ATV2 and XBMC bufferring

kimsharma Wrote:@elcaballo

I have a couple of things to add :
1. On the initial version of XBMC from January (the first release ever), I had no problems playing files up to 8GB on over wired windows SMB share (but ATV2 was on wireless N)
2. On the new version of XBMC, per the Feb 14th/15th release, and using the greenpois0n JB, I have the same issues as you do - buffereing for the same exact files on wired SMB. I tried installing a UPnP server(twesity / ps3 media server) and the buffering is awful! Exact same setup, but significant buffering on the same files that playerd relatively smooth before.

I am going to try a complete wired only test later in the evening to see if that makes it better and will post my observations then. Just so we are on the same page, streaming over wireless ATV2 is totally useless.. I dont believe it is XBMC's fault.. it is just the filesize / bitrate that is not sustainable on wireless N.

Hope this adds to the perspective / discussion.

And yet using the Feb 14 release on a greenpois0n JB I can stream an 11gig 1080p .mkv of Inception on Wireless N with no drops using PS3 Media Server...

After some experimentation with UPnP servers and 720P video streamed over wireless N at 5GHz:

smb - Much Stuttering

UPnP (Majestic Server on early 2007, 2.16 GHz iMac) - Much less stuttering

" (Serviio " " " " " " ) - No Stuttering at all.

The Serviio link is here:

http://www.serviio.org/download

Eric_S Wrote:After some experimentation with UPnP servers and 720P video streamed over wireless N at 5GHz:

smb - Much Stuttering

UPnP (Majestic Server on early 2007, 2.16 GHz iMac) - Much less stuttering

" (Serviio " " " " " " ) - No Stuttering at all.

The Serviio link is here:

http://www.serviio.org/download

I'm curious, what size files 720p are you testing. I am now finding that 720p .mkv rips of television shows aren't stuttering over SMB. They are usually around 1gig+ in size, but 720p movies, which are usually 4gig+ are stuttering.

The file I am benchmarking is a home video, H.264, m4v, 1.31 GB, and 17 minutes duration

elcaballo Wrote:You're right. It's a D-Link DGS-2205 switch, had a five star rating on Newegg so I don't think that is the problem. The fileserver has been rock solid in every other way and all it is doing is serving files to the ATV2. Like I said, there is only 0-5% CPU utilization.

And what I'm saying is not that the ATV2 can't do HD at all. It streams my 2< GB HD TV files with no problems. I'm saying that with any high-bitrate HD file (typically a movie) larger than 4.5 GB, it buffers like crazy, which makes it useless for movies. I bought the ATV2 so that I didn't have to deal with PS3 Media Server but XBMC just can't keep up with larger files.

And all this is with 2/14/11 and a greenpoison JB.

Again, I'm sure the devs will get there eventually. I'll just have to check back in a few months once the program has been optimized.

elcaballo,
Just wanted to say that I understand you're having difficulties with "buffering" when playing large movie files greater than 2GB. As well as having issues playing high bitrate HD files.

For some of the newbies on the forum, file size and the bitrate at any given scene in the movie are different things and the terms shouldn't be used interchangeably.

I agree that it's early in the ATV2-XBMC port and the are bugs to be worked out. However, I just wanted to share my experience so you can help troubleshoot your issues should you want to continue tinkering with XBMC on the ATV2.

I just played and recorded a 1080p (vtb-h264) rips without ANY buffering whatsoever. I don't see the buffering message appear while watching these 1080p movies that can be properly decoded by the ATV's GPU. The file sizes are usually around 7GB-10GB so they are bigger than the 2GB limit you've witness.

Using the xbmc remote and pressing "o", you can see the bitrate go as high as 23Mbps without any buffering in the video below. I have seen the occasionally frame drops on some content. But for the most part, things play nicely for this stage of the port and again, no buffering that many have mentioned they run into.

/**VIDEO Removed **/

Good luck with figuring out your problem. Perhaps it will be resolved in a future build. I wonder if there are different revision of the ATV2's hardware out on the market. I purchased mine the day it was released so it's probably the first version of the ATV2 for all intent and purposes.

dazex Wrote:elcaballo,
J
http://www.youtube.com/watch?v=EVUHiVuMg9k

Good luck with figuring out your problem. Perhaps it will be resolved in a future build. I wonder if there are different revision of the ATV2's hardware out on the market. I purchased mine the day it was released so it's probably the first version of the ATV2 for all intent and purposes.

