The initial 3.26.0 version of the macOS installer package, released on 2020-06-28, was broken and was withdrawn on 2020-06-29. The installed get_iplayer script couldn't locate the bundled version of ffmpeg, so downloaded files were not converted to MP4 and metadata tags were not applied. You will see the message "WARNING: Required ffmpeg utility not found - not converting .ts file(s)" for each download. To correct this problem, all users should install the updated 3.26.1 version:
The initial 3.26.0 version of the macOS installer package, released on 2020-06-28, was broken and was withdrawn on 2020-06-29. The installed get_iplayer script couldn't locate the bundled version of ffmpeg, so downloaded files were not converted to MP4 and metadata tags were not applied. You will see the message "WARNING: Required ffmpeg utility not found - not converting .ts file(s)" for each download. To correct this problem, all users should install the updated 3.26.1 version:
https://github.com/get-iplayer/get_iplayer_macos/releases/tag/3.26.1