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Clipping using Rockbox on Sansa e200

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Gregory:
Originally, all my music was ripped as wma, and for some reason, I never noticed any clipping. 

Then I switched to Ogg Vorbis because it was just flat out better; Gapless playback and smaller filesize were my main reasons for switching.  To create the ogg files, I ripped my music as wav files, and then converted them using oggdropXPd. Worked great. 
But then I started noticing the clipping.

  The clipping I am hearing is not severe, but noticable, and it only occurs during the louder parts of my loudest cds.  I thought it was the ogg vorbis, but a quick test rip to wma vbr at the highest setting produced clipping as well.  I tried the wav files directly from the cd too.  It was still clipping.

I have compared rockbox to the cd in a portable cd player, my computer, and get this, even the original Sansa e200 firmware.  Rockbox was the only variable that was causing the clipping.  A reset of all settings didn't help either.  I uninstalled the bootloader, formatted the e200, reinstalled the bootloader, and started to install the latest e200 Rockbox firmware, but at this time, the e200 zip file is broken (of course).

I have done my best to eliminate variables, but it seems that rockbox is to blame.  Trust me, I don't want to believe it either.

Oh, and here is a link to the the track I was trying during all this: (EDIT: Look at post #11)
(It's hosted on my computer so I can't guarantee that it will always be up and running.)

cpchan:
I am surprised that you didn't hear any clipping on your other equipment. After listening to it and taking a look at the waveform (attached is a screenshot with the "Find Clipping" and "Show Clipping" options in Audacity), I find a large amount of clippings in the file. The original source is a victim of the  "Loudness War"(http://en.wikipedia.org/wiki/Loudness_war).  I suggest you:

1. Replaygain your files with Vorbisgain: http://www.sjeng.org/vorbisgain.html

2. Turn on "Replaygain" and "Prevent Clipping" in Rockbox ("Settings"-> "General Settings"-> "Playback"-> "Replaygain".

To improve sound quality you might with to switch your encoder to AoTuV: http://wiki.hydrogenaudio.org/index.php?title=AoTuV. A quality level of -q 4 should do.

Charles

Gregory:
That is not the problem.

Here is a line-in recording of the same file being played in the sansa firmware and then in the rockbox firmware: http://74.167.183.209/docs/sansa_vs_rock.wav
Listen carefully after the begining of the chorus;  that's the worst part.

It was recorded with a Creative Audigy sound card using asio drivers and a program called reaper.  Sound qaulity should not be an issue here.  Besides, the clipping is quite distinct anyway.

Also, here is the wma (vbr highest bitrate) of the song so someone can compare the two firmwares for themselves. http://74.167.183.209/docs/04-Fading%20Away.wma
By the way, I hear something that sounds like clipping at the beggining of the song in both firmwares, so ignore that.

My sister has the same player and Rockbox as well.  I'll see how that goes.

saratoga:
I decoded it in rockbox and using the decoder in foobar2000:

max(pc-rb)
ans =
         3.0517578125e-005         3.0517578125e-005

On my Sansa, the output is identical to 15 bits for both channels.

If yours is not, then you've probably applied some additional gain in rockbox (via EQ, etc).

Llorean:
That just means the decoder isn't the problem. We know the Codec in the e200 has been a little problematic to configure properly, and may be to blame still.

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