Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Video Encoding > MPEG-2 Encoding

Reply
 
Thread Tools Search this Thread Display Modes
Old 22nd April 2021, 12:37   #1  |  Link
ocmtime
Registered User
 
Join Date: Jun 2011
Posts: 3
resize of the I frames P frames and B frames by a certain factor ?

How to (reduce the pixel count size) resize of the I frames P frames and B frames by a certain factor ?

If I frames are jpeg compressed and the blocksthemselves would be reduced to half resolution and the I frames to half resolution that would already be effective but how please ?

Also the other types of frames P and B containing motion vectors and plain difference between frames those would also need to be halved in resolution and there would be no necesity of recomputing the motion vectors because motion vectors are very robust to resolution
ocmtime is offline   Reply With Quote
Old 22nd April 2021, 14:45   #2  |  Link
videoh
Useful n00b
 
Join Date: Jul 2014
Posts: 1,516
MPEG-2 does not use JPEG compression.

What exactly are you wanting to do? Reduce the size of an existing MPEG-2 file? If so, transcoding to HEVC would seem more rational.

Last edited by videoh; 22nd April 2021 at 14:48.
videoh is offline   Reply With Quote
Old 22nd April 2021, 17:11   #3  |  Link
ocmtime
Registered User
 
Join Date: Jun 2011
Posts: 3
I need to do that for a few terabytes of data and on my computer to hevc the speed is realtime at best. I need it to happen at 10x realtime speed.
ocmtime is offline   Reply With Quote
Old 22nd April 2021, 18:36   #4  |  Link
videoh
Useful n00b
 
Join Date: Jul 2014
Posts: 1,516
Get a decent nVidia GPU and transcode with NVEnc. What percent size reduction are you looking for?

It's much easier to buy more storage.
videoh is offline   Reply With Quote
Old 22nd April 2021, 23:12   #5  |  Link
manolito
Registered User
 
manolito's Avatar
 
Join Date: Sep 2003
Location: Berlin, Germany
Posts: 3,008
@ ocmtime
Your goal seems to be similar to what available CDT (Compressed Domain Transcoder) software already does (DVDShrink or DVD2one). The motion vectors are reused, but the original frames are recoded using a higher quantizer. Plus some other smart tweaks of course.
manolito is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 23:59.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.