3GP → MP3

Yebo, futhi kufanelekile ukuhlela. Izifomethi zombili ziyi-lossy, ngakho-ke i-MP3 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-MP3 kusuka kulo kunciphisa ukudlula okuphindiwe ngokuphelele. 3GP igcina H.263 noma MPEG-4 Ingxenye 2 ividiyo nge AMR narrowband ukukhuluma umsindo, zonke tuned for minimal bitrate hhayi quality. MP3 ilahlekelwa: imodeli ye psychoacoustic isusa iziqongo ezingezona ezivamile, ezivame ukuba ngu-128 kuya ku-320 kbps.

Yebo, futhi kuyinzuzo engokoqobo ngaphezulu kwe 3GP, engeke ikwazi ukugcinwa kuphi naphi. MP3 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. Akukho lutho olushaya i-MP3 ngokuhambisana - i-car stereos, imishini ye-gym, i-DAPs ne-hardware eneminyaka engu-20 yonke ifunde ngaphandle kwemibuzo.

Ngephutha umsindo 0 (umsindo wokuqala, ngokuvamile umsindo omkhulu). Uma 3GP 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 MP3 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-MP3 angeke alahlekile (WAV, FLAC) agweme ukumiswa kwe-bitrate futhi agcine yonke isampula.

Uma i MP3 ifomethi ingekho lutho (WAV, FLAC, ALAC), yonke isampula yangempela igcinwa. Uma i MP3 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-3GP i Container ayinaso isikhundla kulolu hlelo — ukumiswa kwe-codec kuphela okubalulekile.

Ngokungagqibekanga yebo — 48 kHz 3GP umsindo ushintsha ube 48 kHz MP3 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 MP3) isampula-rate dropdown yenza lokhu ngekhwalithi ephezulu yokusatshalaliswa kabusha.

Yebo — susa isibaya se 3GP 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 3GP -> MP3 liphele ngemizuzu engu-3-9 ku-pipeline ejwayelekile. Uma i-MP3 codec ifana ne-source codec esekwi-3GP (ejwayelekile ye-AAC ngaphakathi kwe-MKV / MP4), iyi-remux ecacile futhi isebenza ngemizuzu.

Uma ihele 3GP ligcina i-stream metadata (umculi, isihloko, i-album), sikopa lezi zindawo kuMP3 isitoreji lapho ifomu lixhasa amathegi. ID3v2 (MP3), amazwana we-Vorbis (OGG, FLAC), ama-MP4 atoms (AAC / M4A), RIFF INFO (WAV) wonke abhalwe. Ukungabi nathegi 3GP kwenza MP3 — sebenzisa i-Mp3tag noma i-Picard emva-kwe-ukukhishwa ukuze uthuthukise.

Yebo — imodeli yobumfihlo efanayo nezo zonke iziguqulo. Umsuka 3GP nesokudla MP3 zicutshungulwa kubasebenzi abahlukanisiwe futhi zicishwe ngaphakathi kwemizuzu. Asikwazi ukudlala, ukugcina, noma ukuhlanganisa okuqukethwe. Bona /privacy/.

Kuyinto evamile kakhulu ukungqubuzana kwe-stream-index — 3GP 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 MP3.