iPod and Codecs

[_Spanky_]

I use a Rockbox'd iPod 4G. I've been noticing that MP3 easily eats up 100% of the CPU (80mhz). FLAC uses about 30mhz, OGG uses about 50mhz. MP3 makes it hard to play music with a nice equalizer, it can get choppy at times. FLAC and OGG never have this problem.

My question:
Would it be worth it to convert my MP3 library into OGG? Is OGG as good of quality?

For those that are going to say "Convert 1 song and compare it to a MP3", I can't. My music library is on my main computer that is, well, motherboard-less.

 

[Gow]

Transcoding lossy to lossy is never a good thing and if your intent is to go little CPU usage as possible, have you looked into Musepack (MPC)?

Remember Mp3 and Ogg use two entirely different methods to achieve similar results so that might hurt the transcoding process even further.

A third option is to use Lossy WAV combined with FLAC to utilize the wasted bits feature and produce some Lossy FLAC files. Depending on level chosen in the lossy wav process, you can end up with a transcodable file that is super transparent and half the size of a lossless file.

LossyWAV - Hydrogenaudio Knowledgebase

Going this route would allow you have high quality audio on the go and the ability to transcode. I have switched my entire desktop library over to it but use TAK instead of FLAC since I just use this audio on my computer only.

Though I have a backup of my entire audio collection on DVD in Lossless.

 

[_Spanky_]

Quote:

Originally Posted by Gow /img/forum/go_quote.gif have you looked into Musepack (MPC)?

Never heard of it although a new tab in firefox is heading towards google now.

Actually this is kind of pointless now, the lower the bitrate in MP3 the less CPU is used (big DUH there). I hope to have all my music in FLAC, the remaining MP3's will be like 128kbps for spoken word things.

What would be a better codec for 24-128kbps bitrate files?

I will check out Musepack, I like looking into different codecs

 

[Oya?]

I don't think I've got very much issues with MP3s on my Video with Rockbox. What sort of MP3s are you using anyway? I've got mostly VBR V0. I use EQs as well.

And I've not gotten to play around with OGG extensively but it looks like it performs more efficiently than MP3s even at lower bit-rates. The only reason I have never fully jumped on OGG is because MP3 is near-universally supported, OGG is not. I can't very well give any of my friends my music in OGG format, most of them wouldn't even know what it is nor have players that can play it. But for your purposes you might as well encode to OGG (supposing that you have the original lossless files).

 

[_Spanky_]

Quote:

Originally Posted by Oya? /img/forum/go_quote.gif (supposing that you have the original lossless files).

Never do

What I have is online if you catch my drift.

I would believe you don't have the issues with MP3 with using equalizer because I would hope apple would put a faster processor in each newer version of the iPod. I'm seriously considering doing a trial of like 20 songs and seeing the file size difference.

The reason why I chose OGG is because I believe iTunes can convert to that. Yes I use iTunes for organizing and syncing. Foobar2000 for playback!

Can anyone comment on size differences?

 

[shigzeo]

rockbox is an alternative firmware that hasn't complete access to all functions or builds of the ipod hardware. thus, though an ipod should playback mp3 perfectly in any format, with rockbox it is somehow stunted in its capability. eventually it may be fixed by rockbox. otherwise, you could try aac, ogg etc. but, coding again is not too good.

musepack is good (was amazing) but has not received many updates and is like md, quite dead im sure. i was only using that until 2002 when i found aac and mp3 to be easily up to snuff

 

[yeahx]

iTunes doesn't natively support Ogg. I dont even know if it will encode to ogg with plug ins even. Encoding to Ogg from mp3 would only make the sound worse anyways, which I think was already said.

 

[_Spanky_]

Quote:

Originally Posted by yeahx /img/forum/go_quote.gif iTunes doesn't natively support Ogg.

Alright, I don't have iTunes installed on this computer. Are there any worth-while codecs that iTunes can convert to natively?

I noticed that 128kbps mp3's were eating 100% of the cpu too =\

 

[Gow]

Musepack was dead but is under development again. Slow but progress is being made and they did release a newer build Musepack encoder and decoder.

Musepack SV8 beta is out - Musepack Forums

Check the last page of that thread for a newer build built by GCC and for Windows (or foobar2000 in this case).

However, another option if you are going 128kbps files, I would try Nero AAC with m4a file tag at -q0.4 and work your way down from there. Just convert new files from the source files and test if it sounds alright to you, if it does, go with it.

 

[shigzeo]

itunes can playback ogg and encode from it to mp3, aac, alac, wav, aiff if you install the plugin. same with flac. but it won't playback on the ipod yet.

probably vlc or some other app for iphone will come out soon to allow it

but for good lossy codecs: aac and mp3 are great ones to choose from if you have an ipod without rockbox. i believe it will play mp2 as well but im not sure why you would use that.

of course lossless is: wav, alac, aiff

it has all the major non-proprietary codec support so i find no reason to go for especially ogg. flac i can understand if you want a non-proprietary lossless but still, it is not got a huge hardware support other than those companies who have no dealings in music industry and who want to give their player the extra 'bang' of having a codec that costs nothing to support and gives them iffy audiophile drool support

 

[krmathis]

Quote:

Originally Posted by shigzeo /img/forum/go_quote.gif itunes can playback ogg and encode from it to mp3, aac, alac, wav, aiff if you install the plugin. same with flac. but it won't playback on the ipod yet.

Exactly!
Hence I recommend the OP to stick to an iTunes andiPod supported codec/format..

 

[_Spanky_]

I think I'll give AAC a shot and see the quality/size difference of my spoken word whatnots. Thanks for the help everyone

 

[ameyer17]

Try upgrading Rockbox, it's possible you have a build that's really old and isn't well-optimized.
My Sansa E260 (with build r18456-080908, a similar CPU, not using DSP) plays mp3 at about 50 MHz and ogg at about 42 MHz
Even with crossfeed, eq, and replaygain, ogg's at about 60 MHz and mp3's at about 66 MHz.

(Also, FWIW, they committed some code in the last week or so that should increase AAC decoding performance)

 

[_Spanky_]

Quote:

Originally Posted by ameyer17 /img/forum/go_quote.gif Try upgrading Rockbox, it's possible you have a build that's really old and isn't well-optimized. My Sansa E260 (with build r18456-080908, a similar CPU, not using DSP) plays mp3 at about 50 MHz and ogg at about 42 MHz Even with crossfeed, eq, and replaygain, ogg's at about 60 MHz and mp3's at about 66 MHz.

I try to keep my iPod updated every few days or so. I guess it's the difference in CPU cuz I don't have anything turned on (equalizer, crossfeed, dithering) and 320kbps mp3 will eat 100%/80mhz. Even with it eating 100% I can turn on equalizer and crossfeed but sometimes it gets jumpy.

I've decided to not use crossfeed or equalizer. I found some crossfeed settings on this forum by greenleaves and it's good but the bass is totally gone with it and his equalizer settings bring out way too much treble. To me, flat is best. More battery life

AAC decoder is good news, when I get my computer back I'm probably gonna be converting a lot of stuff over. Thanks for your help.

 

[_Spanky_]

Apparently the Rockbox team has been working on a fix for this for a while.

FS#9318: MP3 synthesis filter on COP

Committed today, this fix lowers the CPU amount needed to decode MP3's. It is in the current build, I suggest you update to see if there is a difference in your situation.