Skip to main content
Topic: VBR is a battery killer, fact or myth? (Read 45314 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

VBR is a battery killer, fact or myth?

The only reason I have not made a switch to MP3 VBR for my Dell DJ 20 gig is concern over whether or not a VBR mp3 will consume more power than a CBR file, say 128kbps. I searched all over the net for answers to this question, yet returned no results. If anyone has an Ipod or such and knows the answer to this question, I would appreciate any responses. Thanks.

VBR is a battery killer, fact or myth?

Reply #1
It won't use more battery then CBR of the same average bitrate.  Higher bitrate, CBR or VBR, will drain battery faster.

Though the difference is not very large on most players.

VBR is a battery killer, fact or myth?

Reply #2
I got the feeling, CBR is the better choice.

VBR is a battery killer, fact or myth?

Reply #3
There is a difference.

In my Rio Karma, plain CBR plays for about 1 hour more.

In my SonyEricsson W800 plain CBR plays for about 1 hour more.

I use LAME V5 and V4 for VBR and 128 or 160 for CBR

That is just my personal experience.
I'm the one in the picture, sitting on a giant cabbage in Mexico, circa 1978.
Reseñas de Rock en Español: www.estadogeneral.com

VBR is a battery killer, fact or myth?

Reply #4
Quote
I got the feeling, CBR is the better choice.
[a href="index.php?act=findpost&pid=365243"][{POST_SNAPBACK}][/a]


Please don't make useless posts.

VBR is a battery killer, fact or myth?

Reply #5
Quote
There is a difference.

In my Rio Karma, plain CBR plays for about 1 hour more.

In my SonyEricsson W800 plain CBR plays for about 1 hour more.

I use LAME V5 and V4 for VBR and 128 or 160 for CBR

That is just my personal experience.
[a href="index.php?act=findpost&pid=365247"][{POST_SNAPBACK}][/a]


Is there some data missing here, or did I miss something?

VBR is a battery killer, fact or myth?

Reply #6
Quote
Quote
There is a difference.

In my Rio Karma, plain CBR plays for about 1 hour more.

In my SonyEricsson W800 plain CBR plays for about 1 hour more.

I use LAME V5 and V4 for VBR and 128 or 160 for CBR

That is just my personal experience.
[a href="index.php?act=findpost&pid=365247"][{POST_SNAPBACK}][/a]


Is there some data missing here, or did I miss something?
[a href="index.php?act=findpost&pid=365257"][{POST_SNAPBACK}][/a]

There's definitely something missing

I remember a test.. I think it was on Misticriver (performed on an iRiver, off course). If I remember correctly, the difference in battery life was negligible, both on a flash and a HD player. I might be wrong, though.

VBR is a battery killer, fact or myth?

Reply #7
usually with VBR, the file size is a little bigger, which may require more HDD usage on a player with an HDD, on a flash player, it wont make much of a difference.

VBR is a battery killer, fact or myth?

Reply #8
Quote
It won't use more battery then CBR of the same average bitrate.  Higher bitrate, CBR or VBR, will drain battery faster.

[a href="index.php?act=findpost&pid=365231"][{POST_SNAPBACK}][/a]


The more useful comparison would not be which of CBR vs VBR uses less power at the save average bitrate, but at the same quality.  (spend the rest of the thread speculating on that ratio, unless you can divine it from one of the listening tests)

VBR is a battery killer, fact or myth?

Reply #9
Quote
Quote
Quote
There is a difference.

In my Rio Karma, plain CBR plays for about 1 hour more.

In my SonyEricsson W800 plain CBR plays for about 1 hour more.

I use LAME V5 and V4 for VBR and 128 or 160 for CBR

That is just my personal experience.
[a href="index.php?act=findpost&pid=365247"][{POST_SNAPBACK}][/a]


Is there some data missing here, or did I miss something?
[a href="index.php?act=findpost&pid=365257"][{POST_SNAPBACK}][/a]

There's definitely something missing

I remember a test.. I think it was on Misticriver (performed on an iRiver, off course). If I remember correctly, the difference in battery life was negligible, both on a flash and a HD player. I might be wrong, though.
[a href="index.php?act=findpost&pid=365272"][{POST_SNAPBACK}][/a]


That is what I was trying to say. Both units usually run for 10-15 hours. So 1 hour is negligible. And one is flash based and the other one is HD-based.

I think it has more to do with the file size. And I correct?

