Windows Media Encoder: AC3 = WMA10

[medic611]

Hello I am in the process of converting all of my DVD for playback and streaming to an Xbox 360.

I am using Windows Media Encoder 9 with WMP11 SDK. The video I have down pat and have no issues that I know of.

My question is in the audio encoding.

I am ripping my DVD to an MPEG2 w/ AC3 sound. Using GSpot I can see that most if not all of the DVD have AC3 with a CBR of 440 kbps and 5.1 sound. My question is what but rate sould I be using to match that. I have been using WMA10 CBR at 440 kbps. Is this ideal of should I be using a higher or lower bitrate? I do not have an issue with sound quality as best I can tell.

If it matters I also have AC3 Filter installed and set to output 48kHz 24 bit PCM.

[ACrowley]

I pers encode always DVD AC3 to the same Bitrate for WMA10Pro 24bit 48khz in 1pass CBR Mode.
AC3 448 to WMA 440 ....For DTS always maximum WMA 768kbps

Dont load your AC3 diretcl into WMencoder trough DIrectshow(AC3FIlter)

The Best Method is to use 6 mono waves:

1. Decode AC3 to Wave with Behappy (NicsAc3Source NO DRc) - Output Wavesplit@mono ( or Wave2mono)

2. Use WMencoder and load the 6 mono waves via Audio Device/Wave . Load your Channels : L R C SL SR LFE

3. Encode it to WMA10 Pro 24Bit 48khz @ 1pass CBR

[medic611]

Is there any way to do that with a two-pass encode. I have been using 2-pass VBR Peak for the video.

[diogen]

...Dont load your AC3 diretcl into WMencoder trough DIrectshow(AC3FIlter)...Would there be a difference between using AC3Filter and going 6 mono first if doing 1-pass encode (AC3Filter never worked for me for 2-pass encode)?
Is there any way to do that with a two-pass encode. I have been using 2-pass VBR Peak for the video.Follow ACrowley advice above and use WM stream editor to mux the video and audio together...

Diogen.

[medic611]

OK I Think I understand.

From my source MPEG:
1. Extract AC3 with BeHappy to 6 wav files
2. Encode 6 wav to wma.
3. Encode video only with normal 2 pass settings
4. Use WM steam editor to combine the two

Correct?

[diogen]

That should work.

For a 2-hour movie, encoding audio and muxing into video
should take about ~5% of the time needed to encode video.

Diogen.

[ACrowley]

Ofcourse you can do a VBR 2 pass Encode for the Audio

But better use CBR 1 pass.
The WMApro on WMVHD DVDs is encoded in 1 pass CBR Mode ,AC3/DTS/EAC3 too

[diogen]

Ofcourse you can do a VBR 2 pass Encode for the Audio...but not using AC3Filter.
But better use CBR 1 pass.
The WMApro on WMVHD DVDs is encoded in 1 pass CBR Mode ,AC3/DTS/EAC3 too
Why "better"?
All WMV HD used CBR for both, audio and video, not because it is better but to limit the bitrate to avoid choking the PC during playback...
And because 2-pass encoding didn't work with Advanced Profile at that time...

Diogen.

[zambelli]

And because 2-pass encoding didn't work with Advanced Profile at that time...
Actually, WMV HD never used Advanced Profile. It was always Main Profile. The format was pretty much dead (due to HD-DVD and BluRay emergence) by the time Advanced Profile finally got approved by SMPTE.

@medic611:
When transcoding one lossy audio format to another lossy format, I tend to actually use *more* bitrate on the transcode. My logic for this is that using a larger bitrate reduces the amount of new quantization artifacts introduced into the sound. I have no empirical proof, of this however - it just always seemed to kind of make sense to me. If quality is a concern, it doesn't seem like a bad choice.

The most reliable way for transcoding AC3 to WMA is still, as everyone else suggested, decoding to 6 mono WAVs and then encoding to WMA. If you're a command-line fan, you can automate this by using the Multichannel WAV Combiner tool (availalbe on Microsoft.com, search for it) to combine 6 WAVs to 1 audio-only AVI, and then feeding it to wmcmd.vbs (see my sig) with the -a_input parameter.

[diogen]

Actually, WMV HD never used Advanced Profile. It was always Main Profile.
IIRC, 1-pass CBR in the first edition of WME had AP.
Are you saying it was the same as MP?
The most reliable way for transcoding AC3 to WMA is still, as everyone else suggested, decoding to 6 mono WAVs and then encoding to WMA.I know that AC3Filter has its problems when used in WME (DTS, floating vs. integer, audio gaps, 2-pass, etc.)
But if it does work (most of the time for me, actually) is there a difference between using it vs. 6 mono files?

Diogen.

[bond]

moved

[zambelli]

IIRC, 1-pass CBR in the first edition of WME had AP.
Are you saying it was the same as MP?
WMV-HD was just the marketing name for WMV high-definition (mostly on red-laser discs). It was never an actual codec name or a codec standard. WMV9 (VC-1) Main Profile was used to produce those commercial movie titles released as WMV-HD.

Advanced Profile didn't exist in the original WME9/WMF9 release. WMF9.5 came with an Advanced Profile that was 1-pass only, but it was the now deprecated "WMVA" versions of AP which is not actually VC-1 compliant. WMF11 was the first version of the SDK to come with a VC-1 compliant Advanced Profile.

I know that AC3Filter has its problems when used in WME (DTS, floating vs. integer, audio gaps, 2-pass, etc.)
But if it does work (most of the time for me, actually) is there a difference between using it vs. 6 mono files?
Probably not. It's all PCM once it's decoded. Mono WAVs just guarantee you correct channel mapping, no gaps, no issues with 2nd pass, etc.