# Choppy video - what's the root cause?



## Moscool (Jun 8, 2003)

I occasionally get very choppy videos (streaming or download) and it is not easy to pinpoint the cause. I'm asking because it will have a bearing on my next choice of machine.

The obvious possible culprits are:

- Processor
- RAM
- HD speed
- HD space
- Video card

The processor seems to play a part 'cuz it seems to happen more often on my G4s than Intels. Note however that it happens on all machines.

RAM; not sure. Quitting aps doesn't seem to have any effect

HD space; ditto - 80 gigs free and still getting probs

Obviously can't compare HD speed or video processing directly...

Thoughts?


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## johnnyspade (Aug 24, 2007)

Are you certain it's not the videos themselves? Have you viewed them on other machines and they weren't choppy?


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## Moscool (Jun 8, 2003)

Good thinking. However this happens often enough for me to conclude that there's an issue at my end...


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## johnnyspade (Aug 24, 2007)

Hmm. Very unlikely to be a RAM or hard drive space issue. Maybe a codec issue? Ensure you have proper and up to date codecs for whatever format you're trying to play. If you can, post a link to a file in question.


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## MACenstein'sMonster (Aug 21, 2008)

Internet connection.

What is your speed?

My wife's uncle upgraded his speed from basic to high-speed for the same reason - huge improvement he claims.


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## EvanPitts (Mar 9, 2007)

^^^
That and... Choppy streaming video is caused by speed being choked when data is flowing inbound, so either your Internet is not fast enough for real time streaming, or they are throttling speed, or the source server is too overloaded. If the ISP is Cable, then the problem can be poor latency caused by too many people in the neighbourhood sharing the upload channel, so if the streaming works well at 2am but is bad at 8pm - then it is just a data overload.

If the video has been downloaded, choppiness can be caused by a number of factors, depending on format and the system. If it is an AVI - then you have to expect choppiness, since it is inherent in the protocol, and is really bad if someone overcompressed the file (so it may not look choppy on a swank new machine, but it is but you can't see it). You could convert a choppy AVI to M4P format and see if it is still choppy - and if not, it's just AVI being what it is.

If it is a standard format, choppiness may be caused by too many background tasks sucking up the CPU or memory. Also, there may actually be a conflict if you have loaded too many Codecs onto the system - so if you have Tiger or Leopard, you should try to use Perian only, if you can, as it is more optimal that running a zoo full of individually bad behaving Codecs.

HD can also add choppiness, especially at higher resolutions, which can only be remedied by a faster CPU coupled to a GPU that can handle the data throughput - though you may be able to optimize the system so that there are less tasks sucking up CPU, and more CPU dedicated to the HD video.

So there are a large number of variables to look at - it's hard to say where to begin - though Johnnyspade give sage advice - see if the videos run properly on other systems, preferably comparable systems, to narrow it down a bit.

Oh, and trying to stream or watch video over WiFi can be the main culprit, since the bandwidth is a major limit - so you should compare running over WiFi to that of just watching it off of the hard drive.


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## Reveeen (Aug 26, 2008)

There is no way to pinpoint the cause of your "problem" without getting specifics. Including, but not limited to, the quality of video you are trying to watch.

A quick test would be playing a "commercial" DVD in the system, this will eliminate immediate hardware (the computer itself) as the culprit, if it plays acceptably then you can discount ram, video, and processor, as the "problem".


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## IllusionX (Mar 10, 2009)

btw... no 1080p x264 on x3100/GMA950 alright ?
even the ATI x1600 (xt??) on a macbook pro won't play 1080p x264 properly.

then again, a 720p x264 video (mkv or mp4) plays choppy sometimes on my 2.2ghz macbook. (intel x3100)




(was it x264 or H264???)


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## Moscool (Jun 8, 2003)

Thanks EvanPitts. Lots to test... Can you clarify what you mean by the following? 



