DV and ATI : analog rules...

[waldok]

Hi,

I just discovered a very interesting thing in my quest for converting family movies on DV to SVCD and watching them on 43" rear-projector. My problem was DV quality when captured. I used to use dv to avi capture through firewire and then for example AVI2SVCD for generating final SVCD mpeg files.
Quality was not good and the time it took was really too long : no hope for transferring all these DV tapes I have to SVCD in a reasonable amount of time.

Now I found a surprising solution, but it works great. I have an ATI AIW 128 Pro capture card, and I must say I never was really happy with the realtime MPEG2 capture/encoding. Poor quality, dropped frames, and so on. I would never have thought about using this for DV material capture/encoding, but now I do it all the time.
ATI just published new drivers and new software (Multimedia Center 7.7) and believe me or not, the real time MPEG2 quality at capture time is excellent !
I decided to give my DV material a try through the analog way, so I plugged the DV cam S-Video output to my ATI, plugged sound connectors, and off you go !
The final quality was great.
I got a SVCD compliant MPEG2 stream with good quality, no visible artefacts, that I burnt to a CD-R as X-SVCD and played on my TV set without any problem.

Capture settings are : 352x576 resolution (PAL here), 2.51 mBits/s constant bitrate, motion estimation set to 96.

I strongly advice all ATI owners here who find DV to SVCD capture/encoding unsatifactory to try this method. I know that going to analog from a digital source to finally produce a digital result may sound stupid, but honestly, this is for the moment the most watchable quality I had and its REAL TIME mpeg2 encoding without a single frame dropped on my poor Celeron 2 566@850MHz! Imagine the possibilities with a far more powerful processor !

Hope this helps and sorry for long post.

Waldok

[bb]

This thread should be moved to the new DV forum.

@waldok:
I capture DV through firewire, then convert to MPEG2 (SVCD) at similar bitrates. I believe that the resulting quality is a matter of good filtering. The filtering is usually done through appropriate digital filters (I encourage you to try tHE fISH's DeNoise 1.0, which is based on Donald Graft's DeFlicker).
In your case the DA - AD conversion creates a smoothing effect having a positive effect on the final quality. But I'd really like to know how the digital and the analogue methods compete, as there are many different filters and filter settings to compare.

bb

[waldok]

And my point was of course not to say that "the analog way" is better than the "digital way" in general.
My point was more oriented towards ease of use and time spent since it can become critical when you have dozens of family tapes you want to move to SVCDs and while you are encoding one tape, 2 more are being produced (the way it goes when you have new born babies) ;) As usual, there is a compromise between quality and time spent, and I'm pretty sure a higher quality can be obtained from Firewire capture and offline MPEG2 encoding with appropriate filtering, but this definitely takes too much time as far as I'm concerned. When I discovered that with this latest drivers set from ATI I could get a more than decent quality in real-time encoding, I said YES !
Now it's true the video is a bit "blurry" and not so sharp as it might be, but I can tell you it's a pleasure when it only takes 1h to build a SVCD out of an old DV family tape and watch it all together on a bog tv screen ! Much more convenient than tape (needless to say).

By the way, I gave this analog process a try for encoding a DVD to SVCD. I usually use DVD2SVCD and I get fantastic wuality out of it. But it takes hours ! I've been trying to capture to MPEG2 froù my standalone DVD player through the S-Video output and I must say the quality, although far from DVD2SVCD, is still more than acceptable. But concerning DVDs, I would rather stock with DVD2SVCD cause it gives sharp and crystal clear pictures.

Anyway, thanks for your remarks and I'll give your method a try with the fish filter!

BTW, I hesitated about putting this to the DV section, but since in the end it all talks about analog capture, well...

Waldok.

[auenf]

doing it that way, you might get more macroblocks than using an encoder, especially if theres a lot of motion.

but it would make it very easy now that ati has a SVCD preset in MMC7.7

Enf...

[AudioVideoMaster]

Which ATI board are you using? I have an AIW 128 pro 32MB. I'm asking b/c I've never been able to NOT get dropped frames with MPEG-2 captures with video sizes above 352x240 (NTSC).

But after about 20 seconds of a 720x480 MPEG-2 capture I start to get dropped frames even after a fresh reboot with minimal background programs running.

Anyone get better results after applying the MMC7.7 driver upgrade? I'm curently using MMC6.2 drivers.

MY PC's specs are at:
http://www.2dreamers.com/avindex.shtml

[waldok]

Hi AudioVideoMaster (The nick says it all!)

I also used to not be able to capture without frame drops with previous versions of MMC. Now with MMC7.7, I can capture at 352x576 (half D1) at 3Mbits/s, with motion estimation at 100 without any frame drop (I captured complete 1h 8mm tapes without a problem).

My setup is quite basic, it's Asus p3V4x mainboard, Celeron II 566@850MHz, ATI AIW 128 Pro AGP 32MB, Hard disk IBM 60GO (can't remember the model) and i have a sblive 1024 with the George Breese latency patch applied to avoid crackles when capturing.

I did a clean manual uninstall for all the former ATI stuff on my PC, then installed (in this order) : Directx 8.1, stable video driver (592), latest catalyst capture drivers (from ati radeon 8500 page on the ati site), windows mpeg2 codecs (they said this was required), and finally MMC 7.6, DVD 7.6, upgrade to MMC 7.7 and DVD 7.7.

It works great, except that with my config I can't get past 352x576 for real time mpeg2 without frames dropped, but this half D1 resolution gives good quality when played back on my Tokai standalone player (this is a DVD compliant resolution, kind of a CVD if you know this).

Of course, at bitrate 3mBits/s, resolution 352x576, and audio at 128 kbits/s stereo, this is no "regular" SVCD, but it plays well and smooth on my tv ;)

By the way, if it can help, I also use Ulead DVD motion factory to generate the SVCD image from my captured mpeg files (I discovered this yesterday and it makes demux/remux unnecessary before burning).

GOod luck.

Waldok

[AudioVideoMaster]

I already have Directx 8.1 installed but the rest I need to go download. But thanks for the advice, especially on the uninstall/install stuff.
ATI stuff can be buggy from time to time to clean up and upgrade. But ATI has gotten much better at making it NOT a pain in the butt to do so. I know b/c I've owned three ATI AIW cards so far.

Now just waiting for the ATI AIW Raedeon 8500 128MB card to come down in price!!!!

Thanks for your reply waldok!