DPF plugins not working in FFMPEG or ecasound

[hellocatfood]

I'm trying to use either ffmpeg or ecasound to do some batch processing using lv2 plugins. I have noticed that all DPF plugins don't work in either software. They return the same error: [dpf] Options feature missing, cannot continue!

Works

ffmpeg -v error -i audio.mp3 -af 'lv2=p=http\\://drobilla.net/plugins/mda/RoundPan:c=pan=0.5|auto=0.800000011920929' output.mp3

ecasound -i audio.mp3 -o output.mp3 -elv2:http://drobilla.net/plugins/mda/RoundPan

Doesn't work

ffmpeg -v error -i audio.mp3 -af 'lv2=p=http\\://distrho.sf.net/plugins/PingPongPan:c=freq=50.0|width=75.0' output.mp3

[dpf] Options feature missing, cannot continue!
[lv2 @ 0x7e8bdc004540] Failed to instantiate <http://distrho.sf.net/plugins/PingPongPan>
[Parsed_lv2_0 @ 0x7e8bdc004440] Failed to configure output pad on Parsed_lv2_0
[af#0:0 @ 0x5b54f98c9d40] Error reinitializing filters!
[af#0:0 @ 0x5b54f98c9d40] Task finished with error code: -22 (Invalid argument)
[af#0:0 @ 0x5b54f98c9d40] Terminating thread with return code -22 (Invalid argument)
[aost#0:0/libmp3lame @ 0x5b54f98c9140] [enc:libmp3lame @ 0x5b54f98c9680] Could not open encoder before EOF
[aost#0:0/libmp3lame @ 0x5b54f98c9140] Task finished with error code: -22 (Invalid argument)
[aost#0:0/libmp3lame @ 0x5b54f98c9140] Terminating thread with return code -22 (Invalid argument)
[out#0/mp3 @ 0x5b54f98c8080] Nothing was written into output file, because at least one of its streams received no packets.

ecasound -i audio.mp3 -o output.mp3 -elv2:http://distrho.sf.net/plugins/PingPongPan

[dpf] Options feature missing, cannot continue!
Segmentation fault