Dan wrote:

Paul wrote:

If nothing else works, ffprobe from the ffmpeg package can tell you
about the content.

How do I use this?

I don't use ffmpeg directly (which has you use the command line). I use
a program that is a front-end to ffmpeg. For example, VideoLan's VLC.
When I play a video file, I can use its Tools - Codec Information menu
to see what was used to encode the contents inside the container file.
For example, I just played an .mp4 file and it had:

stream 0 (video)
codec: H264 - MPEG-4 AVC (part 10)(avc1)

stream 2 (audio)
codec: MPEG AAC Audio (mp4a)

I played an .avi file (no audio) in VLC and its codec info was:

stream 0
codec: Microsoft RLE Video

For an .mp3 file (obviously just audio):

stream 0
codec: MPEG Audio Layer 1/2 (mpga)

All my .mp4 files (that I looked at) all use the same coder. That's
probably due to the video being captured from the Web using the same
stream capture program (Applian Replay Media Catcher). I don't have
many media files and download few directly from a site. The only MP4
codings that I can think of are MPEG-4 AVC (aka MPEG-4 part 10 or H.264)
and MPEG-4 part 2. Those are different formats, so your player saying
MPEG-4 capability isn't telling you which format it supports.

https://en.wikipedia.org/wiki/MPEG-4_Part_2
"Note that MPEG-4 Part 10 defines a different format from MPEG-4 Part 2
and should not be confused with it. MPEG-4 Part 10 is commonly referred
to as H.264 or AVC, ..."
and
"MPEG-4 Part 2 is H.263 compatible in the sense that a basic H.263
bitstream is correctly decoded by an MPEG-4 Video decoder."

H.263 is an older spec than H.264 but both were published (although
perhaps not widely adopted) about the same time (1996 and 2003,
respectively). BD players started showing up in 2003 (but were very
pricey at $3000+). Once you find the coder used for the source video
that you are burning onto BDs, and after using VLC or some other video
player that tells you the codecs used in a video, check the specs on
your father's BD player to see if the same codecs (video and audio) are
supported. If the BD player just says MPEG-4 then check if it also
lists H.263 and H.264.

BD discs come in a variety of flavors: 25GB single-layer, 50GB
dual-layer, 100/200/300GB (BDXL). They can also be encoded using CLV or
CAV. Since you've given no details on brand and model of your BD burner
and you and your father's BD players, no idea what they support.

Is the BD burner drive in your computer, or are you using someone else's
BD burner drive on their computer? From your original message, you and
your father have BD players but there is a hint that you used someone
else's BD burner. If you are using someone else's BD burner drive, is
it the same one now that they had last time (for the BD-R discs that
still work in your players)? If the computer with the BD burner drive
is your computer, and if all you are doing is copying (burning) video
files onto an optical disc, have you tried the in-built burner in
Windows 7? Instead of super-huge video files that require a BD disc or
spanning multiple DVD or CD discs, get a video that will fit onto a DVD
or CD disc (whichever you have that are write-once or writable) and see
if using Windows 7's own burner (which only supports CD or DVD, not BD)
lets you create a disc that is playable in your and your father's
players. See:

https://helpdeskgeek.com/how-to/burn...indows-7-8-10/

You said in another subthread that you "closed the disc". Does that
mean you use the DAO (Disc At Once) burning methond *and* enabled the
Finalize Disc options?

https://cdburnerxp.se/help/References/burnoptions