capture options MPEG vs AVI - the reality ??

backhojo · Post by **backhojo** » Tue Sep 12, 2006 6:17 pm

how processor intensive is it to capture in MPEG format. I am running an AMS athlon XP 2600 (2.1GHZ) with 1gig of RAM and 30Gig of free hard drive space. reading the advice on tutorial and using my gut feel i think it would be better to capture in MPEG as it takes too long to convert from AVI to MPEG. my processor falls a little short of the 2.5 ghz guidelines but an upgrade would be very expensive as 2.5 GHZ + is still quite costly. I would be interested in real experiences others have had - will i be OK ?? thanks.

TDK1044 · Post by **TDK1044** » Tue Sep 12, 2006 6:50 pm

With a decent capture device and a 2.1GHZ processor, you would be perfectly fine capturing MPEG2 video. Obviously, the usual statements about closing down unnecessary background progams during capture applies. For years I captured and edited MPEG2 video with no problems running a 1.8GHZ processor.

backhojo · Post by **backhojo** » Tue Sep 12, 2006 7:01 pm

thanks - what do you mean by "a decent capture device" ?? i am capturing miniDV using IEE1394 ? can the firewire card affect how well i capture or were you refering to analogue footage ?

TDK1044 · Post by **TDK1044** » Tue Sep 12, 2006 7:06 pm

Your method of capturing is fine and you have plenty of RAM. I've always captured MPEG2 using ATI AIW cards and I have had no issues at either 1.8GHZ or 3.0GHZ.

DVDDoug · Post by **DVDDoug** » Tue Sep 12, 2006 7:26 pm

thanks - what do you mean by "a decent capture device" ?? i am capturing miniDV using IEE1394 ? can the firewire card affect how well i capture or were you refering to analogue footage ?

Some analog capture cards (including my Hauppauge card, and I think, some of the ATI All-In-Wonder cards) have built-in hardware MPEG encoders. That takes the load off of the CPU & data bus. With a hardware MPEG encoder, there is actually less demand on the computer... The data is already compressed when it gets to the data bus, so the data bus is handling less data, at a lower data rate, and the CPU doesn't have to do anything except "direct traffic" on the data bus!

That does not apply in your case. If you are capturing from a DV camera, I recommend that you capture to AVI/DV and let your computer take it's time with the (CPU intensive) MPEG encoding. Again, the CPU is only required to direct traffic during capture. Of course, you are free to experiment with MPEG capture... It may work perfectly with your set-up and procedures.

backhojo · Post by **backhojo** » Tue Sep 12, 2006 10:07 pm

how do i change from AVI to MPEG ??? i am looking at the capture screen but cant find any options.....this software is very frustrating !!!!

Post by **Ron P.** » Tue Sep 12, 2006 10:15 pm

In the Capture Step, Click on Capture, then the 3rd Option down Format has a pull-down menu. Click it for other capture format options. MPEG is included..

backhojo · Post by **backhojo** » Tue Sep 12, 2006 10:19 pm

sorry !!! i can see that now....what was confusing me is that this was set to DV. I think all the clips i have captured so far have been DV not AVI - what are the consequences of this ?? everything seems to have worked OK but it takes an age to write the DVD so i was going to experiment - will AVI be quicker than DV ??

thanks for all your help - as you can tell i am new to this and find the manuals / help files too simplistic...they simply dont explain things as good as all the guys on here !!! cheers

Post by **Ron P.** » Tue Sep 12, 2006 10:30 pm

Ok not to confuse you anymore, BUT DV is contained in the AVI wrapper. DV is Digital Video, which is what is transfered using Firewire. So if you have captured to DV it was AVI. Now with that, Full Uncompressed AVI is different then DV.

DV = about 13gig per hour of slightly compressed video.
Full Uncompressed AVI = about 65 gig per hour.

I also echo (too) that if at all possible, Capture and Edit in DV(avi).

DVDDoug · Post by **DVDDoug** » Tue Sep 12, 2006 10:33 pm

I think all the clips i have captured so far have been DV not AVI... - will AVI be quicker than DV ??

Don't panic! An AVI file is a "container" format. It can contain DV, MPEG, DivX, etc. I assume you have a .AVI file that contains DV.

The conversion from DV to MPEG-2 is probably faster than converting anything else to MPEG-2. People often complain that it takes 10-12 hours to convert a DivX file!!!!

sjj1805 · Post by **sjj1805** » Wed Sep 13, 2006 1:35 am

Consider this.
Lets take a 1 hour video on your camcorder.
To transfer this to your computer hard drive in its native DV (avi) format will take 1 hour - the amount of time taken to play the video.

Now at some point in time this video has to be converted to MPEG2 for it to be used as a video DVD (VOB files). Does that conversion take
1. Less than a hour
2. A hour - the same as the video
3. Longer than a hour.

The answer will be 3 - longer than a hour. don't take my word for it - try it for yourself. Here the computer is taking its time and doing a good job of converting from one format to the other.

Now lets step back a bit and capture that same 1 hour video from the camcorder to your computers hard drive. You are now forcing the computer to perform that capture in 1 hour. Do you really expect that the same quality can be achieved.

As DVDDoug has pointed out, do not confuse transfering video from your camcorder with recording from an analogue source such as a TV card which has been purpose built and is equipped with a hardware MPEG encoder.

maddrummer3301 · Post by **maddrummer3301** » Wed Sep 13, 2006 5:50 am