Increasing the audio on a DVD

[njhorn]

Here is what I have done so far: I pulled off the Rose Bowl from my HD-DVR to DVD's using a home theater DVD Recorder... I used the highest quality recording, putting each quarter on a seperate disc... The game is in letterboxed widescreen format with AC3 2.0 sound... I used MPEG Streamclip to edit out the commercials, saved the files as demuxed m2v and AC-3, and then burned all 4 quarters to one DL disc using toast... The DVD looks pretty good, but the sound level is pretty low... How can I increase the sound levels on my DVD?

I really don't want to have to convert to Mpeg-4 to change the sound levels and then convert back to Mpeg-2... Is this the only way I can do it?

Can I demux back to headed Mpeg-2 and AC-3, and then edit the AC-3 files to increase the audio? What software (hopefully free!) can I modify AC-3 files with on a Mac?

[rumplestiltskin]

I think you'll have to convert the AC-3 to WAV or AIFF or some other uncompressed format, then run it through Audiocity (or a similar app) to bump up the volume.

What was the original format of the captured footage?

[njhorn]

Dolby Digital 5.1... But, my 8300HD had to use composite outputs to output the audio/video to the DVD recorder, which encoded in AC3 2.0...

[rumplestiltskin]

Hmmm; yeah, I think you'll have to convert the audio unless there's some kind of tool (unknown to me) that might do the amplification of the compressed audio.

[njhorn]

ok, I've got it uncompressed and have added 14dB to it using audacity (it is saving now)... Will toast use m2v and aiff together to burn a DVD? Will it re-encode back to AC3? thanks for your help...

[Frobozz]

I don't know how to change it after being recorded, but for the future you might check if your standalone DVD recorder provides any adjustment to the audio input. My Pioneer DVR-510H (and most other Pioneer recorders) have settings where you can boost the incoming audio by either +3 or +6 dB.

[rumplestiltskin]

ok, I've got it uncompressed and have added 14dB to it using audacity (it is saving now)... Will toast use m2v and aiff together to burn a DVD? Will it re-encode back to AC3? thanks for your help...

I have QT Pro so this is what I would do:

1. Open the AIFF in QT Player, select all, copy.
2. Open the m2v in QT Player, paste scaled.

Now you have both the audio and video together.

Save as... as reference movie. Note: This is not "export". I think Toast will be happy to work with the reference movie. If not, MPEG Streamclip will certainly do this (while it saves as MPEG2).

Let us know how it goes.

[pianoman719]

A utility called mAC3dec can "normalize" the audio level while converting from .ac3 to .aiff. Try downloading it from SourceForge or VersionTracker:

http://sourceforge.net/projects/mac3dec/
http://www.versiontracker.com/dyn/moreinfo/macos/14479

It's a great little Swiss army knife with adjustable normalize and dynamic range compression, so your final MPEG or DVD sounds loud!

If you're happy with your present workflow and like the results you're getting (except for the low audio), try this:

After demuxing to .m2v and .ac3, use mAC3dec to convert the .ac3 to .aiff. In mAC3dec's preferences, set the Normalize amount to 90% and check the box for dynamic range compression. Then in the main window, preserve the sampling rate of 48.0 kHz for DVD, and convert to .aiff with Normalize checked. If the result is too intense, redo with Normalize at 80%, and dynamic range compression turned off (or vary this recipe to taste).

Depending on what you use to author the DVD (Toast, Sizzle, CaptyDVD, etc.), the final steps may differ. If your authoring app either doesn't like the .aiff audio or is unable to compress it to something smaller, you can use MPEG Streamclip to compress the .aiff to .mp2. Use the file dialog to open the .aiff. In preferences, set the the MP2 Encoding Bitrate to 192 kbps. Then "demux" (wrong nomenclature) to .m1a, and change the file extension to .mp2.

Now with any luck you have an .m2v and .mp2 pair that will be in sync when burned. The audio file is small but probably has loud stereo audio of decent quality. (Still, it's always better to get good audio levels at the beginning of the workflow. Normalizing may increase background noise.)

Some authoring apps reject a separate .mp2 file, but accept .mp2 audio if it's part of a muxed .mpg. In some cases, using BitVice Helper to mux the .m2v and .mp2 before authoring may solve this issue. BitVice Helper can also convert a .wav or .aiff audio file to .mp2, or author a simple one-title DVD with no chapters or menus. It's freeware. Get it here:

http://www.innobits.se/ssl/download.php

[rumplestiltskin]

pianoman719,

That's a great set of resources and instruction. I've saved your missive for future use. I'm sure I'll run across some issues for which your advice will help.

Thanks!

[njhorn]

It worked! I used YadeX to create a single VOB of my DVD, demuxed to m2v and aiff with MPEG Streamclip, used audacity to pump up the volume, and then created a DVD with Toast... After all that, I replaced the original VOB's in my iDVD created disc with my new ones and everything works great

Long process to go through, but it worked...