What are your thoughts about Windows Media Audio Lossless?

Discussion in 'Archived Threads 2001-2004' started by MikeH1, Feb 20, 2003.

  1. MikeH1

    MikeH1 Screenwriter

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    I recently went from WMP 8 to WMP 9 and I must say its a big improvement. A lot of the little things that bothered me about player 8 were fixed in player 9.

    I couldn't help noticing the format Windows Media Audio Lossless. I haven't actually heard a disc using this yet but is there a significant increase in sound quality from WMA 192? I hope there is... the file sizes are absolutely huge. Which leads me to my next question, is this basicly a uncompressed file? If it is, now I see why MP3's became so important years ago and why compressing songs were so needed.

    Has anybody else used WMAL? Is there anything I should know about when using it? (other than keeping an eye on how much hard drive space I have left)

    Thanks in advance.
     
  2. Dominik Droscher

    Dominik Droscher Supporting Actor

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    Losless means that it still has all the information of the original uncompressed file but in a heavily compressed form. Kinda like zip only faster I hope. So it will sound exactly like the CD you ripped the file from ... [​IMG] this may of course lead to a higher CPU usage as the music has to be decoded on the fly. I didn't try this yet but I guess it is better to first test if you system is up to the task.
     
  3. StephenL

    StephenL Second Unit

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    After reading the following claim by Microsoft I was very interested in using a PC with my home theater:

    "Windows Media Audio 9 Lossless, a new mathematically-derived lossless audio codec, delivers the ultimate audiophile performance. Because this technology is capable of compressing CD audio without loss into one-half to one-third of its original size, the listener will enjoy the original sound quality, bit-for-bit. It’s the ultimate “archival” codec for any music library."

    To test this claim I copied a DTS audio CD to my hard drive with Windows Media Player 9 using the Windows Media Audio Lossless codec. My main concern is bit-perfect playback of regular Redbook CDs that have been converted to the WMA Lossless codec and copied to my hard drive. I used a DTS CD as a tool to test the integrity of the audio data because DTS decoders are sensitive to any changes in the PCM bitstream. I converted the WMA Lossless files back to CD audio and copied them to a CD. The original DTS CD (and a copy make with Roxio) plays without any problems with my stand-alone DVD player connected via SPDIF to my receiver, which has a DTS decoder. The WMP copy plays only noise.

    WMP's volume leveling may be altering the data. I've noticed that WMA Lossless music played from my hard drive is louder than the original CD played from the CD drive. From the help file:

    "Volume leveling (also known as normalization) is applied to all tracks that the Player copies to audio CDs. This may cause the CD creation process to take longer, but it results in a more even volume level for all the tracks copied to the CD and prevents some tracks from sounding louder than others."

    There is another problem that prevents bit-perfect SPDIF output from the computer. This thread describes a problem with Windows KMixer and Sample Rate Conversion that corrupts the original PCM bitstream resulting in audible distortion during CD playback and the inability to play DTS CDs:
    http://www.avsforum.com/avs-vb/showt...hreadid=168792

    I want to use WMP 9 and the WMA 9 Lossless codec, but their performance is unacceptable until they achieve the bit-for-bit, lossless audiophile performance Microsoft claims.
     
  4. Camp

    Camp Cinematographer

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    Stephen,

    Just turn volume leveling off. Problem solved. Adding DSP functions can just add noise anyway.
    I don't know what went wrong with your ripping of the DTS disc. If it's a 5.1 disc you can't use the lossless codec (to my knowledge)...instead you have to use Microsoft's WMA Pro codec for 5.1 applications http://windowsmedia.com/9series/Demo...p=AudioQuality.

    My experience...

    I am in the process of ripping all my CDs to WMA Lossless. I was considering Monkey's Audio but the fact that I like WMP 9 so much and that Microsoft (like 'em or not) will no doubt fight to make their lossless codec a standard swayed me toward WMA lossless.

    My big test with WMA lossless was whether I could convert it back the the identical .wav file for burning back to CD (in the event I lost or damaged the original CD). It was also important that the .wav file be as identical as possible for accurate archival.

