MPEG player slow video playback.

[Skeith]

Hi im new here. I recently installed rockbox on my Iriver H10 20GB after contemplating whether to risk my remaining 2 years of warrenty.

Anyway. I am overall impressed with the funtionality of this firmware over the iriver firmware. The layout is nice, custom themes are nice to have as the Iriver theme is boring. And its stable. No more worrying about the stupid iriver firmware freezing on me all the time. (I hate the firmware with a passion for many many reasons wich I wont get into or ill be ranting for a while).

So after getting rockbox running, a theme installed and replaced the backdrop with a quick but cool looking photoshop image I whipped up along with an Icon set. (lookin all fancy ) I decided to give the MPEG player a try.

So I converted a bunch of music videos to 160x128 100-300kbs VBR MPEG1 (framerate varried per video). They all played perfectly. No synch errors or anything. And I was quite surprized with the quality. So I tried a bit longer video. 11min robot chicken ep. plays perfectly fine.

Now for the big task. I converted a dvd I ripped to my laptop a while back to an MPEG stream. (the video being the matrix).
The first try was as follows.

-160x128 250Kbs CBR MPEG1 23.9fps. Ended up being just under 400MB, not bad.

Put it on the player and ran it. It played, no sync issues, so far so good. I let it run and after about 10 - 15 min of playback the video slows down but doesnt loose sync. Its only a teeny bit of a slow down but you can deffinately hear it in the audio.

So I tried encoding it again this time I tried a VBR as it would allow for a bit of a nicer image.
-160x128 100kbs-300kbs VBR 23.9fps MPEG1. Just under 400MB.

Same issue after about 10 minutes or so it slows down. I dont get it. I'd figure that the video would either play slow from the start or maybe loose sync. But no it just slows down. no sync loss at all!

Anyone have this problem or know the sollutoion to it.

I used TMPGenc to encode the MPEG1 stream.

Also does MPEG2 perform better than MPEG1 or about the same on rockbox? I dont have a working MPEG2 encoder right now and am wondering if its worth it to seek one out.

I realy wish I was able to program more than in basic so I could be able to contribute to this project. Never thought I'd be playing videos on my H10. Keep up the good work.

[gnu]

I've never tried longer videos, but mayme it's because of the rebuffering: after some minutes the RAM is filled with video data and it has to be emptied and refilled. But that's just a guess.

[Skeith]

Yeah I was also thinking it was along the lines of buffering. Could the H10s ram be too slow?
Im assuming there is no way to controll how much ram the buffer allocates.

[Llorean]

RAM wouldn't affect the playback speed, at all. Are you saying that the playback rate actually slows (a pitch change in the audio) or are you talking about frame skipping in the movie?

Does it clear up after about a minute or two?

[Skeith]

Yes it actually slows down, the pitch in the audio changes. The video stays in sync with the audio and it still plays just as smooth.

And I do have frame dropping enabled and frame rate limiting enabled.

The video plays fine on my PC too.

This is the weirdest thing ive encountered with videos before.

I just ripped another DVD to my computer, deinterlaced it, encoded to MPEG1 at 200kbs CBR and it still does the same after about 10 minutes.

Could it be a fault in TMPGEnc?

Im goint to try an MPEG2 If I can find a free encoder.

[Llorean]

Try using WinFF from our wiki (or VLC or mencoder, both also there)

[Skeith]

That did the trick!
Well with MPEG2 anyway. Didnt try MPEG1 yet.
I watched the video 40min in, encoded by WinFF and no slowing down!

I wonder what TMPGEnc was doing to the steam that made it do that. heh oh well.

Thanks for the help. I am very greatful.