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vbr vs. cbr
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AumShantiAum
IsraTrance Junior Member
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911
Posted : Jan 11, 2008 02:42
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hello, I wanted to know what exactly is the difference in quality between variable bit rate and constant bit rate in mp3s? I was always under the impression that a constant bit rate has better quality, but then i was looking it up online and many places say that having variable bit rate encoding is better for quality. Could anyone confirm that this is correct?
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Tomos
IsraTrance Full Member
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Posted : Jan 11, 2008 03:42
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The only advantage I know of with VBR is that it produces a better quality-to-space ratio. The less complicated parts of the music are encoded at a lower rate and when there is more happening the bitrate gets put back up. So there is a noticable difference in file size, yet minimal difference in quality between a CBR and VBR file of the same recording with equal maximum bitrate.
In these days of ma-hoooosive hard drives, why bother with anything but the highest constant quality.
Also some playback systems don't support VBR. Someone also told me that VBRs do strange things to his Pioneer CDJ800s, including the tempo being incorrectly reported (as you might expect), and some tracks not playing at all - or incorrectly. |
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AumShantiAum
IsraTrance Junior Member
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Posted : Jan 11, 2008 07:51
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so then does anyone know what happens when a vbr mp3 is converted to a wav file? does the resulting wav file sound the same as if it was a cbr file(maintains the minimal difference in quality)? |
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bukboy
Hyperboreans
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Posted : Jan 11, 2008 08:15
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both vbr and cbr are encoded bitstreams that represent wavs. and both can be decoded back into wavs. The main deciding factor for mp3 quality is encoded bitrate. high bitrate = high quality. (not vbr or cbr, but vbr is a bit more efficient than cbr)
for mp3 I would say high quality is 192kbit/s to 256kbit/s.
transparent quality is above 256kbit/s.
128kbit/s to 192kbit/s is medium.
The main difference between vbr(variable bit rate) and cbr(constant bit rate) is that the vbr encoder CAN choose the bitrate(within configured tolerance limits) to encode a section depending on complexity, so silence can be encoded at a minimal bitrate saving bits. Whereas a CBR encoder always uses the same bitrate for silence or complex sounds. |
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Nabla jpr
IsraTrance Junior Member
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Posted : Jan 11, 2008 10:17
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about the quality, theoretically if we convert an mp3 to wav the resulting quality shoudn't get worse..pratically I think it depends on the decoding algorithm...
data in the mp3 format are encoded so we need to decode (and there are many ways to decode I guess) this data to obtain the waveform.
So imo it might be that the quality get worse if reconvert mp3 to wav, but I've never tried..
Nabla j
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UnderTow
Started Topics :
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1448
Posted : Jan 11, 2008 10:35
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Nabla, the quality doesn't get worse during decoding but rather during encoding. That is when part of the information in the original wave file gets discarded.
Of course some decoders might not be properly implemented so they might cause some more degradation but that is a problem with the decoder itself and not with the principle of decoding.
UnderTow |
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acidkills
IsraTrance Junior Member
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Posted : Jan 11, 2008 11:22
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Nabla jpr
IsraTrance Junior Member
Started Topics :
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Posted : Jan 11, 2008 13:12
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UnderTow, it's exactly what I was saying..I was refering to the way the decoder has been implemented and not process itself( the decoder implement a synthesis filter-bank and Inverse Modified Discrete Cosine Transform so it depends how you implement these functions)
and because there many mp3 encoder with different implementation(and quality) so there are many decoder
but I guess the last test is to listen
Nabla j |
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bukboy
Hyperboreans
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40
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803
Posted : Jan 11, 2008 15:03
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at 320kbps, considering that uncompressed was is 1411 kbps, the compression is only 4:1. At which point people start asking whether it isnt better to use a lossless encoder like ape, which generally gets 2:1.
If ur not gonna use mp3 at around 224 kbps or less u should ask urself whether u should b using mp3 at all. |
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AumShantiAum
IsraTrance Junior Member
Started Topics :
27
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911
Posted : Jan 11, 2008 22:30
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good stuff thanks for all the input people. i think ill just try to stick with 320kbps CBR. cheers! |
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AumShantiAum
IsraTrance Junior Member
Started Topics :
27
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911
Posted : Feb 2, 2008 02:35
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had to bring this up again. if vbr mp3s can be re converted into wavs, wats to stop a person from downloading all these free vbr albums on the internet and then using them to dj? because ive been told that if you use all these downloaded releases to mix with that it doesnt sound as good as orginal cd releases. is this true? |
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Tomos
IsraTrance Full Member
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Posted : Feb 2, 2008 03:39
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You can convert VBR to Wav if you want. That'll overcome the beat counter issue on pioneers.
Nobody will hear the difference if they are well encoded and at highest quality.. especially on a club rig.
But personally I think DJing with stolen songs is just about the lowest of the low. Talk about making your money off of other people, at the very least with cracked software you're still put time and effort into your artwork. But just about anyone can download 200 songs and mix them with some software. Just doesn't seem like much passion in it.
Average DJs are two-a-penny probably for just this reason. |
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AumShantiAum
IsraTrance Junior Member
Started Topics :
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Posts :
911
Posted : Feb 2, 2008 10:33
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man for sure using downloaded music to dj, and then earn money for that djing, thats criminal shit. and mixing with software on computers is just to damn easy, its like driving an automatic transmission vs. a manual trans. but of all the psy djs out there what % do u think are using original cds or downloaded material they paid for? |
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Tomos
IsraTrance Full Member
Started Topics :
84
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Posted : Feb 2, 2008 15:01
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If they are well known DJs or producers then they will often get given tracks by their friends or sent free demo CDs to play, plus their own stuff.
Considering how many bedroom DJs there are now that are trying to get into playing out, probably a large percentage.
Its kinda sad that the general listener doesn't really pay for their music, then at a club the music hasn't been paid for and the producers do it because they love it.
The whole money for music thing is an endless debate, but a little public appreciation goes a long way in my book. |
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acidkills
IsraTrance Junior Member
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Posted : Feb 3, 2008 21:51
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Quote:
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On 2008-02-02 02:35, ohmshantiohm wrote:
had to bring this up again. if vbr mp3s can be re converted into wavs, wats to stop a person from downloading all these free vbr albums on the internet and then using them to dj? because ive been told that if you use all these downloaded releases to mix with that it doesnt sound as good as orginal cd releases. is this true?
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And why would you convert to wav and play that? I mean playing with serato scratch is all in mp3.. I dont use audio cd at all.. If I would I would had to make separate room for all that stuff.. I converted all my cds to mp3.. 320 kbps, no joint, or split stereo, only true stereo does it for me..
 http://www.myspace.com/djacidkills
http://soundcloud.com/acidkills/dropbox |
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