But... remember the problem with the skipping playback on iPods? That has something to do with bitrate and battery life. Doesn't it?
I'm the one in the picture, sitting on a giant cabbage in Mexico, circa 1978.
Reseñas de Rock en Español: www.estadogeneral.com

VBR is a battery killer, fact or myth?

Reply #10
back in the days when I had an iPod mini I conducted some tests and postet the results somewhere in this forum.

There wasn't any difference in mp3 VBR or CBR. In fact, the bitrate didn't even matter. So if you played a 32kbps CBR file or a 300kbps VBR file, the CPU clock speed was the same. The only difference was when using AAC, which used more CPU power and therefore drained the battery faster, but that wasn't the question
--alt-presets are there for a reason! These other switches DO NOT work better than it, trust me on this.
LAME + Joint Stereo doesn't destroy 'Stereo'

VBR is a battery killer, fact or myth?

Reply #11
I have completed numerous battery tests on both my 4G 40GB iPod and newer 5G 60GB iPod.  Apple rated the 4G at 12 hours while they rate the 5G at 20 hours, both for audio playback.  I used randomized playlists for these tests in which all the files were at the same bitrates/settings.  I tested the iTunes mpeg-4 AAC encoder (QuickTime 7) and Lame 3.87b2.  I made a playlist for 128kbps VBR mpeg-4 AAC, -V 5 --vbr-new, 128kbps CBR mpeg-4 AAC, 128kbps CBR mp3, -V 4 --vbr-new, 160kbps CBR mp3, -V 2 --vbr-new, 192kbps CBR mp3/mpeg-4 AAC.
Here are the results for my 4G iPod:
128kbps CBR mpeg-4 AAC              13.5 hours
128kbps VBR mpeg-4 AAC              13.47 hours
128kbps CBR mp3                          13.44 hours
-V 5 --vbr-new                                13.4 hours
160kbps CBR mp3                          13 hours
-V 2 --vbr-new                                12.5 hours
192kbps CBR mp3/mpeg-4 AAC      12.7 hours

Both the 192kbps CBR mpeg-4 AAC and mp3 formats lasted the same time on my 4G.

The following are the results for my 5G iPod:
128kbps CBR mpeg-4 AAC              23 hours
128kbps VBR mpeg-4 AAC              23 hours
128kbps CBR mp3                          22.78 hours
-V 5 --vbr-new                                23.1 hours
160kbps CBR mp3                          22.8 hours
-V 2 --vbr-new                                21.6 hours
192kbps CBR mp3/mpeg-4 AAC      21.7 hours

So, from my tests on my two iPods, there really is not a significant difference in battery life when comparing VBR bitrates to their CBR counterparts.  I received the longest battery life when using the mpeg-4 AAC format at the 128kbps CBR and VBR bitrates.  As for mpeg-4 AAC needing more cpu power, I feal that this is incorrect.  If anything, mpeg-4 AAC requires less cpu power on both the iPod and when running a cpu clocking program on my PC when playing back mpeg-4 AAC and mp3's.  However, a 300kbps VBR mp3 will require more cpu power than a 32kbps CBR mp3 simply because of the large bitrate differences.

    This is why the 4G and 3G iPods sometimes skip when playing back --alt-preset standard (-V 2 --vbr-new) mp3's.  The cpu implements power sving techniques.  When the bitrate of a song drastically jumps from 128kbps to 256 or 320kbps, the cpu must increase its processing power.  The 3G and 4G iPods sometimes have a hard time with this increase and processing power so a slight pause is heard in the track even though it is not in the source mp3.  Believe me, I have had a lot of experience with iPods and am a resident helper over at a iPod specific website and its forums.

    I can't speak for other DAPs as I haven't had any epxerience with them.  I can only state what I have worked with: 4G 40GB iPod, 5G 60GB iPod, and a couple Windows powered PDA's.

VBR is a battery killer, fact or myth?

