Yes, K-lite should be installed to be able to play most of video formats.
You can check which backends are installed on your system by sending a "loader" message to [pix_film]

As an alternative, you can try pof library that is close to Gem.

@whale-av said:

You will find Pd extended here.......

Not sure if it's a good idea to use such an obsolete version, but purr data should contain Gem also.

I did this long time ago that use on canvas to do the (clickable) gui

gswitch.pd
gswitch-help.pd

also the other one:

ggate-help.pd
ggate.pd

You might check clone object for that.
But you need to allocate a maximum number of voices or use dynamic patching technic, but I am not sure it's worth the try.

@omer1789 said:

sfplay~

Under pure data vanilla, you can use readsf~

Here is a way to do it. I would be curious if somebody have a better design in mind:

You might need a symbol atom gui box.
Add -> symbol
Then type any filename in Run mode

1-Go to Media-> sound settings then set your soundcard input / output.

2-Turn on DSP in Media -> DSP ON

3- To ear the input signal, connect the input of sound card [adc~] (Analog to Digital Converter) to the output of soundcard [dac~] (Digital to Analog Conveter):

You can send the "offset X Y" message before creating your window to move gem window on the secondary display and run the patch on the primary instead.
Check gemwin's help files...

@ddw_music said:

My AI professor back decades ago wished that he could start programming with MAX, but it was completely out of the range of the students. I'm hoping to pick up his dream, particularly since he's at a new institution that requires that he teach beginning computer science in Java (?!?)

I suggest also to keep an eye to this web javascript clone of max
https://github.com/Fr0stbyteR/jspatcher

It says the time is the envelope duration. I guess It's like @gate 1 ---> delay 1000 ---> @gate 0