Since I upgraded the firmware from PR1.1.1 to PR1.2 it seems that the video playback of DivX files got less smooth.

In PR1.1.1 the DivX video files played flawlessly, not a single frame drop, the panning scenes were perfect. I was using SiB for playback in PR1.1.1 because SiB played the DivX movies with packed B frames correctly and did not require unpacking of the B frames using e.g. MPEG4 Modifier.

In PR1.2 the same video file stutters in SiB a few times per second. It's quite subtle, it is only apparent when there are rapid panning scenes in the movie. I tried playing the DivX video file with packed B frames in SiB and got this issue. I also tried KMPlayer and Media Player on the file with unpacked B frames, with the similar result.

I then reflashed PR1.2 so that I had a clean device, installed just SiB and tried to play the video file in it. The playback was still jerky.

I also noticed that with PR1.2 the same slight stutter happens when playing the demonstration "9" movie file using Media Player. In the version of the movie included on the latest eMMC, it is slightly apparent in the sequence starting 2:11 and ending 2:14. In the version included in the previous version of eMMC, it can be observed in the zoom out sequence at the beginning of the movie (9 opening the window). I tested this with clean reflash of the device.

I downgraded the firmware back to PR1.1.1. I had to flash just the modem part of the firmware (cmt-mcusw) to PR1.2 in order to get the SIM card recognized (known issue). The video playback on PR1.1.1 device using SiB was now jerky (it used to be smooth using the original PR1.1.1 firmware with PR1.1.1 modem part – before messing with PR1.2). I wonder if the modem part could be the culprit. I believe it is not possible to downgrade the modem part of firmware from PR1.2 to PR1.1.1 (if you attempt to do this, the SIM card will not be recognized).

This issue does not seem to be related to the CPU utilization. On PR1.2, during the video playback the CPU was not 100% utilized. Subsequently, I also tried overclocking to 900 MHz and it did not help. (Using Titan’s enhanced kernel with stock settings did not help either.)

I am positive that I am trying to play the same files in PR1.2 as I was trying to play in PR1.1.1.

The issue does not seem to be related just to SiB or Mplayer because the video playback got less smooth in Media Player on N900 as well after upgrading to PR1.2.

The stuttering seems to be related to MPEG-4 movies in general (incl. DivX, Xvid) on my device using PR1.2.

When changing the firmware I always reflashed eMMC too. I used Maemo Flasher on Windows XP. The official PR1.2 firmware was used, not the leaked one.

Does anyone know how to fix this? Is it just my device or are other devices with PR1.2 affected too? Does anybody know how to revert to PR1.1.1 including the modem part of the firmware (cmt-mcusw)? Watching videos on N900 used to be a joy; it would be a shame giving up this feature.

Details for one of the DivX video files as reported by MPC: Video: DivX 5 640x272 25.00fps [Stream 00], Audio: MPEG Audio Layer 3 48000Hz stereo 129Kbps [Stream 01] (AVI container). 9.mp4 demo video details: Video: MPEG4 Video 800x480 23.98fps [Video], Audio: AAC 44100Hz stereo 1411Kbps [Audio].

divx or xvid video wasn't that great in PR1.1 either, at least when compared to a 5 year old dell axim x51v.
I'm baffled how that old tech plays any vid smooth as buttah yet the n900 hottness has trouble displaying same vids correctly on the gorgeous screen.
I haven't watched any movie yet on the N900 since it's pretty much unwatchable with all that jerky movement.
I pretty much forgot about this until I saw your message, innitially I thought it was just my N900 since it was really unusual to have video playback like that. btw no overclocking here

Of course you could always download kmplayer and use that instead of the regular player. Personally I havent noticed any issues with the media player and DIVX, that being said I am watching a BRRip of Alice in wonderland.

720x400 res
Video Encoded at 1522 kbps
Audio Encoded 384 kbps
Xvid

It stutters a little in regular player, smooth as silk in kmplayer. Which I think is pretty damn impressive for a mobile device.

I only used KMplayer and extra codecs but... since it caught my attention I went ahead and tried to tweak it: downloaded mplayer command line only then from within KMplayer clicked on the down arrow, Select Player, and switched to mplayer from osso-media-server... I have no idea what happened but it's playing even mkv's now, smooth as buttah!! How many players are on this thing and why isn't the right selection defaulted in the first place?

i dont know about you but osso-player plays stuff smoothly on my kmplayer and after all its hw accelerated on some videos.

mplayer is not "on this thing" its something you had to download from the repos. As far as not having the "right selection defaulted" it does. Since the app kmplayer can only assume you have osso installed by default it choose that one.

Recently I updated KMPlayer and suddenly everything works fine! The playback of the previously problematic files is 100% smooth in the updated KMPlayer! It even handles the movies with packed B frames correctly out of the box. Just great.

Thread moved to Maemo 5/Fremantle, and marked Solved.

Either you're seeing 50Mb clips, or I'm doing something wrong...

I got my N900 running at 800/850Mhz, using Sib and consequently mplayer. (Also tried KMplayer) and no 700Mb Divx/Xvid's are not smooth, they weren't smooth in PR1.1.1 and they're still not smooth on PR 1.2...

It's not CPU problem, since like someone said the oldie Dell Axim with a 624Mhz Marvell could play them effortlessly so it's definitely lack of software optimization...

The only player I haven't tried was indeed VLC, so I guess I'll try it next, but I can't really understand why a Cortex A8 (even without the hardware decoding from the DSP) isn't able to play smoothly a Divx/Xvid file.

This is an Nseries device, it's a Tablet, it can be whatever you want, but if I bought something with Divx capabilities and TVout I expect to use them and to work flawlessly ! Just like I love the xterm and my ssh consoles to the numerous Linux machines I got to admin I also love watching a nice movie on the go...

@God_Lx:

No, I tested much larger files. Used KMPlayer (Select Player > mplayer), no overclocking. Worked fine, although I watched just a couple of minutes - the sequences that used to be problematic.