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  1. #1
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    Mar 2013
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    FLAC Stream Quality a Mixed Bag

    I have bad news and better news on the Absolute Radio UK FLAC radio streams. Testing a FLAC capture taken roughly an hour ago with foobar2000 and Audacity, I found the audio to be lossy. Note: the first two images below, frequency analysis/ spectral view and frequency analysis, respectively, represent an Absolute Radio UK capture I took on Feb. 4, 2013, which was lossless. The bottom two images represent the capture I took today, which was not.

    The better news is that I have been through this before with the engineering team at Absolute, and I'm sure they'll get round to correcting the problem -- once informed.
    Attached Images Attached Images     
    Last edited by Memford; 2013-03-13 at 23:24. Reason: added the word "two"

  2. #2
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    Absolute Radio 70s Testing Lossless

    At the moment, Absolute Radio 70s is testing lossless. http://icecast.as34763.net/absoluter....uk/a7flac.ogg in your media player

    When I began writing this follow-up post, at least one of the other streams was still encoded as lossy.

    I fully expect the RED (Radio Engineering Dept). at Absolute will have all streams rolling full soon. But again, as I've stated elsewhere, these streams won't be 24/7 unless more of us use them regularly.
    Last edited by Memford; 2013-03-13 at 23:26. Reason: added ", at"

  3. #3
    Senior Member
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    Oakville,Ontario,CA
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    Quote Originally Posted by Memford View Post
    At the moment, Absolute Radio 70s is testing lossless. http://icecast.as34763.net/absoluter....uk/a7flac.ogg in your media player

    When I began writing this follow-up post, at least one of the other streams was still encoded as lossy.

    I fully expect the RED (Radio Engineering Dept). at Absolute will have all streams rolling full soon. But again, as I've stated elsewhere, these streams won't be 24/7 unless more of us use them regularly.
    the ogg extension, is that just a container ? Also, when I captured some streams mplayer was reporting 128kbps.
    George

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  4. #4
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    Do the Math

    Quote Originally Posted by matka View Post
    the ogg extension, is that just a container ? Also, when I captured some streams mplayer was reporting 128kbps.
    I just took a 60-second foobar2000 capture (using foobar2000's handy converter component) of Absolute Radio 80s ( http://icecast.as34763.net/absoluteradio.co.uk/a8flac.ogg in your media player), and saved a 6.90 MB flac file. Taking 6900 kilobytes and multiplying by 8 bits/byte, we get 55,200 kilobits, then dividing by 60 seconds, we get 920 kilobits/sec.

    The ogg container carries the flac data.

  5. #5
    Senior Member
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    Oct 2005
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    Ireland
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    11,524
    Quote Originally Posted by matka View Post
    the ogg extension, is that just a container ? Also, when I captured some streams mplayer was reporting 128kbps.
    Some of the Absolute stream are reporting in the http icy header 128kbps and this is what mplayer reports. ICY header provides station info (e.g.name, metadata packing ) which can be used by players. It does not have to reflect what is actually broadcast but if wrong can confuse some players (e.g. player use bitrate to estimate cache size).

  6. #6
    Junior Member
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    Mar 2013
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    Take My Word for Nothing

    Quote Originally Posted by matka View Post
    Also, when I captured some streams mplayer was reporting 128kbps.
    Attached please find Media Player Classic MediaInfo text file.a8flac2013-03-17.flac.MediaInfo.txt

    https://archive.org/details/A8flac20130317 to download the 6.9 MB flac file mentioned above

    http://flac.sourceforge.net/document...eneral_options (testing the flac audio file in the FLAC command line)

    As you can see by the MediaInfo output, my estimate of 920 kilobits per second is a bit low.
    Last edited by Memford; 2013-03-18 at 13:20. Reason: changed "test" to "testing"

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