Slow video conversion
May 27, 2008 9:24 AM   Subscribe

Why would a laptop convert videos to iPod formats so slowly? Is this normal? What changes to make it better? Possibly a new computer?

Unencrypted videos (MPEG2, some on the hard drive as .ISO) require between 3x and 6x (!) their playing time in order to get them down to an iPod nano format such as mpeg4 or H.264, 640 or 320 wide. So a one hour video could take up to six hours to convert. It's this slow with all major freeware programs and commercial programs, so it must be that the computer is not up to the challenge.

The laptop: WinXP Home with SP2, 1GB of memory, 60 GB hard drive, 1.5 GHz Celeron M processor. While converting videos, 100% of CPU time is devoted to conversion. About 300meg of RAM is still available for other uses (in contrast to 500 meg when conversion programs aren't running), according to task manager.

Is there any thing that can be changed to make a significant shortening in processing time (significant = bringing down the video conversion time to approximately the playing time). Or is it time to start looking for a new computer? If so, what laptop specifications should minimize video conversion time, and how much improvement would be seen?
posted by paphun123 to Computers & Internet (12 answers total)
 
This is an area where modern dual core (and quad core) machines really shine. Upgrade.
posted by w0mbat at 9:34 AM on May 27, 2008


FWIW, using a Macbook Pro (2.4GHz Core 2 Duo processor, 4GB memory, standard issue Apple laptop hard drive) I can encode a movie from a DVD to the iPod preset in about realtime, if not better, depending on the options I've checked in Handbrake . I'd say you're CPU-limited more than anything.
posted by mikeh at 9:35 AM on May 27, 2008


Response by poster: Any others agree that dual and quad core machines make the significant difference?
posted by paphun123 at 9:38 AM on May 27, 2008


Look for an external hardware encoder rather than a new laptop, unless you just want an excuse to buy a new laptop. El Gato makes the Turbo.264, but it appears to be Mac-only. Here's a Windows one for $60 that claims to encode at 5x faster than real time... YMMV, etc. Your CPU was not optimized for this kind of work. The chips in these external devices were. Now that you know what you're looking for (windows h.264 hardware encoder), I'll leave the googling and review-reading to you
posted by mumkin at 9:42 AM on May 27, 2008


Any others agree that dual and quad core machines make the significant difference?

Yes. You should get almost linear speedup with number of cores. Video encoding is a standard benchmark these days; a few minutes with Google and you'll find all kinds of processor comparisons.

RAM might also be an issue in your case. Watch your memory usage while you're encoding a video... if you're doing a lot of swapping, then you would benefit from an extra gig.
posted by qxntpqbbbqxl at 9:43 AM on May 27, 2008


Any others agree that dual and quad core machines make the significant difference?

Seconded. In fact, I had an old dual-G4 (800Mhz) that encoded much faster than a 2Ghz Intel.
posted by rokusan at 10:14 AM on May 27, 2008


Thirded. I use Handbrake on an AMD Athlon X2 2.8GHz dual-core with 2GB RAM and get slightly better than real-time conversion rates.

Before switching to Handbrake, I had one of these hardware encoders and saw only a slight improvement over using Handbrake. I think you only get a real performance gain if you're converting to YouTube-sized video. Given my hardware setup, I don't think it was worth the extra cost.
posted by phrayzee at 10:28 AM on May 27, 2008


With a 1.33ghz iBook, I got very similar encoding times - 3x play time or longer - whereas with my new 2.4ghz dual-core Macbook, I'm pretty much realtime. As others have noted, video encoding is nearly always CPU-limited at this point (though before too long, HD/CD limiting may start being a bigger issue)
posted by Tomorrowful at 10:34 AM on May 27, 2008


Response by poster: though before too long, HD/CD limiting may start being a bigger issue

What is HD/CD limiting?
posted by paphun123 at 11:44 AM on May 27, 2008


What is HD/CD limiting?

It just means that right now the CPU is the bottleneck, but that as improvements are made in that area, the speed of the hard drive and/or the CD/DVD drive may become the bottleneck instead.
posted by tyllwin at 12:01 PM on May 27, 2008


1.5 GHz Celeron M processor

This your cultprit. The celeron/pentium-m chip is an amazing piece of technology but its from March 2003. Its a 5-year old chip designed for low-wattage use and lightweight tasks- not multimedia encoding.

Your next laptop should be a core duo2 and you'll find encoding times to be significantly faster.
posted by damn dirty ape at 1:12 PM on May 27, 2008


and how much improvement would be seen?

FWIW, my core duo machine at home regularly does better than realtime. YMMV of course on codec, resolution, etc.
posted by damn dirty ape at 1:14 PM on May 27, 2008


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