AC3 Encoding better than Mpeg2???

2 replies [Last post]
May 27, 2003 - 11:21
Klapton
Offline
Joined: Nov 4 2002

Hi all,

I have been using DVDLab 1.1 and it can use audio streams in AC3. Now I did a quick test to see how much space I would save using AC3 over mpeg2.

Not a lot it seems. I used Mainconcept, (new version anyone?) to give me two streams (.mpv,.mp2)

I then took the audio from the original .avi file in Vbud to output to .wav.

I then encoded the .wav using BeSweet to an AC3 file.

Found to my surprise that there is little space gained.

So my question is, apart from using ac3 for titles sent to the US, (as not all US players know about .mp2), WHY USE AC3???

Thanks,

Klapton

Top
May 27, 2003 - 17:20
#1
PhilipL
Offline
Joined: Mar 12 2002

Hi

AC3 is a better a compression algorithm than MPEG. You can encode MPEG and AC3 to be the same bit rate, which I suspect you have done so you will get the same file size, but AC3 is giving you the better quality audio.

As it is a better compression you can compress more than MPEG and save a little bit more space, without it affecting the sound quality. Try encoding your MPEG at say 254Bits/sec and your AC3 at half that rate. They should sound pretty similar, then compress the Mpeg down to match the AC3 and then compare them, the Mpeg sounds much worse.

Regards

Philip

Top
May 28, 2003 - 08:11
#2
Klapton
Offline
Joined: Nov 4 2002

Hi Phil,

Thanks for the reply, I will give that a go tonight and let you know.

Cheers.

Klapton

Top