skipping playback - usb transfer issues?

[usernames_are_stupid]

I have been using rockbox on my sansa e250 for a year or so and its awesome compared to the builtin firmware.

I was happy with recent releases with the USB feature for file transfer.  But ever since I have had issues with skips. It jumps forward a couple of seconds and then it will play a few seconds then replay a few seconds..  At first I thought it was just a goofed up mp3, but I have had the problem off and on with lots of mp3s (music and podcasts).  I recently started using my second sansa e250 and am having the same problem.  Based on a few things I have found on the forums and bug tracking I have narrowed it down to the USB transfer as the issue.  It copies the files over but when I run an MD5 checksum on them, some of them are different.

When I copy files using rockbox and the usb cable, some of the files will have a different checksum then the source file on my hd.  I did this multiple times with the same files, and sometimes the files would be good, other times they would be different.  I did this with different groups of files and had similar results.

I ran the same tests using the default firmware and it went perfect every time.  No checksum errors.

The normal sansa I use an 8gb microsd, this new one I am just transferring to the internal memory.

any suggestions besides not transferring with the rockbox firmware?

[Llorean]

Tried a different cable? If the problem is this common for you, but nobody else is experiencing it at all (and assuming you're using a current build like everyone else is) the most likely concern is the hardware meaning your cable or your PC. Even though it works in the original firmware this might either be a fluke that it is right now, or it might be that Rockbox doing things slightly differently is illuminating a hardware issue before it affects the OF.

[Jomega1]

Ah! so glad to find this forum and this post, because this is exactly what I've been suffering from for some time on my Sansa c240 with RB 3.3.

I absolutely love the Rockbox and have been prepared to put up with this, but now it's just getting too much. Sometimes I even get parts of other albums completely mixed in with a track I am listening to. It does seem to happen more on the longer audio books than the shorter album tracks, and I only have .mp3s of various encodings, including VBR.

I too have an 8Gb SD card, but the problem happens on both the internal 1 GB card as well as the 8 Gb Micro SD card.

I believe I may have isolated the problem to some degree. When I load up my 8 Gb card on a card writer not in the slot of the Sansa, I don't appear to get any problems.

At least this is a solution for now.

I have tried loading the same MP3 both ways, and then copying the MP3s back onto my computer. The MP3 loaded up on the card writer is normal but the MP3 loaded via the RockBox has become corrupted with this stutter.   it's probably happens three or four times for every hour long track.

I don't think there is an issue with my cable as I have two and it has happened with both (unless I'm very unlucky!)

From now on I will do all of my loading via an independent card writer, but if anybody has any more ideas or a solution for being able to work directly with the 8 GB card in the Sansa without these corruptions I would be most pleased.

Many thanks indeed

[Llorean]

Please do not report issues with outdated versions of Rockbox. If at any point in your post you intend to say "I'm using Rockbox 3.3" (or indeed any version of Rockbox other than the most recent) stop writing your post, update to the newest version, see if the problem happens while using the newest version (in a situation like this - only files transferred with the newest version) then if it's actually happening with current code report it.