File compression

Uilleand · Post by **Uilleand** » Mon Aug 18, 2008 8:08 pm

I've got a ton of lovely video currently sitting on my Canon HG10 camcorder that is of absolutely no use to me. This is my 10th day of swimming through the sea of information and my eyes are starting to cross.

I can open the high-def files in ULead, no problem, but I want to convert them to a file that I can use in other video editing software - notably iMovie 06 on my mac. So, I'm thinking AVI or MPEG should be fine, right? Except making that conversion turns 3 minutes of video into a 28 Gig file!!!
Can someone please recommend a file type, or some place to see exactly which settings I should be using when I hit that 'export' button? I'm obviously doing something wrong, and I can't for the life of me figure out what to change.
Thank you.

DVDDoug · Post by **DVDDoug** » Tue Aug 19, 2008 2:50 am

This is my 10th day of swimming through the sea of information and my eyes are starting to cross.

Digital video is not easy. I think the many different video file-format variations are at the root of this big mess we're all in!

I don't use a Mac, and I've never used Movie Factory to "export" a file... Somebody else can probably give you more-specific help.

Can someone please recommend a file type, or some place to see exactly which settings I should be using when I hit that 'export' button

There are so many formats... What formats can iMovie handle? What final-format do you want, and/or what is your target platform? (A standard DVD?, Blu-Ray?, YouTube?, etc?) Do you want to keep it high-definition?

So, I'm thinking AVI or MPEG should be fine, right?

Well... "AVI" is not a single format... It's a "container format" that can contain uncompressed AVI, AVI/DV, AVI/DivX, or anything else. There are 3 basic variations of MPEG (MPEG-1, MPEG-2, MPEG-4), and there are variations of each format, including bitrate and resolution variations.

Are you saying that you can't hook-up the Canon camera directly to the Mac? If your computers are networked, you may be able to copy the unaltered HD file directly from the PC to the Mac... But I don't know if iMovie can handle the format.

Except making that conversion turns 3 minutes of video into a 28 Gig file!!!

I don't know what format that is, but file size is a function of bitrate, and of-course, playing time. For smaller files, use a lower bitrate....

You can estimate file size with the following formula:
File Size in MB = (Bitrate in kbps x Playing Time in minutes) / 140

The formula works for any video format as long as you include the audio bitrate, and consider use the average bitrate if you're using variable bitrate encoding.

Uilleand · Post by **Uilleand** » Tue Aug 19, 2008 3:15 am

Actually, I have the camera hooked up to my PC...because that's the only place the Corel software works. I just want to convert the HD files into something smaller and more managable, so I can transfer them to the iMac via keydrive, or some such thing.
Any MPEG format or Quicktime format would be fine ... just not at 28 gigs! *sigh*

Post by **Ron P.** » Tue Aug 19, 2008 3:57 am

The huge file size is occurring because MPEG-2 is a lessor compressed file format then what's on your camcorder. It probably is using HDV or AVCHD. Those are both very highly compressed formats. So when you convert it to a lessor compressed format, the file size is going to increase. If you take a piece of aluminum foil, and start folding it over and over until it is real small, you would have a highly compressed piece of foil. When you change it to a lesser compressed state (ie; unfold it), it gets larger doesn't it?

Lowering the bitrate would help in decreasing the file size. HD video will use bitrates of 15k or 25k, while SD can use around 9k (give or take a few).

Using another SD codec (compression) format such as MPEG-4, DivX or Xvid may help to get the file down to a manageable size for your intended platform. Corel's video editing program, VideoStudio is able to produce such files, and has a feature in the Share step called Export to Mobile Device.

In the Export to Mobile Device you have template options to include:

etech6355 · Post by **etech6355** » Tue Aug 19, 2008 6:35 am

Uilleand,
What version of MF are you using? The version that came with the camcorder? MF5.6SE or MF6/7.

What format are you using? PAL or NTSC.

I would suggest making them dvd compliant which would be the mpeg2 format.
Depending on the quality you recorded the original videos in (which is the AVCHD format (H264 codec)) your mpeg2 files may come out the same size. It depends on how you originally recorded them in your cam. I think the highest bit-rate for your camcorder is 15MBS. DVD/Mpeg2 is usually about 8MBS so they would come out smaller.
Need to know what version of MF your using and your country format for anyone to help you out.

There are other users in this forum that use your same camcorder.

BTW - You can experiment a little on your own. I think your camcorder can also record directly in the standard definition dvd/mpg2 video format which you could then use those videos directly on the mac. They should have a .mpg extension.

For converting your high definition videos to standard definition videos for the Mac to be able to use then you need to provide more information.
Check your users manual.

randazzo · Post by **randazzo** » Tue Aug 19, 2008 8:50 pm

Did you perhaps save it in uncompressed AVI format? That takes a huge amount of disk space. Although 28 Gig seems even then an awfull lot for 3 minutes of video.