VideoHelp Forum

Our website is made possible by displaying online advertisements to our visitors. Consider supporting us by disable your adblocker or Try ConvertXtoDVD and convert all your movies to DVD. Free trial ! :)
+ Reply to Thread
Results 1 to 3 of 3
Thread
  1. The new Opus format intrigued me half a year ago so I decided to test it out. It reminded me of a new-generation OGG which despite popular propaganda completely sucked and failed to outmatch AAC so I didn't have high hopes. Hydrogenaudio was drooling over it but I didn't trust their rigged listening tests so I did one of my own.
    I thought I'd post it for anyone interested in Opus.

    Code:
    ABC/HR Version 1.0, 6 May 2004
    Testname: grcitrance MP4/OPUS
    
    1R = M:\grcopus32.wav
    2L = M:\grc64MP4.wav
    3L = M:\grc64MP4cbr.wav
    4R = M:\grc32MP4.wav
    5L = M:\grcopus48.wav
    6R = M:\grcopus64.wav
    7R = M:\grc48MP4.wav
    
    ---------------------------------------
    General Comments:
    
    ---------------------------------------
    1R File: M:\grcopus32.wav
    1R Rating: 2.5
    1R Comment: Extremely rough
    ---------------------------------------
    2L File: M:\grc64MP4.wav
    2L Rating: 3.6
    2L Comment: Kinda duller and the upper freqs are distorted
    ---------------------------------------
    3L File: M:\grc64MP4cbr.wav
    3L Rating: 3.6
    3L Comment: cant tell apart from sample2, I believe it's slightly better
    ---------------------------------------
    4R File: M:\grc32MP4.wav
    4R Rating: 2.4
    4R Comment: Somewhat less rough than sample1 but has reduced stereo
    ---------------------------------------
    5L File: M:\grcopus48.wav
    5L Rating: 2.9
    5L Comment: Less distortion than 1 but more than 2 and 3
    ---------------------------------------
    6R File: M:\grcopus64.wav
    6R Rating: 4.0
    6R Comment: Noticeably rougher treble than original and slightly dull but otherwise pretty good
    ---------------------------------------
    7R File: M:\grc48MP4.wav
    7R Rating: 2.8
    7R Comment: It has less distortion in the upper freqs than 5 but sounds duller like the upper freq was cut completely and stereo is reduced
    ---------------------------------------
    ABX Results:
    Original vs M:\grcopus32.wav
        9 out of 10, pval = 0.011
    Original vs M:\grc64MP4.wav
        10 out of 10, pval < 0.001
    Original vs M:\grc64MP4cbr.wav
        10 out of 10, pval < 0.001
    Original vs M:\grcopus64.wav
        10 out of 11, pval = 0.006
    M:\grc64MP4.wav vs M:\grc64MP4cbr.wav
        3 out of 5, pval = 0.500
    That song was a fast-paced trance piece with lots of broadband. Opus outmatched AAC but only at 64 kb/s. At the other bitrates it was a choice between bad treble or bad stereo and the stereo in this song was very wide and pronounced so Opus in my opinion sounded more pleasant by better preserving the channel separation.

    This next song is a very tonal MIDI-like tune, very little broadband besides a drum and cymbals. AAC triumphed this time, being practically transparent at 64 kb/s and audibly better than Opus at every bitrate. Stereo wasn't very prominent in this song so it mattered less than signal distortion which Opus brought plenty of.

    Code:
    ABC/HR Version 1.0, 6 May 2004
    Testname: Mazgal AAC/opus
    
    1L = M:\mazgal64MP4.wav
    2R = M:\mazgal32opus.wav
    3R = M:\mazgal64opus.wav
    4L = M:\mazgal64MP3.wav
    5R = M:\mazgal32MP4.wav
    6L = M:\mazgal48MP4.wav
    7L = M:\mazgal48opus.wav
    
    ---------------------------------------
    General Comments:
    
    ---------------------------------------
    1R File: M:\mazgal64MP4.wav
    1R Rating: 4.8
    1R Comment: The strike of the heavy notes have a little treble accentuation, difficult to notice
    ---------------------------------------
    2R File: M:\mazgal32opus.wav
    2R Rating: 2.4
    2R Comment: Extremely metallic melody
    ---------------------------------------
    3R File: M:\mazgal64opus.wav
    3R Rating: 4.0
    3R Comment: A much reduced form of distortion than 2
    ---------------------------------------
    4L File: M:\mazgal64MP3.wav
    4L Rating: 2.2
    4L Comment: Heavy smearing, top shelf gone, obviously 64kbps MP3
    ---------------------------------------
    5R File: M:\mazgal32MP4.wav
    5R Rating: 3.3
    5R Comment: Stereo greatly simplified, some distortion on upper shelf and kinda echoey melody
    ---------------------------------------
    6L File: M:\mazgal48MP4.wav
    6L Rating: 3.6
    6L Comment: Greater distortion in the treble than 5 but much less loss of stereo
    ---------------------------------------
    7L File: M:\mazgal48opus.wav
    7L Rating: 3.5
    7L Comment: Seems to be more distorted than 6 but with more texture. Not sure what to decide.
    ---------------------------------------
    ABX Results:
    Original vs M:\mazgal64MP4.wav
        18 out of 20, pval < 0.001
    Original vs M:\mazgal64opus.wav
        10 out of 10, pval < 0.001
    Original vs M:\mazgal32MP4.wav
        10 out of 10, pval < 0.001
    Original vs M:\mazgal48MP4.wav
        10 out of 10, pval < 0.001
    It looks to me Opus is good for songs with lots of broadband content (hard rock, trance, distortion, noise etc.) while AAC is better for tonal audio (vocalization, instruments without heavy percussion and so on.)

    I tested these before XIPH released that new Opus beta with supposedly better support for tonal audio but it's not that much better than before if at all so I didn't bother doing a retest.

    And MPEG will soon release the new audio standard (USAC or whatever it's called) that'll beat the shit outta Opus anyway.

    So there you have it.

    EDIT: Samples used in test available upon request.
    Last edited by Mephesto; 6th Oct 2013 at 12:11.
    Quote Quote  
  2. DECEASED
    Join Date
    Jun 2009
    Location
    Heaven
    Search Comp PM
    Originally Posted by Mephesto View Post
    The new Opus format intrigued me half a year ago so I decided to test it out. It reminded me of a new-generation OGG which despite popular propaganda completely sucked and failed to outmatch AAC ---
    Very true --- just like Vorbis, Opus was designed for fitting in the poorly-designed Ogg container. The Matroska devels did have to think too much in order to find an "acceptable" way of putting the wannabe audio codec into MKV files.

    And MPEG will soon release the new audio standard (USAC or whatever it's called)
    Thanks for refreshing my memory, I had already completely forgotten it:

    http://en.wikipedia.org/wiki/Unified_Speech_and_Audio_Coding

    that'll beat the shit outta Opus anyway.
    Oh no, yet another very-low-bitrate audio compressor
    Last edited by El Heggunte; 4th Oct 2013 at 13:44. Reason: tool unlink
    Quote Quote  
  3. Wikipedia page says unlike Vorbis it doesn't require "large codebooks". I don't even know what that means but does it have anything to do with the poor design of OGG you talk about? All I know about Vorbis is that when it doesn't go in OGG it bloats the hell out of any other container with huge overhead. For AVI, 75% of the filesize will be the overhead to store the Vorbis stream, lmao....

    I never liked Vorbis and Opus seems to be its bastard child. Oh well, at least it's free. It might have way better quality if it actually allowed the same framesizes as AAC and others. We'll see.
    Quote Quote  



Similar Threads