[Ffmpeg-devel] Macromedia Flash 8

[Jeff Clagg]

On Mon, Sep 19, 2005 at 09:57:13PM -0400, Mike Melanson wrote:

> Trade-offs, my friend. As you observed, the video was nicer (i.e.,
> bigger and more detailed) and the trade-off is that the data size was a
> bit larger. Let's run some numbers here. I am working off the Serenity
> trailers listed here:
> 
>   http://www.davestrailerpage.co.uk/trailers_s.shtml
> 
> The "full-screen" trailer (what a misnomer) is actually 640x272 pixels.
> It is ~40 MB. The 1080p trailer is 129MB in a zip file. I have
> downloaded this once and unpacked it and the unpacked size is not much
> larger. Let's call it ~130MB. Assume that the files are all video data
> (which they are not, there is also audio and file overhead) and that
> they have the same framerate (not sure if this is true). Assuming that
> 1080p means 1920x1080 pixels, this is the amount of raw data that the
> codec is processing at the different resolutions:
> 
>  640 x  272 =  174080 pixels/frame * 3/2 bytes/pixel =  261120 bytes/frame
> 1920 x 1080 = 2073600 pixels/frame * 3/2 bytes/pixel = 3110400 bytes/frame
> 
> The codec is pushing through almost 12 times as much raw data. Yet the
> file size is only about 3.3 times as large. Not bad.

I should add that in the few cases I've looked into it, it appears to
me that the h.264 trailers on apple's site are not taking very good
advantage of the codec at all. (perhaps relatedly, apple's h.264 encoder
is complete trash qualitywise.) You could probably beat their quality
with a good asp codec like lavc or xvid. I wish they would do this,
since it would decrease the decoding overhead severalfold. I say this
as a drooling h.264 fanboy.