MP4 → Opus

Ndikukhulupirira kuti ndinu oyenera, ndipo ndibwino kuti mupange. Mafomu awiriwa ndi owonongeka, choncho Opus encoder akuchita ntchito kuchokera ku audio yomwe yakhala ikuyenda mwa psychoacoustic pass, ndipo masankho ake oyamba amapanga gawo loyamba. Pa 192 kbps kapena pamwambapa, zotsatirazi ndizosawoneka bwino kwa ambiri owerenga. Ngati muli ndi master yopanda kuwonongeka, kulemba koyamba kwa Opus kuchokera ku yomwe imalepheretsa kupitanso koyamba. Zikuoneka kuti pafupifupi aliyense MP4 m'munda ndi H.264 kanema ndi AAC audio; chidebenso mwalamulo ali HEVC, AV1 ndi VP9. Opus imasintha kuchokera pa mawu a 6 kbps mono kupita ku nyimbo za stereo za 510 kbps m'njira yofanana ndi bitstream ndipo imasintha mobwerezabwereza.

Nthawi zambiri sichoncho. MP4 imasinthidwa ndi chilichonse, kuphatikizapo magalimoto agalimoto ndi osewera okalamba; Opus amafunikira mapulogalamu omwe amadziwa codec, omwe nthawi zambiri amakhala ndi zida zosagwirizana. Ngati malo osankhidwa ndi stereo yagalimoto kapena wosewera wonyamula, ndiye kuti ndi chitsimikizo cholimba chokhala pa MP4. Opus siyimathandizidwa ndi zida zokhazokha - ganizirani kuti ndi pulogalamu yokhayo yosewera, ndipo muyembekezere kuti ma stereo agalimoto azisiya kuganizira.

Poyambira, mpweya 0 (woyamba wa nyimbo, nthawi zambiri ndi woyamba kuphatikizidwa). Ngati MP4 wanu ali ndi mawu ofotokoza, ma dubbing, kapena mawu ofotokoza pa nyimbo zina, wosankha "mpweya wa nyimbo" akukulola kusankha 1, 2, 3... mwatsatanetsatane. Lipoti la nyimbo limawonekera pa mndandanda woyang'anira kuti musasankhe mwamsanga.

Default Opus bitrate ndi 192 kbps (wowoneka bwino kwa nyimbo kwa amayi ambiri). Kusintha kwa 320 kbps kwa audiophile output, kapena 96-128 kbps kwa mawu / podcast komwe fayilo yaying'ono ndi yoyamba. Ma Opus opanda malire (WAV, FLAC) sasamala za kukhazikitsa kwa bitrate ndikusunga zonse.

Ngati Opus ndi mtundu wopanda kuwonongeka (WAV, FLAC, ALAC), zonse zomwe zimapangidwa zimasungidwa. Ngati Opus ndi zowonongeka (MP3, AAC, OGG, Opus), codec imabwezeretsa - pa 192 kbps kusiyana kumakhala kopanda kudziwika kwa zinthu zambiri; pa 96 kbps mutha kunena kuti ma cymbals kapena ma sibilants amawoneka. MP4 yokhala ndi MP4 siyikhudza izi - zosankha za codec ndizofunikira.

Mwa default yes — 48 kHz MP4 audio imakhala 48 kHz Opus audio, 44.1 kHz imakhala 44.1 kHz. Ngati mukufuna kuchepetsa kusamvana kwa kugwirizana (mwachitsanzo, 96 kHz studio masters ku 44.1 kHz CD-quality Opus) mndandanda wolowetsa wa sampling-rate amachita izi ndi kusamvana kwabwino.

Yai - chotsani fayilo ya MP4 ku gawo lotsitsa ndipo tidzachita kutulutsa mofanana. Premium imalandira ogwira ntchito ambiri mofanana; pa fayilo ya 100 (kusonkhanitsa kwa nyimbo za nyimbo) iyi ndi kusiyana pakati pa masekondi a 90 ndi maola a 8.

Audio demux + transcode imayenda mwachangu kuposa kubwezeretsa kanema - nthawi zambiri 5-15% ya nthawi yoyambira. 1-hour MP4 -> Opus imatha m'maola 3-9 pa standard pipeline. Ngati Opus codec imagwirizana ndi codec yoyambira yomwe ili mu MP4 (yofala kwa AAC m'ma MKV / MP4), ndi remux yoyera ndipo imagwira ntchito m'masekondi.

Ngati fayilo ya MP4 imasunga metadata ya stream (mlengi, mutu, album), timakopera masambawa ku Opus komwe mtundu umathandizira ma tag. ID3v2 (MP3), Vorbis comments (OGG, FLAC), MP4 atoms (AAC / M4A), RIFF INFO (WAV) onse amalemba. Opanda ma tag MP4 amapanga Opus osadziwika - kugwiritsa ntchito Mp3tag kapena Picard kutumiza kunja kuti muwonjezere.

Yes - mtundu wofanana wa privacy monga pazosintha zonse. Source MP4 ndi output Opus amachitidwa m'mabungwe osiyana ndipo amasungidwa m'maola ochepa. Sitimasewera, sitisunga kapena sitigawana zinthu.

Pa nthawi zambiri, index ya stream siyigwirizana - MP4 yanu ili ndi maudindo ambiri a audio ndipo tatulutsa ulalo wosayenera (mwachitsanzo, ulalo wofotokozera mawu osalankhula m'malo mwa ulalo wophatikizidwa). Yambitsaninso ndi "audio stream" yosinthidwa yosinthidwa ndi index yoyenera, kapena kusankha "all streams" kuti mutenge ulalo uliwonse ngati fayilo yosiyana ya Opus.