Dawb video thiab audio codec tus tsim Xiph.Org tau tso tawm Opus 1.4.0 audio codec, uas muab kev zoo siab encoding thiab tsawg latency rau ob qho tib si high-bitrate streaming suab thiab lub suab compression nyob rau hauv bandwidth-constrained VoIP daim ntawv thov xov tooj. Kev siv encoder thiab decoder siv tau raug faib raws li BSD daim ntawv tso cai. Cov lus qhia ua tiav rau Opus hom muaj rau pej xeem, pub dawb, thiab pom zoo raws li tus qauv hauv Internet (RFC 6716).
Lub codec yog tsim los ntawm kev sib txuas cov thev naus laus zis zoo tshaj plaws los ntawm Xiph.org's CELT codec thiab Skype qhib qhov SILK codec. Ntxiv rau Skype thiab Xiph.Org, cov tuam txhab xws li Mozilla, Octasic, Broadcom thiab Google kuj tau koom nrog hauv kev txhim kho Opus. Cov patents koom nrog Opus tau tso cai los ntawm cov tuam txhab koom nrog hauv kev txhim kho rau kev siv tsis txwv yam tsis tau them nqi ntawm cov nuj nqis. Tag nrho cov cuab yeej cuab tam thiab cov ntawv tso cai patent cuam tshuam nrog Opus tau txais kev tso cai rau cov ntawv thov thiab cov khoom siv Opus, tsis tas yuav muaj kev pom zoo ntxiv. Tsis muaj kev txwv tsis pub muaj kev txwv thiab tsim cov kev siv lwm tus thib peb. Txawm li cas los xij, tag nrho cov cai tso cai raug tshem tawm hauv qhov xwm txheej ntawm patent txheej txheem cuam tshuam rau Opus thev naus laus zis tawm tsam txhua tus neeg siv Opus.
Opus nta zoo coding zoo thiab tsawg latency rau ob qho tib si high-bitrate streaming suab compression thiab lub suab compression rau bandwidth-constrained VoIP xov tooj daim ntawv thov. Yav dhau los, Opus tau lees paub tias yog tus codec zoo tshaj plaws thaum siv 64Kbit bitrate (Opus overtook cov neeg sib tw xws li Apple HE-AAC, Nero HE-AAC, Vorbis thiab AAC LC). Cov khoom lag luam uas txhawb Opus tawm ntawm lub thawv suav nrog Firefox browser, GStreamer moj khaum, thiab pob FFmpeg.
Cov yam ntxwv tseem ceeb ntawm Opus:
- Bitrate ntawm 5 mus rau 510 Kbit / s;
- Sampling zaus ntawm 8 txog 48KHz;
- Ncej ntev ntawm 2.5 mus rau 120 milliseconds;
- Kev them nyiaj yug rau qhov tsis tu ncua (CBR) thiab sib txawv (VBR) bitrates;
- Kev them nyiaj yug rau nqaim band thiab wideband suab;
- Txhawb suab thiab suab paj nruag;
- Kev them nyiaj yug lub tso suab thiab mono;
- Kev them nyiaj yug rau dynamic chaw ntawm bitrate, bandwidth thiab ncej loj;
- Muaj peev xwm rov qab tau cov kwj suab hauv cov ntaub ntawv poob (PLC);
- Txhawb nqa txog 255 channels (ntau-kwj ntas)
- Muaj cov kev siv los ntawm kev siv floating thiab taag point arithmetic.
Kev tsim kho tshiab tseem ceeb hauv Opus 1.4:
- Optimization ntawm encoding tsis tau ua tiav, tsom rau kev txhim kho cov ntsiab lus ntawm lub suab zoo thaum FEC (Forward Error Correction) tau ua kom rov qab cov pob ntawv puas lossis ploj ntawm tus nqi me ntsis ntawm 16 txog 24kbs (LBRR, Tsawg Bit-Rate Redundancy).
- Ntxiv kev xaiv OPUS_SET_INBAND_FEC los pab kom FEC yuam kev kho tab sis tsis yuam SILK hom (FEC yuav tsis siv nyob rau hauv CELT hom).
- Txhim kho qhov kev siv ntawm DTX (Discontinuous Transmission) hom, uas muab kev ncua kev sib kis ntawm cov tsheb khiav thaum tsis muaj suab.
- Ntxiv kev txhawb nqa rau Meson tsim qhov system thiab txhim kho kev txhawb nqa rau lub tsev siv CMake.
- Ib qho kev sim tshuab "Real-Time Packet Loss Concealment" tau muab ntxiv los kho cov khoom seem ntawm kev hais lus ploj vim yog pob ntawv poob, ua haujlwm los ntawm kev siv tshuab kev kawm technologies.
- Ib qho kev sim ntawm qhov "dub redundancy" mechanism tau muab ntxiv, uas siv lub tshuab kev kawm los txhim kho kev ua haujlwm ntawm lub suab rov qab tom qab pob ntawv poob.
Tau qhov twg los: opennet.ru