[Andrey Babintsev]

If I trim first, then re-encode, nothing changes.

I will try forcing keyframes. Thank you for the example.

In fact LG TV seems to be very capricious to re-encoded video. It didn’t recognize .mp4 created with -slow, slower, veryslow presets for 1280×720 scale. For 1920×1080 situation got even worse.

[Andrey Babintsev]

I think it is the reason why my 5 seconds trimmed video is of 5.68 sec duration. However it is easily played by mplayer and windows media player, but it is incompatible with LG TV.
I tried to trim it while re-encoding, with the same result.

[Andrey Babintsev]

Thank you for response!

1. Trimmed video becomes compatible at 10s.
9s – still incompatible.
10s – compatible.
11, 12, 13.. – compatible

2. Trimming with my original export command:
to 5s – incompatible
to 10s – incompatible
to 20s – compatible

3. I tried the same steps for .MOV video from Panasonic Photo Camera:
exported and then trimmed.
Exported video is played, trimmed video isn’t.

4. I downloaded .avi movie ( I believe that quite experienced person exported it from DVD source) and trimmed it to 5 seconds.
It is compatible! So, LG TV can play 5sec video.

I am newbie in video/audio encoding. Perhaps my initial exports command lacks some keys, may be some metadata should be rebuilt. You said about key frame issue. Is there any way to control it?