[SOLVED] Bash command run from a variable - Shaka packaging problem

Issue

I am trying to package some videos on an ubuntu-ec2 machine using shaka packager and following href="https://shaka-project.github.io/shaka-packager/html/tutorials/tutorials.html" rel="nofollow noreferrer">official tutorial.

So I have a list of multi resolution files i.e. original=x.mp4, converted are x_480p.mp4, x_360p.mp4 and so on. My lowest resolution is 360p. My bash script automatically detects the height and converts lower than that automatically. Using ffmpeg it's done nicely. Now the problem is, I need to automatically package the files in converted directory (all of them) using shaka.

If I run the script in a single line it works.

sudo packager in=dpnd_comp.mp4,stream=video,out=test/video.mp4 in=dpnd_comp.mp4,stream=audio,out=test/audio.mp4

For automatic process I am saving the paths in the vairable inputs. when I run this using variable, it just processes the last video, here 360p only.

This is the part -

# using a for loop here

        inputs="$inputs   in="$output_path"/"$content_id"_"$height"p.mp4,stream=video,output="$packaged_out"/"$content_id"_"$height"p.mp4  "
done


echo "$inputs"

sudo packager "$inputs" 

Note, `echo "$inputs" returns this

in=../bin/converted/0001_720p.mp4,stream=video,output=../bin/packaged/0001_720p.mp4     in=../bin/converted/0001_480p.mp4,stream=video,output=../bin/packaged/0001_480p.mp4     in=../bin/converted/0001_360p.mp4,stream=video,output=../bin/packaged/0001_360p.mp4

Any kind of help would be highly appreciated. If anyone ever worked with shaka and made the process automatic, please help.

Edit: Need to add more arguments after the inputs like this -

sudo packager "$inputs" \
    --enable_widevine_encryption \
    --key_server_url "$key_server" \
    --content_id "$content_id" \
    --signer "$signer_uname" \
    --aes_signing_key "$signing_key" \
    --aes_signing_iv "$signing_iv" \
    --mpd_output "$packaged_out"/"$content_id".mpd \
    --hls_master_playlist_output "$packaged_out"/"$content_id".m3u8"

Solution

Ok I solved this problem (workaround) by running bash commands from python.

cmd_prefix = 'sudo packager..'
cmd_postfix = '--mpd_output "${packaged_out}/${content_id}.mpd" --hls_master_playlist_output "${packaged_out}/${content_id}.m3u8"

for inp in inputs
    cmd_prefix += inp

drm_command = cmd_perfix + cmd_postfix


drm_processor_response = Popen(f"({drm_command})", stderr=PIPE, stdout=PIPE, shell=True)
output, errors = drm_processor_response.communicate()
log_update([drm_processor_response.returncode, errors.decode("utf-8"), output.decode("utf-8")])

This worked and with python I have more control.

Answered By - ashraf minhaj

Answer Checked By - Dawn Plyler (WPSolving Volunteer)