Burning MP4 to DVD

[techmot]

I have been having the same problems trying to convert captured videos (either in uncompressed in avi or converted to mp4) to Nero Video with more than 50 min video of a TV series, captured from a VHS recording, yet everytime I try and converted them to either MP4 or MPEG2 and lower the video bitrate to something which should allow the outputted file to fit onto a 4.7GB DVD with some space left, but all I get in Nero is a reading of 3GB despite the quality having been compressed really bad. On my Panasonic VHS/DVD combi (before it stopped working) I was able to copy/transfer four episodes of a 50 minute TV programme onto one 4.7GB disc, with a bitrate of about 9000kbps and a resolution of 720x576 (and I'm guessing using a variable bitrate for MPEG2), and yet the programmes I've been using on my laptop to convert files don't seem to be able to do the same. I've even lowered the bitrate to 500kbps and even a 250mb file when imported into Nero Video goes just over 3GB. Does anyone know why this is happening?. Is this due to the original captured file?. Lowering the bitrate really low and using VBR you would expect the outputted file to fit easily, but it doesn't.

Also, why are programmes like Shutter Encoder supporting odd frame sizes like 320x180 (is that even a proper size?) 640x360 (shouldn't that be 640x480 like Virtualdub can capture at?). Why are these conversion and capture programmes using different sizes?.

Your numbers are very confusing and I suspect you may have copied them to this post incorrectly.

First, it is impossible to put four episodes of a 50-minute program (200 minutes total) on a DVD with a 9,000 kbps bitrate. That amount of video would require a bitrate of about 2,800 kbps.

I think a second source of confusion is probably the same thing that was confusing the OP two months ago and that is when you bring video in some programs (like DVD Architect in the OP's case), it will re-encode it using its own set of calculations, depending on how you have the encoding set. This is why a small file may get a lot larger, or vice versa.

The ONLY thing which determines file size is bitrate. 320x180 or 640x360 or 640x480 or 720x576 will all end up at exactly the same size if encoded at the same number of bits per second. Yes, that is confusing to everyone when they first hear it, but the reason this is correct is contained in the definition: the encoder uses "x" number of bits each second, and so the number of bits times the number of seconds of video determines the file size. However, if you use the same number of bits per second for a 320x180 video, it will produce far fewer artifacts than if you use the same number of bits per second to encode a 1920x1080 video.

It is confusing, especially for myself with limited knowledge. I have since found a programme on my laptop which I had forgotten about called Convert X to DVD, and I was able to convert/encode 4 50 min files to a TS folder. Quality is OK. Why Shutter Encoder, even when I reduced the bitrate down to 500kbps when imported into Nero Video still had the file size at about 3GB for one 50 min video.

[jagabo]

Why Shutter Encoder, even when I reduced the bitrate down to 500kbps when imported into Nero Video still had the file size at about 3GB for one 50 min video.

The size of the source files is irrelevant if the video is going to be re-encoded. All that matters is the average bitrate of the re-encoded video. The equation is simple:

size = bitrate * running time

It follows from the definition of bitrate:

bitrate = size / running time

The requirements for a movie DVD are very specific. If your source doesn't meet those requirements it has to be reencoded. Some programs will reencode even if your source already meets those requirements.