[FFmpeg-user] Error extracting srt

[Alex Zachopoulos]

Hi all,

I want to extract the SRT stream from mp4 files.
On my MacPro with High Sierra running ffmpeg 3.3 all is fine.
On my MacBook Pro with Catalina running ffmpeg 4.3 I keep getting an error.
This is the command I use to extract Stream #0:2 (subtitle) from file
1.mp4, on both computers:

ffmpeg -i 1.mp4 -vn -an -codec:s:0.2 srt 1.srt

On the MacBook Pro with Catalina and ffmpeg 4.3 is complains, twice:
First, somewhere down the middle of the dump it says:
*[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fd3b4009800] stream 0, timescale not set*

Then at the end of the dump it says:
*[srt @ 0x7fd3b300ce00] Invalid stream specifier: s:0.2.*
*    Last message repeated 1 times*

Like I said, the same command works without a hitch on the MacPro.
Anyone can help with any pointers, it'll be much appreciated.
Alex