Help with piping FFmpeg

Chris G

I have this command:

ffmpeg -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" -cenc_decryption_key "************" -i "************.mpd" -map 0:v:$(ffprobe -v quiet -select_streams v -show_entries stream=index,width,height -of csv=p=0 -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" "************.mpd" | sort -t"," -k2,2nr -k3,3nr | head -n1 | cut -d"," -f1 || echo 0) -map 0:a? -map 0:s? -c copy -f mpegts -tune zerolatency pipe:1

If I run it manually, it works, but if I try to pipe it in TVH it doesn't.
pipe://ffmpeg...

If I remove the ffprobe part and mapping options, it works.
Does anyone know why it won't work with them?
2024-06-23 21:41:19.250 iptv: stdin pipe 87 unexpectedly closed: No data

Chris G

It seems TVH doesn't like the command substitution bit:
$(ffprobe -v quiet -select_streams v -show_entries stream=index,width,height -of csv=p=0 -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" "************.mpd" | sort -t"," -k2,2nr -k3,3nr | head -n1 | cut -d"," -f1 || echo 0)

Any ideas?

kbhasi

Chris G
I wonder if it would be possible to use bash -c to have Bash interpret the command substitution?

Something like this:
pipe://bash -c 'ffmpeg -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" -cenc_decryption_key "************" -i "************.mpd" -map 0:v:$(ffprobe -v quiet -select_streams v -show_entries stream=index,width,height -of csv=p=0 -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" "************.mpd" | sort -t"," -k2,2nr -k3,3nr | head -n1 | cut -d"," -f1 || echo 0) -map 0:a? -map 0:s? -c copy -f mpegts -tune zerolatency pipe:1'

It might be a bit confusing with all of the " marks in it, so as an alternative, it may be possible to put the command in a shell script and have Tvheadend run that in the pipe command.

Flole

Run it in a shell so the command substitution is actually valid. Tvheadend is not a shell.

Chris G

Flole
Thanks. Can you give me an example please?

#EXTINF:-1,Channel1 pipe://ffmpeg -i "*URL*" -map 0:v:$(*gets the best quality track* || echo 0) -map 0:a? -map 0:s? -c copy -f mpegts -tune zerolatency pipe:1

Chris G

I am unsure how to run the command in a shell without putting it inside a script file.
Can anyone help?

Chris G

Thank you, bash -c worked!
I used ChatGPT to fix the quotes and escaping.

pipe://bash -c 'ffmpeg -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" -cenc_decryption_key "****" -i "****" -map 0:v:$(ffprobe -v quiet -select_streams v -show_entries stream=index,width,height -of csv=p=0 -user_agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36" "****" | sort -t"," -k2,2nr -k3,3nr | head -n1 | cut -d"," -f1 || echo 0) -map 0:a? -map 0:s? -c copy -f mpegts -tune zerolatency pipe:1'

kbhasi

Chris G
I knew it would work because I knew the command substitution stuff were specific to Bash* and that Tvheadend runs IPTV pipe commands directly.

*(and probably a few other command-line shells too, but I'm accustomed to Bash as that's what Debian uses by default)