WebM → AAC

Yebo, futhi kufanelekile ukuhlela. Izifomethi zombili ziyi-lossy, ngakho-ke i-AAC encoder isebenza kusuka kumsindo osele udlulele engxenyeni eyodwa ye-psychoacoustic, futhi iziphakamiso zayo zihlanganisa isiqephu sokuqala. Ku-192 kbps noma ngaphezulu, imiphumela ihlala icacile kakhulu. Uma une-lossless master nganoma yikuphi, uku-encoding i-AAC kusuka kulo kunciphisa ukudlula okuphindiwe ngokuphelele. WebM idinga ukucophelela: VP8 noma VP9 ividiyo (AV1 manje) nge Vorbis noma Opus umsindo, futhi akukho okuthile okuningi. I-AAC ilahlekelwa yizinto kodwa isebenza kahle kunayo i-MP3, futhi iphatha kuze kube yi-48 channels ngokusemthethweni ngaphezu kokuboshwa ku-stereo design.

Yebo, futhi kuyinzuzo engokoqobo ngaphezulu kwe WebM, engeke ikwazi ukugcinwa kuphi naphi. AAC ifaka isihloko, umculi, i-album, unyaka, inani le-track kanye ne-cover art efakwe ngaphakathi kwebhokisi, ngakho-ke i-library yomculo ifaka ngokulungile ngaphandle kokufaka isandla. I-AAC izwakala ingcono kakhulu kune-MP3 ngaphansi kuka-128 kbps futhi iyi-audio track ejwayelekile ku-MP4, YouTube, Apple Music ne-broadcast.

Ngephutha umsindo 0 (umsindo wokuqala, ngokuvamile umsindo omkhulu). Uma WebM wakho ufaka umlayezo, ama-dubs, noma umsindo ochazayo kuma-tracks angeziwe, umkhethi othuthukisiwe "umsindo" ukuvumela ukuthi ukhethe 1, 2, 3... ngokucacile. Uhlu lwe-track lubonisa ukufinyelela kokubuka kuqala ukuze ungakhetha ngokuzifihla.

Iphutha AAC i-bitrate yi-192 kbps (icacile kuma-earphones amaningi). Nciphisa ku-320 kbps nge-audiophile output, noma 96-128 kbps ngezwi/podcast lapho ihele elincane liyisisekelo. Ama-AAC angeke alahlekile (WAV, FLAC) agweme ukumiswa kwe-bitrate futhi agcine yonke isampula.

Uma i AAC ifomethi ingekho lutho (WAV, FLAC, ALAC), yonke isampula yangempela igcinwa. Uma i AAC ingekho lutho (MP3, AAC, OGG, Opus), i-codec icindezela futhi — ku-192 kbps ushintsho alukwazi ukulizwa kuningi kwezithameli; ku-96 kbps ungalizwa ama-cymbals noma ama-sibilans abandayo. I-WebM i Container ayinaso isikhundla kulolu hlelo — ukumiswa kwe-codec kuphela okubalulekile.

Ngokungagqibekanga yebo — 48 kHz WebM umsindo ushintsha ube 48 kHz AAC umsindo, 44.1 kHz ushintsha ube 44.1 kHz. Uma ufuna ukuncipha kwesampula ukuze kusebenze (isibonelo 96 kHz studio masters kuya ku 44.1 kHz CD-quality AAC) isampula-rate dropdown yenza lokhu ngekhwalithi ephezulu yokusatshalaliswa kabusha.

Yebo — susa isibaya se WebM amafayela endaweni yokulayisha futhi siqhube ukukhishwa ngokufanayo. I-Premium ithola abasebenzi abafanayo abaningi; ku-100-file batch (uhlelo lwemiculo-video olujwayelekile) lokhu kuyinto ehlukile phakathi kwamasekondi angama-90 namaminithi angama-8.

Umsindo demux + transcode usebenza ngokushesha kakhulu kunakhodi yevidiyo - ngokuvamile 5-15% yesikhathi somthombo. Ihora le-1 WebM -> AAC liphele ngemizuzu engu-3-9 ku-pipeline ejwayelekile. Uma i-AAC codec ifana ne-source codec esekwi-WebM (ejwayelekile ye-AAC ngaphakathi kwe-MKV / MP4), iyi-remux ecacile futhi isebenza ngemizuzu.

Uma ihele WebM ligcina i-stream metadata (umculi, isihloko, i-album), sikopa lezi zindawo kuAAC isitoreji lapho ifomu lixhasa amathegi. ID3v2 (MP3), amazwana we-Vorbis (OGG, FLAC), ama-MP4 atoms (AAC / M4A), RIFF INFO (WAV) wonke abhalwe. Ukungabi nathegi WebM kwenza AAC — sebenzisa i-Mp3tag noma i-Picard emva-kwe-ukukhishwa ukuze uthuthukise.

Yebo — imodeli yobumfihlo efanayo nezo zonke iziguqulo. Umsuka WebM nesokudla AAC zicutshungulwa kubasebenzi abahlukanisiwe futhi zicishwe ngaphakathi kwemizuzu. Asikwazi ukudlala, ukugcina, noma ukuhlanganisa okuqukethwe. Bona /privacy/.

Kuyinto evamile kakhulu ukungqubuzana kwe-stream-index — WebM yakho iqukethe i-multi-track audio layout futhi siyikhuphule i-stream engalungile (isibonelo, i-audio track echazayo emnyama endaweni ye-main mix). Phinda uqhube nge-"audio stream" ethuthukisiwe ekhethiwe ebekwe kwi-index efanele, noma khetha "zonke iziqukathi" ukukhishwa kwe-track ngayinye njengefayela elihlukile AAC.