D2+ Firmware problems with ogg

[realsuamor]

Hi,

So far I've created many ogg files from my records or from other sources. I've never noticed any slight problems. I haven't checked every file but most are at 44100 Hz.

Now recently I recorded with a new device in much better quality. 88200/24bit. From there I directly converted to OGG-Vorbis with audacity using Ubuntu 12.04 (Precise).

The files created are played correctly on the system with both ogg123 and mplayer.

When copying them to my D2 with D2+ firmware (I'd estimate the last update about a year ago), the files were playback extremely slow . The (variable) bitrate is in average 168 kb/s.

Do you have any idea how to fix that problem ?

The records can be found here: http://archive.org/details/SummerCampConcertPerast

Thanks in advance

[CrowdAds]

[skip252]

This doesn't fall in the category of a firmware problem. There's nothing in the specs http://www.jetaudio.com/products/cowon/d2plus/ that say it can handle files encoded to the settings you used.

OGG:~Q 10, 44.1 KHz , Mono/Stereo

Is what's specified. Your files are outside that spec so them not decoding properly could be expected. The decoder isn't set to handle them as they are.

I've seen report from those with FLAC files that have higher bit depths and sample rates than what Cowons can handle that experience the same slow playback. The only solution for them was to convert and down sample the files. The resulting files played at the right speed.

With lossless files properly down sampled and dithered during conversion there shouldn't be an audible difference. Lossy to lossy conversion causes a loss in quality that can't be avoided.

I'm not sure if you'll hear a difference in your case. The only way to know would be for you to try it and listen.

[realsuamor]

Hi,

Thanks for clearing up, I didn't know about that limitation in the specs.
The reasons to make high quality oggs come from the original recording, I still have the original (uncut) but unfortunately my lossless (cut) FLAC files were stored as 16bit not 24bit (this is an audible difference - I don't know why audacity does convert it to 16bit and also haven't found any settings for that afterwards - edit: There is a button there on the export file dialog but so badly designed that it's easily overlooked).

Anyway it seems I have to look for more modern and faster cowon player (or just use my Samsung media player with rockbox) in the long run (unfortunately even C2 is limited to 44100 - not even 48khz are possible :-( )

[skip252]

I won't attempt to tell you you don't hear a difference between 88200 and 44.1. That type of thing usually deteriorates very quickly into an argument. Most people that say they hear the difference end that argument by saying "I know what I hear!". As I've never found a way to confirm what anyone else hears I won't suggest there isn't an audible difference when you listen.

I do suggest that you do some investigation as to why you shouldn't hear a difference. I found most of what you might want to look at in this article http://people.xiph.org/~xiphmont/demo/neil-young.html. I can't say it better than how it's said there so I'll just recommend you give it a read. I found it very informative. I hope you will also.

Rockbox should play the files but they would be resampled to 44.1. That's the only samplerate the playback engine can handle so everything that isn't 44.1 gets resampled. I'm surprised how many times someone has praised the excellent sound quality Rockbox produces for them playing files at samplerates other than 44.1. The Rockbox resampler uses linear interpolation and is considered to be pretty bad.

None of this is meant to tell you you're not hearing a difference or trying to tell you how you're going about producing your files is wrong. I believe everyone should create and listen to their music in the form that suits their needs and taste. I also believe that the more information they have, the better their choices can be for their needs.