Why can't N900 play videos smoothly?
 

Members keep talking about how awesome and powerful the N900 hardware is but it really isn't that special. Many of the features on the N900 have been around on other phones before and if you are referring to the processor and graphics, they really aren't very special either.

I downloaded a couple of media files (music videos) in flv format. The quality is good but not amazing. I would have thought that the N900 should be able to handle it no problem but, firstly the default media player does not play the videos at all, even after installing the extra codecs from the repositories. Then I tried mplayer with SiB which does actually play the media but the video runs so slow that is falls completely out of sync with the audio. I also tried KMPlayer and had the same problem. This happens with other media formats as well. (avi, mp4, mpg)

Running the same videos on an old P3 800MHz which is the oldest hardware I've got lying around, the video plays 100% smoothly and only uses around 40% CPU at most. (I used vlc media player on Win XP and system has 512MB memory)

For the cost of the the device why can't the N900 handle the music videos?

Re: Why can't N900 play videos smoothly?
 

i think the n900 is very picky with the codec and bitrate of a movie file.

for example, when you play the n900-video which is on the device already, it looks fantastic and perfectly smooth.
then i copied a movie which looks mediocre on my computer to the n900 and it would stutter quite a bit.
other movies, that look quite good on the computer, run well on the n900.

Re: Why can't N900 play videos smoothly?
 

Firstly are you using Linux on that P3?
Secondly, I don't think the Cortex A8 is close to as fast as a P3 800!

A PC is x86 architecture, the N900 is ARM, very different beasts. One is an ancient CPU design that just has newer stuff stuck on it each time its revised with little concern for what effect this has on power consumption, the other is carefully crafted with battery life in mind, they are not remotely comparable to each other. Now add to that the fact that the PC has many many years of x86 optimisations on its codecs (and because new features are just stuck on you can rely on them still being there on newer versions of the CPU), you can't expect the same kind of optimisation on a ARM CPU as they might have to remove older optimisations to save on power consumption, cost and size (they have to be super small and energy efficient to save on battery and heat dissipation).

Linux is primarily written for x86 and not everything can just be recompiled for ARM and work the same, anything CPU intensive will often have architecture specific optimisations which you basically have to throw away when changing architectures. So those years of optimisations for PC have to be rewritten, as such some codecs might simply not be available at all for the N900 as they were written specifically for PC hardware.

PCs do not have to worry about power consumption so can include all the old inefficient tricks on their newer CPUs, whereas something like ARM is trying to squeeze as much as possible out of your battery, so they have to be really picky about what they include in there. Video playback on Linux on PCs is still hit and miss today to some extent, so its no surprise the N900 is that bit worse. The fact is on PC you can playback many video files purely on the CPU with no help from the GPU, the N900 CPU has no chance at doing that which is why its so picky as GPU acceleration relies on much stricter rules than CPU playback, again because hardware optimisations have to be tightly refined for power consumption and cost.

As for "Many of the features on the N900 have been around on other phones before", well no **** sherlock. We don't buy the N900 necessarily for those "many" features, we buy it for the ones that aren't around on other handsets. I myself came from Windows Mobile which has always multi-tasked, but I have never been able to play music and use the web browser at the same time in any usable fashion before, the music would just break up too much. And I have never been able to stay online all the time before, as Windows Mobile turned off WiFi when in standby thus taking me offline, the N900 keeps me online all the time.

So please THINK before you make bold claims, there are many things the N900 does that older handsets did, but it does them better. There are some things it does worse, but video playback is not one of them. Only now are handsets coming out supporting the wide variety of formats the N900 supports and even then in reality they will have limitations. Sure its not perfect, but if you can find a handset that is then by all means go buy it.

Re: Why can't N900 play videos smoothly?
 

You should rephrase the question to "Why can't N900 play _my_ videos smoothly?" because for many users it plays smoothly. It greatly depends on the codec, resolution, and bitrate, though. If you give the phone the type of media it likes, then you'll get great results.
Just because there's no iTunes you have to squeeze (transcode) your videos through for loading them onto the device doesn't mean that they will all play fine without transcoding.

Re: Why can't N900 play videos smoothly?
 

If you consider that an 800MHz P3 can handle video with 40% CPU usage, which is around 320MHz, then it seems reasonable to expect the 600Mhz processor in the N900 to be able to handle the same content at 100% with the changes in architecture for battery savings etc.

I don't expect to be able to play super high quality videos on my N900 but the videos I'm trying to play are not even very high quality and yet the audio and video falls completely out of sync making it absolutely pointless to watch.

