concat the output of the subquery?

i have a query which would return values but i need them as a single output separated by commas..

So i tried to concat the output with the comma but it didn't work?

select id from videos where duration=0;  /// this would return some rows

I tried concat and concat_ws but didn't work

select concat(select concat(id,',') from videos where duration=0);
select concat((select id from videos where duration=0),',');
select concat_ws(',',(select id from videos where duration=0));

i need the id's of all rows with the comma separtor

for example the output should be 1,4,6,78,565

any ideas?