I have a H.264 (ex-MOV, ex-Flash) video of 550px x 250 px. In the HTML player (videojs), I can easily set its size to 640px x 290px and it still looks OK (only a 16.363636% increase in display size).

Or should I increase it's size in "real pixels" by exporting it as H.264 from, say, Avanti or Handbrake at a bigger size? In Avanti, under "Frame size" I specified 640 x 290 and the file size increased by 8% and data rate from 200 kbps to 215.

What are the trade-offs - would enlarging via HTML be stressful for low-end CPUs? Is the 8% increase in file size and kbps worth it for the extra quality, if any?

1 Answer 1


If it is a flash source, then there is a good chance it has vector elements. You should export at a higher resolution from the source rather than trying to upscale the mov file.

Working from the original will ensure accurate pixel data for any vector elements and produce a much higher quality upscale. (This is actually one of the major reasons for Flash's early popularity.) If that isn't an option or it was a raster format asset in Flash, then it is really a toss up between the two options depending on the quality of the original encoding.

Encoding to a new size can do slower and more accurate upscaling that will produce fewer artifacts, but if the original source you are upscaling from is already pretty low quality, a second generation of encoding loss may very well exceed the amount of quality improvement you get from the rendered out upscale.

So in summary, the best option is to export from Flash at a higher resolution. If you can't do that, re-encode if you can do it without another generation of loss or have a high enough quality source (200kbps is not high enough for a re-encode most likely). Finally, if you don't have that, then stick with the re-size in the player on the fly.

  • Got it. Just exported new MOVs from Flash at 640 x 290. After Handbrake at RF 22 the mp4 file size is about the same as using the old-MOV-to-MP4 method, kbps is 220. As for quality, will take a good look later. Sep 5, 2014 at 16:47
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    Follow-up: exporting a 550 px flash movie as 640 px does result in lower image quality/sharpness when you finally get it into Mp4. The solution I found (on an Adobe forum) was to convert the existing 550px movie into a movie clip, make a new flash file of 640 px, paste the 550px movie clip into the 660 movie's library, insert the clip on the first frame of the 640 movie, increase it's size to 640px, then create the same number of frames in the 640 movie as there are in the 550 clip, then export as MOV. Everything scales, no loss of quality. Feb 11, 2017 at 15:46
  • The Adobe link above is forums.adobe.com/thread/909211 - see final (not first) answer from robdillon Feb 19, 2017 at 17:24

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