Audio mp2 and mp3 problems!

[Matsaki]

It was a very low volume on my VCD movie so I converted the biles.mp2 in to an .aif file which I could give higher gain/volume.

But How will I not get it back to an mp2 file so I can muxe audio and movie in ffmpegX ???

[ZeroSix]

Don't use .aif. You will get better results with a .wav file using this method. You can export your .aif file to .wav in quicktime.

Open the terminal and type the following:

mp2enc -V -o /path/to/desired/output.mp2 < /path/to/input/file.wav

This is only if you have the program "mp2enc" installed on your machine.

If you do not, consider using ffmpegX.

Open the .wav file and set your output.

Do not use any presets. Uncheck the box "ENCODE VIDEO"

Under the AUDIO tab, set it to .MP2, 44.1 KhZ, 224 kbps.

Under options, uncheck everything except "KEEP ELEMENTARY STREAMS"

Click on encode.

Hope this helps.

[Matsaki]

Thanks for the reply,
but there is a problem with ffmpegX when trying to convert from wav tp mp2. The output looks like this:

MEncoder CVS-030128-17:21-3.1 (C) 2000-2003 Arpad Gereoffy (see DOCS)

AltiVec not found
Reading /Users/matsjidk/.mplayer/codecs.conf: can't open '/Users/matsjidk/.mplayer/codecs.conf': No such file or directory
Reading /usr/local/etc/mplayer/codecs.conf: this codecs.conf is too old, incompatible with this mplayer release! at line 6
Using built-in default codecs.conf
File not found: 'frameno.avi'
Reading config file /Users/matsjidk/.mplayer/mencoder: No such file or directory
font: can't open file: /Users/matsjidk/.mplayer/font/font.desc
font: can't open file: /usr/local/share/mplayer/font/font.desc
success: format: 0 data: 0x0 - 0x43B43EE
Audio file detected.
Audio file detected.
sh: line 1: 461 Bus error /usr/bin/mencoder /Users/matsjidk/Desktop/biles.wav -oac copy -audiofile /Users/matsjidk/Desktop/biles.wav -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1000:keyint=240:vqmin=2:vqma x=15 -ofps 29.97 -vop scale=640:352 -o /Users/matsjidk/Desktop/tigr
Encoding completed on Sun Mar 16 12:16:02 EET 2003

[ZeroSix]

Ok... ffmpegX is attempting to use mencoder to perform the conversion and that isnt what you want.

ff now defalts to mencoder for a video codec, so try changing it to MPEG2 [mpeg2enc] for the video codec and still uncheck the box for encode video. Maybe that will tell it to use mp2enc instead of mencoder.

If that brings you no success, try using the terminal command I posted above.

That way will work for you and it isn't that hard.

[Matsaki]

Thnx a million man In the terminal the conversion worked fine!

Now I want to change the dimension og the biles.mpv that now is widescreen with letterbox bars (PAL) into the normal 4:3 (352x288) format. Do you have any simple terminal commands for that too

[ZeroSix]

so the movie right now is 4:3, just not in VCD resolution, correct?

And it is .mpv file...

The easiest way to scale the movie down, provided that the black bars are already there would be to use ffmpegX again.

mux the .mpv file with the .mp2 file you got eariler.

Open the .mpg file in ffmpegX and select your output.

from the presets, select FAST MPEG 1 PAL.

Under the audio tab, change the sampling rate to 44.1 kHz

Under the options tab, change it to what you want it to be,high quality, etc.

Under the tools tab, make sure you author it as a .bin file, but use your own discretion when spilttign into multiple chunks. Toast sometimes does not like the mpg files generated by ff, but toast is also forced to accept .bin files in VCD mode.

Then click on encode. This is a pretty fast encoder, and I know of no other way to change the resolution of the file without re-eocoding -- except see my note below.

Now another way to "scale" the mpv file would be to edit the headers using HexEdit, which would "trick" your dvd player into thinking it was at the correct size but this is untested by me. Maybe i will mess arounf with that once i get sick of Phantasy Star online, which wont be happening anytime soon.

Hope this helps.

[Matsaki]

Tried that but the dimensions still get to 320x240 stupid letterbox and not the disered 352x288

[havema-1]

> Don't use .aif. You will get better results with a .wav

Why is wav better than aif as a source when encoding mp2 with mp2enc?

...I used to export wav but recently switched to aif because it "feels" like a more native format to Mac (iMovie extracts its audio as aif, for example).

I haven't noticed any difference between encodings starting either form wav or aif although I haven't tried to listen subtle differencies in quality.

I'm using mp2enc via MissingMpegTools 0.9.1, if it matters.

[ZeroSix]

Matsaki --

Try manually typing in the resolution in the boxes on ffmpeg after you select the preset. Maybe this will help for you. If not, then i dont know. If you are relying on quicktime to tell you what the resolution is after it is finished encoding, keep in mind that quicktime has several shortcomings when it comes to MPEG files, epecially in this regard. Try burning it and see what the results are anyway.

havema--

Aif is a format use primarily by Apple, and the .wav format is primarily used by everyone else [Unix, Linux, PC] for PCM audio. All of the terminal programs are Unix based, and in my experience, encoding FROM .wav to .mp2 is over 400% faster. I encoded 20 minutes of .mp2 from a .wav file and it took less than one minute. When going from .aif it took about 5 minutes. Again, this is just based on my experience and perhaps you may have different results. PCM audio is PCM audio is PCM audio in the end and .wav and .aif are both PCM audio formats.

Major, Kai, Ross, somebody please clarify this if you can, because I'm really not too sure.

[Matsaki]

No luck Tried all possible settings in ffmpegX for VCD now and the reesolution is always the same letterbox

[ZeroSix]

i dunno man... if yo uwant me to help you further please consider IMing me at zerosix[AT]mac.com