Battery benchmarks on ipod nano - results

[delt]

Hello all,

In my other thread about batteries, saratoga wrote:

Don't change the sample rate.  That'll eat up a lot more CPU power and reduce quality since rockbox has to convert it back to 44.1kHz for playback.

This night and the night before, i benchmarked this, and the results are odd: with 44.1KHz mp3's at 128kbps, the player lasts 9:10:47, and with 32KHz mp3's at 80kbps, it lasts 9:48:01. Perhaps because at 44KHz there's more information per second to decode?

I did these tests with the parametric EQ on, but using only the middle band, ie. the 4 other bands have zero gain. For comparing EQ on and off, i did some tests a few days ago, and the EQ does in fact eat up a lot of battery when using all 5 bands.

I don't think it would be such a good idea to copy/paste the entire battery_bench.txt files here, so i put em in my web directory:

http://www.deimos.ca/rockbox/

Hope this helps!

[saratoga]

Thats not really surprising.  The CodecPerformanceComparison wiki page says that going from 96k to 128k uses up 8.5MHz, which is certainly more then our linear interpolating resampler uses, so you're mostly just seeing the impact of bitrate on power consumption.

[soap]

For comparing EQ on and off, i did some tests a few days ago, and the EQ does in fact eat up a lot of battery when using all 5 bands.

http://www.rockbox.org/twiki/bin/view/Main/IpodRuntime
I would love to see your benchmark test with and without the EQ posted to that wiki page.

[delt]

Okie, just give me a few pointers (i'm a noob when it comes to editing wiki sites)

linear interpolating resampler

Honestly, even with linear resampling, the sound quality is quite excellent.

[Chronon]

Make sure you have a twiki account and write permission.  Choose the "Attach" link at the bottom of the page and click the FileAttachments link under Help for more info.

[soap]

Copying the appropriate line above where you are going to insert your entry is your best bet.  Then it is simply a matter of replacing the relevant fields with your info.  Otherwise you really need to pay attention to all the |s, as they are what makes the wiki table.