Match Source settings doesn't match the source file after export

[Jens Mama]

Hi there.

I've been categorizing some old home footage that has been transfered from VHS to DVD and finally converted to MP4.  The MP4 files are my source material and they look fine with a little bit of "natural" grain.  I'm not doing any editing except for cutting off some VHS artifacts here and there. 

My problems are:

• Whenever I export with 'Match Source Settings' the file size is reduced with more than 50%

• It loses some of its grain so it looks "smoother" (in a bad way)

• The colors look a tiny bit desaturated

I tried to import the entire source video without doing anything but exporting the whole file just as it is. It still reduced the file size from 5,83 GB to 2,41 GB. Below here are the properties for the exact same video before and after export. The only difference I can spot (execpt for the file size of course) is that the source video says "Variable Frame Rate Detected" at the end. 

I just want the exported video to match the source video as much as possible — can anybody help me?

Source video (before)

Type: MPEG Movie

File Size: 5,83 GB

Image Size: 768 x 576

Frame Rate: 25,00

Source Audio Format: 48000 Hz - Compressed - Stereo

Project Audio Format: 48000 Hz - 32 bit floating point - Stereo

Total Duration: 01:32:52:23

Pixel Aspect Ratio: 1,0

Alpha: None

Color Space: Rec. 709

Color Space Override: Off

Input LUT: None

Video Codec Type: MP4/MOV H.264 4:2:0

Variable Frame Rate Detected

Exported video (after)

Type: MPEG Movie

File Size: 2,41 GB

Image Size: 768 x 576

Frame Rate: 25,00

Source Audio Format: 48000 Hz - Compressed - Stereo

Project Audio Format: 48000 Hz - 32 bit floating point - Stereo

Total Duration: 01:32:52:23

Pixel Aspect Ratio: 1,0

Alpha: None

Color Space: Rec. 709

Color Space Override: Off

Input LUT: None

Video Codec Type: MP4/MOV H.264 4:2:0

[Ann Bens]

Every conversion will cost you image quality (quite noticeable on old SD footage), and the compression used by Premiere is most likely more efficient than the one used in the source file: hence the lower file size.

[Jens Mama]

Thanks Ann, so are you saying that Premiere's compression efficiency is likely to reduce the file size anyway?

[R Neil Haugen]

"Match Source" is not designed replicate the previous file ... it is designed to replicate the file main parmeters. Which are framerate/framesize, pixel aspect ratio, audio channels (if possible).

The user is responsible for things like bitrate. And no, it isn't obvious. But there it is.

As that is VFR, I would highly recommend converting to CFR in Handbrake or ShutterEncoder prior to importing to Premiere. It's fast, doesn't give a quality hit, and you have proper media for an NLE to work with.

I know of people professionally needing to work with 'legacy' media on 1080 projects, who are using the new Topaz up-sizing capabilities and are able to work without notable penalty doing that. The 768x576 media you've got can often get to 1080 ok ... but they do note, the older 400-ish stuff is still problematic.

[Jens Mama]

Thanks R, I wil try and convert to CFR in Handbrake before importing to Premiere. But I have already tried to increase the bitrate, which increased the file size, but it still sort of "smoothed" the picture and removed all the natural/analogue grain.

[R Neil Haugen]

The removal of the 'grain' you added is due to primarly the choice of codec. H.264/5 uses block encoding practices for "smallification" purposes. Which doth remove minor things like grain.

ProRes and DNx variants tend to hold such things better, but at vastly larger file sizes, of course.

This is why noted colorist Walter Volpatto has mentioned he doesn't waste time on fancy 
film grain emulation routines in the movies he grades. The deliverables are most typically a variant of H.264/5 in reality ... and when he's tested in the exact deliverable specs, whether for theatrical (DCP) or network/streaming use, and put the media up on either projectors (DCP) or large TVs (files for b-cast/streaming services) .... no one could tell which process was used.

And yes, in his experience, the compression schema used by the H.264/5 process is easily the most destructive to 'film grain' work.

[Jens Mama]

Thanks, now it all makes a little more sense.