[nick3331]

I think we've got a little misunderstanding here: "Buffering" means, the buffer works as expected: It is filled, and the movies (or mp3-files or sth) are playbacked out of this buffer - hopefully smooth as from a Bluray or DVD. Buffering in the wrong slang-usage means: The buffer ran empty and the media-file stuck and waits for the buffer to fill.

Now my problem is, that there seams to be no buffer, what means, the media doesn't stuck, wait for the buffer to fill and go on untill it again becomes empty, but the media has many stucks like for shorter than a second, which leads to the idea, that there might not be a buffer (or a buffer of appropriate size).

It's difficult to say which problem everyone of you means.

[chad473]

my testing really seems to be pointing to issues with the buffer on xbmc, or lackthereof. specifically, I have an mkv that still buffers on the 2/1/11 nightly build. It's buffering less, only did it twice in the 45 minute length last night. Still, this same file converted to m4v via mkvtools (which just repackages, no transcoding done so the file is essentially the same, bitrates unaffected) when played through the stock appletv firmware from an itunes share does not have these issues. In fact, after just 3 minutes I paused at a point that caused buffering last night on xbmc (fairly high bitrate spike) and in the timeline at the bottom it showed at least another 3-4 minutes already in the buffer. To me, this says that network throughput is not the issue but rather how xbmc is handling the file. It seems, at least in my test environment, there's a bottleneck somewhere in how xbmc is handling the file. I'm hopeful that it's an issue that can be resolved once we have some control over the buffer size.

If any of the coders are keeping up with this thread..do we have any indication what the buffer is on xbmc right now? It really seems like this is the issue, and would explain why the streaming is perfectly fine for some people, but not others. Excellent network conditions probably wouldn't see an issue, but if the buffer is too small then slight lags or hiccups might be enough to throw off the stream.

I can post a full pastebin, but here's what looks like the relevant info from the debug log. This stuff is mostly greek to me, but it looks like it gets to a point where it's requesting data and doesn't get anything. Again, since it streams just fine through itunes when just repackaged and not reencoded, it makes me think there's not enough of a buffer (if itunes buffers more, it would make sense that by the 3 minute mark there was already a few more minutes in there, and no hiccups were seen). Watching the codec info screen the cpu never goes above 80 or 81%. Doesn't seem as if decoding is the issue.

Code:

22:27:48 T:149921792 M: 72097792   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:27:49 T:169062400 M: 72093696 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
22:27:51 T:149921792 M: 72097792 WARNING: Previous line repeats 1 times.
22:27:51 T:149921792 M: 72097792   DEBUG: HttpApi Start command: GetVolume  paras: GetVolume
22:27:51 T:169062400 M: 72097792 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
22:27:51 T:149921792 M: 72097792   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:27:52 T:169062400 M: 72097792 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
22:27:53 T:167563264 M: 72097792 WARNING: CDVDMessageQueue(video)::Get - asked for new data packet, with nothing available
22:27:53 T:166678528 M: 72097792   DEBUG: CDVDPlayer::SetCaching - caching state 1
22:27:53 T:166678528 M: 72097792   DEBUG: CDVDPlayer::HandleMessages - player started 2
22:27:53 T:166678528 M: 72097792   DEBUG: CDVDPlayer::HandleMessages - player started 1
22:27:53 T:149921792 M: 72097792   DEBUG: ------ Window Init (DialogSeekBar.xml) ------
22:27:54 T:149921792 M: 71700480   DEBUG: HttpApi Start command: GetVolume  paras: GetVolume
22:27:54 T:149921792 M: 71700480   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:27:57 T:149921792 M: 71688192   DEBUG: HttpApi Start command: GetVolume  paras: GetVolume
22:27:57 T:149921792 M: 71688192   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:28:00 T:149921792 M: 71667712   DEBUG: HttpApi Start command: GetVolume  paras: GetVolume
22:28:00 T:149921792 M: 71667712   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:28:01 T:166678528 M: 71663616   DEBUG: CDVDPlayer::SetCaching - caching state 0
22:28:01 T:169062400 M: 71663616   DEBUG: CDVDPlayerAudio:: Discontinuity - was:126084922.540147, should be:126048028.290147, error:-36894.250000
22:28:01 T:149921792 M: 71659520   DEBUG: ------ Window Deinit (DialogSeekBar.xml) ------
22:28:03 T:149921792 M: 68403200   DEBUG: HttpApi Start command: GetVolume  paras: GetVolume
22:28:03 T:149921792 M: 68317184   DEBUG: HttpApi Start command: GetGUIStatus  paras: GetGUIStatus
22:28:04 T:169062400 M: 72024064   DEBUG: CDVDPlayerAudio:: Discontinuity - was:129085251.331813, should be:129095285.562785, error:10034.230972
22:28:06 T:167563264 M: 72024064   DEBUG: CPullupCorrection: detected pattern of length 1: 33366.67, frameduration: 33366.666667

[adrianme]

just thought id mention that I was able to fix all my buffering/stuttering issue's by uninstalling and reinstalling XMBC..

