MJPEG to MPEG2 for svcd

[kwmarriott]

Hi: ok I'm new and this may have been discussed beofre. I have a Marvel G400 and I want to end up with an mpeg2 file that I can use to make a SVCD. I have tried MJPEG (converted with Ulead DVD STUDIO) and I end up with rips in the picture when played on a stand alone dvd player-I am assuming this is an interlacing problem as I don't get it on VCD. I have tried using YUY2 and grabbing to DIVX (I can get full screen capture this way with very little frame dropping) and the capture stops at 35 mins, and it isn't the 2gb file limit as the file is only 1.2 gb.

Just what is the best way to capture full screen video with the G400, convert it to mpeg2 and make a svcd-coz this is driving me nuts and I have a pile of duff cdr's to prove it!

[Flying dutchman]

I have a G200, but Picvideo and Huffyuv work perfectly for me. I can capture for hours and hours without any drops.
I don't know where the 35-min limit comes from, maybe it's in the DivX encoder?

[kwmarriott]

I tried the huffy thing but the file sizes were massive and the old 2gb limit kicked in: I don't know where the 35 minute limit comes from! It doesn't do it with MJPEG. I am using the flying dutchman's (not you I presume) YUY2 patch for the marvel g400.

If you ARE USING HUFFYUY how are you compressing to a managable size?

As a general question: is the mpeg2 for svcd interlaced or deinterlaced? I would have thought it was interlaced but this sappears to be where the rips in the picture are comijg from.

When I grab at 705x576 with YUY2 compressing to divx 4.1, using freevcr to deinterlace I get a very good capture which converts perfectly to mpeg2: just can't capture for more than 35 mins!!

[Brian Ellis]

There is MPEG-2 and then there is MPEG-2. You MUST use the version specifically for burning SVCD PAL or NTSC, as the case may be. I've absolutely zero problem burning SVCDs from hardware MJPEG AVIs using either the Ulead plug-in for MSPro 6.5 or Movie Factory, at 480 x 576 (or 480 x 480 in N. America. If you choose simply MPEG-2, you'll have problems.

[kwmarriott]

Brian: I am astonished, I have ulead 6.5 and if I burn to svcd from the plugin, from a mjpeg capture I get horizontal tearing in the picture. Which version of the matrox driver and vid tools do you have installed?

[Brian Ellis]

Use 5.41 and 1.52 resp. Make sure your Field Order is set to B at all stages of the operations.

[Flying dutchman]

Yes I'm the patching Dutchman.

I use Avi_io for capturing; it automatically creates segments
no longer than 2 gb in size so it's just not a problem anymore. The resulting full-size files are interlaced of course. As a rule, you can say that anything captured from composite video or TV with more than 288 lines vertical resolution is interlaced. So if you create SVCD mpeg-2's with 480 or 576 lines they are interlaced. If you get artefacts on TV, you probably got the field order wrong. Seeing artefacts on a pc monitor doesn't mean you get them on TV.

[kwmarriott]

Ah (or should that be arrrrrrrrr) I have the field order the wrong way round! Git it set to A. So: if I capture in mjpeg (field order B), do I need to deinterlace the capture before changing it to mpeg2 for SVCD? And, to the flying dutchman-which drivers are best to use with the YUY2 patch...Which is wonderful by the way..

[Flying dutchman]

For SVCD - don't deinterlace. Your TV knows perfectly well how to handle interlaced source material. Just get the field order right throughout the process.

I capture under Windows 2000 myself (Powerdesk 6.28, vidtools 2.04.15 with macrovision tweak) but the best versions for Windows 98 are indeed 5.41/1.52.


I'm going away for a week now, won't be able to monitor this thread.

[kwmarriott]

Thanks flying dutchman! The 35 minute problem seems to be because I was using your YUY2 patch with the last release of the Matrox drivers for the Marvel G400, installed the version you advised and it's fine. Now for some interesting news for people trying to create SVCD with the G400.

