iPod 5.5G 80GB - audio playback pauses

[itsmusicinmyears]

Hello,

I have a serious issue on my rockboxed iPod. I switched from an iRiver H320 because of the higher amount of disk space, but now it doesn't make any fun at all ....
I'm using Ogg Vorbis files @ 192 kbps, and when i start audio playback, it interrupts every 10-20 seconds for about 5-10 seconds.
What seems quite ominous about that is, that this issue occurs not with every file i play. In fact, there are some files that ALWAYS can be played without stops and some files, that get ALWAYS interrupted. Quite weird, as I use only Ogg Vorbis files, no other file types involved.
I'm running my database loaded in RAM, which has, as I guess, no influence on that, as this issue happens not only at the beginning, but all the time I have my iPod turned on.

Thank you!

[Llorean]

What SVN revision is the build on your player?

[itsmusicinmyears]

I'm sorry, I haven't got the player with me, but I think it is one that has been published 2-3 weeks ago.

[Llorean]

As we say, quite regularly here including mentioning it in the guidelines, you need to be using a current build provided by us, not one from weeks ago.

As well, as a first step I'd recommend checking your disk for errors.

[jwalker1196]

I can come up with three things immediately that will cause this, all without it being a rockbox bug at all. Read them all before trying any, cuz they aren't in any particular order.

An good check to start with is "System-->Debug-->View buffering thread" while it's playing. Does one of the bars--the PCM one (top) as I recall--fill to a point, music plays, but it doesn't stay filled, and the pauses coincide with it's emptying? If it's not, then it's none of these three. (Conversely there are a few more, albeit uglier and more complex, things that will cause this as well.)

First, what program did you use to encode your OGGs? This was an issue I once had with AAC+ files, which don't play realtime and produce the same thing you talk about. (I thought they were regular AAC and was completely baffled for at least 5 or 10 minutes til I saw their bitrate was like 96 and realized they were the versions I'd transcoded for ringtones.) I know there's a rarely used but existent vorbis format that uses spectral band replication like AAC+. Maybe that's it. More likely, since I doubt rockbox would even touch OGG with SBR as it's not standard, the bitrate changes (it's almost certainly not true CBR 192, but more like ABR) aren't written to standard. Probably it's the encoder.

Second, as Llorean said, checking the disk can't hurt. Or it could even be fragmented so heavily as to cause this depending on the bitrate. My dad plays only WAV files (I can't get him to use compressed lossless no matter how hard I try) on the ipod I gave him, and he filled it completely and ran into this til I defragged it for him. But it's just as likely that your oggs could be just flaky... this symptom presents in both superfrag'd disks and music that won't play realtime.

So I'd plug it to your PC, analyze w/ defrag, see what comes up. After that I'd go.. START MENU-->run-->"X:\chkdsk /f" (where X is the drive letter of the ipod) and see what comes up. Don't screw up the slashes' directions.

Third, and most likely given OGG should decode fine... perhaps your boost got locked below a certain point... I forget how to play with that exactly, but unless you have good reason, "System-->debug-->cpu frequency" can cause weird things... If you go in there it can be locked to 24, 30, and 80 MHz by using the center button and scrollwheel, to where the top figure will say 24000000 or 30000000. Locked to 80 would just rape your battery but it'd decode fine, but locked to 24 or 30 will cause your problem... I just reproduced the problem that way as well. Putting it back to autoboost took some fiddling.. Safe answer would be to do a settings reset to default, but I clicked the center button again and scrolled til freq was 80 again and Boost Counter was zero, and it returned handling the boost on its own. (When on autoboost you'll see it bounce between 300000000 and 80000000 and the boost counter will uptick with it, all without your intervention.)

Feel free to PM me, I'll give you my email addy and you can attach one of the OGGs, I'd be glad to give it a look, if it's not the disk or the ipod's CPU being locked.

[Llorean]

I'd strongly recommend against defragging your disk until you've tried other solutions. There's no real reason this should cause a problem as you've described it.

If you're always playing the songs in the same order, and it always happens during the song playing during rebuffering there is a small possibility disk fragmentation could be the cause, but then you'd only see this immediately when you started playback, then again once every time the disk spins up (approximately once every 24 or 45 minutes depending on which amount of RAM you have). It wouldn't occur on the same songs unless you listen to songs in the exact same order every time.

As well, defragging can wear your disk a good deal, and shouldn't be necessary. You might wish to check disk fragmentation just to see if it looks bad, but it's very unlikely to cause a real problem in most cases.


As to the "boost" issue - your player will always automatically boost when needed. Unless you've been in the debug menu and set it otherwise, this isn't the problem. Even then, it will reset to automatically boosting every time you turn it on (these settings aren't saved) so if you've had the problem across multiple boots of the player, this isn't your issue.

[GodEater]

Just as an aside, if you really want to defrag your players disk, the best way to do it is actually to copy all the music off it, delete everything from the player's disk, and then copy it back on again. This doesn't wear the disk in the player nearly as much, and will likely prove massively quicker.