Perhaps Linux and the specific media players are the cause of the video playback problems due to the lack of optimization for the ARM architecture but if this is the case, is there any hope of improvements that will make it possible to play video content more smoothly?

I didn't ask for a perfect phone and I didn't say I expect N900 to be perfect, it certainly has plenty of downfalls that I have seen and accepted but I though it was reasonable to expect the device to be able to do something as simple as playing back videos in a reasonable quality while no other applications are running in the background.

Re: Why can't N900 play videos smoothly?
 

i cant speak for flv since i havent tried them on my n900 yet, but all of the mpeg, mp4, avi and wmv vids i've thrown at it are played smoothly no problem. only grumble is the way it plays at 200% speed for the first second or two after using the play bar

Re: Why can't N900 play videos smoothly?
 

I play 1 gig unopptimized avi's with no problem. I do switch much of everything off to do so though...what are you running in the background?

I also loath flv though.

Re: Why can't N900 play videos smoothly?
 

Is there a simple way to check the details of my videos to find out if they are within a reasonable resolution and bit rate? The specific files I want to play on my N900 are flv files and I don't know where to see the info in question.

If I convert the media files I don't want the audio and video to degrade too much because they are already not particularly fantastic and I would like to be able to connect my N900 to my TV and watch the videos without them being too grainy.

Re: Why can't N900 play videos smoothly?
 

The N900 plays Videos beautifully, and at better than DVD quality remember the resolution of the display. However the codecs will not support anything over 800x480.

Try some that I made up

on the fast cars thread

http://talk.maemo.org/showthread.php...ight=fast+cars

Many of these were transcoded from FLVs

Re: Why can't N900 play videos smoothly?
 

If I try to play large files which tend to be good quality, say 700MB movie for example (avi), the files do not play properly. The video is smoothe but slow, which causes it to fall behind the audio. This gets worse the longer the video plays. I'm using Mplayer with SiB.

I do not run anything else in the background while playing videos.

I have checked the CPU usage when videos are playing and it runs at 100% almost constantly until I stop the video and then it drops down to less than 5%

I have managed to play some videos smoothly but it's almost always the low quality videos. The videos that I really want to play almost always have video / audio sync issues.

Re: Why can't N900 play videos smoothly?
 

N900 plays 480p .mp4 files downloaded from youtube perfectly smooth for me.

BTW, 600MHz P3 is much faster than 600MHz Cortex A8 for general compute.

Re: Why can't N900 play videos smoothly?
 

Thanks I will try these and report back.

My videos definitely have a lower resolution than 800x480 otherwise, as mentioned, they would not play. The quality is close but not quite DVD quality.

The Vivo videos on YouTube are the kind of quality I'm reffering to. Does anyone agree with me that it is reasonable to think that N900 should be able to handle that?

Re: Why can't N900 play videos smoothly?
 

it may also be down to the player you are using and not the N900s capabilities-try a dedicated player if there is one for the files you want to play, or try kmplayer. you could also wait for the official release of vlc player, which should be able to handle almost all video files, and give an indication of whether the N900 is really up to the job or not. the N900s built in player seems to jump/skip with some videos that work fine on a pc, although strangely it does not seem to always be a high bitrate or high resolution issue with all types of video

Re: Why can't N900 play videos smoothly?
 

If you want smooth playback you have to transcode videos if they aren't in right format for standard player. It plays videos with DSP and more optimized for ARM while mplayer plays all with CPU. I use MPEG4 and MP3 codecs and avi or mkv containers. 800x450@25 fps and 3Mbit/s plays fine. I think you don't need better quality for this screen.
I played a 192Kb/s MP3 song with standard player and CPU load was about 40% @250MHz. Mplayer did the same with 70% @500MHz (through pulseaudio). And note that N900 don't use DSP for audio. All of this is just low level optimization for particular CPU.

Re: Why can't N900 play videos smoothly?
 

I have a great deal of movie backups in from avi, xvid for SD video and some h264 with AAC sound for HD. SD files are all various resolutions, none over 720x480 (DVD) moderate bitrates (1500 Kbits max. I think). My N900 plays them no problem. Just copy and paste o.O for the HD part, I am using format factory (free) to recompress to .mp4, resize from 1920:1080 to the screen resolution of 800:480. bitrate usually down to 2000Kbits. I am talking stock N900 here.

Re: Why can't N900 play videos smoothly?
 

As for flv have you read?

http://talk.maemo.org/showthread.php?t=43993

I'll address the other question when back on a PC. Most likely the resolution is too high though. My avi's are dvd rips.

Re: Why can't N900 play videos smoothly?
 

I also watch vids in offline mode.

Re: Why can't N900 play videos smoothly?
 

