Occasional Stuttering Video

Hi Folks,

Recently installed ATV flash - very nice piece of software! I have a large iTunes library and wanted everything unwatched to be stored locally, to avoid streaming issue (like, well, stuttering videi). So, I recently purchased and installed aTV Flash and a 500GB Seagate FreeAgent portable USB HDD.

With the exception of a small struggle to get the USB drive to show up, everything went without a hitch. After a couple of days, I have about 400BG of video ready and waiting.

I am experiencing occasional stuttering video playback with iTunes content. With purchased HD movies and purchased HD TV shows. I was able to watch an SD video that I created myself w/ Elgate Turbo HD 264 - that seemed to playback without any interruption.

The stuttering playback is as others have described on this forum: at different intervals, a video freeze of about 1/2 second occurs, followed by a brief period of sped-up video (as if it’s catching up), followed by normal playback. Repeat until annoyed. The interval for a particular video seems to be constant, but differs between different videos. I haven’t done thorough testing, so I can’t give repeatable specifics (I can do this, if it’s helpful).

I read through the forum and, as others have suggested, disabled Apple’s h.264 codec. To my surprise, that fixed the problem with an HD movie I was watching and I thought the problem was solved. Last night I watch an HD episode of Mad Men and the stuttering was back. I verified that that Apple h.264 codec was still disabled - it was. I also verified that I have updated/installed the latest versions of aTV Flash and Perian, et al.

Of course, I am suspect of the HDD - that is, aTV reads N bytes into its cache and before the aTV needs to read again, the drive spins down. Then, the aTV reads again, but the drive is slow to respond causing a delay in playback with a subsequent speed-up for a moment.

I don’t believe the Seagate FreeAgent drive’s ‘eco features’ are customizable, but I know other models support this (e.g. Western Digital’s MyBook). Before I go out and a.) buy another drive and b.) again, copy 1/2 TB of videos over the wireless network… can anyone tell me if this is a known problem, or is the stuttering playback another issue, entirely?

I guess what I should do is re-view the offending video with my hand on the hard drive. I can feel the vibration (slight as it is) and should be able to match up the start/stop with the pauses of the video.

I’ll report back what I find.

  • Ken

Update: re-ran the problematic video from last night. That is, reset as not viewed in iTunes, waited for it to download to the Apple TV and watched. Of course, nothing went wrong… :slight_smile:

So, I tried another video in HD purchased from the Apple Store (Rubicon). This one had a hiccup early into the video. I rewound and re-played. No hiccup on the same spot, which eliminates the theory that the problem is a bad sector, et al. on the external HDD. And, drum roll please, the external HDD never stopped spinning throughout playback. So much for that theory.

However, I was sitting right next to the Apple TV throughout playback so I could keep my hand on the HDD to feel the vibration of spinning. Guess what happens before every pause in the video? A subtle clicking sound from the Apple TV’s INTERNAL hard drive.

I’ve heard this before (since I bought the Apple TV) and sounds normal for a drive of the type (those little Toshiba iPod hard drives).

My new theory is that a background process on the Apple TV is coming to life during video playback, accessing the internal HDD, but guess what? It’s not spinning anymore because… the movie is playing from the external hard drive. That’s why I never had this problem with the internal HDD enabled as primary iTunes storage (i.e. before aTV Flash).

So, aTV Flash would probably need to periodically ‘touch’ the internal drive during video playback so that whenever another process accesses the internal drive, there is no spin-up time. Is there something that normally runs within Apple TV’s software that periodically performs a task during video playback?

I thought about testing my theory by closing iTunes on my Mac and re-running the above test. I wonder if the periodic task is a check to see if there is new content on iTunes.

Anyone from aTV Flash want to comment at this point?

Update: I ran the SmartInstaller and (I think) it updated my installation of aTV Flash. Then I watched a video this morning. Better… the stuttering seems rare now, after one viewing - happened only once or twice in the course of a 45 minute episode.

I will re-verify that I have the latest and greatest software and see how it goes.

I will tell you, however, that even a single stutter during a movie IS ABOUT AS ANNOYING AS READING THIS ALL IN CAPS.

You end up sort-of anticipating the next occurrence, which is very distracting.

BTW, does anyone from aTV Flash read these messages or should I be contacting support directly?

OK, I updated to aTV Flash 4.1.5 last night and re-verified that everything else was up to date.

Then, I watched a couple of purchased HD videos and saw a horrible increase in video stuttering (as in every 30 seconds or so), after about 30 minutes of playback.

So… I stopped the video playback and pulled and replaced the power cord (i.e. hard booted). I also installed Sapphire and uninstalled XBMC and Boxee (what are these for, anyway, if you already have a nice 10’ UI with Apple TV?).

Then, played an SD purchased iTunes video, which ran without any stuttering.

This weekend, I will try more videos (my archived DVDs and BDs from my personal collection) and report back.

One more thing… having disabled the Apple h.264 decoder, the aTV startup video plays with no sound and a horrible amount of macro-blocking.

– Ken

What type of files are you having trouble with? It’s possible some of the HD files (Blu-ray rips in particular) may be of a higher resolution/bitrate than the AppleTV can currently support.

