AAC Enantion MP3 :D

[gryllos_001]

Akousate ta nea? to neo format symbieshs mousikhs me psyxoakoustikes idiothtes onomazetai Advanced Audio Coding (AAC) kai tha einai akolouthia tou kalou kai gnorimou MPEG2! Vasizetai se aporripsh syxnothton pou etsi kai allios xanontai se ena synhthismeno xoro mono pou se afthn thn periptosh o tropos aporripshs ginetai poly poly kalytera se sxesh me to palio pia mp3! oson afora to thema ths symbieshs exeis dikaioma epiloghs toso tou Bandwidth (evros syxnothton) apo 6000hz eos kai 48000hz (exeis dikaioma epiloghs akoma kai endiamesa format tou stul px 23500hz!)-pou tetoia tyxh se enan mp3 encoder??? (ekana metrhsh bandwidth me spectrum analyzer se mp3 arxeia pou metetrepsa me musicmatch jukebox,lame,radium mp3 codec,audiograbber kai den xsepernouse ta 32000hz asxeta oti o codec orize encode sta 44100!)--alla kolpakia tou aac? epilogh encoding me xrhsh stereo texnikhs (MS-IS-MS/IS...to exoun afto kai merikoi mp3 encoders!), epilogh LFE (gia xamhles syxnothtes arketa kalo gia encoding syxnothton kato ton 80hz-efkairia na spasoun kai merika tzamia dhladh an exete kalo subwoofer-pragma pou sto mp3 deixnei makrino...) alla? xmmm... batch processing (encodings pollon arxeion sth seira-to yposthrizoun merikoi mp3 encoders afto)... ego metetrepsa mp3 sta 128kbps kai AAC sto idio bitrate kai safos to AAC htan poiotikotero poly pio poly! to mystiko einai oti to AAC einai metavlhth symbiesh analoga me to evros ton syxnothton pou anaparagontai se kathe xronikh stigmh para to gegonos oti exeis epilexsei ston encoder stathero bitrate (eno sto mp3 otan tou les stathero bitrate teleiose einai stathero!)-vevaia yparxoun kai yposthrixtes pou lene oti metatrepontas se stathero bitrate exeis kalyterh poiothta kai oti to metavlhto bitrate den einai axsiologa kalo... einai kathara thema kodika an o codec einai epaggelmatikos h metavlhth symbiesh einai apsogh an einai xalia o encoder... <P> ektos ap ta kala merh tou aac exoume kai kapoia ellatomatakia!<P>1) to aac xrhsimopoiei PARA poly epexsergastikh isxys se sxesh me to mp3 toso sto encoding oso kai sto decoding, opote mbolikh cpu den kanei pote kako...<P>2)akoma toulaxiston to aac den einai diadedomeno kai etsi ta diathesima programmata toso gia decoding oso kai gia encoding einai liga! episis yparxoun polla sub-formats (ypokathgories) se afthn thn kodikopoihsh opote kai oi asymvatothtes pote den leipoun...<P><BR> telos gia osous akoma den peisthkan akoma to AAC tha xrhsimopoihthei se pshfiakes doryforikes metadoseis thleoptikon shmaton sto mellon (DAB) kai einai hdh diethnes standard se arketes megales organoseis se themata akoustikhs genikotera! (e ma dhmiourgia ths thompson kai ths fraunhoffer einai ti allo thelete na nai??)<P> ola afta den ta eipa gia na kathgorhso to mp3, kathos eimai mp3akias kai go kai asxoloumai me to mp3 encoding alla meta apo tote pou epiasa sta xeria mou to AAC peisthka ti esti sta akra poiotiko encoding!!!<BR>

[Επισκέπτης]

Καταρχάς καλοσόρισες στα forum... <BR>Λοιπόν έχω κάτι να συμπληρώσω - διορθώσω<P>1..Έχεις δοκιμάσει variable bitrate σε mp3?<BR>Η ποιότητα είναι πολύ καλή και μόνο με τρομερά συστήματα ήχου καταλαβαίνεις την διαφορά.<BR>2..Και το mp3 όταν ξεκίνησε ήταν πολύ 'καταναλωτικό' σε πόρους και επεξεργαστική δύναμη. Τώρα όμως που είναι fix οι εντολές του mp3 σε επεξεργαστές (βλέπε 3dnow(+), sse(2)). Τότε έκανες mp3 ένα τραγούδι 50mb σε 5 λεπτά, τώρα σε μερικά δεύτερα είναι έτοιμο!!! <p>[ 03-10-2001: Message edited by: timiman ]

