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  1. Member
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    ive been testing out audio bitrates and codecs and found opus to be the best at this bitrate my ears cant tell the difference when compered to 320kbps mp3/aac
    i just have 1 problem when i rip a cd to opus meda info in media player classic shows the khz as 44.1khz same as what the original cd is but vlc player and the app on my phone both say the audio is 48khz


    General
    Complete name : G:\All Time Low\Nothing Personal\04 All Time Low - Lost In Stereo.opus
    Format : Ogg
    File size : 3.98 MiB
    Duration : 3 min 47 s
    Overall bit rate : 133 kb/s
    Album : Nothing Personal
    Album/Performer : All Time Low
    Part : 1
    Part/Total : 1
    Track name : Lost In Stereo
    Track name/Position : 4
    Track name/Total : 12
    Performer : All Time Low
    Label : Hopeless Records
    Genre : Pop / Rock
    Recorded date : 2009
    Writing application : Opus 1.3.1
    ISRC : USHR20947004
    ENCODER_OPTIONS : --bitrate 120
    Style : Pop Rock / Power Pop / Punk / Pop Punk
    Catalog # : 710
    Source : CD (Lossless)
    Encoded By : dBpoweramp Release 17.4
    Encoder Settings : -bitrate="120"
    AccurateRipResult : AccurateRip: Accurate (confidence 2) [3D071E1E]
    AccurateRipDiscID : 012-00120512-00a952af-8f099f0c-4

    Audio
    ID : 1888 (0x760)
    Format : Opus
    Duration : 3 min 47 s
    Channel(s) : 2 channels
    Channel layout : L R
    Sampling rate : 44.1 kHz
    Compression mode : Lossy
    Writing library : libopus 1.3-26-ge85ed772, libopusenc 0.2.1-2-g9cb17c6
    so im confused is media info wrong or has it really converted the 44.1khz to 48khz and will there be any problems so far the 2 cds i ripped sound fine without problems
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  2. Member
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    It says sampling rate 44.1 in the report above
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  3. Member
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    Originally Posted by davexnet View Post
    It says sampling rate 44.1 in the report above
    yes but all other programs say it 48khz
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  4. Member Cornucopia's Avatar
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    Assuming you did NOT do any SRC (sample rate conversion), ALL CD rips would be 44.1kHz, and so would any compressed version from them. So, I must deduce that those other apps are wrong.
    MediaInfo does not do any SRC, it just shows you what the metadata is in the file. Would love to see some of these other apps that are reporting otherwise.

    Scott
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  5. DECEASED
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    Originally Posted by jamespoo View Post
    ive been testing out audio bitrates and codecs and found opus to be the best at this bitrate my ears cant tell the difference when compered to 320kbps mp3/aac
    i just have 1 problem when i rip a cd to opus meda info in media player classic shows the khz as 44.1khz same as what the original cd is but vlc player and the app on my phone both say the audio is 48khz.
    From Wikipedia's article about the Opus audio format:

    Opus allows the following bandwidths during encoding. Opus compression does not depend on the input sample rate; timestamps are measured in 48 kHz units even if the full bandwidth is not used. Likewise, the output sample rate may be freely chosen. For example, audio can be input at 16 kHz yet be set to encode only narrowband audio.

    Code:
    Abbreviation          Audio bandwidth    Effective sample rate
    
    NB (narrowband)        4 kHz               8 kHz
    MB (medium-band)       6 kHz              12 kHz
    WB (wideband)          8 kHz              16 kHz
    SWB (super-wideband)  12 kHz              24 kHz
    FB (fullband)         20 kHz              48 kHz
    Last edited by El Heggunte; 27th Oct 2021 at 20:40.
    "Like this facility, I don't exist."
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  6. Member Cornucopia's Avatar
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    Wow.

    This was news to me.

    Reading those docs, it appears Opus applies SRC both on encode and (usually) on decode, And there are also built in lags for that src as well as for packet resiliency, and a few other codec-switching-trick functions.

    This may be cool for some of those features, but the audiophile in me says F**k No! I have so far rarely used the codec family, mainly because I have few hardware devices that support it, but it seriously gives me pause about using it again. I don't want any app applying SRC that isn't fully under my control.


    Scott
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