Performance does not degrade noticeably when the text track is enabled (this is "characters-only" text, there is no "burned-in" pre-rendered bitmap). The text track is a bonus offered by Apple's Xtra (the text is taken from the labels of the Score markers in Director), and can be used to index into the movie using the pop-up menu next to the movie controller. Due to an apparent bug in Apple's QuickTime Plugin 1.1, the text in the pop-up may not show up when the text track is enabled (scrolling the page in the browser should fix the problem). Several additional attributes could be applied to the text track (styled, scrolling), possibly further degrading playback speed. It is also interesting to find out how text rendering fares across platforms, with different fonts (although this particular test is not very stringent since there is a fair amount of extra space around each caption).
Performance does not degrade noticeably when the text track is enabled (this is "characters-only" text, there is no "burned-in" pre-rendered bitmap). The text track is a bonus offered by Apple's Xtra (the text is taken from the labels of the Score markers in Director), and can be used to index into the movie using the pop-up menu next to the movie controller. Due to an apparent bug in Apple's QuickTime Plugin 1.1, the text in the pop-up may not show up when the text track is enabled (scrolling the page in the browser should fix the problem).
Several additional attributes could be applied to the text track (styled, scrolling), possibly further degrading playback speed. It is also interesting to find out how text rendering fares across platforms, with different fonts (although this particular test is not very stringent since there is a fair amount of extra space around each caption).