As I mentioned in the postings above, all of the files are purchased videos from the iTunes store.

Thanks,

Ken

More video stuttering with purchased videos from iTunes. It comes and goes in cycles. I went back into Maint. and re-enabled the Apple h.264 decoder, because the Perian version was having problems smoothly playing back HD videos created from source media (i.e. not downloaded from the iTunes store running at 1280x720, 4.5 Mbps w/ AC3 pass-thru).

After rebooting, all was well… I watched the second half of an HD movie without a single stutter (about 60 minutes of playback).

I will watch some more TV shows and see if things are working again, but from what I read on here it looks like I can forget about VIDEO_TS folder playback for a while (cataloging stuff with Sapphire being broken and stuttering VOB playback - this is kind of odd, since MPEG-2 video is much easier to decode, processor wise, than h.264).

If I see more stuttering this weekend, I am going to try a different hard drive - it’s possible that the data stream is being interrupted by the HDD with something like background disk scrubbing (all the Hi-Cap drives do this now); but, the stutter is so quick that I can’t believe that the playback software’s internal buffering wouldn’t compensate for such a short interruption.

I love the Apple TV’s 10-foot UI (I never have to help my wife or 8 year-old daughter), the device is quiet, looks elegant next to the TV and the syncing with iTunes is really easy to use. Wireless streaming of my HD videos was too much of a crap-shoot, however, so I came to aTV Flash to enable external HDD support. For that feature alone, I am hoping things are resolved.

Ultimately, the problem with aTV Flash is the Apple TV itself - the device is underpowered and, hence, presents unassailable functionality limitations.

– Ken

OK, so far, so good. Going back to the Apple h.264 decoder and changing drives seems to have made the difference.

I was suspect of the Seagate Free Agent 500 GB external, USB-powered HDD, so I decided to try another drive.

I bit the bullet and ‘started over’ with a Western Digital Passport Essential 1 TB USB powered version. I had started with an older WD externally powered MyBook, but that was a disaster. The drive went to sleep and never spun back up; the Apple TV was frozen during the file copy process. Apparently this is a known issue with the previous generation WD MyBooks. If you have one of these, throw it away and get one from the newer generation; the firmware doesn’t seem to be upgradable on the older ones (nice how that works, isn’t it?). By new generation, I mean the ones with the white, plastic top cover and the brushed aluminum looking case. I have a number of these and they have been very reliable and compatible.

After the WD MyBook failure, I cannibalized my laptop’s backup disk (the WD Passport) and went through the arduous process of changing drives and re-syncing my collection. I watched a movie last night and a couple of iTunes purchased TV shows today. Not a single stutter. Huzzah!

Since starting this process I’ve upgraded aTV Flash twice (currently on 4.1.5), I’ve changed drives twice (currently on the WD 1 TB Passport) and I’ve changed the default h.264 decoder setting twice (currently on the Apple h.264 default decoder).

When folks in the trade press complain about Apple TV being behind the competition on features, you can re-read my entire thread on this topic and understand why the Apple TV doesn’t support other media file types and external hard drives.

And, I have two words for Fire Core, LLC: COMPATIBILITY MATRIX. If you have anyone on your staff with a background in Engineering Test, ask them what that means and what value it provides to your customer base.

I’ll stop ranting… I have it working now, but would hesitate before recommending this product to my friends.

– Ken

We’re glad you’re back on track. I’ll pass your thoughts along as we’re always looking to improve.

Ken,

Are you still stutter free using the WD Passport 1 TB? The stuttering is killing me! I am using a rather new WD My Book 1 TB. Would love to fix this problem!

No, I am not stutter free and am about to pull the plug on aTV Flash.  I have tried a variety of settings, but I cannot stop the occasional stuttering, which is really, really annoying when you are trying to watch TV.

The behavior I am seeing with the 1 TB WD Passport is similar to what I experienced with the FreeAgent.  I am starting to wonder if this system can reliably work with a USB powered, portable drive.

I suppose I could try purchasing (yet another) HDD - this time, one that is wall-wart powered, faster and one that will probably stream better.  But, frankly, keeping with streaming demands should be trivial even for the slowest drive.

I have seen some different behavior after shutting down and rebooting the Apple TV, which anecdotally leads me to think that the real problem is aTV Flash.  Something is running in the background and hogging the CPU, causing periods of starvation and, hence, occasional stuttering video.  The gen-1 Apple TV is underpowered for what it's trying to do - running anything else at the same time will probably cause stuttering video.  Just a guess...

I am also discouraged by the lack of response to this issue from fireCore; other than the usual '...what types of files are you playing...' no one at fireCore seems to be experiencing the same problem, though clearly many of their customer are.  I actually saw a recent response to a similar posting that suggested trying a different cable :)

If I need to spend more money, then I am going to purchase a 2nd generation Apple TV and go back to streaming from iTunes running on my Mac Mini.  From what I've read, the A4 processor in the new ATV is much better for streaming playback, which is what brought me to this product in the first place.

Cheers and Good Luck,

Ken