Maybe PE8 problem??? .avi worse than .mpg

[cknittle]

Guys,

I take a lot of video of my kids sporting events to create end of season highlights for the team. Since I'm the coach for one of my kids, someone else uses their HV20 and provides me with a bunch of .mpg clips - standard def, widescreen. For each game, I edit all the clips on the timeline and write to a single large .avi file after creating a DV Widescreen project.

My experience previously with PE4 is that the .avi resulting from File->Export->Movie is the best quality, assuming I uncheck the "Recompress" box. After installing PE8 I noticed the .avi file is *worse* than the .mpg file. Much worse, IMHO. Near as I can tell, the default settings for PE8's Share->AVI using the DV NTSC Widescreen preset is "uncompressed" since the "Quality" in "Basic Settings" is set to 100%. For some reason, PE8 won't let me change this anyway.

The attachment was too large to upload with this post, so I've put a .zip file on my website. Should be able to right click the link below and select "Save Target As" to save to hard drive.
http://www.theknittles.com/videos/MPEGShareNTSCDVDWidescreenDefaults.zip

Three files in the .zip:
1) OriginalFile.mpg - original file from friend
2) DVNTSCWidescreenDefaultSettings.avi - Share->AVI->DVNTSCWidescreen Preset, default settings
3) MPEGShareNTSCDVDWidescreenDefaults.mpg - (apparently re-encoded) Share->MPEG->NTSCDVDWidescreen Preset, default settings

Even the re-encode to .mpg looks better than the .avi. Problem is, I did this test in PE4 after noticing it, and the results are the same.

Don't know if it matters, but background rendering is disabled.

Any idea what's going on? Did PE8 install a new .avi encoder that is now also used by PE4?

Hope you can help.

C

[Steve Grisetti]

The downsampled video from that HV20 should be in DV-AVI format, not MPEG. Putting it into MPEG format means that Premiere Elements has to take it through another level of conversion -- and that will result in reduced quality (in addition to some possible interlacing issues).

If you'll use DV-AVIs from that HV20 as your source files in a project set up for standard DV, you'll get as-good-as-original results.

[cknittle]

The downsampled video from that HV20 should be in DV-AVI format, not MPEG. Putting it into MPEG format means that Premiere Elements has to take it through another level of conversion -- and that will result in reduced quality (in addition to some possible interlacing issues).

If you'll use DV-AVIs from that HV20 as your source files in a project set up for standard DV, you'll get as-good-as-original results.

Agree that using the original dv-avi format would be best. But he's a newbie and apparently has figured out only how to convert to .mpg and save to dvd using his software. I understand the loss of quality with each re-encode.

I don't expect this much degradation in quality that I'm seeing. Given the original .mpg looks pretty darn good, I'd expect .avi output to be nearly identical to the decoded .mpg, since I disable "recompress". And why is the re-encoded .mpg file better quality than the .avi? I'm assuming PE re-encodes when I share as .mpg.

Thanks. Appreciate your thoughts.

C

[Steve Grisetti]

Unfortunately, it's going to recompress anyway, c.

Premiere Elements uses a DV-AVI workflow. That means that, in standard DV editing mode, everything gets assimilated and converted to a DV-AVI before it becomes anything else. Even if you start with an MPEG and ouptut an MPEG, it's converted to a DV-AVI in between. That's probably why you're seeing reduced quality -- You're starting with an HDTV MPEG downsampled to a DV-AVI, then converted to a VOB, then converted to a DV-AVI, then converted back to an MPEG.

I guarantee you that, if you get DV-AVIs directly from that HV20, you'll get pristine results!

[cknittle]

Unfortunately, it's going to recompress anyway, c.

Premiere Elements uses a DV-AVI workflow. That means that, in standard DV editing mode, everything gets assimilated and converted to a DV-AVI before it becomes anything else. Even if you start with an MPEG and ouptut an MPEG, it's converted to a DV-AVI in between. That's probably why you're seeing reduced quality -- You're starting with an HDTV MPEG downsampled to a DV-AVI, then converted to a VOB, then converted to a DV-AVI, then converted back to an MPEG.

I guarantee you that, if you get DV-AVIs directly from that HV20, you'll get pristine results!

Did you take a look at those files? The AVI is terrible. And we're dealing with SD from the start, although your comments about the DV-AVI workflow remain valid.

But this still doesn't explain why Sharing using MPEG is better quality than Sharing using AVI share. I'd expect it to be the other way around.

I'll have to work with the dude to get AVI files from him.

[Steve Grisetti]

It's all about the source files. c. And how many conversions (and from what) it went through on the way to the program.

As I've said, if you can get your hands on DV-AVIs directly from that camcorder, you will get excellent outputs, no matter what you output them as!

[dalelpaq]

I'm jumping in here kind of late, but I'm confused. I shoot with an HV30 and download through HDVSplit m2t files. I know these are highly compressed. Are you saying that these files are then converted to DV AVI - 720 X 480 resolution - then go through the editing pipeline, and then get up-converted to MPEG-2 for playback on Blu-ray? My goal is to stay HD all the way through to Blu-ray. Is this possiblem or am I just misunderstanding? Thanks

[Paul LS]

If you use a high definition project preset they are not converted to AVI at 720x480. When you render the high definition .m2t file it is rendered as a high definition MPEG2 file so no down conversion to standard definition.

[dalelpaq]

Thanks, was worried there for a minute.

Is there a way to create a custom preset? Most of what I do is visual effects with After Effects and work usually in a 1920 X 1080 p30 comp. Typically I output to PE with an uncompressed file (often avi). In PE, however, the closest HD preset I have is 1440 X 1080 p 30 (anamorphic with PAR 1.33). PE accepts the file but must convert it to the latter.

Thanks, Dale

[Chuck Engels]

Maybe it's time to go Pro Dale?

[Bob]

Is there a way to create a custom preset?

Are you are up to experimenting?

From the splash screen, start a new project. When the new project dialog comes up, select the HDV 720p 30 preset and click on the new preset button. Don't change anything, but click on the save button. Give it a name and a description and save the new preset. That will create a custom preset of that name. Exit Premiere Elements.

Now you need to find the custom preset file. In Vista, it's located at "C:\Users\LoginId\AppData\Roaming\Adobe\Premiere Elements\7.0\Settings\Custom" replace loginid with your login id and use your Premiere Elements version instead of the "7.0". It will be a different path in XP, but still in your user files. The appdata folder is a hidden folder, you may want to change your settings to show hidden folders.

In PRE7, the custom preset will be named something like "My 1920x1080 test.prpreset" -- except it will have the name you gave the custom preset when you created it.

Temporarily rename the file by adding a ".txt" to the end. Now edit it with notepad and replace all occurances of 1280,720 with 1920,1080 (you can use the find and replace feature of notepad to make it easier) then save. Rename the file back to what it was -- i.e. remove the ".txt".

You now have a 1920x1080p 30 preset to play around with. No guarantees that it will work like the real preset that Pro would have. But, play with it and see what you think.

[Chuck Engels]

Nice hack Bob, between you and RJ we will all be writing our own code and fixing all those annoying bugs ourselves