[FFmpeg-user] webm encoded from individual frames is not as long as input when using '-lossless 1'

[Carl Eugen Hoyos]

Am Do., 30. Apr. 2020 um 19:05 Uhr schrieb Rob Hallam <ffmpeg at roberthallam.com>:

> I am creating a yuva420p webm file from 300 RGBA PNG images. I intend to
> have a framerate of 60, and so have a clip exactly 5 seconds long. However
> this is not the case; the resulting file has (ffprobe) DURATION of 4.934
> seconds. Visually checking the video output, it does not end on the
> expended frame but a few frames early. Based on the DURATION I would guess
> it is 4 frames short.
>
> I have earlier in the day created another webm instead with 60 and 180
> frames, each has a DURATION to an exact second and with the correct ending
> frame.
>
> The same command without '-lossless 1' produces a file with the correct
> duration.

This is ticket #7759.

Carl Eugen