slight problem with VCD creation using Tmpgenc

[steverae]

I've started converting Divx's and DVDRIP's to VCD with the following settings in tmpgenc

Bitrate 900 or 950 CBR, audio 44100 96kbs

The movie plays fine on my standalone player (cyberhome 528) but every so often the video sticks for a fraction of a second then carries on. This is not really spoiling my enjoyment of the movie but it is a wee bit anoying.

Has anyone got any idea's why this would happen and how to fix it. I use the bitrates mentioned to fit the movies onto a single CDR.

[banjazzer]

If I were you I would use one of the standard VCD templates. Most films will fit on 2 CDs. 1 CD does seem a bit parsimonious! If this still causes problems, I'm not sure what to suggest.

Two things are always worth doing IMO when converting DivX to VCD.

1. Extract the audio as uncompressed wav first using Virtualdub
2. Check the framerate in Virtualdub, and load the appropriate PAL, NTSC or NTSC(film) template. 8)

[ratt794]

What you are experiencing is un-corrected bit error's from the CDR disc.

VCD and SVCD are written in Audio mode with only 2 layers of error correction. A "perfect" disc will have 6-7 errors over the full 80 minutes.

CD-ROM's add a 3rd layer to combat this problem and are far more robust.
I use CD-ROM over VCD because my APEX 5131 plays them flawlessly.
I have noticed erros with VCD / SVCD type discs and they increase as the disc is scratched.

Some DVD players may conceal these errors better than others but they all have them. There is really nothing you can do except try a different brand CD-R as some are better than others. If your lucky enough to have a DVD player that will play MPEG's on a CD-Rom than use that format as it is 1000 times more robust against bit errors.

[banjazzer]

I'm not sure I agree with this. I have 2 stand-alones - one will play pretty much anything I throw at it, the other is picky. On the picky one, I can encode a re-writeable as mentioned earlier, and it will play perfectly. Once I up the bitrate, it stutters. Re-encode at a lower bitrate and it works again!

[ratt794]

What I stated are facts - the error correction on a Video CD is limited to at best a 10^-9 bit error rate after correction. Do the math and this works out to 6-7 average errors over the full 80 minute disc. This error rate is fine for audio but not for Data. This is why CD-Roms have a 3rd layer to increase correction to 10^-12 bit error rate or about 1 error in 185 disc's.

What you are likely experiencing is the CD-Motor speed limit for that player is being reached. My Apex 5131 will do the same thing above a 5000K bitrate on a XSVCD or 4200K on a CD-Rom. The CD-rom plays error free while the XSVCD will have ocasional glitches (bit errors).
Some players do read CD-RW discs better than CDR but mine seems not to care either way.

[banjazzer]

And what I stated are also facts - the maths is irrelevant. On my picky DVD player, CDR or CDRW, anything over 1850 kbps stutters. Below that, no problem. It is possible we are *both* correct!

[DjPj]

Uhm... To me it just sounds like an ordinary Ntsc>Pal convertion. The ntsc standard framerate is 23.97 and the pal is 25, so the encoder displays one frame twice every second. check your input & output bitrates.
Hope it helps

[steverae]

:D Hi guys, everything you have said seems to follow having high bitrates, i'm trying to lower the bitrate to fit a movie onto a single disk in VCD format. I have a cyberhome ADL528 which plays most things no problem.

After further testing and turning on the PBC function of the player, the problem seems to be less of a problem.

I have read that some people have encoded VCD's with variable bitrates but this doesn't seem to play on my machine.

I have also noticed that reducing the audio bitrate from 224kbp to 96kbp doesn't seem to effect the quality of the audio one bit (Although something must have to give)

Just thought i'd re-iterate my point so that original problem discussed in this thread doesn't get lost.

BTW the format is the same NTSC -> NTSC PAL -> PAL etc.

Thanx for all you help so far