Force 4-3 in Stream and container from 16-9

Started by Hushpower, January 19, 2024, 02:57:02 AM

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Hushpower

Gday, I'm trying to change a 16:9 video to 4:3 without recoding.

When I set the Output Format>Configure to "Force " 4:3, the AR change is shown in VLC Player and my NLE but not on my TV. The tV stays on 16:9.

If I use CleverFFMpeg-GUI (which has a specific option to change "stream and container"), the 4:3 is shown on my TV as well.

Given that, when we choose "Force 4:3" in AVIDemux we want the video to be 4:3 on all players, would it be possible to reprogram AVIDemux to change both the container and stream?

AVIDemux is simpler to use than other programs and it would be very handy to have this feature.

Hushpower


eumagga0x2a

If pixel aspect ratios specified via container and VUI (video usability information) part of codec extradata disagree, a player is free to choose (and good players, both sw and hw like a TV set, allow user to override whatever the player has decided automatically). In theory, recreating codec extradata with just the VUI modified is possible. Practically, this is difficult even for H.264, other codecs need entirely different implementations and video streams with in-band (MPEG-TS style) extradata would need each keyframe to be recreated. In other words, don't hold your breath, especially as time I am able to invest into Avidemux has shrunk dramatically. Quality patches welcome.

By the way, a capability of modifying timing (e.g. spreading PTS evenly in the container while fixing wrong codec time base) without re-encoding would be IMHO much more important, but also even more difficult.

Hushpower

Thanks Eumagga0x2a. I appreciate your response.