Project Settings

[Ossie]

Hi Guys
I'm trying to author a movie and had quality problems. The screen image is not crisp and the playback hiccups for a split second on a couple of occasions.

I edited my movie in MSP, captured from a Sony Z1 so the files are MPEG. The editing settings were:
24bits, 720x576, 25fps
Lower Field First
DVD PAL 16:9
Variable data rate (8,000kbps)
Audio data 224kbps
MPEG audio layer 2 48Khz, Stereo.

I think I found the main problem as the data rate in MF was set at Variable 7,000kbps, instead of 8,000. However before I burn again, could someone tell me if the speed quality in compression should be identical as well? In MSP it's set at 70 but in MF it's at 90 (I thought it mirrored the settings of the imported project). Should I make it 70 as well for my MF output?

Also, my MF settings wern't the same for audio, which was set to dolby. I have set now to MPEG audio, the same as the MSP project. However I cannot set "layer 2" (as it doesn't appear in the dropdown, only "stereo"). The audio bit rate is 224kbps. Is the audio OK?

I'd really welcome some quick advice please on these two questions.

[DVDDoug]

There should be an option that says "Do Not Convert Compliant MPEGs". (I've forgotten where that option is... maybe on the 'burning' screen... It may depend on the version of MF you're using.) If your 8000kbps file fits on a DVD without re-comrpessing to 7000, you should be OK leaving it as-is.



On the other hand, re-encoding to 7000 shouldn't be that bad either. Most commercial DVDs seem to be encoded at about 5000-6000kpbs.

I think "Do Not Convert..." is supposed to work for the audio too. You theoretically loose quality if you convert from Dolby to MPEG-2 audio, but if the MPEG audio sounds OK, it's not a big deal since all PAL players are required to play Dolby AC3, LPCM, and MPEG-2 audio. (NTSC players are not required to play MPEG audio.)

[Ken Berry]

The 'Do Not Convert' box is found in the second icon from left in the bottom left of the MF screen. That should indeed take care of all your problems.

MPEG audio for DVDs is always 'mpeg-1 layer 2' so it doesn't matter if 'layer 2' doesn't appear.

The quality slider doesn't actually change any of the settings, such as bitrate. All it represents is a balance between the speed of rendering and the final quality. To me, it has always been marginal and I have always accepted the default settings, whether in VS or MF. Some people, though, swear by it. Note that the higher the figure (e.g. 90) the longer it will take to render but in theory at least, the better the final quality since the program takes more time to analyse and work out optimal ways of dealing with variable bitrates throughout a video. I personally have never noticed any significant improvement in quality when I have experimented with the slider settings, but maybe that is just my tired old eyes. Some people have, as I already said, and swear by it...

[Ossie]

Thanks for your advice, guys.The "Do not convert" box was ticked in project settings. Anyway, I've left MF as 8,000 variable and see what happens.

[Ossie]

Hi Guys
Another quick question; should I burn with "two-pass conversion" enabled? I see there's a similar setting for saving the video file in MSP8 (should I enable it there as well?)

[DVDDoug]

Of course, if you're not re-encoding, the Movie Factory setting shouldn't matter at all.

I really don't know if 2-pass will help at 8000kbps. The idea of 2-pass encoding is that if you are using variable bitrate encoding, it can analyze the entire video on the 1st pass and then allocate higher bitrates to scenes with lots of motion and lower bitrates where there is less motion. It's a way of getting the best quality into a given file-size.

Generally, 8000kbps constant bitrate (CBR) will be better than variable bitrate (VBR). At low (average) bitrates, VBR is better.

[Ossie]

Hello again
I applied what I picked up here and my authored DVDs are getting worse. They keep sticking and jumping when played back on the actual DVD player, yet playback on the PC is good.

I lowered the datarate to 7000 and altered the field setting from "lower field first" to "frame-based". The first playback was fine but the secod time it started sticking and jumping again. I know what you are going to say, so I played other DVD's I'd made recently (using the same disc brand) as a comparison and they played cleanly; so it doesn't seem to be the player or the discs.

