diff. between mp2 & wav quality?

[Marley_]

Hey guys,

I just put my movie through dgmpgdec (alternative to dvd2avi) and it gave me an .ac3 file. According to https://www.videohelp.com/mpeg2tovcd.htm if I had used dvd2avi, I would have received an .mpa file after it went through the process. I figured since dgmpdec is just a modified dvd2avi, that it would produce the same. So now I am stuck with this .ac3 file.

Now, I am wondering what the difference is between converting this .ac3 to a .wav and .mp2. And what program has proven to produce the least amount of sync and playback errors.

Also, as far as a side-by-side comparison, which format seems to turn out better as far as movie audio goes? I assume .mp2 sounds better and takes up more room, but i'm not sure.

What i'm really wondering is if one or the other produces more sync or playback problems.

I'm trying to fit my backup on one cd (x)vcd. What do you guys suggest?

[reboot]

Mp2 sounds the same and takes up less room.
AC3 is dvd spec audio.
Because you're making an xvcd, transcode the ac3 to mp2 in ffmpeggui.

[Marley_]

reboot, thank you for your suggestion on ffmpeggui. It looks like a great program. I did try and convert my .ac3, but came out with an empty .mp2. (0kb in size). I looked at the ffmpeg status window and at the very bottom it stated "Unsupported codec (id=11) for input stream #0.0"

Is there something i'm missing? perhaps as the above suggests a codec?

Thank you again for your help in directing me to what looks to be a great program!

[celtic_druid]

You need to use a version of ffmpeg that supports AC3 decoding. I wouldn't recommend ffmpeg for mp2 encoding anyway as libavcodec's mp2 is not the best quality.

My last build I think had everything enabled except for AMR.
http://www.aziendeassociate.it/cd.asp?dir=/ffmpeg

[reboot]

Wouldn't the basic ac3decode "codec" work? It's downloadable and free...I think it works on mine, but now I'm curious...brb.

Edit: You're right, it doesn't work.
gonna have to download the latest ver

p.s. Why do you put stuff in IZarc format? Even Winzip had a seizure trying to open it. Can't you use something more universal such as .rar?

p.p.s A tiny text file, explaining the install procedure would also be nice, for those noob's that don't know what to do with it.

[akrako1]

Just to clarify for you...

Mp2 and AC3 are both compressed form of audio. I've heard that they sound similar at the same bitrates. AC3 can also do multitrack.

Wave (or LPCM, or PCM) is completely uncompressed - ie perfect quality. I don't believe you can use uncompressed sound with a vcd - but I may be wrong.

[HockeyStick]

At the same bitrate, AC3 win hands down over MP2. When i was doing SVCD's, i remember that i was always complaining about some hissing in high frequencies heard in low bitrate MP2 (192 kbps). Even MP3 wins over MP2 at the same bitrate.

[celtic_druid]

Should point out though that MPC is based on mp2, so an mp2 encoder tuned by Frank could offer better quality, then again I think he spoke of applying his psycho acustic model to AC3.

The format is 7-zip and winrar supports it. As I have said before if someone can recommend something that can compress better, I will switch.

For use with ffmpeggui, just replace the version of ffmpeg that comes with it with the one from the 7z file. There really is no install.

[reboot]

I have Winrar, and it doesn't work (at least MY version doesn't, I probably should upgrade).
I know how to get it working, but a noob would be lost, just a suggestion anyhow
Thanks for the superb upgrade!

[Marley_]

so, where is this 7z file you refer to?

Do you recommend a diff. program?

thanks guys! I appreciate all the help.

[vitualis]

You can get very good fidelity audio with MP2 compression but it does not do as well at lower bitrates. At 128 kbit/s, MP2 would sound terrible compared to MP3. At 224 kbit/s and above though, it is unlikely that you would pick the difference.

Regards.

[reboot]

Download ffmpegui.
Download the 7z file from here: http://www.aziendeassociate.it/cd.asp?dir=/ffmpeg
Unzip it.
Put the file ffmpeg.exe into the same folder as ffmpeggui.
Run ffmpeggui.
Transcode from AC3 to MP2.

[Marley_]

You can get very good fidelity audio with MP2 compression but it does not do as well at lower bitrates. At 128 kbit/s, MP2 would sound terrible compared to MP3.

I originally tried backing up with eazy vcd at 128 kbit/s and it was in MP2. I'm sure it can't compare w/ mp3, no doubt, but the sound was really good I thought.

anyways, i will try the above and let ya know how it goes!

[celtic_druid]

If you are already creating an XVCD you could always just use mp3 instead of mp2. ffmpeg uses lame for encoding so the quality is fine. They really should add toolame support (for mp2) like with mencoder.

[Marley_]

If you are already creating an XVCD you could always just use mp3 instead of mp2.

for the purposes of trying to fit it all on one disc, i'm assuming mp2 would take up less room. But yeah, if you're going for just higher audio quality, then I can see why.

Well, so far so good. It encoded to .mp2 and had no problem being encoded w/ video in tmpegenc.

Kudos to all of you!

no, not praise, I mean those gross little granola bar things. You all get one.

no, really, thanks for your help guys.

[Soopafresh]

There's an option in dgmpgdec to demux the sound file, or convert it to WAV.

[Baldrick]

upgraded ffmpeggui. it now includes celtic_druid ffmpeg build.

[reboot]

If you are already creating an XVCD you could always just use mp3 instead of mp2. ffmpeg uses lame for encoding so the quality is fine. They really should add toolame support (for mp2) like with mencoder.

Won't most players crap out on mp3 audio though? I know my 3 won't play (S)VCD/KVCD with mp3.

[Marley_]

dgmpegdec vs. ffmpeggui

does it make a difference which one to use?

[reboot]

dgmpgdec will demux, or make a .wav only.
This is fine if the original audio that it demuxes is mp2.