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Why does video encoding take so long?

DannyNguyener

DannyNguyener

macrumors regular
Original poster
Mar 13, 2010
117
0
I'm ripping TV shows from a disc using handbrake. My laptop is heating up and lagging like crazy. It says encoding and is taking forever. Why?

My specs:
2010 13"MBP
2.4ghz
8GB ram
330m nvidia
500GBHDD
 
Because it takes time to decode the MPEG-2 encoded video from the video DVD (if you meant that with "disc") and decode it again as MPEG-4 encoded video with much smaller file size and the same quality.

Be glad you don't work with AVCHD footage on that thing.
 
lack of cpu cores, encoding a tv show on my i7 box literally takes about 10~15 minutes.
of course my i7 is on an ssd raid and is clocked at 4ghz


10~15 is off the top of my head, I stopped encoding when my cap card went belly up.
 
simsaladimbamba said:
Because it takes time to decode the MPEG-2 encoded video from the video DVD (if you meant that with "disc") and decode it again as MPEG-4 encoded video with much smaller file size and the same quality.

Be glad you don't work with AVCHD footage on that thing.
Click to expand...

What's AVCHD? So what kind of specs do you got to have to rip videos efficiently and smoothly? I thought I had it good for a laptop....
 
DannyNguyener said:
What's AVCHD? So what kind of specs do you got to have to rip videos efficiently and smoothly? I thought I had it good for a laptop....
Click to expand...

AVCHD is another video format... for more info, google or wikipedia is your friend. Decoding and re-encoding is a vast number crunching exercise even for a single frame. If you have a program at say 30 frames per second, it will take time to re-encode this, even for servers.

Just curious, but how long did you expect your re-encode would take to complete with handbrake? A 1hr programme would certainly not take 5 mins to do... not a chance.
 
roliath said:
lack of cpu cores, encoding a tv show on my i7 box literally takes about 10~15 minutes.
of course my i7 is on an ssd raid and is clocked at 4ghz


10~15 is off the top of my head, I stopped encoding when my cap card went belly up.
Click to expand...

I want that...My MBP takes 1 hour and 10 minutes to convert hour long tv shows. Im finally down to the last 200 episodes on a drive that had altogether about 2400 episodes between every tv show.

Of course I have 4 computers all converting them simultaneously.
 
DannyNguyener said:
What's AVCHD? So what kind of specs do you got to have to rip videos efficiently and smoothly? I thought I had it good for a laptop....
Click to expand...

Actually that laptop is a core 2 duo. Unfortunately that's far from a cutting edge CPU these days, and encoding video hits the CPU very hard.

I wouldn't encode video on a laptop unless I absolutely had to.

You need as many cores as possible, the highest clock speed possible, and I'd want a desktop i5 or better.
 
brentsg said:
Actually that laptop is a core 2 duo. Unfortunately that's far from a cutting edge CPU these days, and encoding video hits the CPU very hard.

I wouldn't encode video on a laptop unless I absolutely had to.

You need as many cores as possible, the highest clock speed possible, and I'd want a desktop i5 or better.
Click to expand...

Why desktop i5? I thought for laptops the intel core 2 duo was powerful and would last quite a while?
 
DannyNguyener said:
Why desktop i5? I thought for laptops the intel core 2 duo was powerful and would last quite a while?
Click to expand...

The core 2 duo is an excellent CPU for many things, and it's absolutely appropriate for a 13" notebook. However it's still an aging architecture that's coming up on 5 years old.

It's not so much that the CPU is sub par for that machine, it's that the machine you are using isn't an ideal tool for video encoding. Video encodes are amongst the most CPU intensive applications. If you want to do it on the 13" MBP you can expect it to run really hot and take forever.
 
...

it takes a long time on my 2.4ghz macbook pro and it also takes a long time on my i3 imac...it needs serious cpu power like a very fast i7
 
DannyNguyener said:
So what did people use for encoding before i7's?
Click to expand...

The fastest thing we could get our hands on.

I used:
-Overclocked quad Core 2 desktop
-Then i7 2.66 quad
-Now, 6 core 3.33GHz i7

Video encodes will always benefit from additional cores, higher clock speed, and a more efficient architecture. It's one of those applications that will always make use of whatever power you throw at it.

Also, since it uses your CPU at 100%, it presents a cooling challenge. It's very possible that your MBP is throttling the CPU down due to heat issues. That's why it's ideal to do this on a desktop.
 
Last edited:
I have the 2009 13" mpb so my machine is wimpier than yours. I've used handbrake on many movie dvds and I don't have a problem with it. I use the canned high profile setting.

The first thing I do is put the mpb on little wooden blocks to raise it off of the table about an inch (better airflow under the belly).

Then I start smcfancontrol and set the low speed of my fan (which normally spin at 2000 rpm) to 5000 rpm.

Then I start handbrake. A 2 hour movie takes maybe 3-4 hours to finish. My mbp's highest temp is about 170 F.
 
xlii said:
A 2 hour movie takes maybe 3-4 hours to finish. My mbp's highest temp is about 170 F.
Click to expand...

This is perfectly fine if you don't do many encodes, since you can let it run overnight if needed.

On the other hand, if you encoded video for a living, or were looking to convert a library of HD content.. or 800 DVDs you'd just be killing your notebook and taking forever.
 
Core 2 Quad? Hexacore CPUs?
I used a core 2 duo (dual core processor) to encode, but that was 2006... Now if I was looking for a CPU for serious encoding I'd pick up a 6 core or more processor.
Then I start handbrake. A 2 hour movie takes maybe 3-4 hours to finish. My mbp's highest temp is about 170 F.
Click to expand...
The F? My MBP from 2006 could crunch through a 2 hour movie faster than that... What encoding settings are you using?
 
brentsg said:
This is perfectly fine if you don't do many encodes, since you can let it run overnight if needed.

On the other hand, if you encoded video for a living, or were looking to convert a library of HD content.. or 800 DVDs you'd just be killing your notebook and taking forever.
Click to expand...

I've done about 100... for a while I was doing one or two a night. While it is running handbrake I don't use the machine.

You are correct anyone who does encoding for a living should have a machine with multiple cpus and enough memory and cooling. I disagree that it will kill someone's laptop.

I rev the fans up to 5000 rpm before I start handbrake because I discovered that apple's fan software wouldn't rev my fans up until the temp got into the 190s F. It is much easier to keep the machine cool from the start than to try lower the temps 20 degrees... after the machine gets that hot and then the fans kick it... just too late.
 
thejadedmonkey said:
Core 2 Quad? Hexacore CPUs?
I used a core 2 duo (dual core processor) to encode, but that was 2006... Now if I was looking for a CPU for serious encoding I'd pick up a 6 core or more processor.
The F? My MBP from 2006 could crunch through a 2 hour movie faster than that... What encoding settings are you using?
Click to expand...

The canned high profile setting...
 
DannyNguyener said:
I'm ripping TV shows from a disc using handbrake. My laptop is heating up and lagging like crazy. It says encoding and is taking forever. Why?

My specs:
2010 13"MBP
2.4ghz
8GB ram
330m nvidia
500GBHDD
Click to expand...

Try checking your computer specs again, as you are getting a 13" confused with a 15".

13" does not have 330m
 
Use a 12-core Xeon X5690 3.46GHz Dual Processor machine to render, you see your encoding speeds speed up, it's about the fastest desktop machine for encoding right now. 24 Virtual encoding cores @ 3.46GHz per core in Handbrake.
 
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