What is HDV? It is the video format that was developed by Japanese electronics makers such as JVC and Sony. JVC first introduced an HDV camcorder that supported both standard DV (480i) and HDV (720p30). Sony’s camcorder supports HDV 1080 interlaced format. The file extension used for HDV is .m2t. And its video compression is based on MPEG-2. So the average bitrates are about 25 Mbit/s for 1080i and 19.7 Mbit/s for 720p, respectively. Furthermore, the audio compression is MPEG-1 Layer II (MP2) with a bitrate of 192 kbit/s per channel.
In order to edit HDV files on Macs, they must be converted into appropriate formats. And the best video application for this purpose is MPEG Streamclip from Squared 5. MPEG Streamclip lets you read M2T-formatted files. There are many video formats and compression methods. And which format and compressor to use depends on how you are going to use your video clips.
For example, if you are going to use your HDV clips with Apple’s Pro applications including DVD Studio Pro and Final Cut Pro, then you should convert the format into MPEG. (Choose ‘Convert to MPEG…’ under ‘File.’) In this way, you will lose as little data as possible due to the conversion. Then use Apple’s Compressor to read/convert MPEG files and import them to Pro applications. Note that converting a clip into MPEG requires Apple’s MPEG-2 Playback component.
If you are going to edit HDV clips with other applications such as iDVD, iMovie and Adobe After Effects, then you have largely two options. One is use of DV compression, which takes a lot of space because it only uses spatial compression (intra-frames). Another option is use of MPEG-4 (DivX, H.264, MP4, XviD…). A choice of DV or MPEG-4 is up to you. If you aren’t sure, think about why MPEG-4 was developed in the first place.
If you are going to use MPEG-4, choose ‘Export to QuickTime…’ under ‘File’ and select a compressor you prefer to use. H.264 is a good choice if you don’t know which compressor to choose.
Furthermore, if you have Toast and Apple’s MPEG-2 Playback component, you may actually want to convert your video into MPEG and then drop it onto the Toast window to create a DVD. Read admin’s comment below for more information.
The HDV video clip we used comes from VASST TRAINING. And the following video clip is compressed in H.264 (file size: 1.8 MB). It’s posted with written permission being granted by Sundance Media Group/VASST.
Click on the button to watch it. 
We forgot to mention what to do when you have Toast. If you have Roxio’s Toast Titanium, then convert your m2t file into mpeg with MPEG Streamclip. Then simply drop the converted file onto Toast and select ‘DVD-Video.’
Then? Then just plug and play. You can play back Toast’s DVD video with VLC from VideoLAN or Apple’s DVD Player. If you aren’t sure of what you are doing, save the toast window as a disk image and see if you can watch it with VLC or Apple’s DVD Player before buring a DVD.
duel g5 powerpc, lots of ram, os 10.4.10
sdk 24, mpeg Sclip 1.8, qt with mpeg2 converter, imovie6, toast8
Everything works great and have had much success with converting my .m2t files. I want to know more about compression and the different file formats. I am taking the .m2t to dvd and want the highest quality with little compression. what do you think will work best. It is coming off a dvr and I want to put it back on a dvd. thanks,
ı want to program.wery good