720 x 540, huh?…? Don’t worry, most likely it is fine.
problem solved, remember this, technical/production
notesatlarge.com
A client I sometimes consult for was making MPEGs of some commercials to be submitted to the competition at Cannes Lions 2008 advertisement festival. The service beam.tv that they were using to submit the clips insisted on strict specs, amongst others the frame size had to be 720 x 576 pixels. But my client made the transportstream first using DVD SP and then Compressor and each time when she checked the frame size in Quicktime, it reported 720 x 540. What was going on?
Somewhat confusing both Final Cut Pro, Compressor and Quicktime will report the displayed frame size and not the actual pixels of the clip. But this only happens to MPEG-2 materials and not to other formats, as it has to do with the MPEG-2 playback component of Quicktime. 720 x 540 is the frame size of a 4:3 clip that is 720 pixels wide when using square pixels. As we very well know, TVs dont use square pixels but another pixel aspect ratio ( 1.064:1 for 4:3 PAL and 0.9117:1 for 4:3 NTSC) whereas computer screens do use square pixels, so thats why the displayed size has to be recalculated on computers screens if one wants to preserve the correct aspect.
So if Quicktime is showing 720 x 540 it probably is 720 x 576 (PAL) or 720 x 480 (NTSC), but do check it just to be sure.
To validate the frame size use tools such as mplayer, ffmpeg or, interestingly, DVD SP.
The apple doc for this issue can be found here. (next post)
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