QuickTime Player: Problem changing seconds view to frame view

> I guess I can't view it on my Mac in frames, then?

Some other apps might be able to do that.

For example, Avidemux can show the frames but I wish it would have an option to show them frames, not as fractions of a second (at 25fps one frame is 1/25 = 0.04 fractions of a second). But as a very neat feature it displays the GOP pattern with I, B and P frames:

The movie must have embedded timecode for SMPTE timecode or Frame count display options:

Here is a short HEVC sample .mp4 with timecode (also many .dv files might have a similar timecode). (This sample has Chroma subsampling 4:2:2 (Bit depth 10 bits) so unlike 4:2:0 in Big Sur it has an error message "This file contains media which isn't compatible with QuickTime Player". But it opens anyway in Big Sur but fails in Mojave).

[Link Edited by Moderator]

The movie must be encoded with embedded timecode and AFAIK it is not possible to add it later.

For example, in ffmpeg I have encoded my old interlaced 25fps PAL .dv movies to double frame rate 50fps bob-deinterlaced (i.e. preserving all fields) HEVC .mp4 with the following command. "-timecode 00:00:00:00" forces the timecode to start at zero instead of what timecode happens to start the first .dv clip (option "-write_tmcd off" would disable timecode and there would be no SMPTE timecode or Frame count display options in QuickTime Player).

for i in *.dv; do ffmpeg -i "$i" -vf bwdif=1,scale=788:576,crop=768:576:10:0,setsar=sar=1/1 -c:v libx265 -crf 18 -preset slow -timecode 00:00:00:00 -tag:v hvc1 -c:a aac -b:a 128k "${i%.*}_converted.mp4"; done