Do you get them by stream, or are they on the 32GB internal Memory, or are they on a SD Card?

Re: Why can't N900 play videos smoothly?
 

To get the facts straight:

1. Forget MHz/GHz. In the 21st century it is an almost completely meaningless indicator due to differences in processor architectures. Forget it. Really.

2. Only the built-in media player uses hardware acceleration. If you don't play it in that, it's not accelerated (=it's slow).

3. Flash will gain acceleration in 10.1 when it gets released for ARM.

Re: Why can't N900 play videos smoothly?
 

My media files are on the 32GB internal storage.

Re: Why can't N900 play videos smoothly?
 

I did not know that the built-in media player uses hardware acceleration because I rarely use it. The videos that do work in the built-in player do not run any better than in Mplayer with SiB and the flv videos do not work at all in the built-in player.

I hope that Nokia will make improvements to the media player to improve performance and hopefully a codec will be released to bring flv support because I have lots of flv videos.

As for VLC, I look forward to trying it and hope that it supports hardware acceleration.

Re: Why can't N900 play videos smoothly?
 

You mentioned Vivo, surely they are available in H264 (.mp4) as well as flv? I can't check as Vivo is blocked in the UK due to licensing :mad: but almost all files on Youtube are available in mp4 these days and play perfectly on iPod and the N900.

I have downloaded music videos from Youtube in mp4 format before and they play perfectly in media player. You really shouldn't be playing in anything else unless it absolutely doesn't work. I love mplayer but its real CPU hog (as is vlc) even on desktop Linux, its not even closely comparable to playing back the same files in Windows for example.

Re: Why can't N900 play videos smoothly?
 

I watched a video today from a company called Nokia that explained how a device called the N900 worked when switching windows, etc.

The video was about one minute and thirty seconds long. I tried and tried to play it, but the furthest I got was about fifteen seconds from the end. I didn't get any error messages, the video just stopped. I spent about ten minutes working on playing it, never saw the end.

I don't know why that was, but I don't think my system is set up in a super-impaired way.

Re: Why can't N900 play videos smoothly?
 

MPlayer on desktop is beaten by very few things in CPU consumption, especially as it supports vapi, vdpau and dxva now.. The ffmpeg decoding libraries are one of the fastest, if not the fastest around, and also used on windows by the awesome ffdshow package...

Re: Why can't N900 play videos smoothly?
 

It doesn't play even the videos recorded on the same N900 that well. Actually, playback is often pretty awful. Sometimes it plays audio only and video gets stuck.

Re: Why can't N900 play videos smoothly?
 

Surely that is more the fault of the provider than the N900?

Re: Why can't N900 play videos smoothly?
 

ooh - nice shot! LOL

Were yo ustreaming that from YouTube? What was the format of the video? I've found that Youtube sometimes has a hissy halfway through streaming and that will stop the stream mid flow.

Re: Why can't N900 play videos smoothly?
 

Agreed, I think there are definitely improvements to be made and I think the hardware is capable of better performance if the software is optimized better.

Re: Why can't N900 play videos smoothly?
 

To avoid confusion - the built-in media player acceleration happens on codecs/format level. The accelerated ones are IIRC MP4, DIVX, XVID, WMV9, baseline H264. It might play back others (especially with the extra codecs pack), but that does not mean everything gets acceleration.

Sadly, it doesn't. And if it would, it would have to go through the same subsystem as the media player goes through, i.e. they would in essence have the same performance (the media player is just a front-end for the gstreamer multimedia framework).

Re: Why can't N900 play videos smoothly?
 

It's not so bad: the built-in player do it through gstreamer and any other player that use gstreamer as backend will get hardware acceleration too. But it supports only a limited set of codecs and this is not a technical problem, but licensing and patents AFAIK.

Re: Why can't N900 play videos smoothly?
 

A note about many xvid in avi files in the wild, alot of them use a nonstandard "packed b frames" thing, which hides b frames with p frames. The N900 doesn't see the b frames and playback is approximately 1\3rd to one half of "proper" framerate.

Re: Why can't N900 play videos smoothly?
 

ive just tested both mplayers.... KMplayer runs more smoothly than SiB with what ive tested.

SiB on some video that was running poorly on the N900s default player can be slightly jittery, its not bad, but does fall behind KMplayer in quality. KMplayer seems to have no problems, the same video plays flawlessly. i havent fully tested KMplayer and SiB with video audio yet, to see if most videos im testing stay in synch till the very end. Ill need to convert some long videos to test

Re: Why can't N900 play videos smoothly?
 

Maybe so, but its much easier to get a smooth consistent frame rate on Windows and you find far fewer video files that have problems.

