Joel E. Tohline

Alumni Professor
Department of Physics & Astronomy
Louisiana State University

Generating Animation Sequences in High-Definition
for HDTV Broadcasts

Quicktime Movies for Standard Digital Displays

Over the past 10 years, we have routinely generated animation sequences (movies) from our 3D hydrodynamic simulations in order to illustrate the results of each simulation for both local analysis and for more public broadcast. In the past, we usually have produced Quicktime-format movies (using Quicktime's default "Sorenson Video 3" codec) in which the pixel resolution of each movie frame is relatively low – typically 640 × 480 pixels. [See, for example, this movie ensemble, or this collection from a recent simulation.] The accompanying page outlines the steps that we generally have followed in order to create each of these movies.

Our objective, now, is to develop tools that can be used to routinely generate animation sequences at "high definition" (HD) resolution (frames with a 16:9 aspect ratio and 1920 × 1080 pixels) in a format/codec that can be immediately broadcast to HDTV monitors. To begin with, we will be generating and/or editing our HD animation sequences on a Power Mac G5, and our specific aim is to develop a means by which these HD movies can be displayed on a Dell W3000 LCD monitor, which includes a YPbPr component input to receive and display HDTV broadcasts.

Meeting the "High-Definition" Challenge

We expect that the following steps will need to be taken in order to generate and then immediately view a high-definition movie of our hydrodynamic simulations.

  • Follow the steps numbered 1 - 4 on the accompanying page exactly as they have been outlined for the production of standard Quicktime movies, except the Maya MEL script should be modified in such a way that each generated TIFF image has a resolution of 1920 × 1080 pixels. [Each 24-bit color TIFF image will then have a binary file size of approximately 1920 × 1080 × 24 bits = 6075 KBytes.]

  • As described in step number 5 on the accompanying page, a large number of sequentially numbered TIFF images should be produced to serve as the sequential frames of the movie, but the concatenation of these images into a single movie file will need to be handled more carefully than before. Initially, our strategy is

  • to concatenate the TIFF images using Quicktime Pro's default codec (expecting to generate a ".mov" output file type);

    Answer (tentative): From information that I've been able to gather over the web, I suspect that Quicktime 7 does not produce HD MPEG-2 on output, but with an appropriate program extension (see below) it should be able to play these files.

  • this file will be imported into Final Cut Pro HD [it will be necessary to upgrade Final Cut Pro HD to version 5 – probably 5.0.2 – which, in turn, will require that we upgrade the operating system of our Power Mac G5 to OS 10.3.9 (panther), but not all the way to OS 10.4 (tiger)];

  • then the movie will be exported from Final Cut Pro 5 HD using "Compressor 2" and the "HD MPEG-2" codec (expecting to generate a ".m2v" output file type).

    Answer (tentative): According to this on-line PDF manual that reviews compressor's new features, apparently the answer is "yes," because Compressor 2 supports "HD resolution video formats up to 1920 × 1080, with bit rates up to 29 Mbps."

  • We should be able to open this ".m2v" file with Quicktime 7 Pro (although it looks like it will be necessary to purchase a separate "MPEG-2 Playback Component"), and play it on the Power Mac's digital monitor without any problems. But in order to view a "1080i" movie at its full resolution, we'll have to use one of Apple's HD Cinema HD Displays [the 23" model M9178LL/A has a native resolution of 1920 × 1200 pixels; the 30" model M9179LL/A sports a 2560 × 1600 pixel resolution].

  • The final step is to demonstrate that the ".m2v" file can be displayed directly onto an HDTV monitor. In particular, as mentioned above, initially we would like to show the movie on a 30-inch, Dell W3000 LCD TV, which should be able to display a 1080i (interlaced) or 720p (progressive) signal that it receives through an HDTV, YPbPr component input. [The Dell W3000 LCD monitor has a native resolution of 1280 × 768 pixels, so in practice a 720p broadcast (16:9 = 1280:720 resolution) will be represented faithfully in HD, but a 1080i (16:9 = 1920:1080 resolution) will not. Nevertheless, we should be able to use this monitor to test whether the HD MPEG-2 compression scheme works even at the highest HDTV (1080i) resolution.]

    One path that should lead us to this goal is to purchase a product from Convergent Design called HD-Connect LE™. This box is advertised to accept an HD MPEG-2 stream through a (IEEE 1394a) FireWire and convert it on-the-fly to an HDTV-compatible signal that is transmitted via a YPbPr component output stream.

  • Summary Expectation:    If we run a cable from the 400 Mbps (6-pin) FireWire port on our Power Mac G5 to the 1394a port on the HD-Connect LE, and run three cables from the YPbPr ports on the HD-Connect LE to our Dell W3000 LCD monitor, we should be able to play any of our "HD MPEG-2" (m2v)-formatted movies with Quicktime 7 Pro on the G5 and simultaneously view the movie on our Dell W3000 LCD "HDTV" monitor.

    Question: I am assuming that the G5 will automatically recognize that its 6-pin FireWire port is attached to a peripheral device (the HD-Connect LE) and that it will automatically stream the Quicktime movie out to that device, but is this a correct assumption?

    Of course, if all of this works as planned, we will have accomplished two, much broader goals: (1) With our "G5 plus HD-Connect LE" setup, we should be able to play our m2v-formatted movies on any HDTV display that accepts a component (YPbPr) video input; and (2) our m2v-formatted movies should be "broadcast ready," in the sense that we should be able to send these movie files to anyone else who has the ability to display or broadcast HD-quality movies.

    — strategy developed in August, 2005

    Footnote:    I continue to be amazed by the large divide that separates the digital computer world from the television broadcast industry. This divide was understandable back in the days when a computer monitor's "digital RGB" signal had to be converted into an "NTSC (or PAL) composite analog" signal for analog video recording or over-the-air analog television broadcasts. But one would think that because the broadcast community is converting from predominantly analog to predominantly digital communications and "HD" broadcasts, in particular, are largely derived from digital media, the two worlds would virtually merge. Alas, the formats required for HDTV broadcasts have been built upon an entrenched history of analog and interlaced television signals. So the divide is destined to remain for quite some time into the future. One of the best on-line accounts that I have found of the history of television broadcast formats has been provided at a URL entitled video-basics.

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