INTERACT FORUM
More => Old Versions => Media Center 11 (Development Ended) => Topic started by: modelmaker on September 08, 2003, 08:34:25 pm
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what's the difference in quality between an mp3 ripped at "best" VBR and 320?(other than the size of the file)
I don't seem to hear a difference, Jay.
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Hi Jay,
The max bitrate for a frame in mp3 is 320 kb/s. Then when you encode files in CBR 320k, all frames (small chunk of music) are encoded at 320 even those with very quite music or silence ! It's then, IMHO, an "awful waste of bits"
In VBR modes, each frame will be encoded with the most appropriate bitrate up to 320, depending on the complexity of its content. Therefore the file size will be much smaller for a similar quality.
My humble opinion is then to always choose mp3 VBR. Well, unless you wanna try another (better) format like mpc or ogg ! ;)
more information on encoding, listening tests and other stuff for specialists can be found on http://www.hydrogenaudio.org/.
Have a nice day,
Christian
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That was what I thought, thanks for the confirmation Christian.
I've been using vbr for quite a while, but I've been seeing a lot of 320 mp3s lately and just wanted to confirm that I wasn't losing any quality between these two.
High quality mp3s ok for me and my aging ears for jukebox function. More demanding and favorites that I listen to criticaly and/or loud, I save as ape files. I also burn everything of value (to me) to CD (wav and data), just in case my main and backup HDs were both to kick the bucket.
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Now I can't quote chapter and verse as to where I saw it, but I have seen some experts out there (like some of the contributors to the lame source), that will also tell you that it is theoretically possible that a Joint-Stereo VBR can exceed a 320 CBR for certain known awkward cases that mp3 has problems representing correctly. I believe for instance that the "--alt-preset" options for lame are specirally tuned partially to maximise quality that is not possible with CBR.
This adds up so that you may actually notice a better result for some VBRs.
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I believe for instance that the "--alt-preset" options for lame are specirally tuned partially to maximise quality that is not possible with CBR.
The --alt-presets use some "code-level tweaking" that is not accessible by using the normal LAME command line switches. Also, I believe this is only true for the VBR --alt-preset settings (standard and extreme). Settings like --alt-preset cbr 320 do not use the code-level tweaking.
Rob
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IIRC, the highest quality LAME encoder preset is "--alt-preset insane" which is 320 kbit/second, CBR, and specially tweaked like the other alt presets.
Here's the Hydrogen Audio List of recommended LAME settings (http://www.hydrogenaudio.org/index.php?act=ST&f=15&t=203&)
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There truly is no comparison, just by nature of process a 320 CBR will always be higher quality than any VBR file. Yes, even silence will be encoded at 320, but that's some high quality silence, no? ;)
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How big a song in Lame 320?
Much less than in APE?
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I believe 320 CBR is about a 5-1 ratio. APE is about 2-1.
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I heard that mp3s of <=192 uses a different logarithm than 320? I have some 192s that sound pretty decent (good bass).
When I encode mp3s, I always use Lame VBR but I can tell the difference between mp3s and ape files. That's why I use ape for my complete albums.
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If i was looking to good sound ,ready to use as much room than a 320 mp3 but not as much as APE ,in this case i would use the higger setings for MPC.
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Now I can't quote chapter and verse as to where I saw it, but I have seen some experts out there (like some of the contributors to the lame source), that will also tell you that it is theoretically possible that a Joint-Stereo VBR can exceed a 320 CBR for certain known awkward cases that mp3 has problems representing correctly. I believe for instance that the "--alt-preset" options for lame are specirally tuned partially to maximise quality that is not possible with CBR.
This adds up so that you may actually notice a better result for some VBRs.
Actually, you can use some command line decoders and the right encoders and have bitrates that exceed 600 kbps.
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I like VBR just for the size savings. I keep everything on my hard drives in APE format.
When I need something for the portable or for a car system I use LAME to encode using this option:
--preset extreme --scale 1
If you look at the console while it is encoding you will see that it is encoding from 32 to 320 as needed.
The --scale 1 just leaves the levels at par for better results with ReplayGain
BTW- --alt-preset cbr 256 does give you the preset tweaks but in CBR.
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BTW- --alt-preset cbr 256 does give you the preset tweaks but in CBR.
According to this (old) thread linked in the HA FAQ, the code-level tweaks are only used in the standard, extreme and insane presets.
http://www.hydrogenaudio.org/index.php?act=ST&f=15&t=3076
JohnV wrote:
Sure, there are different switches used for different bitrates, but those are not exactly code-level tweaks. Those are just normal preset alias settings implemented with different switches and bitrates, but which do not include actual code level tweaks like standard,extreme and insane.
Rob