Reply #12
Quote
I have completed numerous battery tests on both my 4G 40GB iPod and newer 5G 60GB iPod.  Apple rated the 4G at 12 hours while they rate the 5G at 20 hours, both for audio playback.  I used randomized playlists for these tests in which all the files were at the same bitrates/settings.  I tested the iTunes mpeg-4 AAC encoder (QuickTime 7) and Lame 3.87b2.  I made a playlist for 128kbps VBR mpeg-4 AAC, -V 5 --vbr-new, 128kbps CBR mpeg-4 AAC, 128kbps CBR mp3, -V 4 --vbr-new, 160kbps CBR mp3, -V 2 --vbr-new, 192kbps CBR mp3/mpeg-4 AAC.
Here are the results for my 4G iPod:
128kbps CBR mpeg-4 AAC               13.5 hours
128kbps VBR mpeg-4 AAC               13.47 hours
128kbps CBR mp3                           13.44 hours
-V 5 --vbr-new                                13.4 hours
160kbps CBR mp3                           13 hours
-V 2 --vbr-new                                12.5 hours
192kbps CBR mp3/mpeg-4 AAC       12.7 hours

Both the 192kbps CBR mpeg-4 AAC and mp3 formats lasted the same time on my 4G.

The following are the results for my 5G iPod:
128kbps CBR mpeg-4 AAC               23 hours
128kbps VBR mpeg-4 AAC               23 hours
128kbps CBR mp3                           22.78 hours
-V 5 --vbr-new                                23.1 hours
160kbps CBR mp3                           22.8 hours
-V 2 --vbr-new                                21.6 hours
192kbps CBR mp3/mpeg-4 AAC       21.7 hours

So, from my tests on my two iPods, there really is not a significant difference in battery life when comparing VBR bitrates to their CBR counterparts.  I received the longest battery life when using the mpeg-4 AAC format at the 128kbps CBR and VBR bitrates.  As for mpeg-4 AAC needing more cpu power, I feal that this is incorrect.  If anything, mpeg-4 AAC requires less cpu power on both the iPod and when running a cpu clocking program on my PC when playing back mpeg-4 AAC and mp3's.  However, a 300kbps VBR mp3 will require more cpu power than a 32kbps CBR mp3 simply because of the large bitrate differences.

     This is why the 4G and 3G iPods sometimes skip when playing back --alt-preset standard (-V 2 --vbr-new) mp3's.  The cpu implements power sving techniques.  When the bitrate of a song drastically jumps from 128kbps to 256 or 320kbps, the cpu must increase its processing power.  The 3G and 4G iPods sometimes have a hard time with this increase and processing power so a slight pause is heard in the track even though it is not in the source mp3.  Believe me, I have had a lot of experience with iPods and am a resident helper over at a iPod specific website and its forums.

     I can't speak for other DAPs as I haven't had any epxerience with them.  I can only state what I have worked with: 4G 40GB iPod, 5G 60GB iPod, and a couple Windows powered PDA's.
[a href="index.php?act=findpost&pid=365396"][{POST_SNAPBACK}][/a]


That's the kind of test we've been waiting for, nice job! 

(I've always thought Jojo talked crap about this anyway, heh)

VBR is a battery killer, fact or myth?

Reply #13
Quote
Here are the results for my 4G iPod:
(...)
[a href="index.php?act=findpost&pid=365396"][{POST_SNAPBACK}][/a]

Very nice test - thank you very much! 

Quote
     This is why the 4G and 3G iPods sometimes skip when playing back --alt-preset standard (-V 2 --vbr-new) mp3's. The cpu implements power sving techniques.  When the bitrate of a song drastically jumps from 128kbps to 256 or 320kbps, the cpu must increase its processing power.

Therefore, AAC VBR shouldn't be free of suttering issues on iPod. That's maybe why Apple's VBR is so lymphatic compared to other VBR encoders/format and doesn't offer sudden huge disparities in bitrate.

VBR is a battery killer, fact or myth?

Reply #14
Great test. 5-7% difference between 128 / 192k and another reason to ditch CBR for good.
wavpack 4.8 -b3x6c

VBR is a battery killer, fact or myth?

Reply #15
Quote
...
Very nice test - thank you very much! 


Therefore, AAC VBR shouldn't be free of suttering issues on iPod. That's maybe why Apple's VBR is so lymphatic compared to other VBR encoders/format and doesn't offer sudden huge disparities in bitrate.
[a href="index.php?act=findpost&pid=365416"][{POST_SNAPBACK}][/a]


I personally haven't had any experience with using VBR mpeg-4 AAC encoders other than the tracks that I downloaded off of the iTunes music store or ripped with iTunes/QuickTime.  The Nero VBR mpeg-4 AAC encoder seems to be more VBR than the iTunes VBR option.  My 4G didn't have any problems with VBR mpeg-4 AAC tracks but again, I didn't try Nero's VBR mpeg-4 AAC encoder.  I imagine that there could be a problem with Nero's VBR mpeg-4 AAC encoder on 4G and 3G iPods if the bitrates fluctuate as in the Lame VBR presets.  Then again, mpeg-4 AAC requires less processing power (assume about 20% less when compared to mp3) to decode so this problem may not come up.  I will have to try this while I still have my 4G.

