã°ããããã¹ã¿ãŒé³æºããªãªãŒã¹ããéã®åŸåŠçãšããã»ã¹ã«ãã£ãŠé³æºããŒã¿ãã©ã®ãããªåœ±é¿ãåããã®ããäŸç€ºããŸãããå ·äœçã«ã¯ããã深床ãèœãšãå Žåã®ãã£ã¶ãŒåŠçãšãã€ãºã·ã§ã€ããŒã®è©±é¡ããããŠãYouTubeãäŸãšããã¢ããããŒããããé³æºãã©ã®ããã«å€åããããã°ã©ãã瀺ããªãã説æããŸããã
ããããªãããããããµãŒãã¹ãæ¡çšããŠããCodecã«ããé³è³ªå€åã«ã€ããŠã¯ãå°ãçç ®ãæããããæŽã«è©³ããæ€èšŒããæ¹ãããç解ãé²ããšèããä»åãæ°ãã«æ€èšŒããŠã¿ãŸããã®ã§ããåèã«ããŠé ããã°å¹žãã§ãã
ååã®æ€èšŒã§çšããã®ã¯ã20Hzïœ160KHzã®äžã§ãç¹å®ã®åšæ³¢æ°ã®ä¿¡å·ãã¹ãããç¶ã«å ¥åãããã®ã§ããããå€ãã®Codecãæ¡çšããŠãããå§çž®ã¢ã«ãŽãªãºã ã¯ä¿¡å·ã®åçæåã«å¿ããŠãããããéåŒãåŠçãè¡ãããŠãããé³é¿å¿çåŠã®ç¥èŠãçšãããã®ãäž»æµãšãªã£ãŠããŸããå ·äœçã«ã¯ãçã©ãŠããã¹æ²ç·ãå§çž®ã®éŸå€ãšããæ¹æ³ããŸãããã¹ãã³ã°å¹æãå©çšããæ¹æ³ãªã©ã§ããããç°¡åã«èšãã°ã人éã®è³ã«èŽãããªãã¬ãã«ã®é³ãéåŒãã倧ããªé³ã§ãã¹ãã³ã°ãããé³ãçç¥ãããšãã£ãã€ã¡ãŒãžã§ããå®éã®å§çž®ã®ã¢ã«ãŽãªãºã ã¯ãã£ãšæã®èŸŒãã è€éãªåŠçããããŠãããæ°åŠçãªæ å ±å§çž®ïŒãããã³ç¬Šå·åãªã©ïŒãè¡ãããŠããŸãã
以äžãéã¿ãä»åã¯ãå®éã®æ¥œé³ãã¢ããããŒãããŠèŽæã®éãã瀺ãããšãäž»ç®çãšããä»å æ å ±ãšããŠã20Hz~20KHzã®ã¹ã€ãŒãä¿¡å·ãå ¥åããå Žåã«ã©ã®ãããªç¶æ ã«ãªãã®ããç®èŠã§ãããããªã°ã©ããçšæããŸããããŸããååã¯YouTubeã ããåãäžããŸããããFaceBookãšXïŒæ§TwitterïŒãžã®åç»æçš¿ãå€ãããšãããããããžåç»æçš¿ããå Žåã®é³è³ªå€åãã«ããŒããŸããã
ãåç»äœææã«æ¡çšããé³å£°Codecã®éãã«ããæ€èšŒã
åç»é³å£°ã¯çè ãã¬ã³ãŒãã£ã³ã°ãããã¢ãã®é³æºïŒ32bit / 352.8KHzïŒããã¹ã¿ãªã³ã°ããé©æ§ã«24bit / 48KHzã«ããŠã³ã³ã³ããŒããããã®ãåç»é³å£°ãšããŠåã蟌ã¿ã以äžã®3çš®ã«ãšã³ã³ãŒããã¢ããããŒãçšã®åç»ãšããŸããã
ã
åç»é³å£°
ã»AAC_LC 256kbps
ã»Opus 256kbps
