knitr mp4 movie embedding does not work on Windows XP
问题 I knit a Rmd file (to html) with a chunk producing a mp4 movie : ```{r clock, fig.width=7, fig.height=6, fig.show='animate'} par(mar = rep(3, 4)) for (i in seq(pi/2, -4/3 * pi, length = 12)) { plot(0, 0, pch = 20, ann = FALSE, axes = FALSE) arrows(0, 0, cos(i), sin(i)) axis(1, 0, "VI"); axis(2, 0, "IX") axis(3, 0, "XII"); axis(4, 0, "III"); box() } ``` knitr generates the following html code for embedding the mp4 movie : <p><video controls="controls" loop="loop"><source src="figure/clock.mp4"