No change in bitrate (audio & video) after shrinking?

[moviebuff2]

Hi

I wanted to see what would be reduced after shrking a DVD. So, using DVDshrink I compressed my DVD 90%. I am perplexed to find nothing changed in both video and audio bitrates.

The original DVD was read by TMPGEnc Author 1.6 as 8000 kbps for video, and 48,000 hz 224 kbps for audio.

The shrunk version was read exactly the same, also by TMPGEnc Author 1.6.

I did the test again with Video Redo. Same results.

This is impossible because the size of the DVD was reduced.

Can someone enlighten me ?

[guns1inger]

First, DVD Shrink doesn't touch audio, ever. It can remove streams, but it cannot re-compress them.

Second, it depends on how the bitrate is being read. Some programs only read the header information written by the encoder. As Shrink is a transcoder, I don't believe it re-writes the header, so TDA might be seeing only the unchanged header details. You need to look use something like the latest g-spot, which actually scans the stream and reads the true bitrate. VideoRedo and Womble also only read the header, and don't show the true bitrate.

The simplest test - is the overall size smaller ? If so, Shrink did it's thing.

You should also remember that with many discs, once extra languages etc are removed, the total size can often be accommodated on a DVD5 without further reduction.

[moviebuff2]

Hi guns1inger:

As I said, the DVD size was indeed reduced. That indicates that DVD did its job. What surprised me is that nothing seemed change (no caucus talking ), according to TMPGEnc Author 1.6 .

But as you said , perhaps TMPGEnc is just like Video Redo, it only reads the header which is not touched by DVD Shrink.

I will see what gspot says.

BTW, no foreign languages are involved here. This is pure music.

[guns1inger]

If you are really curious, try the same exercise, but with DVD Rebuilder and HCEnc. This time you would be really re-encoding, and I suspect you will find that the header information gets changed along the way.