[gryllos_001]

na sai kala! oson afora to mp3 metavlhtou bitrate symbieshs nai to exo dokimasei kai exei poly kala apotelesmata! afto omos pou exei shmasia etsi oste to mp3 Variable Bit Rate na einai koryfaio einai o encoder! h metavlhth symbiesh san format einai koryfaia alla ta perissotera programmata pou kanoun encoding gia mp3 (erasitexnika) den dinoun toso kala apotelesmata se VBR kai afto giati h sxesh tou bitrate me tou evrous syxnothton kata to encoding den efarmozetai kala kai se merikous encoder efarmozetai "elattomatika". den eimai programmatisths gia na xsero to akrives mathimatiko montelo alla to thema tou encoder pou tha epilextei paizei rolo sto teliko mp3 arxeio! vevaia sto spiti mas exoume kai alla provlhmata akoustikhs (pollaples kakes anaklaseis,stasima kymata klp) opote to thema tou "teleiou" VBR encoding einai to ligotero telika! einai poly ligoi oi xoroi se spitia pou exoun prosextei akoustika kai etsi loipon h diafora metaxsy VBR anaforas kai VBR "erasitexnikou" telika den yparxei kai yfistatai se xorous akoustika prosegmenous! afto pantos pou me stenoxorei stous mp3 encoders einai to oti sxedon oloi meta ta 32khz (ara 16khz akoustikes syxnothtes) efarmozoun filtrarisma, opote telika to pragmatiko akousma den einai 20khz alla 16! <P>ypopsin!! den kathgoro to mp3 me afta pou grafo!

[adams]

Na mpo kai ego sto 8ema (an kai mh Eidikos san ton gryllo)....h megalh diafora mp3 kai aac sthn apodosh einai se xamhla bitrades...64-128...se ayta ta bitrades o to mp3 exei polla problhmata poy ta kseroume oloi...o aac omos ta katafernei para poly kala mporo na po oti mexri ta 128 o aac apodidei dan 192 mp3 kai den einai ypervolh kai einai epishS poly kalytero apo to neo mp3 pro kai wma<BR>Gia opoion endiaferetai gia perissotera exei to hitech ena para poly kalo ar8ro me sygkritika apotelesmata gia olous tous encoders....kai nomizo an exei xrono o gryllos na dosei kana link<BR>opos leei kai to hitech: AAC rules!!!!!!<BR>Gia osous psaxnoyn na vroun poies etairies to yposthrizoun kai apo poies dhmioyrgh8hke na po einai mia synergasia Fraunhofer-IIS AT&T SONY KAI DOLBY

[gryllos_001]

to gegonos oti to AAC tha xrhsimopoihthei para poly se doryforikes metadoseis thleoptikon programmaton (DAB) toulaxiston gia thn ora einai mia apodeixsh oti to AAC kala kratei kai elpizo pos me thn katallhlh yposthrixsh toso apo tis etaireies oso kai apo tous programmatistes tha ginei poly kalos codec antistoixos isos k kalyteros apo to mp3! file adams oson afora ta provlhmata tou mp3 se xamhla bitrate opos eipes einai dedomena kyrios se kakous encoders alla symfona me akousmata kai me peiramata pou exo kanei me afto to thema exo diapistosei pos ena 60% rolo paizei kai o tropos me ton opoio o encoder tha kodikopoihsei thn yparxousa stereofonia tou kommatiou! oi yparxouses dynatothtes gia to mp3 einai treis:<P>MS Stereo (Middle Side Stereo): sthn periptosh afth kodikopoiountai oi anaklaseis pou proerxontai apo ta plagia merh synhthos 180 moires dexsia aristera se sxesh me to kentriko akousma! <P>IS Stereo (Intensity Stereo): sthn periptosh afth afairountai oi "diafores" fashs ton 90 moiron apo thn stereofonikh eikona tou kommatiou, pou shmainei oti megalo meros ths aisthisis tou xorou den kodikopoieitai!<P>Joint Stereo: h stereofonikh eikona "Athrizetai" (L+R) kai kodikopoieitai sto kommati me apotelesma na akougetai me para poly kontinh stereo eikona!<P>apo ekei kai pera aftoi oi 3 tropoi kodikopoihshs paizoun shmantiko rolo sto teliko apotelesma tou mp3!!!<P>oson afora ta links pou zhthses efxaristos tha shkoso tis epomenes meres (tora eimai sth douleia kai den thymamai apexso), toso gia themata sygkrisis oso kai gia programmata encoding-decoding AAC!

[trustfm]

Yparxei kai akoma kalutero format apo to acc <BR>(apo to forum tou <A HREF="http://www.r3mix.net" TARGET=_blank>www.r3mix.net</A> ) : <BR>MPC 4.7<BR>AAC 4.4<BR>OGG 3.4<BR>LAME 3.3<BR>WMA 3.3<BR>XING 2.0