I need a reasonable DVD version as it's a local charity event and this is getting a bit irritating as I'm losing so much time. Anyone any ideas?

[DVDDoug]

This is still difficult to nail down (obviously)...

1. You might have an "issue" with the MPEG from MSP. I don't fully understand why this happens, but I've had "perfectly good" files* that cause weird problems when making a DVD. Even if the authoring program doesn't re-compress, I believe the file gets re-multiplexed, and something seems to go wrong during that process. You can try re-encoding the MPEG with SUPER (FREE!!!) using similar bitrate settings, etc. (Re-encoding will potentially degrade quality, but sometimes you don't have a choice.)

2. You may have a bad disc or a bad burn. If you have Nero, you may already have a program called Nero CD-DVD Speed or Nero DiscSpeed. The Nero program can tell you if you have a "physical" problem... It checks to see if the data can be read from the disc (or if the computer has to slow-down & re-read... It does not tell you if you've written "bad data" onto the disc.

If the Nero program indicates a problem, you can burning at a slower speed, you can try a different batch of discs, or you may need to try a different burner. If Nero indicates no problems reading the data, then the MPEG data/structure is getting fouled-up somewhere along the way.

3. Maybe Movie Factory is the problem, and maybe you need to try a different authoring program.


I've had enough "bad burns" that I test all of my discs with CD-DVD Speed after burning.



*My "problem files" were not from MSP... I don't have MSP.

[Ossie]

Many thanks Doug
A mystery. I can't work out why any of my burned DVDs play perfectly on the PC but not in the DVD player. I'd have thought a bad disc/ data would not have played at all on either. Then there was one disc that played perfectly in the DVD player but when I played it later it stuttered and stalled lilke the others; bizare!

I have two Samsung drives (one is Blueray) and get the same result from both. I've generally used - RW discs so I can scrub them once I have a good version but I've also tried -R discs (and I've also used various disc brands now). I thought my MF software may have been corrupted but I have Nero (v6) and ran the disc check as you advised. It suggests all is OK, so I assume MF is authoring the data to disc OK.

The scan disc gave a 100% good surface scan result for the three chapters/ movies but the disc quality scan's start button was greyed out. The benchmark test gave the following (which seems OK - but once we get into numbers I get a bit hazy):
[08:55:38] Drive: TSSTcorpCD/DVDW SH-S182M SB05
[08:55:46] Disc: DVD-RW, 0.50 GB, OPTODISCW004
[08:56:01] Starting transfer rate test
[08:57:41] Speed:3-4 X CAV (3.88 X average)
[08:57:41] Elapsed Time: 1:40
[08:57:41] Starting access times test
[08:57:48] Random Access: 73 ms
[08:57:56] 1/3 Access: 76 ms
[08:58:05] Random Access: 97 ms
[08:58:05] Elapsed Time: 0:25
[08:58:05] Starting CPU usage test
[08:58:20] CPU usage at 1X: 6 %
[08:58:36] CPU usage at 2X: 12 %
[08:58:51] CPU usage at 4X: 23 %
[08:59:20] CPU usage at 8X: -
[08:59:20] Elapsed Time: 1:14
[08:59:20] Starting burst rate test
[08:59:22] Interface burst rate: 25 MB/s (25462 KB/s)
[08:59:22] Elapsed Time: 0:02
[08:59:22] Starting spin-up/down test
[08:59:26] Spin-up time: 2.45 seconds
[08:59:39] Spin-down time: 2.32 seconds
[08:59:39] Elapsed Time: 0:17
[08:59:39] Starting load/eject test
[08:59:40] Eject time: 1.70 seconds
[08:59:42] Load time: 1.07 seconds
[09:00:01] Recognition time: 19.82 seconds
[09:00:01] Elapsed Time: 0:23

Don't know if any of the above triggers a Eureka moment for anyone looking in to this thread? One thought; the two movies are fairly similar (one a shorter version to show to traders and one a bit longer for general consumption), could there be some kind of conflict?