ã»PCM 24bit/48KHzïŒå§çž®ç¡ãïŒ
ãŸãã20Hz~20KHzã®ã¹ã€ãŒãä¿¡å·ãã°ã©ãã§èŠãŠã¿ãŸãã
ãYouTubeã«ããé³è³ªå€åã
ãªãªãžãã«(PCM 24bit/48KHz)
AAC_LC 256kbpsã§äœæããé³å£°ããŒã¿ãYouTubeãžã¢ããããŒãããåŸã«åçãããã®
Opus 256kbpsã§äœæããé³å£°ããŒã¿ãYouTubeãžã¢ããããŒãããåŸã«åçãããã®
PCM 24bit/48KHzã§äœæããé³å£°ããŒã¿ãYouTubeãžã¢ããããŒãããåŸã«åçãããã®
ãªãªãžãã«ã«æ¯ã¹ãŠå€åãå°ãªãé ïŒé³è³ªå£åãå°ãªãïŒã¯ãPCMâOpusâACC_LCãšãã䞊ã³ã«èŠããŸãããšãã«500Hzããäžã«ãããŠãACC_LCã¯ããªãåºãç¯å²ã«æ»²ã¿ãåãã§ãããäžé«åã§ã®é³è³ªå£åã¯PCMããã³Opusããæ¿ããããšãèŠãŠåããŸãã
äžæ¹ãOpusã§ãšã³ã³ãŒããããé³å£°ãYouTubeã§ã©ã®ããã«åŠçãããã®ããèå³ãããç¹ã ãšæããŸããYouTubeã§ã¯åçš®é³å£°ããŒã¿ã¯Opusã«ãšã³ã³ãŒããããŸãã®ã§ãäºåã«Opusã«ãšã³ã³ãŒãããé³å£°ãæºåããŠããã°ãYouTubeã®ãµãŒãåŽã§ã®åãšã³ã³ãŒããé¿ããããããç¥ããŸãããããããªãããã°ã©ãã§èŠãéãPCMãšOpusã§ã¯åŸ®å·®ã§ã¯ãããŸããéããèŠãŠåããŸããåŸã£ãŠãOpusã§ã¢ããããŒãããŠãåãšã³ã³ãŒãã¯ãããŠããŸããšããããšãèšãããšæããŸãã
ãé³æ¥œãã¢ããããŒãããå Žåã®èŽæäžã®éãã«ã€ããŠã
ããã§ã¯å®éã«é³æ¥œåç»ãã³ãŒããã¯ãå€ããŠã¢ããããŒãããçµæãèŽãæ¯ã¹ãŠã¿ãŸããåããæãããã«ããªãªãžãã«ãšã®å·®åãæœåºããŠæ¯èŒããŠã¿ãŸããå·®åã®é³å£°ãå°ãããã°å°ããã»ã©ããŸãããªãªãžãã«ã®é³æ¥œã€ã¡ãŒãžãããæããããªããã®ã»ã©ãCodecã«ããé³è³ªå£åãå°ãªãããšãæå³ããŸãã
â»å·®åã®ããŒã¿ã¯é³éãå°ããã®ã§ããããã³çã§ãèããã ããã
ãªãªãžãã«ãšã®å·®åïŒOpus 256kbpsã§äœæããé³å£°ããŒã¿ãYouTubeãžã¢ããããŒã
ãããã§ãããïŒã¹ã€ãŒãã®ã°ã©ãã§ç®èŠããéããAAC_LCãšãªãªãžãã«ãšã®å·®åã¯ãPCMã§ã¢ããããŒããããã®ã«æ¯ã¹ã楜æ²ã®æåŸãã³ãŒããããæãããããã®ãšãªã£ãŠãããšæããŸããã€ãŸããAAC_LCãããããªãªãžãã«ãšã®ããã¿ãšæªã¿ãå€ãå«ãã§ãããšèšãããšæããŸãã
