imovie 06 formats and importing options

[Leo D]

I have some MPEG-2 home movies that I want to edit in imovie HD, and obviously they will need to be converted. They're currently in MPEG-2 format and the container is Mpeg Program Stream. They're in 720x480, some are 4:3 and some are 16:9 aspect ratio.

The only way I've found so far to copy the audio is to run them through MPEGStreamClip, which offers many options for exporting. I also discovered that if I select 720x480-NTSC for a video clip with an aspect ratio of 4:3, it comes out of MPEGStreamClip with an aspect ratio of 3:2. I can fix this by selecting 640x480, but I don't know if that's the best choice in terms of preserving quality. I haven't tried a 16x9 clip yet, but I'm assuming that I will have to choose something other than 720x480-NTSC for those as well, in order to preserve the aspect ratio.

I want to preserve the quality of the original videos, as much as possible, as I intend to create DVD's to be viewed on a widescreen TV. The videos are standard definition, so I don't expect them to look like HD, just as close to the original quality as I can possibly get. Can anyone suggest which options would give me the best results? I've tried some tests with H.264 which look pretty good, but it's hard to tell how that will work overall based on one or two short clips. One thing I like about H.264 is it uses the same chroma subsampling format (YUV420p) as the original videos, so the color and brightness characteristics are preserved.

Also, is it better to deinterlace before editing, after editing, or never? I've done a lot of research but haven't really found a definitive answer. Anyway, the H.264 conversion produces a clip that, according to VideoSpec, is progressive. It still seems interlaced, though, so maybe VideoSpec is giving incorrect information in this case.

Another thing I'm confused about...I can import the Mpegs directly into imovie from my camcorder, and imovie will automatically convert them into the QT .mov container (with audio). However, if I copy the same Mpeg2 from my camcorder to my computer's hard drive, imovie won't allow them to be imported, they're greyed-out. That seems strange? Some of my videos are no longer on my camcorder's hard drive (it's a Sony DCR-SR100), only in my computer, so those will have to be converted. But I'm wondering if it's a good idea, in the future, to import directly into imovie as Mpeg-2's, or convert to something else first. I've read that Mpeg-2 isn't really a good format for editing. Imovie is probably converting it to something else, but I haven't figured out a way to check that.

To summarize, I'm looking for suggestions regarding format, container, size, and deinterlacing. Hopefully, someone with more knowledge and experience than me can save me a lot of time...this trial and error stuff is getting old!

 

[spinnerlys]

It's almost always better to let iMovie do the conversion.

To find out, what iMovie uses, go to Users / YOU / Movies 7iMovie and look for the imported media and open it in QuickTime Player and then press CMD+I to open the Movie Inspector.

Most likely, iMovie converts that footage into .mov files using the DV codec.

 

[Leo D]

It's almost always better to let iMovie do the conversion.

To find out, what iMovie uses, go to Users / YOU / Movies 7iMovie and look for the imported media and open it in QuickTime Player and then press CMD+I to open the Movie Inspector.

Most likely, iMovie converts that footage into .mov files using the DV codec.

Your suggestion to let imovie do the conversion only applies to one scenario: when I have videos in my camcorder. That may be the best option for that scenario, but what about the Mpeg-2's on my computer hard drive that imovie won't allow to be imported? They have to be converted to something first, presumably through MPEGStreamClip to copy audio as well as video. Checking the format of the imported media as you suggested reveals that imovie is converting video imported from my camcorder to Apple MPEG2 SD Camcorder video, an option that's not available in MPEGStreamClip, so I have to select something else. MPEGStreamClip offers a variety of export options (e.g. export to QT, export to DV, export to other format, etc), and for each export option there are many, many choices (e.g. H.264, Apple Intermediate Codec, Apple MPEG-4 compressor, etc).

If I could just import these files from my computer into imovie, I would do so and see if the results were acceptable, but imovie won't import them. Those files will have to be converted to something before importing to imovie. Trial and error could take forever, so I was hoping for suggestions to at least narrow down my choices.

I also have about 20 Hi8 cassettes from my first camcorder, which I no longer have. I will probably have these tapes transferred to an external hard disk so I can get them into my computer for editing. They should be encoded optimally for import directly into imovie with minimal quality loss.

And finally, I am less confident than you that imovie will make the right conversion automatically, since imovie doesn't know what I'm going to do with the project. For example, the best conversion to make a DVD, and the best conversion for uploading to the internet, may be two different things.

 

[KeithPratt]

As you're bothered by quality and subsampling, I'd recommend Apple Intermediate Codec (which is 4:2:0) over DV (which is 4:1:1).

Use Streamclip to batch convert all to:
AIC, 720x480, 29.97fps, interlaced
Uncompressed audio, stereo, 48kHz

Now start a new 'DV Widescreen' iMovie project, save it and close. Then right click on the icon, select 'Show Package Contents', and drag all video files to the 'Media' folder. When you open your iMovie project again it'll tell you it's found some stray files in the Trash, and ask if you'd like to see them. Click yes and drag them all to the clips browser.

If you're mixing 16:9 and 4:3 you can either pillarbox or stretch the 4:3. I think iMovie will automatically stretch (when in DV Widescreen project), but to pillarbox you may need to find an app other than Streamclip that can pad 90 pixels on the left and 90 on the right (with output remaining at 720x480).

Once you've edited, now's the time to be tailoring the video for output. For DVD you want to leave it interlaced at 720x480, and if I recall correctly you can send it to iDVD directly. For the web you'll want to de-interlace and set dimensions to 854x480. For this I'd export using expert settings to match to those of input files (AIC, interlaced, etc.), then use Streamclip to de-interlace, scale and compress to H.264 for upload to YouTube.


This is the longer but higher-quality way. In the future, using iMovie to import direct from your camcorder will be less hassle and the quality might not be noticeably worse — you'll have to test and make up your own mind.