How to edit xvid audio (AC3) file (too low volume)

[kthan]

I had some XviD viles (with AC3, 448kbps) and they had too low volumes (I can barely hear the sound even at max volumes).

Does this something to do with its higher bitrate? How to resolve this issue? I opened Soundforge 8 (to nomalize the file again), but this cannot read the file. Is there any plug-in to read XviD? Or, do I have to save it to wav. and reprocess (but, I don't think I can reproduce xvid<ac3> again in soundforge).

Since I will view the files in DivX-compatible player, I need to keep XviD format (not encode with MPEG2). Please advise me the best (easiest) way to do it.

[Caple]

Did you try to play it on your standalone player to see how is the audio?
When running XviD files with AC3 audio on computer I always load the "loud" preset on AC3 Filter config, then it's ok.

[mats.hogberg]

@448 kbps, it's probably 5.1 AC3 - and not easily edited. Basically, you'll have to decode to 6 WAVs, normalize them and then reencode them back to a 5.1 AC3. Not many tools around for that...

/Mats

[kthan]

It worked by adjusting the volume in AC3 filter configuration.
But, I am not sure it will produce enough volume when it plays with divx-compatible player. I will post here after I played it tonight. Out of curiorcity, is there any reasons that AC3 audios play with lower volume at computer?

[WolfPac_Ite]

Check your volume settings for your codecs, as well as going to Start>All Programs>Accessories>Entertainment>Volume Control.

Also, not to hijack the thread or anything, but I was wondering about a similar situation. I convert from MP3>WAV>AC3 for videos that will be played on a DVD player in standard DVD format. The volume is lower by a small amount. I was just wondering how one would raise the volume level while still keeping the original volume ranges, such as not normalizing it, etc.

[Stealth3si]

kthan - normally I would leave the untouched ac3 5.1 as it is and add in a second audio track that is stereo with raised volume using Besweet. FYI, Ac3 5.1 is not suppose to be modified because I use to raise the volume on it all the time and the ac 5.1 quality wouldn't come out right for example the audio would be too loud even if you raised it by one notch. Again, just copy the ac3 5.1 file and use Besweet to convert it to stereo so it can be louder yet still retain the quality. Then remux the new stereo ac3 back in the xvid file as a second audio track. Now you have 3 tracks, one video , one 5.1 audio, one stereo audio. You divx player should have an audio button to between the tracks. Besdies the ac3 5.1 surround carries over to the divx player pretty well. IOW, the low volume you hear on the comptuer will not happen on the divx player. But if you still want to raise the ac3 5.1 then this is what you do..

1.) demux the original source ac3 from the avi file (direct copy)

2.) Use besweet GUI or BesweetLight to increase the volume (all settings should be the same so that your entire audio format remains the same, including retaining the 5.1 surround sound format (i.e. 448 kbps, ac3 5.1 sound)
- HOWEVER, you have 3 options to raise the volume
- 1.) change the boost levels (3-7, 0.95)
- 2.) change the normalization levels (100%)
- 3.) use HYBRID Gain levels to adjust automatically for you
- you can also combine the 100% normalization AND boost levels to make it even louder
- AND MAKE SURE that "-stereo" option is not included in the command line or your output will be gibberish.

3.) remux the new ac3 back into the avi file and YOU'RE DONE. No need to convert into wavs.

I use to do this all the time on xvid files with that type of ac3 and the 5.1 surround plays on the divx or dvd players louder as I want it BUT make sure you thoroughly re-test the sound volume on the your comp to make sure it won't be too loud in the end.

[ark]

Did you try Mediacoder? Mediacoder has a selection for increasing the volume, marked in dB and handles AC3.
Even BeSweet can take 5.1AC3 and boost the volume and create another 5.1AC3 file with increased volume.