Re-encoded MPG will not fit on one CD

[webberm73]

Hello all,

I'm trying to re-encode an MPG from 1GB to fit on one CD. The original MPG has a CBR of 1150 and I need to re-encode it to have a CBR of 825.

I unlocked the VCD template in TMPGEnc and saved it as my own template to fit the movie onto one CD. According to TMPGEnc, the disc should be around 780 MB when it is finished encoding.

When finished, the resulting MPG is almost the same size of the original (1GB). I don't understand! I changed the "video format" setting in TMPGEnc to "MPEG-1 System (automatic)" and the resulting file was 772 MB. I thought I finally did something right, but Nero showed the file to be too large, possibly because it wasn't recognized as a VCD file.

Any help would be appeciated and thanks in advance...

Regards,
Matt

[DVD_Ripper]

Matt,

I would kinda like to see what a video at a CBR of 825 looks like.

What is the final destination of this video? Web, CD for PC Playback?

[webberm73]

At 825, the VCD won't really look that great. I just wanted to fit it on one CD so it can be played back on a stand-alone player. I'm not going for quality. This is driving me crazy!!!

[mats.hogberg]

Are you sure you set the multiplexing type to "Video CD Non Standard" instead of "Video CD"? If not, that explains what you experience...

/Mats

[webberm73]

Hi Mats,

Yes, that is how I encoded it the first time around and the result was 1GB, even though TMPGEnc said ~780MB. I even tried loading the MPG into Nero and it exceeded the capacity of the CD.

I believe I ran into this problem before but I can't remember how I fixed it.

Does this have something to do with re-encoding an MPG instead of an AVI?

I am taking two DAT (MPG) files from two VCDs and joining them in TMPGEnc with the multiplexing option of VideoCD (non-compliant). Then, I am re-encoding it from 1150 to 825 with the video standard set as "MPEG-1 VideoCD (non-compliant)". No matter what I try, the video when completed still comes out too large, just a few KB from the original.

Obviously, I doing something wrong...

-Matt

[Abond]

1. You can verify the bitrate of the encoded file in some application (Virtualdubmod come in mind, File-File information). Look if it is really 825 kbps.
2. I suspect you are using TMPG 2.59. If it is so get rid of it and use another version. 2.59 is known to produce oversized files (bug).
3. You will be better using variable bitrate with 825 average (2000 max) two pass. As you are breaking already VCD standard such an approach will give you better results, cause the bitrate will be better distributed. The final file size is determined with the average bitrate.

[kozo]

I had the same problem. I reduced the bitrate to 1000 ang ended up with a slightly bigger file. Next I tried again to reduced the bitrate to 900 and had similar results. I have used the tutorial which is on tis sight:

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[adam]

Using a bitrate calculator is definitely the first thing you need to do. See if the bitrate is actually what you specified. If so, this is a multiplexing issue and I'd just try using BBmpeg for multiplexing instead. I never did trust TMPGenc's multiplexing.

Actually Abond, simply using less then 1150kbits in a VCD does not make it non-compliant as long as its still CBR. The 1150kbit bitrate requirement is the limit, you can go as low as you want. I agree though, VBR would help some.

[superunknown]

hi mark, i think the problem you have is that in nero,you need to uncheck the box which says create standard compliant cd and use disc-at-once mode in the burning settings.when you import the file to nero ,it will read it as the size you wanted and it will be able to fit unto a 800mb cd.i've done this successfully.
you can also use vcd easy as with this you woudn't need to adjust anything.you need to select video cd non standard in tmpgenc or mpeg 1(video cd) options.you can copy 740 mb of vcd or svcd mode data on a 74 min disc and about 805 on a 80 min cd-r without overburning.i've tried this on nero 6.3 and vcd easy successfully

[Abond]

@adam
Maybe you are right. My thoughts about the standard were 80 min CD=80 min VCD. That means 1150 kbps CBR video and 224 kbps CBR audio. But as I said maybe you are right.

[hp_lovecraft]

Hi Mats,
Does this have something to do with re-encoding an MPG instead of an AVI?

Yes and no.

The problem is that when you re-encode something, the encoder sees the compression artifacts from the 1st encoding as NOISE, and tries to encode it making the size larger.

Or, the problem could be that the original VCDs were made with commercial encoders, which are simply more effecient. (especially motion-adaptive algorithms).

To trim the movie down a little, try:
Using the noise filter.
Trim the sides a little
Use the Kwag specs (last resort)

nick

[jimmalenko]

Hi Mats,
Does this have something to do with re-encoding an MPG instead of an AVI?

Yes and no.

The problem is that when you re-encode something, the encoder sees the compression artifacts from the 1st encoding as NOISE, and tries to encode it making the size larger.

I would have thought that it would assign the bitrate you have specified to the picture, but some of this bitrate would be eaten up by noise, resulting in a grainy or pixelated output. It won't make the file bigger, it'll just make the quality worse.

Or, the problem could be that the original VCDs were made with commercial encoders, which are simply more effecient. (especially motion-adaptive algorithms).

At the end of the day, bitrate determines the file size. Commercial encoders may obtain better quality, but the file size will remain exactly the same.