Distortion and Crackles playing Ogg Vorbis files

Hello!
Well, I managed to get my Ogg files recognized by the Clip but now there are some strange sounds. When playing the files on the PC they sound completely clean but on the clip there is some distortion and “crackling” occuring. I don’t know.
I used foobar to encode them with Oggenc2.85 aoTuVb5.5 (Q4.5 and Q5).

Regards,
Jonas

i use foobar too with the same encoder but with -q8 and i have no problems at all

The Clip is said to have problems with Ogg files with quality less than q6.

Hi, thanks for your replies!

Well, it would be sad if this could not be fixed because Vorbis has got its strenghts especially at lower bitrates like 128… (which would be Q3 or Q4). At higher rates the difference to Lame MP3 isn’t too big. Hm. Now I have to decide if I will stick with MP3 V4 or switch to bigger Vorbis Q6 files.
Well hopefully there will be a fix in the next firmware soon.

Regards,
Jonas

the main difference between ogg and mp3 is that ogg doesn’t use lowpass filter. so with ogg you have all the original frequencies. ( 192kpbs mp3 usually cuts off off on 16khz or 18khz ) but ogg has lower bitrate and that could actually decrease the overall quality. it’s a trial and error thing… whatever sounds better to your ear :slight_smile:

Thank you for your replies!

@fuflo wrote:
the main difference between ogg and mp3 is that ogg doesn’t use lowpass filter. so with ogg you have all the original frequencies. ( 192kpbs mp3 usually cuts off off on 16khz or 18khz ) but ogg has lower bitrate and that could actually decrease the overall quality. it’s a trial and error thing… whatever sounds better to your ear :slight_smile:

 

Well I’m pretty sure that there is more than just the lowpass filter. I can’t agree with the bitrate argument since you can control the bitrate via the Q settings. There was a listening test in a German magazine some years ago (c’t) which included blindtests with “chosen” audiophiles who brought their own equipment and hundreds of readers. Ogg won, especially for the lower bitrates. 

Yes, there may be personal preferences but for me Ogg Q5 (transparent with my “on-the-go” headphones) is better than Lame MP3 V4 so I’m a bit sad that it doesn’t work on the clip.

Yes, OGG uses better compression methods, than mp3 (and it’s not the matter of the low-pass, which you can turn off in LAME).

OGG and AAC (the successor of the mp3 codec) are both better than the “old 'n rusty” mp3 :wink:

Using the same bitrate - they offer better sound quality

While maintaining the same sq - they weight less.

And finally - they are both extremely effecient with the lowest bitratrates. That is, using >128kbps - they are better than mp3, using <128kbps - they massacrate mp3 codecs :wink:

Given the 1.01.29a firmware, there is a problem with the Sansa Clip oggvorbis decoding that results in crackled audio on one or more output channels.

Shooting in the dark without a “real” scientific control variable, I will experiment…

Hypothesis [A]: Crackling audio is due to a particular vorbis encoder

Hypothesis [B]: Crackling audio is due to high/low bitrate

eshattow@zontar:/media/disk/MUSIC/BRC2008$ for i in *.ogg; do ogginfo “$i” > /tmp/vout/"$i".log; done

eshattow@zontar:/tmp/vout$ grep libVorbis *| cut -d’:’ -f2- | cut -d’ ’ -f3- | sort | uniq
libVorbis I 20011231 (1.0 rc3)
libVorbis I 20020701
libVorbis I 20020717 (1.0)
libVorbis I 20020717 (GTune 3, beta 1)
libVorbis I 20030909 (1.0.1)

eshattow@zontar:/tmp/vout$ grep Nominal\ bitrate * | cut -d’:’ -f2- | sort | uniq
Nominal bitrate: 112.001000 kb/s
Nominal bitrate: 112.015000 kb/s
Nominal bitrate: 128.000000 kb/s
Nominal bitrate: 128.003000 kb/s
Nominal bitrate: 160.003000 kb/s
Nominal bitrate: 160.032000 kb/s
Nominal bitrate: 192.003000 kb/s
Nominal bitrate: 192.032000 kb/s
Nominal bitrate: 212.003000 kb/s
Nominal bitrate: 256.006000 kb/s
Nominal bitrate: 96.001000 kb/s

So, I can test 5 encodings briefly and incompletely.

