How do you get the best quality on Apple Tv using Imovie08?

Question

I have done some searching and still have some questions. I have been creating movies from my home movie DV (digital8) tapes. when I am done I export using the highest setting. I am thinking that most D8 cameras are 480i or P. When exported higher does the computer upscale this? Should I export in 640x480 and let the tv do the upscaling or does the DV have enough lines to do the higher setting. There is a lot of discussion about 06 but since I started with 08 I find it difficult to navigate and after several posts it seems that the quality is no different. I do have quicktime pro so if it is better to export from Imovie to quicktime then to apple tv into Itunes please advise.
Thanks
GE

Answer 1

My Question is on QTP what should the data rate be for DV.
It depends on which variant you are using. The DV Stream options for DV and DVCPRO (also known as DV25 and DVCPRO25) are typically between 28.5 and 29.0 Mbps for the video track and the same for the audio track while DVCPRO50 has twice that data rate for both audio and video tracks. The QT DV and DVCPRO video codecs used by the "Movie to QT Movie" option are typically about 23 Mbps with DVCPRO50 coming in at about 46.0 Mbps. As to the audio data rate component, it all depends on which audio codec you use. Most people probably opt for the Linear PCM 16-bit 48 KHz combination which is usually on the order of about 800 Kbps.
Original Data rates for some full QT conversions are over 20k This is as you know not supported by ATV.
Correct. And, since iMovie '08 converts from whatever compression format that was originally imported to the application, doesn't it make more sense to export DIRECTLY to the final compression format you plan to use with your TV device? You can export directly/indirectly to iTunes (i.e., via the "Movies > Sharing" folder) using the sharing option or you can export via the "Using QT" option to either the contextual (CAVLC) Progressive Main Profile preset or using your own custom settings.
If one of you would be so kind as to list the largest file that can be played in ATV using quicktime in the form of input that would be great.
The maximum H.264 display dimensions at 24/25 fps is 720p (1280x720) and at 30 fps 540p (960x540) and a max video data rate of 5 Mbps with AAC-LC audio limited to 160 Kbps and a 48.0 KHz sampling rate in M4v, MP4, or MOV file containers. The maximum MPEG-4 Simple Profile dimensions of 720x432 at 30 fps at a max data rate of 3 Mbps with AAC-LC audio limited to 160 Kbps and a 48.0 KHz sampling rate.
Since I am still uneducated about the relations to all these numbers and see different sizes that play ok in ATV I need some advice. I have even exported from quicktime and let Itunes compress to ATV. The file was bigger than what was sent from Imovie, the data rate was more, but per second was the same.
Pre-sets and user settings "target" a data rate but content variables such as lighting, contrast, color saturated, amount of action and its motion vectors, frequency of scene changes/key framing, etc. all affect an end product. Further, when dealing with multi-pass encoding, the data rate excursion (i.e., variation above and below the targeted video data rate) may also come into play. For instance, an iPod file target with a video data rate of 1500 Kbps in extreme cases may have an instantaneous data rate between 600 Kbps and 3750 Kbps using the "Download" setting and can prevent iTunes synchronization. Haven't looked that deeply into TV since I use a custom iPod setting for day-to-day use of a a single file for iPhone, iPod, TV, as well as, web site, server, peer-to-peer, QTL, and reference file sharing of media. (I.e., I use my original DVDs when I want "full" audio and video quality.)