[FFmpeg-user] text overlay will not work on rtmp stream

[Anthony Griffiths]

I stream video from a canopus advc100 device to a vps running nginx
using ffmpeg with the following command:
dvgrab -format dv1 - |
/home/<me>/Downloads/ffmpeg-git-20170817-64bit-static/ffmpeg
-deinterlace -f dv -i - \
-vf [in]drawtext="fontfile=/home/<me>/packages/Fonts/verdana.ttf:textfile=/home/<me>/screentext.txt:fontcolor=white:fontsize=20:x=30:y=30:reload=1"[out]
\
-codec:v libx264 -preset slow -aspect 16:9 -s 320x180 -b:v 1500k
-maxrate 500k -bufsize 1000k -vf scale=-1:240 -threads 0 -f flv \
-framerate 15 -qscale:v 20 -codec:a aac -b:a 64k -af aformat=s16:44100
rtmp://<ip-address>/<name-nginx>

the video plays fine at the other end but there is no text overlay on
the video. the file /home/<me>/screentext.txt does have text in it.

whats strange is this command does work with text overlay. It streams
the same source to the same vps but to red5 server rather than nginx.
dvgrab -format dv1 - | /home/<me>/bin/ffmpeg -deinterlace -f dv -i - -f flv \
-vf [in]drawtext="fontfile=/home/<me>/packages/Fonts/verdana.ttf:textfile=/home/<me>/screentext.txt:fontcolor=white:fontsize=20:x=30:y=30:reload=1"[out]
\
-y -vcodec flv -s 320x240 -r 10 -b:v 400k -vcodec libx264 -preset
veryfast -crf 25 -maxrate 1000k -bufsize 6000k \
-g 20 -c:a libfdk_aac -ac 1 -ab 32k -ar 22050 'rtmp://<ip-address>/<name-red5>'

The first command is the one I want to use because it works for
playback on a smart phone but i can't get the text overlay to work.
can anyone see whats wrong with the command?