EvanPitts;806329... if you have Tiger or Leopard said:


> If it's a flash based video, I use Safari (4 beta)
> If it's a download I use Quicktime + Flip4Mac or Quicktime + DivX (both available in my system prefs)
> If QT doesn't work I use VLC 0.9.8
> 
> ...


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## kloan (Feb 22, 2002)

Flash video has been consistently choppy on every Mac I've ever owned. I've got a rev B Macbook Air and anything Flash-based is choppy while streaming (playing back from the HDD is hit and miss).

Blame Apple for your choppy video, not your hardware. It's Apple developers not being able to get it right.


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## EvanPitts (Mar 9, 2007)

Moscool said:


> Thanks EvanPitts. Lots to test... Can you clarify what you mean by the following?


It all comes down to what kind of video you are attempting to watch. The various video formats have different "drivers" called Codecs (which are used to encode and decode the digitized video). So something like QuickTime has a fair selection which will automatically run without needing anything extra. But for something like DivX or XviD, you need the extra to augment the library that something like QT or VLC will need, so they can be downloaded and installed, and life is happy. But if you are a person that had a need to watch videos that are in some arcane format, you will have to keep adding Codecs. Now this can cause some real hassles, as the various Codecs can end up in conflict.

So a utility like Perian builds a large number of Codecs into one unitary package - which squashes out any chance of conflict. Of course, I'd rather use a utility like iSquint / Handbrake / VisualHub to convert "alien" formats to something like M4P, thus avoiding the need to maintain Codecs on a number of machines, since M4P is inherent to QT.

The conflicts between the various Codecs can cause some real problems, but since it looks like you are basically doing QT+DivX, it should not be a problem. But to narrow down, you have to pinpoint which video formats are stuttering, and go from there. If it is something like an AVI, they will stutter, it's inherent in AVI - so generally speaking, converting AVI to M4P with one of the utilities like HandBrake should get rid of stuttering. Of course, the video file will grow, since the data compression will be removed - but so will the stuttering.

Stuff like Flash video is more problematic, as a number of factors can be at work - but as a generalized rule, the same path of converting the FLV to a standard format should smooth things out. I have a fair selection of FLVs that would stutter all the time on my system, but once converted to M4P - no problems. And remember that Flash video is intended for the fastest data transfer over the Net, so going to M4P will make the file bigger, but release the CPU from having to decompress the video before rendering.

That would be my first step, just to list those formats that are problematic - and then see if simply converting them to a standard format is the solution to the stuttering and stalling; then go from there.


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## Ottawaman (Jan 16, 2005)

kloan said:


> Flash video has been consistently choppy on every Mac I've ever owned. I've got a rev B Macbook Air and anything Flash-based is choppy while streaming (playing back from the HDD is hit and miss).
> 
> Blame Apple for your choppy video, not your hardware. It's Apple developers not being able to get it right.


Wouldn't we blame Adobe?


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## kloan (Feb 22, 2002)

Ottawaman said:


> Wouldn't we blame Adobe?


I don't see why.... Flash works perfectly fine on PCs.

I read somewhere that it was OS X and it's inability to process it properly. I don't believe it had anything to do with Adobe's end of things.


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## EvanPitts (Mar 9, 2007)

kloan said:


> I don't see why.... Flash works perfectly fine on PCs.
> 
> I read somewhere that it was OS X and it's inability to process it properly. I don't believe it had anything to do with Adobe's end of things.


On who's PC? Flash has been causing all kinds of problems on some of the PC's that people I know are running, and is a fairly acute problem with a few of the last "updates".

Of course, Java has been causing some real grief as well, with all kinds of failed "updates". Sun is becoming just as bad as Adobe at making crudwarez - though Adobe is still the world leader when it comes to cripplewarez and bloatwarez - they are blowing the Evil Empire out of the water these days in all three categories of software...


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## kloan (Feb 22, 2002)

Oh, I'm not sure about recent updates... I was referring to when I was using a PC, which was sometime last year.


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