Virtualdubmod direct stream copy aud/vid output problems

[xycer]

some xvid videos that i do a direct stream copy with virtualdub, the audio is out of sync. do you know what could be causing htis? i did cut some of the start and end of the video if that makes a difference.

[guns1inger]

VBR MP3 audio ? Not good. Convert to CBR MP3 before editing.

[xycer]

how should i do that?

[guns1inger]

Set audio to full processing mode, set compression to CBR MP3 at a good bitrate (depends what the VBR average is) and save the results to a file. Use that to replace the original audio.

[redwudz]

Follow this guide: https://www.videohelp.com/virtualdubaudio.htm

Then add the WAV audio back in and use VD to encode it to CBR MP3. Mux it back with the original video, full audio processing, direct stream processing for the video.

When you drop the video into VD, it should tell you immediately if you have VBR MP3 audio.

[xycer]

i dont see a CBR option in the compression settings for the audio.

i understand how to extract the audio to a wav file, but again, how to i encode it to CBR and how do i mux it back with the video?

[xycer]

i think i figured out how to remux it with the extracted audio. i saved as wav in full processing, then for audio, i selected wave audio and selected the extracted wav file.

but is it normal to have the output size more than double the original size? the video was about 350mb, now its over 800mb. i did a directstream copy for the video, and full processing for the audio.

[FulciLives]

i think i figured out how to remux it with the extracted audio. i saved as wav in full processing, then for audio, i selected wave audio and selected the extracted wav file.

but is it normal to have the output size more than double the original size? the video was about 350mb, now its over 800mb. i did a directstream copy for the video, and full processing for the audio.

WAV audio is HUGE in size. The format uses a "fixed" bitrate of 1536kbps vs MP3 which is normally done at 128kbps up to 320kbps at the max. That's a huge difference. The higher the bitrate the larger the file size.

Once you edit you can convert the WAV back to MP3 but you should still use CBR MP3 instead of VBR MP3.

I don't undrestand why the geek DivX and XviD internet creaters insist on VBR MP3 ... surely they should know by now that it is BAD.

- John "FulciLives" Coleman

[xycer]

i just saved the video with the new extracted wav, but this time i compressed it with ac3 codec and its much smaller now. i was going to compress it with MP3, but all the choices for quality sucked and there werent very many choices (well not as many as AC3 did).

[redwudz]

If you want more MP3 options in VDM, add Lame MP3. Even with the default MP3, if you check 'Show all formats' you will see other options. Lame MP3 does have options for VBR and ABR variable rates, though if you ever plan on re-encoding the file to other audio formats, neither are advisable.

[xycer]

i do have lame and razor lame installed (lamegui). i suppose lame converts wav to mp3 too? i use lame to convert my vbr mp3's to cbr because my mp3 player has problems with some vbr songs.

how do i add lame to list for more options in VD? i guess i can just use razorlame, but itd be nice if i could do it within vdub. all the options i have in vd now for mp3 are all under 60kbps and the highest is 24000khz (i would like 48000khz because im converting to DVD).

[redwudz]

Add Lame MP3 and VDM will use it. For more Lame MP3 options, check 'Show all formats' in VDM.

[xycer]

thanks. i had lame all along, and i didnt have it installed. razorlame works, however, and it didnt work when i didnt have lame.

anyway, thanks for the help so far, but ive run into another problem. the audio i extracted to wav compressed with ac3 is noticeably quieter than the source. i find compressing it with mp3 to be true to the db level of the source i stupidly deleted the source videos because i thought they were ok, until i listened to the sound on my dvd player. is there anyway i can rip the dvd files and make the audio louder?

[FulciLives]

thanks. i had lame all along, and i didnt have it installed. razorlame works, however, and it didnt work when i didnt have lame.

anyway, thanks for the help so far, but ive run into another problem. the audio i extracted to wav compressed with ac3 is noticeably quieter than the source. i find compressing it with mp3 to be true to the db level of the source i stupidly deleted the source videos because i thought they were ok, until i listened to the sound on my dvd player. is there anyway i can rip the dvd files and make the audio louder?

Once you get your WAV file you want to normalize it.

There are different ways or should I say software for doing this.

One popular choice is GOLDWAVE.

- John "FulciLives" Coleman

[redwudz]

If you want to try a freeware alternative to Goldwave, there is Audacity.

[xycer]

do either/both of these programs handle .ac3 files? i usually use ffmpegGUI to convert .wav to ac3 and use that along with the m2v file from TMPGEnc into TDA when i convert my xvid/divx movies to dvd. i noticed my videos have been quieter than the source, and was wondering why. i just realized that ac3 is quieter. the reason i convert to ac3 is because i heard its more compatible with dvd players, compared to mp3. to play mp3 audio, the dvdplayer will have to support mp3 right?

[redwudz]

Never tried either with AC3, but I don't believe Audacity can handle it. Why not normalize them when they are a WAV in Audacity? Then do your AC3 conversion with ffmpeggui. That's the way I do it if they need any adjustment. Audacity does accept WAV files when using 'Project>Import Audio'.

Or even easier, when you save out the audio as a WAV in VDM, adjust the volume there before saving. That's not the same as normalize, but it will boost the levels. VDM also has some audio filters available after checking 'Use advanced filtering>Filters>Add', but I've never tried them.

[xycer]

well, i extracted the audio compressed with mp3, and the audio was the same as the source. when i converted the wav to ac3 with ffmpeggui, the audio was quieter, so i think its the ac3 thats making it quieter.