Sorry for the late reply. I tried that out and it worked. Now i am at the point that mplayer is playing the song in the node red with the exec node. I can see it is playing from the debug output but i hear no sound over the dlna speaker. This is the output from the dubug:
MPlayer 1.3.0 (Debian), built with gcc-8 (C) 2000-2016 MPlayer Team
Terminal type `unknown' is not defined.
Playing /mount/musik/alte.mp3.
libavformat version 58.20.100 (external)
Audio only file format detected.
Clip info:
Title: Die alte Hÿhnermutter
Artist: Revolverheld
Album: Giraffenaffen 2
Year:
Comment:
Genre: Unknown
Load subtitles in /mount/musik/
Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
AUDIO: 44100 Hz, 2 ch, s16le, 192.0 kbit/13.61% (ratio: 24000->176400)
Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I, II, III)
AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A: 0.0 (unknown) of 209.0 (03:29.0) ??,?%
A: 0.0 (00.0) of 209.0 (03:29.0) ??,?%
A: 0.1 (00.0) of 209.0 (03:29.0) ??,?%
A: 0.3 (00.2) of 209.0 (03:29.0) 0.8%
A: 0.5 (00.4) of 209.0 (03:29.0) 0.9%
A: 0.6 (00.5) of 209.0 (03:29.0) 0.9%
A: 0.8 (00.7) of 209.0 (03:29.0) 0.8%
A: 0.9 (00.9) of 209.0 (03:29.0) 0.8%
A: 1.1 (01.1) of 209.0 (03:29.0) 0.8%
A: 1.3 (01.3) of 209.0 (03:29.0) 0.8%
A: 1.5 (01.5) of 209.0 (03:29.0) 0.8%
A: 1.7 (01.6) of 209.0 (03:29.0) 0.8%
If I play it in normal terminal window i can see it it the dlna messages that the song is being handed over to the speaker but here nothing. And i have the pavucontrol installed. Same here: When i play the song in terminal i see an input here. With node red nothing. But the song must be played from what i see in the debug log.