ãFaceBookåç»æçš¿ã«ããé³è³ªå€åã
次ã«ãFacebookãžåç»æçš¿ãããå Žåã«ã€ããŠèŠãŠãããŸãã
å ãšåæ§ã«ã20Hz~20KHzã®ã¹ã€ãŒãä¿¡å·ãã°ã©ãã§èŠãŠã¿ãŸãã
ãªãªãžãã«(PCM 24bit/48KHz)
AAC_LC 256kbpsã§äœæããé³å£°ããŒã¿ãFacebookãžã¢ããããŒãããåŸã«åçãããã®
Opus 256kbpsã§äœæããé³å£°ããŒã¿ãFacebookãžã¢ããããŒãããåŸã«åçãããã®
PCM 24bit/48KHzã§äœæããé³å£°ããŒã¿ãFacebookãžã¢ããããŒãããåŸã«åçãããã®
ãªãªãžãã«ã«æ¯ã¹ãŠå€åãå°ãªãé ïŒé³è³ªå£åãå°ãªãïŒã¯ãPCMâACC_LCâOpusãšãã䞊ã³ã«èŠããŸããå šãŠã«å ±éããŠèšããããšãšããŠãYouTubeãžã¢ããããŒããããã®ã«æ¯ã¹ããªãé ·ãå£åãèŠãããŸããã©ãããããã»ã¹ã§çããã®ãäžæã§ãããåé³ããåå°ãããããªäœæ¬ãã®çŽ°ãçãå šåã«ããã£ãŠèªããããŸããã8KHzããã¯ãããªãã®é³éã§æãéãªã£ããããªæªã¿ãããžãã¯ãã³ã§èœæžãããããã«åž¯ãšãªã£ãŠåºçŸããŠããŸãããŸããé«åã¯20HKzãŸã§ã¯åçã§ããã17.5KHzãããã§éåããŠããŸã£ãŠããŸãã
泚ç®ãã¹ãã¯Opusã§ãšã³ã³ãŒãããé³å£°ããŒã¿ã¯æãå£åãé ·ããé«åã®ã¿ãªããäœåãæªã¿ã®æåãåºã滲ãã§ãããFaceBookãžã®åç»æçš¿ãOpusã§è¡ãããšã¯ææªã§ããããšãåãããŸããAAC_LCã¯PCMãšæ¯ã¹ãŠãé¡èãªå·®ã¯èªãããããããã¯FaceBookã®ãµãŒãã»ãšã³ã³ãŒããçŸåšã®ãšããAAC_LCã§ããããšãé¢ä¿ããŠãããšæãããŸããããããªããåãã³ãŒããã¯ã§ãåãšã³ã³ãŒãã¯ãããããã§ãAAC_LCã®2KHz~7KHzãããã®æªã¿ãå¢ããŠããããšã確èªã§ããŸãã
ããã§ã¯ãYouTubeã®ãšããšåæ§ã«é³æ¥œããŒã¿ã§æ€èšŒããŠã¿ãŸãã
â»å·®åã®ããŒã¿ã¯é³éãå°ããã®ã§ããããã³çã§ãèããã ããã
ãXïŒæ§TwitterïŒåç»æçš¿ã«ããé³è³ªå€åã
æåŸã«XïŒæ§TwitterïŒåç»æçš¿ã«ããé³è³ªå€åã«ã€ããŠèŠãŠãããŸããXã®åç»æçš¿ã¯é³å£°ãPCMããã³Opusã®ãã®ã¯åãä»ããŸããã§ããã®ã§ãAAC_LCã§ãšã³ã³ãŒããããã®ã ããæ²èŒããŸãã
20Hz~20KHzã®ã¹ã€ãŒãä¿¡å·ãã°ã©ãã§èŠãŠã¿ãŸãã
ãªãªãžãã«(PCM 24bit/48KHz)
