Divx-VCD file size query

[elkdanger]

Hi

I noticed that whenever I convert a DivX movie to VCD using TmpGEnc the file size of the vcd usually ends up way bigger than the original Divx. I usually encode a full film at ~800kbps.

While I realise that VCD is a fixed bitrate format, is there anything I can do on the Divx side of things to make sure that the final vcd will encode to a similar size? I read somewhere that encoding the Divx to a high bitrate (~1600kbps) helps, which I am trying as I type this.. of course, I could be talking BS..

Also, I would like to be able to convert to SVCD using the same program, but when I go to encode, the source time stays on 0 for the duration, and the film doesn't encode. Any ideas?

Thanks for any help!

[setarip]

Standard compliant VCDs are based on running time (like music CDs), not on filesize. As such, you can typically fit up to 80 minutes of compliant video onto a 700Mb 80 minute CD-R.

As far as I know, changing an .AVI's bitrate will have no effect on the creation of a standard compliant VCD...

[elkdanger]

Ah yeah, that's what I originally thought, but I have an 8-minute divx5 video, which is ~80MB, that I would like to convert to VCD, but according to TmpGEnc the final vcd video would be around 420MB...

The divx vid is encoded at 1400kbps, but if you say it's the running time, there must be something i'm not doing right.

Some videos will be fine, however - but being only slightly past a n00b it seems random to me..

Ta!

[Thingy]

check the bitrate, it should be 1150kbps for a standard-compliant vcd.
it's probably set to something like 4000.
You could set the bitrate to anything though. Using to pass encoding might allow you to use a average bitrate of 800~900 kbps.
Also make sure that the system tab under setting is set to MPEG-1 Video-CD or the non-standard option.

[elkdanger]

Yeah, the bitrate is as it should be for vcd (1150kbps), but have found that TmpGEnc sometimes detects the length of the video wrong.. For the 8 min video I described above, it detects it as being 48 mins, hence the bigger size. Another video I tried was fine, yet a further test said that a 147 min video was only 107 mins..

Is this a known bug and is there anything I can do to correct the source file?

Edit: Just opened the movie in question in both Winamp and Media player, and they detect the correct playing time, which leads me to believe its a TmpGEnc thing..

Thanks again

[Thingy]

You could always try to demultiplex the audio and video in VirtualDub.
Open the avi in VirtualDub.
Audio->direct stream copy select save wav... from the file menu. This will actually save the audio of the avi to a new file and name it wav. It will NOT be a wav unless it was so in the avi.
Then select direct stream copy for the video and no audio for the audio.
Save this to a new avi.

Now you have to files that you can select in Tmpgenc. Hopefully these will be read with the correct duration.

You could also, after you have saved the audio with VirtualDub, frameserve the video part. This way you will be sure to get the same number of frames that Virtualdub sees. And VirtualDub is seldom wrong.

[elkdanger]

That seems to have worked now - thanks very much. I tried the demultiplexing method and that found the correct film time.

Cheers!

[Thingy]

Glad it worked