Save video

[santiam]

I joined two video clips and saved them as a single clip. They are both .mov files. One is 18mb and the other is 15mb, so I assumed the new file would be 33mb. When I save the new file in .mpg, however, it is only 27mb. When I try saving it in .mov, it balloons to over 120mb. How should I save the new clip to maintain the original size and ensure I'm not losing any quality?

Also, when I save the clips it seems to be converting the original 640*480 aspect ratio to 720*480. How do I preserve the original aspect ratio? Thanks.

[Ron P.]

One is 18mb and the other is 15mb, so I assumed the new file would be 33mb.

If it was as simple as adding the two numbers that would be correct, but it's not. The file size is determined by the Bit-rate (VIdeo Data Rate) and the codecs being used.

Now when you tried to render using MPEG, I'm assuming here that it is NTSC DVD (MPEG-2), the bit-rate was probably lower than the clips in your project. MPEG-2 is a lessor compressed format than MPEG-4, so the file size should have ballooned at that point. When you tried to render to MPEG-4 again, what properties/codec did you use? It should not have such a huge file size. Try to keep the Bit-rate (Video Data Rate) as close to your original source clip's.

Also, when I save the clips it seems to be converting the original 640*480 aspect ratio to 720*480. How do I preserve the original aspect ratio? Thanks.

The Aspect Ratio is different than the frame sizes. You listed the frame sizes. To find the aspect ratio divide the width by the height (640/480= 1.3333, 720/480= 1.5). 1.333 is a 4:3 aspect ratio, wide-screen aspect ratio (16:9) is 1.777, so the 720 x 480 is not a true 4:3, and not quite a 16:9 aspect ratio.

If you're wanting to just maintain the frame size, then use a video file format that allows it. NTSC DVD does not. I don't know what you're intending on using the video for, DVD, uploading to the Internet, or just keeping it to view on your PC. For PC viewing (internet or just personal) I would look at using WMV.

Finally I made the assumption that you're using one of the more current versions of VS, like VS X3 or VS X4. These do not allow rendering to non-DVD compliant MPEG-2 or MPEG-1. VS X2 and older does.

[santiam]

Thank you for your prompt and thorough response. Yes I am using VS X4. I just want to save my clips in their original .mov format. I thought this would allow me to maintain the same level of picture quality and bit-rate, as you mentioned.

But for some reason this increases the size of the clips dramatically, and changes the frame size. I was hoping to make a DVD, so using a DVD-compatible format is important. Any other ideas?

[Trevor Andrew]

Hi

Right click your original Mov file and select properties, what are they?

What are you trying to make……..
Are you intending to use the final video for the internet, maybe YouTube, upload to web site etc
Or are you intending to burn a standard DVD?

[Ron P.]

I was hoping to make a DVD, so using a DVD-compatible format is important.

For your video to be DVD Compliant, they must be in MPEG-2. So I would convert them to PAL or NTSC DVD. This will be done either by you in the Share>Create Video File, or by whatever DVD authoring program you choose to use, just prior to burning the disc.

[Trevor Andrew]

Hi Ron

Sorry I missed that text but saw this from the first post.

Also, when I save the clips it seems to be converting the original 640*480 aspect ratio to 720*480. How do I preserve the original aspect ratio? Thanks.

[Ron P.]

Since Trevor brought back to the forefront, the concern about the conversion changing the original frame size (640 x 480) to 720 x 480, I'll again emphasis that video files that are going to be used to burn a video DVD must meet the DVD Specs, and 640 x 480 frame size does not meet those specs.

Corel has over the recent versions, since VS X2, simplified having to know a lot of the intricate details with video editing and producing video discs. With VS X2 you had the choices of MPEG-1, MPEG-2, AVI, and others. You could have selected MPEG-2 for the compression, created your video and subsequently tried to burn your DVD. However you may have found that for some reason your MPEG-2 file was being re-coded in the burn module. You understood that for video DVDs the video file format must be MPEG-2. However there's several other attributes within an MPEG-2 that also must be met. Frame size, bit-rates, audio compression are some of them. So in VS X2 (and earlier), you could create an non-compliant MPEG-2 by using a frame size of 640 x 480. Prior to being burned onto disc, VS would re-code the video file, making the frame size one that is compliant.

So now if you notice when you select MPEG as the file type, you're presented with NTSC or PAL DVD. If you would go the Custom route, (Share>Create Video File>Custom), then select MPEG as the file type, and press the Options button, and go to the compression tab, you still only have NTSC or PAL DVD. Now go back to the General tab, and press the drop-down menu for Frame Size, you will see what those allowed frame sizes are;

If's it not one of those than it can not be used on a video DVD.

This next screenshot is from VS X2. I used the same route to obtain the frame sizes shown. As stated before, MPEG-2 can also be non-compliant. You see here that 640 x 480 is listed. Selecting it would not give you a DVD Compliant MPEG-2 video file.

[santiam]

Thanks again for everyone's input. It looks like the bit-rate of MPEG-2 is lower than the bit-rate of the original .mov file. So this necessarily means I will be losing some video quality when making a DVD with these clips? If so, I find that a little disappointing.

[Ron P.]

It could have an affect on the quality, because the bit-rate does determine this. However one thing that is jumping out at me, that will definitely have a negative affect is the frame sizes. If your original MOV files are using the frame size of 640 x 480, they will be enlarged. This is similar to taking a photo and zooming in on it. With your MOV files the only data available is no larger than 640 px wide by 480 px high. For the DVD, the program will add 80px to the width. These additional pixels are made up out of nowhere. The best that it could do is just use adjacent pixels and guess at how it is suppose to look.

Quite simply put, you can not use MOV as a file format on video DVDs. You're limited to MPEG-2 for Standard-Def video DVDs. High-Def videos can use different codecs, such as AVCHD, or the HDV specs for MPEG-2. These are rules set up by the international community, so when you put a DVD into a DVD player it will play. It has nothing to do with Corel, Adobe, Pinnacle or any other developers. I just sense in your post that you may think Corel VS is responsible for not allowing you to use your original MOV files to burn to a video DVD. You could just burn a data disc, using your original source MOV files, then use a PC to watch them. But for an actual video DVD, that you could play in a stand-alone DVD player, the rules are set in stone.