Moetsi oa mahala oa li-codec tsa video le audio Xiph.Org o lokolotse codec ea molumo ea Opus 1.4.0, e fanang ka khouto ea boleng bo holimo le latency e fokolang bakeng sa khatello ea molumo o phahameng oa bitrate le khatello ea lentsoe lits'ebetsong tsa VoIP tse thibetsoeng ke bandwidth. Ts'ebetso ea litšupiso tsa encoder le decoder li tsamaisoa tlasa laesense ea BSD. Litlhaloso tse felletseng tsa sebopeho sa Opus li fumaneha phatlalatsa, mahala, 'me li amohetsoe joalo ka maemo a Marang-rang (RFC 6716).
Codec e entsoe ka ho kopanya mekhoa e metle ka ho fetisisa e tsoang ho Xiph.org's CELT codec le Skype's open source SILK codec. Ho phaella ho Skype le Xiph.Org, lik'hamphani tse kang Mozilla, Octasic, Broadcom le Google le tsona li ile tsa kenya letsoho ntlafatsong ea Opus. Litokomane tse amehang ho Opus li fanoe ke lik'hamphani tse amehang ho nts'etsopele bakeng sa tšebeliso e sa lekanyetsoang ntle le ho lefa meputso. Litokelo tsohle tsa thepa ea mahlale le lilaesense tsa patent tse amanang le Opus li abeloa lits'ebetso le lihlahisoa tse sebelisang Opus, ntle le tlhoko ea tumello e eketsehileng. Ha ho na lithibelo mabapi le boholo le tlhahiso ea mekhoa e meng ea ts'ebetsong ea mekhatlo ea boraro. Leha ho le joalo, litokelo tsohle tse fanoeng li hlakoloa haeba ho na le linyeoe tsa patent tse amang theknoloji ea Opus khahlano le mosebelisi ofe kapa ofe oa Opus.
Opus e na le boleng bo holimo ba likhoutu le latency e fokolang bakeng sa khatello ea molumo o phahameng oa bitrate le khatello ea lentsoe bakeng sa lits'ebetso tsa mohala tsa VoIP tse thibetsoeng ke bandwidth. Pejana, Opus e ile ea vouteloa e le codec e ntle ka ho fetisisa ho 64Kbit (bahlolisani ba Opus ba sa sebetseng hantle joalo ka Apple HE-AAC, Nero HE-AAC, Vorbis le AAC LC). Lihlahisoa tse tšehetsang Opus ka ntle ho lebokose li kenyelletsa sebatli sa Firefox, moralo oa GStreamer, le sephutheloana sa FFmpeg.
Lintlha tse ka sehloohong tsa Opus:
- Bitrate ho tloha ho 5 ho isa ho 510 Kbit / s;
- Khafetsa ea sampole ho tloha 8 ho isa ho 48KHz;
- Nako ea foreimi ho tloha ho 2.5 ho isa ho 120 milliseconds;
- Ts'ehetso bakeng sa li-bitrate tsa kamehla (CBR) le tse feto-fetohang (VBR);
- Ts'ehetso bakeng sa molumo oa narrowband le wideband;
- Tšehetso ea lentsoe le 'mino;
- Tšehetso ea stereo le mono;
- Ts'ehetso bakeng sa tlhophiso e matla ea bitrate, bandwidth le boholo ba foreimi;
- Bokhoni ba ho khutlisetsa molumo oa molumo haeba ho lahleheloa ke foreimi (PLC);
- Ts'ehetsa liteishene tse fihlang ho 255 (liforeimi tse nang le melapo e mengata)
- Ho fumaneha ha ts'ebetsong ho sebelisoa lipalo tse phaphametseng le tse tsitsitseng.
Litlhahiso tsa bohlokoa ho Opus 1.4:
- Ntlafatso ea liparamente tsa encoding e entsoe, e ikemiselitseng ho ntlafatsa matšoao a mantlha a boleng ba molumo ha FEC (Tlhahiso ea Phoso ea Pele) e nolofalloa ho khutlisa lipakete tse senyehileng kapa tse lahlehileng ka litheko tse nyane ho tloha ho 16 ho isa ho 24kbs (LBRR, Low Bit-Rate Redundancy).
- Khetho e ekelitsoeng OPUS_SET_INBAND_FEC ho nolofalletsa ho lokisa phoso ea FEC empa ntle le ho qobella SILK mode (FEC e ke ke ea sebelisoa ka mokhoa oa CELT).
- Ts'ebetsong e ntlafalitsoeng ea mokhoa oa DTX (Discontinuous Transmission), e fanang ka ho emisoa ha phetisetso ea sephethephethe ha ho se na molumo.
- Ts'ehetso e ekelitsoeng bakeng sa sistimi ea kaho ea Meson le ts'ehetso e ntlafalitsoeng ea moaho o sebelisang CMake.
- Mochini oa liteko oa "Real-Time Packet Loss Concealment" o kentsoe ho khutlisa likaroloana tsa puo tse lahlehileng ka lebaka la tahlehelo ea pakete, e sebetsang ka ts'ebeliso ea mahlale a ho ithuta ka mochini.
- Ho kenyelitsoe ts'ebetsong ea liteko tsa "deep redundancy" e sebelisang mokhoa oa ho ithuta oa mochine ho ntlafatsa katleho ea ho hlaphoheloa ha molumo ka mor'a tahlehelo ea pakete.
Source: opennet.ru