What protocol did you use? SMB or UPnP? You YouTube movie is btw blocked. Anywhere else where you can show it to us?

Hope that that add in a future release UPnP scraping support, that solve for a lot of people the buffering issues.

elcaballo Wrote:And what I'm saying is not that the ATV2 can't do HD at all. It streams my 2< GB HD TV files with no problems. I'm saying that with any high-bitrate HD file (typically a movie) larger than 4.5 GB, it buffers like crazy, which makes it useless for movies. I bought the ATV2 so that I didn't have to deal with PS3 Media Server but XBMC just can't keep up with larger files.

I tested my ATV2 setup with a 16GB 1080p high bit-rate h.264 version of {a movie} over my wired network (on the 2/8/2011 XBMC release). I was amazed that the AppleTV played the video without any stuttering. When the video first started up there were a few frame-drops and I would see occasional frame-drops during high action scenes, but I didn't have any buffering issues.

The video was streamed from my Revo 1600 in the living room which has a 3TB hard drive hooked up with USB 2.0 and a gigabit network connection. The Revo 1600 is running Ubuntu 10.04 and is serving up the files via Samba (v 3.4.7). Like you hinted at, it's probably not a processor issue as file shares don't take a lot of resources, but for purposes of full disclosure the Revo only has a Atom 230 @ 1.60GHz.

Reverb Wrote:What protocol did you use? SMB or UPnP? You YouTube movie is btw blocked. Anywhere else where you can show it to us?

Hope that that add in a future release UPnP scraping support, that solve for a lot of people the buffering issues.

Darn...that was fast. It was only a short clip mainly to show the OSD. Perhaps I can crop just to show the OSD with the framerate info?

Anyways, it was over SMB. Content shared via headless Windows box in the closet over 10/100 network. More pertinent info was in the Youtube link that is now block. :|

I would be happy if i had this problem only with HD files but i also have slowdowns every 10 seconds in SD tv show files which are about 350 MB of size for 40 minutes playtime. Due to the fact that my synology nas broke recently, i had to use my pc to share files for my new atv2. The pc is connected only by 100 Mbit lan and the atv2 is connected via wireless-n. I use upnp for that and tried tversity, twonky and xbmc for windows so far and with each of them i get short slowdowns in all my SD tv shows, HD playback i don't even wanna mention! When i use my ps3 instead of atv i have no problems at all with any of my media, SD and HD, so it is definitely not my network setup. Atv on the other hand is playing my itunes files just perfectly, both SD and HD. So i assume this must be a problem with xbmc itself
Am i the only one with this kind of problem? Can it be that my pc is the problem and that steaming from a nas would be better for atv at least with SD files?

Figured I would vent out what I have been seeing after some quick testing. Ran into some buffering on ATV2 with a 720p .M4V file of How To Train Your Dragon. File sits on a synology nas. ATV2 is wireless on a N network. Played around a little with the wireless setting on a Cisco E3000 router and was only able to make slight improvement. Note Router sits in basement and ATV2 is on second floor and pretty much at the ceiling too. So it is a good long haul.
Next I ran a wired connection (Gigabit) to the ATV2 and it played perfect. Also checked file on a ATV1 wired and played perfect on that as well. So looks like the wireless connection is a possible problem.
However I then decide to open a itunes home share on my office PC and stream the file from there. PC wired but wireless to ATV2. No problems no buffering. And the progress bar showed the entire 2.5GB file loaded in about 5-7 minutes into the movie. So the wireless network is actually fast enough.
So how can we figure out how to get XBMC to handle the network like itunes and more importantly how to get it to write or buffer a larger part of the movie? What protocol is itunes homeshare using?
I feel like XBMC is only taking small chunks at a time and if you get a small network slowdown you run into problems as the buffer is not large enough and/or it is allowed to run to close to empty before pulling more content. But maybe that is part of the equation, maybe itunes is actually pushing content to the ATV2 where we have XBMC trying to pull to the ATV2.
Daville we need for you to work some more magic! I don't know maybe see if we can get some more temporary storage allocated or something. Got to be something we can do. Maybe figuring out the itunes home share may yield some insight.