[Reverb]

Have a weirder case:
When i play a 720 .mkv on my Apple TV 2G(connected to ethernet) the video is buffering about every minute. The weird thing is, when i play the exact same video on my iPad(Airport extreme N) it play flawlessly. Just plugged-out the ethernetcable and the video also now play fine on the Apple TV... How weird...

Must say, that particular movie(Psych:9 720p), was the first 720p movie that was stuttering on my Apple TV 2G.

[GalBrill]

Have a weirder case:
When i play a 720 .mkv on my Apple TV 2G(connected to ethernet) the video is buffering about every minute. The weird thing is, when i play the exact same video on my iPad(Airport extreme N) it play flawlessly. Just plugged-out the ethernetcable and the video also now play fine on the Apple TV... How weird...

Must say, that particular movie(Psych:9 720p), was the first 720p movie that was stuttering on my Apple TV 2G.

It isn't weird, is't just because the LAN in the ATV2 is 10/100 and N WiFi (when connected to you AirPort) hits 300

Th weird thing is - why apple didn't put 10/100/1000 Ethernet on the ATV

[davilla]

It isn't weird, is't just because the LAN in the ATV2 is 10/100 and N WiFi (when connected to you AirPort) hits 300

Th weird thing is - why apple didn't put 10/100/1000 Ethernet on the ATV

because 1000BaseT is not needed to play 45Mb content.

[dragonfly_aut]

Turn off generate thumbnails.

please don't hurt me, but: how to do this??

i searched for approx. 30 minutes but didn't find any hint... maybe i searched the wrong way!?

[SavellM]

Im not sure if this could affect it or not.
But the Apple TV 2 does not have a HDD, and because of this has a really low amount of space. So maybe its just unable to hold a big buffer of 720p content?

Could be totally wrong, but just thinking out loud.

[Shoesy]

System > Video > File Lists > Extract thumbnails and video information

Turn that off.

[chad473]

Im not sure if this could affect it or not.
But the Apple TV 2 does not have a HDD, and because of this has a really low amount of space. So maybe its just unable to hold a big buffer of 720p content?

Could be totally wrong, but just thinking out loud.

There is 8gb, plenty of room for a buffer. I haven't used xbmc in years prior go the appletv2 build, but there were settings to allocate different buffer sizes. These aren't in the current build and if I had to guess, the buffer is very, very small. It would explain why many are having issues yet streaming larger and higher bitrate stuff from iTunes works fine. You can easily see the buffer on the timeline when you pause iTunes content.

[Zipp425]

There is 8gb, plenty of room for a buffer.

Isn't that the same amount that the original modded Xbox had? XBMC was first made for that system and if it worked there should be enough here too. haha. Of there was no HD streaming back then...

[Reverb]

It isn't weird, is't just because the LAN in the ATV2 is 10/100 and N WiFi (when connected to you AirPort) hits 300

Th weird thing is - why apple didn't put 10/100/1000 Ethernet on the ATV

Still weird. 100mbit is more then enough for streaming. And with a AirPort Extreme Wireless N you never reach 300mbit. More likely is 50-80mbit.

[dragonfly_aut]

System > Video > File Lists > Extract thumbnails and video information

Turn that off.

THANKS!!

[hospadam]

I'd like to thank Chad for his tests. His results mirror mine - though mine weren't as scientific.

From the AppleTV2(latest build) and wireless:

MKV "Buffered" at least once every 10 minutes... more depending on if the bitrate would spike (lots of action on the screen).

From an iPad, in the exact same location on the same wifi, with the same nightly build (but the iOS version):

MKV "buffered" once, about 30 seconds in, and then played fine the rest of the way through.

The more I look and test... I'm almost positive the AppleTV has no buffer at all. When the Bitrate spikes unexpectedly, and the wifi can't handle that jump... it "buffers".

I know the dev's are busy - but I hope one of them can let me know if I'm crazy or not...

[Reverb]

I'd like to thank Chad for his tests. His results mirror mine - though mine weren't as scientific.

From the AppleTV2(latest build) and wireless:

MKV "Buffered" at least once every 10 minutes... more depending on if the bitrate would spike (lots of action on the screen).

From an iPad, in the exact same location on the same wifi, with the same nightly build (but the iOS version):

MKV "buffered" once, about 30 seconds in, and then played fine the rest of the way through.

The more I look and test... I'm almost positive the AppleTV has no buffer at all. When the Bitrate spikes unexpectedly, and the wifi can't handle that jump... it "buffers".

I know the dev's are busy - but I hope one of them can let me know if I'm crazy or not...

Got almost the same. On my iPad a 720p file play great without buffer and the same file on my Apple TV is every 5 minutes buffering and are in the same wifi area. Must say it only about 1 movie of my 25 library