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frame number vs time

Started by Papou, December 26, 2019, 07:02:27 PM

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Papou

Hi,

I've done something the other day explained in a text requiring frame numbers.
Isn't the best idea to display both frame times and numbers?
(like I suggested to display window title bar buttons not side configurable but on both sides to save the configuration hassle and to see them whichever corner is off screen, Columbus egg).

TIA

eumagga0x2a

This doesn't make sense in Avidemux where the preview can show a complicated segment layout with multiple source videos with or without frame reordering. Add field-encoded streams to the mix, what would you expect to see as frame number then?

Papou

I would expect frame_number = frame_time * frames_per_second.
That of the output file, of course.

eumagga0x2a

Quote from: Papou on December 27, 2019, 01:32:50 AM
I would expect frame_number = frame_time * frames_per_second.

This would presume a perfectly constant frame rate and also absence of B-frames in the output. These assumption doesn't hold in general.

QuoteThat of the output file, of course.

The output file may be a result of re-encoding a filtered video. Filters can alter the number of pictures, so what you see in the video preview, which by default shows unfiltered video, is not what you get in the output.