The 5G iPod is completely free of these VBR mp3 skipping problems.  Even the problematic tracks that I downloaded off of a past thread here were skip free.  This is most likely due to Apple using a more powerful processor, better battery saving techniques, and changes in firmware.

I appreciate the thanks and glad that I could help.

Edit:  Yes, I think that advancements in recent DAP's make it so that VBR encoding is as viable an option as CBR encoding especially with nominal differences in battery life.  High RAM buffer capacities are making players more ideal to play back high bitrate VBR files.  The 5G 60GB iPod has 64MB of buffer alone.

Edit: Spelling

VBR is a battery killer, fact or myth?

Reply #16
To see if strong AAC bitrate variation may cause playback problems on iPod on exceptional case, I mixed two files (simple crossfading) and encode the result with Nero 3.2.0.15 "fast" mode, which is very sensitive with some specific signal (tonal or continuous moments).

The sample is downloadable >>here<<


I made an bitrate graph:




EDIT: if someone could take a look, I don't have any iPod.
EDIT2: the first part is a quiet piano passage and the second correspond to a bagpipe.

VBR is a battery killer, fact or myth?

Reply #17
Thanks guruboolez, I will have to check that out.  Unfortunately I don't have the internet at home and will have to wait until Tuesday when I get back in the office to download it.  Still, it is worth trying.

VBR is a battery killer, fact or myth?

Reply #18
Quote
I have completed numerous battery tests on both my 4G 40GB iPod and newer 5G 60GB iPod.  Apple rated the 4G at 12 hours while they rate the 5G at 20 hours, both for audio playback.  I used randomized playlists for these tests in which all the files were at the same bitrates/settings.  I tested the iTunes mpeg-4 AAC encoder (QuickTime 7) and Lame 3.87b2.  I made a playlist for 128kbps VBR mpeg-4 AAC, -V 5 --vbr-new, 128kbps CBR mpeg-4 AAC, 128kbps CBR mp3, -V 4 --vbr-new, 160kbps CBR mp3, -V 2 --vbr-new, 192kbps CBR mp3/mpeg-4 AAC.
Here are the results for my 4G iPod:
128kbps CBR mpeg-4 AAC               13.5 hours
128kbps VBR mpeg-4 AAC               13.47 hours
128kbps CBR mp3                           13.44 hours
-V 5 --vbr-new                                13.4 hours
160kbps CBR mp3                           13 hours
-V 2 --vbr-new                                12.5 hours
192kbps CBR mp3/mpeg-4 AAC       12.7 hours

Both the 192kbps CBR mpeg-4 AAC and mp3 formats lasted the same time on my 4G.

The following are the results for my 5G iPod:
128kbps CBR mpeg-4 AAC               23 hours
128kbps VBR mpeg-4 AAC               23 hours
128kbps CBR mp3                           22.78 hours
-V 5 --vbr-new                                23.1 hours
160kbps CBR mp3                           22.8 hours
-V 2 --vbr-new                                21.6 hours
192kbps CBR mp3/mpeg-4 AAC       21.7 hours

So, from my tests on my two iPods, there really is not a significant difference in battery life when comparing VBR bitrates to their CBR counterparts.  I received the longest battery life when using the mpeg-4 AAC format at the 128kbps CBR and VBR bitrates.  As for mpeg-4 AAC needing more cpu power, I feal that this is incorrect.  If anything, mpeg-4 AAC requires less cpu power on both the iPod and when running a cpu clocking program on my PC when playing back mpeg-4 AAC and mp3's.  However, a 300kbps VBR mp3 will require more cpu power than a 32kbps CBR mp3 simply because of the large bitrate differences.

     This is why the 4G and 3G iPods sometimes skip when playing back --alt-preset standard (-V 2 --vbr-new) mp3's.  The cpu implements power sving techniques.  When the bitrate of a song drastically jumps from 128kbps to 256 or 320kbps, the cpu must increase its processing power.  The 3G and 4G iPods sometimes have a hard time with this increase and processing power so a slight pause is heard in the track even though it is not in the source mp3.  Believe me, I have had a lot of experience with iPods and am a resident helper over at a iPod specific website and its forums.

