KVCD: Possible Fix for my Stuttering Video?

falcon · #1 10-02-2003, 02:56 AM

I've been doing a LOT of testing using a CD-RW to get things to work. Player in question is a Koss-KD230 and it is PICKY about what it wants to read.

My main problem was various stuttering during playback. It would freeze, sometimes just video and sometimes audio would too if the video froze for long enough and then it would continue like normal. Seemed like an underrun to me although no multiplexer would indicate so.

I'll have a more complete report after I tweak this and get it working, but it is very close right now if not correct already. I'm using 10minute test clips, and the programs used are:

VirtualDub
TMPGEnc
BBMpeg
Nero

The test video is 352x240 29.97fps. Encoding MPEG1 VBR, I'm using 2pass until I can figure out how to do the CQ encoding and get a predictable file size, right now I use the little Java bitrate calculator on VCDHelp.org. Here are the encoding specs that worked best. I'd put in the movie length + 1 minute on the calculator and use the average bitrate that it gives. Video in question was about: 1h 57min 44sec so it came out to something like 790kbit. (This includes adding an extra minute for good measure.)

790882 avg rate
1510000 max rate
600000 min rate
2 pass VBR MPEG1

VBV buffer 20

Audio was done at 128kbit 44khz J-stereo MP2.

This worked for the 10min test clip. Changing the min rate to 300k and the audio to 112kbit to get a bit more out of the video didn't work, so I am going to try to lower the VBV to 16 and see if that helps. When the VBV is automatic (0) or at 40-48 it stutters early. I'll do some more testing tomorrow and see if i can stabilize it on the test clip a bit better, but the problem seemed to be with the VBV buffer since the stuttering seems like the player is expecting more data and waiting for it, so I am thinking that lowering the min bitrate to 300 might require a smaller VBV buffer.

To multiplex it I was using BBMpeg since since TMPGEnc hoses it up pretty bad. I use VCD with VBR and program end code and a forced mux rate of 0 in BBMpeg and that worked best just it is picky now lowering the audio a bit and the min video rate. I'm going to test the audio and min rate a bit more until the test clip plays good and then will try a full 2 hour clip.

Burning these in Nero as non-standard VCD 2.0s of course.

falcon · #2 10-02-2003, 03:14 AM

Ok that didn't work, I'm going to try 600kbit min rate and 112kbit audio still and 20 VBV tomorrow and see if that works. I think the Koss-KD230 doesn't like low bitrate video.

kwag · #3 10-02-2003, 03:34 AM

Hi falcon,

CDRW media, sometimes is a big problem

I have a lot of problems on my standalone players when I use CDRWs, but no problems at all when I use CD-Rs. So maybe you should run some tests on CD-Rs

Did you try the KVCD Compatibility image V2, available for download in the "What's happening" section of the forum

-kwag

falcon · #4 10-02-2003, 03:38 AM

Good point the read speeds and write speeds on CD-RWs is so much lower. I'm going to sleep now but I'm encoding the full 2hrs over night and going to burn that to CDR and see how it fares, then I will try it again at different specs on CDR and see how that goes. I was kind of hoping it was the media, it will save me some headaches if it is. I'll try the compatibility image too.

Jellygoose · #5 10-02-2003, 06:27 AM

Don't burn your CD-Rs too fast either. I burn my movies at 4x. Above 8x my Player refuses to read the CD-R

andybno1 · #6 10-02-2003, 11:20 AM

Quote:

Originally Posted by kwag

Hi falcon,

Did you try the KVCD Compatibility image V2, available for download in the "What's happening" section of the forum

-kwag

kwag have u considered doin or gettin someone to do a pal kvcd test cd for ppl who can't play ntsc movies on their dvd player?

falcon · #7 10-02-2003, 12:01 PM

Yea I've been burning at 2x on CD-RW, I think I'd still burn CD-Rs at no more than 8x, maybe even 4x for good measure. I'm not that impatient.

kwag · #8 10-02-2003, 12:35 PM

Quote:

Originally Posted by andybno1

kwag have u considered doin or gettin someone to do a pal kvcd test cd for ppl who can't play ntsc movies on their dvd player?

No, because I don't have any PAL sources. But anyone is welcome to do a KVCD PAL test image. I'm thinking on updating the NTSC image, and then uploading to Bit Torrent network, so the downloads can be spread throughout clients in the net. This way, I don't have to keep the image in the server, and we all benefit on the distribution. See, there's a perfectly legal use for Bit Torrent

I'm currently looking into this, and possibly I'll have something in a couple of days. Same goes for KVCD samples. Instead of having everyone downloading from our server ( which increases the monthly bandwidth, and the cost per month! ), everyone can share the samples and everyone helps the distribution. And of course, ONLY SHORT KVCD SAMPLES, made from TV captures

.

-kwag

andybno1 · #9 10-02-2003, 12:58 PM

I have done meself one but bein on dialup I don't have the patience to upload it lol

falcon · #10 10-02-2003, 09:42 PM

Well I've burned it to a CD and it works, I stuck with a smaller VBV but it probably would work with the default but as long as it works its ok. 2 hrs on a single CD is pretty nice.

)

Add Koss KD-230 to the compatibility list just don't burn as an SVCD and stick with MPEG1 @ 352x240 and you are ok.

kwag · #11 10-02-2003, 10:12 PM

Quote:

Originally Posted by falcon

Add Koss KD-230 to the compatibility list just don't burn as an SVCD and stick with MPEG1 @ 352x240 and you are ok.

Done

Thanks,
-kwag

falcon · #12 10-02-2003, 11:02 PM

Actually I need to test the full compatibility image still, I'll report what the KD-230 can play. I need to get batteries for my remote to skip tracks.

oops

mdskinner · #13 10-31-2003, 10:24 AM

Kwag, if you're going to put it on BitTorrent without seeding the file yourself, it will quickly disappear from the network. Lots of files get put up these days and the original source expects others to take over the seeding but this doesn't happen., and most files dissappear after 2 weeks.

You'll still need to store it somewhere and seed yourself really. If that's your intention then yes BitTorrent will definitely spread the load.

I would very much appreciate a PAL KVCD test image also - I'm having probs because my Sony player only does NTSC > NTSC TV or PAL > PAL TV and my TV only does PAL. My player does not do any NTSC > PAL conversion.

I tried the NTSC image on my player and it just resulted in a pixelated / garbled mess on all 6 tracks.

If anyone knows of link or someone who has done this, that would be really great.

Dialhot · #14 10-31-2003, 10:36 AM

A NTSC picture sent to a pure PAL tv set results in a picture in black and white. And not at all a pixelated or anything else.

If you have such problems that means that your player does not support KVCD. Either NTSC or PAL .

What Kwag should provide is a KVCD image disc burnt in VCD and an other one burnt in SVCD. Because all players do not like KVCD in VCD but accept them in SVCD.

Jellygoose · #15 10-31-2003, 11:59 AM

Quote:

Originally Posted by Dialhot

A NTSC picture sent to a pure PAL tv set results in a picture in black and white. And not at all a pixelated or anything else.

If you set your output to RGB and have a true RGB-Scart cable, the picture will not be black and white anymore...

mdskinner · #16 10-31-2003, 02:45 PM

I have heard of other people having success though with PAL KVCD's burnt at 352x288 resolution with my Sony DVP NS300 - therefore it should work for me too surely!

Leads me to beleive if it's not the NTSC/PAL issue, AND my player does play KVCDs, the nit must be the way I am burning or the media.

I'm using CD-RW, which plays fine when I create a normal compliant VCD and I'm using Nero to burn at 4x (can't select any slower speed). Is this still too fast?