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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 -vf "drawtext=fontfile='/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf':text='test text':x=text_w:y=50:fontsize=24:fontcolor=black"

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 -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"

Using ffmpeg for to attempt the same ends with the same result

ffmpeg -i -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"
share|improve this question
Not an expert on the filters, but have you tried in the latest version? It's at least at 0.11 now. – slhck Jul 11 '12 at 15:05
I don't understand the problem. The command you wrote: avconv -i -vf "drawtext=fontfile='/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf':text='t‌​est text':x=(main_w-text_w)/2:y=50:fontsize=24:fontcolor=black" works fine for me. – abhshkdz Jul 11 '12 at 17:01
abhshkdz: The command does not error for me, but it does fail to center the text. The calculated x location is the same as if 'text_w' were replaced with 0. Is the text centered properly in your output video? Sounds like this could be a bug on this version. – Chris White Jul 11 '12 at 20:21
Works for me using ffmpeg from FFmpeg (and not the fork that Ubuntu now uses): – LordNeckbeard Jul 13 '12 at 18:27
Is anyone else able to confirm the bad behavior on the libav fork that Ubuntu uses? If this is recreatable I'd like to file a bug report. – Chris White Jul 13 '12 at 18:55

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