Rockbox Technical Forums

Rockbox General => Rockbox General Discussion => Topic started by: ElFishie on August 30, 2006, 01:37:21 PM

Title: Preferred Ogg quality setting
Post by: ElFishie on August 30, 2006, 01:37:21 PM
I wonder what your choices are for encoding ogg-files for use in rockbox.

Browsing other sites I found rare opinions suggesting less than q2 and a few over q7 mostly suggesting q10 right away. In between arguments spin around transparency (in portables), disk space and battery life.

My stuff is mostly q5, but this is not the result of any in-depth analysis. Rather a little non-ABX testing.

So what is your take?

edit:
would be nice to learn about the reasons that drove your choice:
- audio quality (maybe rockbox specific: high quality ogg had been reported to skip)
- file size
- battery life (maybe rockbox induced parsimony with battery life: earlier X5 builds had been too generous)
- insanity
- etc.
Title: Re: Preferred Ogg quality setting
Post by: Febs on August 30, 2006, 02:14:04 PM
As we discussed via PM, please edit your post to indicate specifically what you are asking with respect to Ogg and Rockbox.  Thanks!
Title: Re: Preferred Ogg quality setting
Post by: ryran on August 31, 2006, 07:18:39 AM
For any votes in the q8+ group, you can just go ahead and assume there's "insanity" involved. ;)
Title: Re: Preferred Ogg quality setting
Post by: senab on August 31, 2006, 07:24:01 AM
I personally use Q4.25 on aoTuV's Release 1 encoder.
Title: Re: Preferred Ogg quality setting
Post by: Siku on August 31, 2006, 10:44:54 AM
I use q2 on aoTuv's latest encoder. I know it's not transparent on every sample but in real life use, I can't tell the difference with the original audio. I even tried to ABX between q2 and original, but I failed. The main reason to use such a low bitrate is the file size.

Using anything above ~128kbps on DAP is an overkill. Most of the people couldn't tell the difference on 128kbps Vorbis even with very hi-quality HiFi system. But by all means, use what quality you ever want. It's just highly recommended to do some blind testing to see what quality is transparent for you.
Title: Re: Preferred Ogg quality setting
Post by: Llorean on August 31, 2006, 10:49:04 AM
Here's why I use Q6 (I'd use Q10 on an HD player if I didn't have FLAC so readily available, and enough space):

The placebo effect. I know for a fact I can't ABX at Q8 or higher. In fact lower than that, it often depends on problem samples. But, it *feels* like it's better quality. Even though I know logically that I cannot here a difference, a small part of my brain says "Yes, this sounds... cleaner than it does at lower quality. No, I DON'T know what cleaner means. Quit asking. It's better. Okay. Just trust me."

And so I listen at higher quality levels because I can afford the space and battery life costs without concern. Because even if I can't consciously hear the difference, it makes me a little bit happier.
Title: Re: Preferred Ogg quality setting
Post by: Deano on August 31, 2006, 11:01:55 AM
And so I listen at higher quality levels because I can afford the space and battery life costs without concern. Because even if I can't consciously hear the difference, it makes me a little bit happier.

I think that is commonly something we all suffer from. When I have messed about with .ogg I had similar issues and being paranoid. Think it is the way things go.

The human brain is annoying! hehe

Title: Re: Preferred Ogg quality setting
Post by: Llorean on August 31, 2006, 11:03:15 AM
Hey, if my brain is telling me it sounds better, even if it doesn't *really* sound better, it does for me. That's all that matters, that I think what I hear sounds better, so long as I don't try to force it on others. :)
Title: Re: Preferred Ogg quality setting
Post by: ryran on August 31, 2006, 12:15:32 PM
I hear that.

haha...er.. roight.
Title: Re: Preferred Ogg quality setting
Post by: dcr693 on August 31, 2006, 02:48:50 PM
OK, I'm going to risk a thorough spanking :) and admit that I encode at q0. Yes, q0. That's 64kbps average. I do it because I have a 1 gb iPod nano (got it as a free promo item) so I have to compress to fit a good amount in there.

Can I tell the music is compressed? Oh you bet. But I typically use the nano when I'm running and commuting to work on the subway. Under those conditions, I can make the sacrifice. I must say though, that ogg at 64k sounds surprisingly good for most music types. A typical CD encodes into 20-30mb. For classical music though, I can't encode at less than 96 or it's just unlistenable.

FWIW, I also have a 30 gb iPod Photo and I encode in mp3 using LAME and 128k ABR. I did some blink ABX testing and really could not tell the difference with my headphones. I don't have a particularly great hi-fi setup at home, so it didn't matter.
Title: Re: Preferred Ogg quality setting
Post by: CatBus on August 31, 2006, 03:14:22 PM
I didn't do a proper ABX test, but not too long ago I did do an informal multiformat, mutibitrate test before I started encoding my collection.  I burned compressed samples back to a CD, and did my testing on a stereo instead of a PC (to cut down on background noise and resampling issues), and used some decent headphones.  I read up online on problem samples, what to listen for, etc.  I fully expected to need nearly 200 kbps to get something that sounded EXACTLY like the source.

And then, for me, LAME MP3 VBR reached transparency at ~160kbps, which impressed me.  aoTuV Vorbis reached transparency at Q2 (~96kbps), which completely shocked me and I had to re-test to confirm I hadn't accidentally mislabeled my test CDs.

So given that choice, it was pretty clear which one to use!
Title: Re: Preferred Ogg quality setting
Post by: Siku on September 01, 2006, 10:50:09 AM
I guess all of you could distinguish between encoded and original file if you knew what to look for. Every codec leaves characteristic artefacts in audio, which can usually be distinguished with proper training. But I don't personally want to train my hearing. Ignorance is a bliss :)
Title: Re: Preferred Ogg quality setting
Post by: CatBus on September 01, 2006, 11:17:57 AM
I guess all of you could distinguish between encoded and original file if you knew what to look for. Every codec leaves characteristic artefacts in audio, which can usually be distinguished with proper training. But I don't personally want to train my hearing. Ignorance is a bliss :)

Don't be so sure.  I'd done careful training and preparation and came to the exact same conclusion as you: Q2 is transparent.  Maybe deafness is bliss :)
Title: Re: Preferred Ogg quality setting
Post by: jaybeee on September 01, 2006, 11:46:56 AM
q4

- sounds bloody great to me, so why go any higher.
- small files at that setting & so less impact on battery than with a higher setting
- as I rip all my CDs to flac I just transcode to Ogg Vorbis for DAP listening. So that allows me to choose a lower quality setting that if I were simply ripping to Ogg Vorbis from CD for archive purposes (I'd never do that anyway).

I use the Lancer (http://wiki.hydrogenaudio.org/index.php?title=Lancer) compiles btw. Ogg Vorbis encoding is fast, and with lancer it just flies.
Title: Re: Preferred Ogg quality setting
Post by: belly917 on September 01, 2006, 12:15:49 PM
I voted for q5 because it's the average of what I encode at.

But I will change that depending on what I'm encoding.

q4 for stuff I won't listen to all that much

q5 for most of my music

q5.5 or q6 for high rotation music
Title: Re: Preferred Ogg quality setting
Post by: senab on September 01, 2006, 04:43:12 PM
Don't be so sure.  I'd done careful training and preparation and came to the exact same conclusion as you: Q2 is transparent.  Maybe deafness is bliss :)

If I listen extremely closely, I can ABX q4.25 and WAV. But when I listen that closely I'm not enjoying the music so why bother?