MSP7 and MPEG output quality

[sheinb]

I have a couple of problems with MPEG2 output from MSP7 and I was wondering if these are known limitations or I might be doing something wrong.

First, if I take two clips of mpeg video (and mpeg audio -- elementary streams) and align them side by side (no transition) and set the project up to match their quality, I can get SmartRender to spit these out as a single program stream without re-encoding (which I think is a "good thing"). The problem is that at the transition point I will sometimes see the end of the first clip repeat itself after the second clip has started. I also sometimes see the same thing when abutting an MPEG clip to an DV-AVI clip and output as MPEG (obviously smart render can only be smart about the MPEG portion of this output). These MPEG clips were encoding with the cinemacraft encoder and I'm careful about the field order, etc. I do not, however, "Close GOPs" -- could this be the problem for MSP?

Second, more generally, is it accepted that the MPEG output from MSP is somewhat inferior (in terms of quality) to other encoders (such as CCE)? It definitely seems like using a frameserver to the stand alone encoder produces cleaner MPEG files, but I was just wondering if this is due to settings I can play with inside of MSP7.

Thanks!

[Terry Stetler]

first of all I'm presuming the project settings closely match the stream properties of the clips? If you're unsure click on the clip in Insert Video and click the "Info" button to get the info.

When exporting from Create/Video File/Video Editor you should also check the box labeled "Add keyframe at clip edge". This should place an I frame at the tail end of the clips when you export.

I frames??

Most MPEG's consist of GOP's, groups of pictures, 15 or 18 frames long. GOP's most often start with an I frame (full bitmap) and are followed by 14 (or 17) synthsized P and B frames, some of which have data for reverse playback. This high proportion of synthetic data is what makes for the high compression ratio in MPEG files.

Putting an I frame (the clip-edge keyframe mentioned above) at the tail end of the last GOP can help the transition to the next clip. Otherwise it's possible the reverse playback data could find its way into the next clip.

Try it and see before committing Hari-Kari

My next idea would be to convert the MPEG's to some other format, such as DV or MJPeg, for editing them re-export them as MPEG's again. This is called using a "transitional codec" and is often used when such problems are encountered.

As far as quality goes, MSPro uses the same MainConcept MPEG engine used in Premiere and many other programs. The lower quality at export is largely based on the setting of the Quality slider in the export settings being set at only 70. Up it to 85 or 90 and the quality goes up quite a bit.

You can also enable an Advanced menu which gives you access to the entire MainConcept control panel by opening this file in Notepad;

c:\documents and settings\(username)\application data\ulead systems\ulead mediastudio pro\7.0\MSP.INI

Now look for the heading labeled [VIODRIVER] and add the following entry;

[VIODRIVER]
Advance=1

You will now see the Advanced menu on the MPEG options page.

Most settings here will stick, but not all. Min/Max/Average VBR is one that is troublesome, but other important settings like closed GOP, motion vectors, DC compensation etc. do stick.

[sheinb]

Thanks -- that's very helpful. I will definitely enable the advanced panel to see the MainConcept encoder dialog. Regarding smart render, can you think of any reason why a render that appears to do a fast frame copy (if that's what it's called) would look any different from the original in terms of blockiness? I have noticed that even when original MPEG streams seem to be copied unaltered, they don't playback exactly as the original (all of this happening many seconds from any transition, so the GOPs should be identical?).

Thanks again for the pointers -- I will give the insert keyframe at clip boundaries a shot.

-David

[Terry Stetler]

Hmmm.....if it were smartrendered it shouldn't change the GOP's or compression ratio, so blockiness shouldn't be there. Is this defecftive playback being done in MSPro, MediaPlayer or ??

I know I've never seen it, though I don't like to edit conventional MPEG because it's not really an editing format...it's a distribution format. The only consumer MPEG format intended to be edited is HDV; the HDTV codec being used in many new HD camcorders.

I use the transitional codec route: converting MPEG's to DV or MJPeg for editing then re-exporting as MPEG when finished. Most often I use MJPeg because it can be set up for near-lossless edits.

[sheinb]

What exactly is "different" in the resulting playback? Blocky, aspect ratio not correct etc.??

Blocky during particular scenes.

[Terry Stetler]

Check the edit.....done after I reread the post

[sheinb]

I use the transitional codec route: converting MPEG's to DV or MJPeg for editing then re-exporting as MPEG when finished. Most often I use MJPeg because it can be set up for near-lossless edits.

As an example, I have proshow gold outputs (slideshows) in MPEG2 format (because they don't have a DV codec). Would you recommend turning these into MJpeg from within MSP -- I guess as a simple standalone project? Then placing that in my timeline until the output stage?

[Terry Stetler]

IF you're going to add more than just cut edits then in my experience usiong a transitional codec is a good option.

If, on the other hand, you're just joining MPEG clips together without changes then the method above of adding a keyframe at the clips edge can work, but some mpegs will even give this method fits.

In that case using a program made expressly for simple MPEG joining/edits. One such program is the TMPGENC MPEG editor;

http://www.pegasys-inc.com/en/product/tme.html

The free trial is good for 14 days

[sheinb]

In that case using a program made expressly for simple MPEG joining/edits. One such program is the TMPGENC MPEG editor;

http://www.pegasys-inc.com/en/product/tme.html

The free trial is good for 14 days

Yes, I use VideoReDo for this purpose, which works quite well (http://www.videoredo.com).

Adding keyframes at clip boundaries did seem to remove the glitches I had been seeing. As for quality, setting the quality slider up to 85-90 does help, but the encoder is quite slow compared to frameserving (debugmode) to the cinemacraft encoder. I also get the feeling that for my footage the CCE Basic encoder is clearer, but it's a pretty subjective thing. I couldn't get the advanced options to show using your suggested change to the msp.ini file. I found the [VIODRIVER] section, but "Advance=1" did not add any obvious new buttons to the MPEG export dialog. Is that where it should have appeared?

Thanks again for your help.

-David

[rwernyei]

David,
Follow these instuctions for enabling the ADVANCE options for Ulead's MPEG encoder.

I clicked START;
I clicked MY COMPUTER;
I clicked C: drive;
I clicked the DOCUMENTS & SETTINGS folder;
In the WINDOWS TOOLS menu, I clicked FOLDER OPTIONS;
I clicked the VIEW tab;
I ticked the option to SHOW HIDDEN FILES AND FOLDERS;
I clicked OK;
I clicked the ALL USERS folder;
I clicked the APPLICATION DATA folder;
I clicked the ULEAD SYSTEMS folder;
I clicked the ULEAD MEDIASTUDIO PRO folder;
I clicked the 7.0 folder;
I clicked the MSP I-N-I (configuration) file;
Under the [VIODRIVER] heading, I typed Advance=1;
I saved the change.

Under Compression is where you will see the new activated button. Hope this helps.

[sheinb]

David,
Follow these instuctions for enabling the ADVANCE options for Ulead's MPEG encoder.

I clicked the ALL USERS folder;

Under Compression is where you will see the new activated button. Hope this helps.

Perfect, thanks. I changed my personal msp.ini file instead of "ALL USERS". Now I see the modified dialog box.

[Terry Stetler]

That was my bad.

I meant to type "all users" but got brain-locked and typed "username" instead. Probablly fatigue from testing MSPro 8 'til all hours

Sorry....