     I can't speak for other DAPs as I haven't had any epxerience with them.  I can only state what I have worked with: 4G 40GB iPod, 5G 60GB iPod, and a couple Windows powered PDA's.
[a href="index.php?act=findpost&pid=365396"][{POST_SNAPBACK}][/a]


Agreed.  There is no significant difference between VBR and CBR.  What makes the most sense is turing off the EQ and backlight.  Also, it helps to have small playlists.

VBR is a battery killer, fact or myth?

Reply #19
Quote
usually with VBR, the file size is a little bigger
[a href="index.php?act=findpost&pid=365338"][{POST_SNAPBACK}][/a]

That's nonsensical.

VBR is a battery killer, fact or myth?

Reply #20
Quote
Quote
usually with VBR, the file size is a little bigger
That's nonsensical.
it depends on the source but I guess with most modern mainstream music audioflex is right.
Nothing but a Heartache - Since I found my Baby ;)

VBR is a battery killer, fact or myth?

Reply #21
Quote
Quote
...
Very nice test - thank you very much! 


Therefore, AAC VBR shouldn't be free of suttering issues on iPod. That's maybe why Apple's VBR is so lymphatic compared to other VBR encoders/format and doesn't offer sudden huge disparities in bitrate.
[a href="index.php?act=findpost&pid=365416"][{POST_SNAPBACK}][/a]


I personally haven't had any experience with using VBR mpeg-4 AAC encoders other than the tracks that I downloaded off of the iTunes music store or ripped with iTunes/QuickTime.  The Nero VBR mpeg-4 AAC encoder seems to be more VBR than the iTunes VBR option.  My 4G didn't have any problems with VBR mpeg-4 AAC tracks but again, I didn't try Nero's VBR mpeg-4 AAC encoder.  I imagine that there could be a problem with Nero's VBR mpeg-4 AAC encoder on 4G and 3G iPods if the bitrates fluctuate as in the Lame VBR presets.  Then again, mpeg-4 AAC requires less processing power (assume about 20% less when compared to mp3) to decode so this problem may not come up.  I will have to try this while I still have my 4G.

[a href="index.php?act=findpost&pid=365431"][{POST_SNAPBACK}][/a]


AAC-LC uses less processing power then MP3?  I'd always heard the opposite.  At very least I would expect similar requirements given the similarities of the codecs.  20% less seems unreasonable.

Quote
The 5G iPod is completely free of these VBR mp3 skipping problems.  Even the problematic tracks that I downloaded off of a past thread here were skip free.  This is most likely due to Apple using a more powerful processor, better battery saving techniques, and changes in firmware.


The 5G uses the same processor as the Mini Rev2, which incidently had the biggest problem with skipping.

VBR is a battery killer, fact or myth?

Reply #22
Quote
Quote
Quote
usually with VBR, the file size is a little bigger
That's nonsensical.
it depends on the source but I guess with most modern mainstream music audioflex is right.
[a href="index.php?act=findpost&pid=365450"][{POST_SNAPBACK}][/a]


Bigger then what?  128k CBR verses -V 3?  Sure.  APS verses 320 CBR?  No way.

The statement is nonsensical since it depends on what settings are used.

VBR is a battery killer, fact or myth?

Reply #23
There's also the fact that 128kbps CBR is lower quality than say, 130kbps VBR. So even if the bitrate was slightly higher, you're trading off a lot more than just 2kbps of size.

VBR is a battery killer, fact or myth?

Reply #24
Quote
Therefore, AAC VBR shouldn't be free of suttering issues on iPod. That's maybe why Apple's VBR is so lymphatic compared to other VBR encoders/format and doesn't offer sudden huge disparities in bitrate.
[a href="index.php?act=findpost&pid=365416"][{POST_SNAPBACK}][/a]

Are you speculating that Apple needs to significantly alter the iPod hardware and decoding software to make it more reliable for playback of files with large frame size fluctuations? And, hence the current frame size restrictions in iTunes AAC VBR mode are designed to limit possible fluctuationes from very low to very high frames, and so the files that work reliably on a limited (flawed?) decoder?

(I say this as an iPod owner perfectly very pleased by the quality of iTunes AAC VBR.)

 
SimplePortal 1.0.0 RC1 © 2008-2019