20011231 (1.0 rc3): Fail (192kb/s); Pass (192kb/s); Pass (160kb/s) Pass (112kb/s)

20020701: Pass (96kb/s)

20020717 (1.0): Pass (256kb/s); Pass, I think… sample music was from glitch genre (192kb/s); Pass (160kb/s); Pass (128kb/s)

20020717 (GTune 3, beta 1): Pass (212kb/s); Pass (192kb/s)

2003090 (1.0): Pass (192kb/s)

The ogginfo output of a file that exhibits these crackles on the .29a firmware:

eshattow@zontar:/tmp$ ogginfo -v Radiohead\ -\ nice\ dream.ogg
Processing file “Radiohead - nice dream.ogg”…

New logical stream (#1, serial: 4d6f4e6b): type vorbis
Vorbis headers parsed for stream 1, information follows…
Version: 0
Vendor: Xiphophorus libVorbis I 20011231 (1.0 rc3)
Channels: 2
Rate: 44100

Nominal bitrate: 192.032000 kb/s
Upper bitrate not set
Lower bitrate not set
User comments section follows…
    ALBUM=The Bends
    ARTIST=Radiohead
    DATE=1995
    GENRE=Other
    REPLAYGAIN_ALBUM_GAIN=-7.48 dB
    REPLAYGAIN_ALBUM_PEAK=1.11347675
    REPLAYGAIN_TRACK_GAIN=-5.81 dB
    REPLAYGAIN_TRACK_PEAK=1.04714048
    TITLE=(nice dream)
    TRACKNUMBER=06
Vorbis stream 1:
    Total data length: 5668416 bytes
    Playback length: 3m:53.093s
    Average bitrate: 194.545796 kb/s
Logical stream 1 ended

*Edit 2008-09-12* I found a file that is encoded with the rc3 libVorbis and at nominal 192kb/s rate which does pass the listening test. Weird stuff.

*Edit 2008-09-12* Also, I notice that the crackling happens mostly on the left channel with files that do not play properly. Disconnecting the left channel, the audio sounds (mostly) normal

Message Edited by lucent on 09-12-2008 06:42 PM

For the purposes of debugging ONLY there are two data files I am providing. One is an oggvorbis file that plays fine on the sansa clip, the other exhibits crackling noise on decode. Both files play without errors in the reference Xiph ogg123 decoder. I am providing these files in a password-protected zip archive (password = sansafix) so that the manufacturer may tell us what the problem is and if there is a possible fix: http://osclab.net/sansafix/sansa29a_vorbis_test.zip (14M)

 Hello  -

 I am also having this problem with my new 8gb Clip. Only it isn’t just with OGG files. It is happening with some flac files as well. And possibly also with Mp3 files. I haven’t had time to try MP3 yet.

 Anyway, I was listening to Amused To Death by Roger Waters and when it gets to the part where there’s an explosion in the recording, the clip plays this with a terrible crackling distortion. It happens in exactly the same spot with either OGG or flac. I’ve noticed it (to a lesser extent) on the peaks in other songs as well. 

 I have already updated the firmware so unless there was an update between last night and right now, that won’t do any good. This problem is in addition to the problem I posted about in another thread about some slight skipping in some songs. I really hope this is just a firmware thing that will be worked out. 

Message Edited by randomprecision on 03-07-2009 01:24 PM

I might have a similar problem on my fuze v2: lower bitrate oggs ar distorted, unless I set equalizer to flat/normal. Does that get rid of the problems on the clip as well? Kind regards, L’apomikt

I wanted to listen to the test files, but they are not availble.   I have a version 2 clip,  Firmware 2.xx.32F…    Something obvious but I didn’t see anyone list thier firmware revision…   I wanted to hear the files to see what you were experiencing. 

One thing to note on Ogg vs  MP3…   is Ogg takes 30-40% more battery power …  over mp3.    They had to clock the cpu faster to do the encoding for Ogg. 

Niko

O.O;   old post …  no wonder the test files are gone :P…   But now im wondering if the noise heard in lower qality Ogg files is still an issue with the CLIP,  and Fuse?

Niko