I downloaded a utility called freevcr (easier to use then virtual dub). I have been able to set the capture size to 352x288 in YUY2 in video format, then select a custom format of 480x576, use DIVX 4.1 for compression and capture an SVCD sized file which is much smaller then 2gb. The file size doesn't really matter because freevcr will split the file into smaller chunks as it captures.

Because the capture size is 480x576 (svcd size) it converts to mpeg2 very quickly. At the moment the quality seems very good although I am still trying to find the best way of removing adverts.

An added bonus of freevcr is it will lock the video to the audio stream so the audio stays in sync with the picture-I think it does this by dropping the odd frame but at least the sound fits the picture.

[Brian Ellis]

KW

You worry me. IMHO, there is no point in burning SVCDs if your original capture is in 352 x 288. You should burn VCDs, which use the same format, and last for up to nearly 1 hour max.

What you are doing is to take 1 litre of milk, pouring out half of it into an empty 1 litre bottle and selling it, wasting half the space and potentially contaminating it. To fill your bottle (ie obtain the best visual quality), you should capture in a format larger than the SVCD, such as 704 x 568, do all your editing in that format to maintain max quality and only in the last stage convert it to the 480 x 568 MPEG-2 and burn your CD.

FWIW

[John Wray]

Originally posted by Brian Ellis
KW

You worry me. IMHO, there is no point in burning SVCDs if your original capture is in 352 x 288. You should burn VCDs, which use the same format, and last for up to nearly 1 hour max.

FWIW

Well, there's more to SVCD vs VCD than resolution. The SVCD standard also allows a higher bit-rate than VCD (and maybe allows variable bit-rate - I don't remember), and this can make a significant quality difference, even for 352x288 sources. Of course, you're not getting the most out of the SVCD format with a low-res source, but it should still look better than VCD.

But I agree, for maximum quality, you want to capture in a higher-res format. I use avi-io for capture at full resolution using minimum compression hardware MJPEG, then use TMPGenc to encode to SVCD.

John

[kwmarriott]

Ah: but vcd are mpeg1 which is worse quality than mpeg2. although the YUY2 is set to 352x288 the quality of the capture is much clearer than vcd at mpeg1, and i do mean much clearer. maybe freevcr is actually changing the capture size to 480x576 but the picture looks great-much better than capturing to mpeg2 at half D1 then converting it to svcd. Of course I would love to capture full screen and convert it but a) it takes ages, B) unless I use mjpeg I drop too many frames. Having said that although the divx capture is near perfect I am still getting audio sync problems when coverting to mpeg 2 with ulead mediastudio-so maybe this isn't 'the answer'.

[Brian Ellis]

Personally, I find I get best quality with native Marvel hardware MJPEG 704 x 576, top quality, captured via AVI_IO. Never lost synch, even though an occasional dropped frame (worse since I installed 120 Mb on a RAID 0 array). I then convert to SVCD with MSPro/Movie Factory.

In the early days, I did a capture at 352 x 288 and I burnt both a VCD and an SVCD for comparison. Viewed critically on an ordinary TV, I was hard put to say which one was better (it may have been different had I been a panning/zooming maniac, but I ain't). I then did a capture at 704 x 576 and burnt an SVCD. The result was more than convincing enough that I have never captured at 352 x 288 since, nor have I burnt a VCD.

To date, I've not made a similar comparison with DVD, because the DVD-RW disc doesn't work in my DVD player and the DVD-R discs are too darn expensive for playing around with trials. I'll wait until I have a full DVD project finished and extract parts of the original capture onto SVCD to make the comparison. Frankly, I don't expect much improvement because 480 pixels wide is already approaching the resolution limit of ordinary TV sets. Maybe a wee bittie.

[mrtj1]

can i ask for some help on this topic?

i tried to make some svcd's out of my caps with the g400 with the cinema craft encoder SP but i cant get it to use all the files i choose. i mean i enter cap.oo.avi and cap.01.avi etc, but it does them one at a time as opposed to using them all. i want to use the VBR option in this and it gives great quality files.

any ideas how to get around this problem? kind of goes against the point of VBR if i have to do each file individually