That doesn't work[1], but ffmpeg -v quiet -f data -i file.txt -map 0:0 -c copy -f data - does. [1] “Encoder 'text' specified, but only '-codec copy' suppor

That doesn't work[1], but ffmpeg -v quiet -f data -i file.txt -map 0:0 -c copy -f data - does. [1] “Encoder 'text' specified, but only '-codec copy' supported for data streams”