Setting widescreen aspect ratio flags in FFmpeg?

[Master Tape]

I want to encode some anamorphic DVDs that are in 720x576, so what command should you type in FFmpeg to get this squished picture to stretch out to the correct 16:9 ratio?

[JVRaines]

You can specify the ratio using the -aspect option.

[pandy]

Or you may try to use exclusive codec syntax (x264/x265 case). Setting aspect in wrong place may trig unwanted libswscale behaviour.

[Master Tape]

Thanks, that's sorted it. And keeps the file size down without me having to resize it in AviSynth.

The odd thing is, Mediainfo is reporting the 'Display aspect ratio' of the original VOB file as 2.40:1, yet it displays as 16:9 when played in VLC player (which it should be)

[JVRaines]

MediaInfo makes bad guesses from time to time. Don't assume it's the Word of God.

[Master Tape]

What's even more bizarre, it actually plays in 2:40:1 when loaded into Windows Media Player (not that i use that anymore) but it does look wrong/squished.

[JVRaines]

So perhaps you need to follow pandy's advice and tell the encoder about the ratio. For example, using libx264

-x264_params sar=1:1.48

(that colon probably needs some kind of escaping, but I'm too lazy to figure it out!)

[Master Tape]

It's not an issue in general, it still does what i want it to do by outputting to the correct 16:9 without affecting the resolution. Just thought it was funny the VOB played like that in Windows Media Player, but not in VLC.

[fornit]

Or you may try to use exclusive codec syntax (x264/x265 case). Setting aspect in wrong place may trig unwanted libswscale behaviour.

Please allow me a question: Why not simply scale it with -vf scale=1024:576?