avconv and ffmpeg - drawtext filter text_w evaluates as 0 in Ubuntu Precise
- by Chris White
I'm attempting to draw text onto a video using either the avconv or ffmpeg commands. When specifying x= for where on the final video to place the text, the 'text_w' value is evaluating to 0, rather than the width of the rendered text as it should.
I'm using Ubuntu 12.04
I've got avconv version 0.8.3-4:0.8.3-0ubuntu0.12.04.1
and ffmpeg version 0.8.3-4:0.8.3-0ubuntu0.12.04.1
Example command:
avconv -i test.mov -vf "drawtext=fontfile='/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf':text='test text':x=text_w:y=50:fontsize=24:fontcolor=black" texted.mov
This command causes the text to be printed as if x were set to 0.
What I'd really like to be able to do is center the text horizontally using something like this:
avconv -i test.mov -vf "drawtext=fontfile='/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf':text='test text':x=(main_w-text_w)/2:y=50:fontsize=24:fontcolor=black" texted.mov
Using ffmpeg for to attempt the same ends with the same result
ffmpeg -i test.mov -vf "drawtext=fontfile='/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf':text='test text':x=(main_w-text_w)/2:y=50:fontsize=24:fontcolor=black" texted.mov