    I tested this by first ripping a CD to .wav files. I then ripped the same CD to .wma lossless and converted those .wma files to .wav using PowerAmp Converter (http://www.dbpoweramp.com/). I'll use one track as an example:

    The CD to .wav file size was 36447 KB.
    The .wma lossless file size was 22759 KB
    The .ape (Monkey's Audio lossless) file size was 22226 KB
    (usually I see closer to 50% compression from .wma & .ape lossless...I don't know why this track didn't compress more)
    The converted .wma & .ape files to .wav were each recognized by WinXP as identical to the original .wav at 36447 KB.

    Next, I used CDex's "Compare Two Files" feature to compare the original .wav from CD to the .wav's converted from .wma & .ape. The result of CDex's test was "No differences have been found" (the result was exactly the same for the .wma & .ape to .wav conversion. The track used in the example above showed a total difference of 2 bytes.

    Original .wav = 37321580 bytes
    Converted.wav = 37321582 bytes (converted from .wma and .ape lossless)

    A few other files showed a similar difference of 2 bytes but that isn't a large enough threshold for CDex to determine the files as "different"...and I challenged myself to hear the 2 extra bytes in the .wma to .wav file and just couldn't do it. [​IMG]

    In my book these are bit-for-bit duplicates of the original .wav. I cannot hear a difference between the either lossless codec and the original CD. Nor can I hear a difference between the original CD and the .wav files converted from either lossless codec.

    This is the most efficient and accurate way I have yet found to archive my CD collection. CD ripping with either lossless compression scheme is about twice as fast than with CDex and LAME. Files do take up a significantly greater amount of HD space but I purchased a 120GB drive just for this purpose.
     
  5. StephenL

    StephenL Second Unit

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    Camp, volume leveling is off, but apparently WMP9 always applies it to all tracks that the player copies to audio CDs. I guess you avoided this problem by using PowerAmp Converter. A DTS audio CD is encoded in the Redbook audio CD format, so it should work, and it's a good way to test for bit-perfect output or copies. Regardless of whether or not I can make bit-perfect copies, I haven't found any way to get bit-perfect output to my receiver using WMP9 because of the KMixer problem. I wanted to use a PC as a CD jukebox. I like WMP9 because it plays tracks continuously from one to the next, without gaps in between.
     
  6. Camp

    Camp Cinematographer

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  7. MikeH1

    MikeH1 Screenwriter

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    Thanks for the info guys. I think I'm going to use this WMAL but I'm not going to store any big files for long. A seperate 120 G. hard drive would be ideal for this and I'll have to look into it.

    How do I turn the volume levelling off? I looked in the options and couldn't find it.

    EDIT: Also, is this volume levelling actually effective in volume levelling? I have some "quiet" old skool rap discs and some very "loud" ones ... will this levelling actually work so I don't need to always be adjusting volume when playing it back? Thats one of my biggest peeves and I'll take a bit of a hit on sound quality for these compiled discs. After all, there only for the car...
     
  8. Wayne Bundrick

    Wayne Bundrick Cinematographer

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    I just tried converting a loooong WAV file (Pink Floyd's "Dogs") to WMA9 lossless and then back to WAV using dbPowerAmp. The files are not perfectly identical, but it was because of some minor differences in the WAV file format headers. I compared the pure PCM data contained in the data chunks, and they are identical.

    I also tried ripping a DTS CD to WAV, converting to WMA9 Lossless and back to WAV, then burning both the original WAV and the new WAV to CD. I burned the original WAV so that, if there was a problem in the process, I would be able to tell whether the codec was responsible. The DTS still worked for both tracks. I used Nero to both rip and burn.

    There might be other pieces of Microsoft stupidity such as Kmixer getting in the way of perfect output from the PC to the receiver, but WMA9 Lossless really is a lossless codec.

    By the way, the lossless codec really chokes on the already compressed DTS data. The WMA file was 89% of the size of the WAV file.
     

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