AAC_LC 256kbpsã§äœæããé³å£°ããŒã¿ãXãžã¢ããããŒãããåŸã«åçãããã®
Xã§ã®ãšã³ã³ãŒãã«ããå£åã¯ãæ³åããŠãããããé ·ãã¯ãªãå²ãšç¶ºéºãªãã®ã«ãªã£ãŠããŸãããFaceBookãšæ¯èŒããŠãããªãå£åãæããããŠããŸãããã ããé«åã¯15KHzãŸã§ãéçã§ã20KHzã«è³ãåã«éåããŠããŸãã
é³æ¥œããŒã¿ãã¢ããããŒãããå Žåã¯ã©ãã§ããããã
â»å·®åã®ããŒã¿ã¯é³éãå°ããã®ã§ããããã³çã§ãèããã ããã
Xã®å Žåã¯ã³ãŒããã¯ã®å¥ã«ããæ¯èŒãã§ããªãã£ããããYouTubeãšFaceBookãžã¢ããããŒãããå Žåã®å·®åé³å£°ãèŽãæ¯ã¹ãŠã¿ãŠãã ããã滲ã¿ã¯å°ãªããã®ã®ãªãªãžãã«ã®æ¥œé³ã€ã¡ãŒãžã®æ®åã®ãããªãã®ãäžçªåŒ·ãæããããŸããå£åã®çšåºŠå·®ã¯ãã¡ããã§ãããããããå§çž®ã¢ã«ãŽãªãºã ã«ããçã®ãããªãã®ãããããããäœãšãªãæããé³è³ªã®éãã«ãªã£ãŠãããããªæ°ãããŸãã
ãæåŸã«ã
以äžãYouTubeãFaceBookãXãžåç»ãã¢ããããŒãããå Žåã®é³è³ªå€åã«ã€ããŠå ·äœçãªçŽ æãããšã«æ€èšŒããŠããŸãããSNSã®é³å£°å質ã«ã€ããŠã¯ãæçš¿ç®çã«ãã£ãŠäœ¿ãåãã人ãå€ããšæããŸãããã¡ãããäŒè©±ãå€å¥ãããšãã¹ãããåç»ã®æ§åãåãããšããã¬ãã«ã§èšãã°ãã©ã®ãµãŒãã¹ãç³ãåã®ãªãã¯ãªãªãã£ãæ ä¿ãããŠãããšæããŸãã
ããããªãããé³æ¥œã³ã³ãã³ããé«ãã¯ãªãªãã£ãŒã§èŽããŠããããããšããå Žåã¯ãå°ãç«ã¡æ¢ãŸã£ãŠèããå¿ èŠãããããç¥ããŸããã
äŸãã°ãFaceBookãšXãžã®æçš¿ã¯ã¿ã€ã ã©ã€ã³äžã§èªååçããã®ã§ãé²åºé »åºŠãããã¯åçåæ°ã®é¢ã§æå©ã«ãªããããååããã¢ãŒã·ã§ã³ãšããŠæŽ»çšããã±ãŒã¹ãªã©ããããããšæããŸãããŸããåSNSã®ãŠãŒã¶å±€ïŒå¹Žéœ¢ãé³æ¥œãžã£ã³ã«ã®å奜ãªã©ïŒã«å¿ããæçš¿å 容ãšããããšãèæ ®ã®å¯Ÿè±¡ã«ãªãããšæããŸãã
ããããèžãŸããŠãé³è³ªã¯ç ç²ã«ãªããããŒã±ãã£ã³ã°ã®èŠ³ç¹ããåçåæ°ã皌ããSNSãéžæããå ŽåããããšæããŸããããã®äžæ¹ã§é³æ¥œãåçãããã«ã¯ããããªãèããå£åãã€ãºãå«ãã é³æ¥œãæ°å€ãæ¡æ£ããããšã«ãªãããšããããšã«ã¯çæããŠãããããç¥ããŸããã
ã²ãšã€ã®å€æææããŠããåèã«ããŠé ããã°å¹žãã§ãã