@Richard-hardy

Please see this topic and this topic - although it refers to Video pro X it applies to Movie Edit Pro as well It may help.

John EB

Forum Moderator

Hi, I read through those two topics you linked but didn’t find an answer. Could you help me out with my question?

@Richard-hardy

Hi

Hopefully the 2 topics I linked indicated to you that Smart Copy / Render is somewhat finicky in when it will occur and under what conditions and that if MEP says it is going to use them, it sometimes it does not and re-renders the video.

. . . . the file size & bitrate of the smart rendered file is different to the source file’s. So they don’t match . . . .

1. What settings did you use for the export and were they set to the same as the source video?
    
2. Did you see or get a message at the end of the export that Smart Copy or Render was used or not?
    
3. Is the source video all from the same camera / source
    
4. What are you using to compare the source and export?
    
5. Analysing a source clip and the export with MediaInfo, and compare them to the settings you used in item 1.

John EB

The export settings I used were exactly the same as the source's. They are VOB files that I have taken off a miniDVD disc because I wanted to make some light edits.

I am using MediaInfo to do the comparing, and that is where I'm seeing the difference. It shows me that the supposedly smart rendered video's file size & bitrates are not identical to the source's. Is this a bug do you think? Because why else would MEP tell me that it is and has smart rendered but then end up with a file that doesn't match the original? It doesn't make any sense to me.

@Richard-hardy

Hi

Hopefully the 2 topics I linked indicated to you that Smart Copy / Render is somewhat finicky in when it will occur and under what conditions and that if MEP says it is going to use them, it sometimes it does not and re-renders the video.

. . . . the file size & bitrate of the smart rendered file is different to the source file’s. So they don’t match . . . .

1. What settings did you use for the export and were they set to the same as the source video?
    
2. Did you see or get a message at the end of the export that Smart Copy or Render was used or not?
    
3. Is the source video all from the same camera / source
    
4. What are you using to compare the source and export?
    
5. Analysing a source clip and the export with MediaInfo, and compare them to the settings you used in item 1.

John EB

Take a look at the screenshots I've uploaded and you'll hopefully be able to see what I mean. The VOB is the source file, and the MPG is the smart rendered one.

@Richard-hardy

Those figures are so close that I would not question that there is a difference. What puzzles me more is that the exported file has Mpeg2 Audio instead of AC-3!

What was set in the export template and did you use the default Intel codec / encoder or the Main Concept encoder.

BTW - Selecting the Tree or Text view in Media Info gives us a much more detailed view of the file characteristics.

Peter

@Richard-hardy

Those figures are so close that I would not question that there is a difference. What puzzles me more is that the exported file has Mpeg2 Audio instead of AC-3!

What was set in the export template and did you use the default Intel codec / encoder or the Main Concept encoder.

BTW - Selecting the Tree or Text view in Media Info gives us a much more detailed view of the file characteristics.

Peter

Hi,

Well, the source file is an MPEG VOB file, so for export I selected MPEG-2. However, in the audio settings dialog the audio codec is locked to MPEG Audio, so I can't select AC-3.

I used the default Intel codec.

@Richard-hardy

Hi

I have to agree with Peter - the VOB and mpg are identical, the somewhat insignificant differences are probably due to the way the VOB and mpg bitrate data is calculated.

If you do the calculations based on the bitrates of the 2 files there should be a difference of approx 75 frames, ie 3 secs @ 25 fps, difference in length - however they are both the same length.

With this and assuming you cannot see a difference in the quality, which you have not mentioned and which with DVD format is very poor as the image is only 720 x 576 pixels to start with, then there is nothing to worry about.

. . . . in the audio settings dialog the audio codec is locked to MPEG Audio, so I can't select AC-3. . . .

It is certainly there as you can see below - it all depends on the export setting you select:

Setting output to same as source will override this!

HTH

John EB

@Richard-hardy

Hi

I have to agree with Peter - the VOB and mpg are identical, the somewhat insignificant differences are probably due to the way the VOB and mpg bitrate data is calculated.

If you do the calculations based on the bitrates of the 2 files there should be a difference of approx 75 frames, ie 3 secs @ 25 fps, difference in length - however they are both the same length.

With this and assuming you cannot see a difference in the quality, which you have not mentioned and which with DVD format is very poor as the image is only 720 x 576 pixels to start with, then there is nothing to worry about.

. . . . in the audio settings dialog the audio codec is locked to MPEG Audio, so I can't select AC-3. . . .

It is certainly there as you can see below - it all depends on the export setting you select:

Setting output to same as source will override this!

HTH

John EB

 

 

Thanks for your help. But I am still confused as to why a smart rendered file would not be exactly identical to the source with regards to file size & bitrate. If smart rendering is meant to leave the a video as it is without re-rendering it, then surely the file size and bitrate of the smart rendered file should be exactly the same as the source’s??

@Richard-hardy

Hi

Forgot to add this in my previous post.

You did mention some light editing - this is likely to have required the edited sections being re-rendered in which case there are going some slight changes in the overall and video bitrates.

John EB