Its not uncommon for VDPAU to break on some files and certainly when you start trying to deinterlace 1080i files, its often really really hard to get it to work properly where on PowerDVD on Windows "it just works".

As I understand it though, because mplayer is heavily optimised for CPU playback they hit a big snag when dual-core came out, as mplayer is optimised for single-core CPUs. It relies on knowing exactly what is going on in the CPU cache which means no multi-threading, as you spread the load over multiple cores that way but cannot optimise to the same degree so it would have far far worse performance on single-core machines than it does now.

Its not that mplayer is bad by any means, its my preferred player on Linux, but its optimised to do things one way and as VDPAU is relatively new I think its still somewhat in catchup mode. I hear the latest development version now plays Blu-ray as long as its already been decoded/ripped to the HDD, so its certainly getting there. But there a lot more scope for things to go wrong than on Windows as things like VDPAU can break unexpected and without you realising what has happened, whereas on Windows if anything like that broke generally the whole system would stop working. Its both a blessing and a curse that Linux sometimes tried to go on even when something is not working quite right.

Re: Why can't N900 play videos smoothly?
 

If I am watching K900 videos which are being sent to my TV via the audio/video lead I received with the phone.. can I switch off the N900s own screen, since at this time only the tv screen need to be showing the video, and not the mobile screen?

I prefer using KMPlayer as it gives a better frame rate than both the default one built in and SiB, although I guess if KMPlayer does not allow the screen to switch off and still play the video, its not possible? Unless the phone itself has a similar screen switch off, whilst still playing the video with no problems-anyone know?

I was thinking if the N900 cant make the screen go into "sleep mode" whilst still playing a video file, it would be a handy tool to install if someone made an installable unofficial version

Re: Why can't N900 play videos smoothly?
 

FYI
KMPlayer is just frontend. Default setting for that player is to use offical mediaplayer (hw accelerated) but it can also use external mplayer.

Re: Why can't N900 play videos smoothly?
 

any ideas on how to turn the N900s screen off whilst watching the output (eg a video) on a connected TV? theres no point having both showing at once.........

Re: Why can't N900 play videos smoothly?
 

try this video ^^
http://www.megavideo.com/?d=O365TEB4
its Boa - Energetic
I converted it
thats the one only one English..
I converted a lot of videos.. but they are Korean MV
I also converted Movies.. but I dont upload it
all my videos play really smooth and really high quality..
so just test it out~

and that video detail is here

Encode to File Format: MP4
Use Video Codec: MPEG-4, 800:432 (16:9), 9600kbps, 30 fps
Use Audio Codec: AAC LC, Stereo, 256 kbps, 44100 Hz

Converter by Shini

if you want to download Korean MV for N900 go to my Korean blog
http://blog.naver.com/lrb1000
no id require ^^ feel free to download

Bonus*
http://www.megaupload.com/?d=0MN2JYN1

SNSD - Run Devil Run
Encode to File Format: MP4
Use Video Codec: MPEG-4, 800:432 (16:9), 9600kbps, 30 fps
Use Audio Codec: AAC LC, Stereo, 256 kbps, 44100 Hz

as you can see its different are then Boa MV
just see different ^^ for me I put videos on my 32GB N900
and I put all my music on my 16GB Memory Card
I dont have any lags on Videos or Music playing

Re: Why can't N900 play videos smoothly?
 

[IMG]\YouTube - Jal Jal Ke Dhuan.flv Format : Flash Video File size : 18.2 MiB Duration : 4mn 25s Overall bit rate : 574 Kbps httphostheader : v4.cache5.c.youtube.com Video Format : AVC Format/Info : Advanced Video Codec Format profile : Main@L3.0 Format settings, CABAC : Yes Format settings, ReFrames : 3 frames Muxing mode : Container profile=Unknown@3.0 Duration : 4mn 25s Bit rate : 463 Kbps Width : 640 pixels Height : 272 pixels Display aspect ratio : 2.35:1 Frame rate mode : Constant Frame rate : 29.970 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.089 Stream size : 14.7 MiB (81%)[/IMG]
i need help on this ,up there is the detail of video song i tried to play ,at first it was okey but on the day 3rd ,when i played again n again ,video was too lagging behind ,dont know if thats a pixel issue or what ? any help would appreciated .

Re: Why can't N900 play videos smoothly?
 

n900 can't play youtube videos even with extra decoder support. I have the same problem, it still does not have a solution.

Also, I might add that this thread is pretty old.

Re: Why can't N900 play videos smoothly?
 

i typed here cuz i dont know how to start a new thread and 2ndly i thought may be there will be any solution on this page ,OLD PAGE.:)