How to downscale MP4 without losing quality?

[Master Tape]

I have several 1080i MP4 videos recorded from my Youview box, but the issue is alot of the material is SD 576i, and the box upscales everything to 1080i which just adds artifacts and causes bigger file sizes. I want to be able to archive all these shows to Blu-ray discs for watching back on my player, and would be able to fit alot more on the one disc if it was back to it's actual resolution.

What's a good method (wont say the best way because there probably isnt one) of downscaling the resolution of the MP4 files without risking quality?

[teodz1984]

Any MP4 to MP4 conversion will be lossy.. Just keep your videos as is

[netmask56]

Do a search for how to turn off upscaling if it's possible with your box.

[Master Tape]

Do a search for how to turn off upscaling if it's possible with your box.

Unfortunately the lowest it goes down to is 720p, probably due to it being a HDMI only device. So stupid though to have a box were the majority of the channels are in SD and it doesn't let you display in that resolution.

[jagabo]

Easiest is a program like Handbrake.

[pandy]

Do a search for how to turn off upscaling if it's possible with your box.

Unfortunately the lowest it goes down to is 720p, probably due to it being a HDMI only device. So stupid though to have a box were the majority of the channels are in SD and it doesn't let you display in that resolution.

HDMI support even 240p resolution so it can't be blamed for limitations of source. Raise complains to manufacturer and request to support at least 480/576 modes which are mandatory for HDMI (480p/576p must be supported by definition of HDMI compliance and if your source not support this video mode then it is not HDMI compliant source - as such it can't use HDMI logo).

[Master Tape]

Easiest is a program like Handbrake.

Can you re-encode to interlaced though? All the presets seem to be in progressive.

HDMI support even 240p resolution so it can't be blamed for limitations of source. Raise complains to manufacturer and request to support at least 480/576 modes which are mandatory for HDMI (480p/576p must be supported by definition of HDMI compliance and if your source not support this video mode then it is not HDMI compliant source - as such it can't use HDMI logo).

I stand corrected, it actually has a scart and composite connections on the back (for some reason i thought it was only HDMI) This means i may be able to transfer them to DVD discs instead (for shows that aren't already saved to my computer) Though if the device doesn't display in 576i, would that be technically possible?

[jagabo]

Easiest is a program like Handbrake.

Can you re-encode to interlaced though? All the presets seem to be in progressive.

Why would you want to convert 1080i25 to 576i25? Use the bob deinterlace to convert to 576p50.

[Master Tape]

Easiest is a program like Handbrake.

Can you re-encode to interlaced though? All the presets seem to be in progressive.

Why would you want to convert 1080i25 to 576i25? Use the bob deinterlace to convert to 576p50.

So i can watch it back on my tv. Deinterlacing it would degrade the picture quality. I want to keep it close to the source as possible.

[jagabo]

Easiest is a program like Handbrake.

Can you re-encode to interlaced though? All the presets seem to be in progressive.

Why would you want to convert 1080i25 to 576i25? Use the bob deinterlace to convert to 576p50.

So i can watch it back on my tv. Deinterlacing it would degrade the picture quality. I want to keep it close to the source as possible.

If you do it properly it will can look better as 576p50 than 576i25. The major damage has probably already been done by upscaling the original interlaced SD video to interlaced HD.

By the way, are you sure your 1080i videos really contain interlaced content? Almost everything shot on film will really be 25p, even it it's transmitted ast 25i. Such material can be easily be restored to the original progressive film frames and encoded as 25p. Live sports and news are the major exceptions that are truly broadcast as interlaced video.

Post some samples here if you want some analysis of the actual content of the videos.