[FFmpeg-user] R: multiple srt outputs with tee

[info at mbsoft.biz]

The example say:

ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"

My command is:

ffmpeg.exe -f gdigrab -framerate 25 -offset_x 0 -offset_y 147 -video_size 854x480 -draw_mouse 0 -show_region 0 -i desktop -filter:v "scale=-2:720" -vcodec libx264 -x264-params "nal-hrd=cbr:force-cfr=1:keyint=250" -preset medium -profile high -pix_fmt yuv420p -tune zerolatency -b:v 1000k -bufsize 1200k -f tee -map 0:v "output.mkv|output2.mkv"

it seems exactly the same as the example

and again don't work:

[tee @ 00000283f2e95f40] Slave 'output.mkv': error writing header: Invalid data found when processing input
[tee @ 00000283f2e95f40] Slave muxer #0 failed: Invalid data found when processing input, continuing with 1/2 slaves.
[tee @ 00000283f2e95f40] Slave 'output2.mkv': error writing header: Invalid data found when processing input
[tee @ 00000283f2e95f40] All tee outputs failed.
Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input
Error initializing output stream 0:0 --
Conversion failed!

It seems tee do not support gdigrab as input?

If I remove tee the same command works!