Quality (loss?) and DTS/AC3/AAC conversions

[poisondeathray]

I'm assuming you used the correct profile ? E.g. if you are using 5.1 audio source, the encoding profile should be 5.1 wma pro , not stereo or something else

[CasanovaFly]

Yes, I used the correct profile.

[poisondeathray]

maybe they just want you to pay for the pro version?

You can try another encoder GUI like wmnicenc

[CasanovaFly]

They do want me to buy their over-priced pro version that only has AC3 (and not DTS) codecs in it.

I just tried wmnicenc and it gives me this error in the .WMV:
"FFindex: can't open target directory"
(FFMS2.avsi; line 32)
(C:\AVS location, line 1)

[poisondeathray]

open the .avs in vdub , post the error message if any .


make sure the paths and directories are correct; if the .avs is in the same directory as the video, it shouldn't need the full path, other wise you need "c:\path\video.avi"

[CasanovaFly]

Same error. I just put "target directory" and "AVS location" in instead of typing out the full directory path.

[poisondeathray]

Post your full script. Verbatim

What is your source video format ? use mediainfo (view=>text)

Are you running as administrator and have permissions / folder access ?

[CasanovaFly]

False alarm. I've been moving stuff around on my hard drives and changed the directory accidentally. No errors in vdub, running through wmnicenc right now...

[poisondeathray]

If you can open the script in vdub and have things sorted out - you might try running it through EE again as well

[CasanovaFly]

wmnicenc took a couple minutes and spit out a 2 second video.

Still getting an error with EE.

[poisondeathray]

Presumably the source video was longer than 2 seconds ?

Can you scrub through the video in vdub (seek to middle, end) ? (By loading the avs script) ?

[CasanovaFly]

Yes, it was longer than 2 seconds. And yes, I can scrub through the movie in vdub.

[poisondeathray]

Can you encode the avs script successfully using a different encoder e.g. xvid/lame mp3/ avi in vdub ?

If you can - it's not the script , avisynth or ffms2's decoding fault , then it's likely a problem with your windows media encoder installed components

If you can't , there is a problem with decoding the video and/or audio - check if you can go frame by frame (play the script in vdub) past a minute or so . If this is the problem then you might have to use another source filter, or the problem might be with the source itself

[CasanovaFly]

I don't know how to use a different encoder in vdub or play a script in vdub.

[poisondeathray]

Push the play button , it's the 3rd button on the bottom with the triangle and "o" for output pane . The 2nd button is "i" for input pane

To encode , you need to have vfw encoders installed such as xvid, and ac3acm (since mp3 doesn't support 5.1, and you are testing 5.1 input file)

With the .avs loaded, video=>fast recompress, video=> compression, select xvid from the list (don't worry about configuring encoding options) . Audio=> full processing mode, audio=> compression, select ac3-acm from the list, and the channel configuration eg. 384kbit/s, 48000Hz, 5.1 channels . File=> save as AVI

[CasanovaFly]

The play button wouldn't work. It says "dub in progress" in the title bar, but nothing.

I encoded the video file to AVI without issue; just finished now.

[poisondeathray]

When you encoded the AVI, was the input into vdub the .avs or the video directly ?

If both video & audio are fine in the AVI with the .avs input (make sure you double check it in vdub by loading the AVI directly and scrub throughout the timeline), this means the decoding & script are fine and that the problem is the wmv components

Try re-installing windows media encoder , then try the same avs with wmnicenc

[CasanovaFly]

Tried everything, same result from wmnicenc.

[poisondeathray]

No idea, but it seems to me that something is wrong with your wme installallation, maybe corrupted?

There is no way to encode outside of wme (and it's GUI derivatives) for wmapro 5.1 (ie. nothing open source like ffmpeg)

[CasanovaFly]

Who knows? I'm content with having fixed most problems by rolling back LAVFilters. For the couple errors that squeeze through, I'll just go with 1-pass CBR and call it a day.

Thanks for the help.

[hello_hello]

Now my knowledge of CBR and VBR is amateur. CBR is constant, so constant quality. VBR is variable, so it varies. Essentially, it means that VBR may give me a smaller file size OR will allow me to use a lower bitrate while still getting some of the positives of a higher bitrate when it is needed.

The way I look at that you've kind of got it backwards. If anything, VBR should give you the constant quality as the bitrate can vary as required. More bits where they're needed and less where they're not. CBR can potentially waste bits in places and not have enough in others, so effectively the bitrate it constant but the quality is not.

I don't know much about the programs you're using, but why 2 pass encoding for audio? Lossy encoders such as LAME or NeroAAC have a quality setting which does quality, VBR encoding using a single pass. There's no way to ensure the final bitrate/file size, but for a given quality setting, the quality relative to the original should be the same each time. I generally use the default NeroAAC setting and for movies containing 5.1ch audio (assuming the same duration each time), I'm pretty sure the size of the audio after conversion generally wouldn't vary by more than 100MB.
No single pass VBR encoding method with the program's you're using?

Could I ask if there's a particular reason why you're encoding using WMV as the output format? Are you encoding for distribution or just personal viewing?

[CasanovaFly]

I use 2-pass encoding because I'd always assumed it was best. There aren't any single-pass VBR methods with my encoder. And I'm using WMV because a) Windows likes it and b) potential playback on the Xbox 360 (with 5.1 audio).

[hello_hello]

To be honest I know very little about WMV and Microsoft encoders etc. I assume much of it is proprietary and as a result most people around here would use free software with different encoders.

2 pass VBR should give better quality than single pass CBR or ABR (at least at the same average bitrate) but I'd guess generally most people here would use single pass, quality based, VBR encoding if they use VBR. But of course you'd also need to be using an encoder which supports it such as LAME for MP3 or NeroAAC etc.

I only asked why you picked WMV as most people around here would generally use one of the free encoder GUIs which support x264 encoding for video, which also has a quality based, single pass encoding method (I've no idea if the Microsoft encoder does). It's much faster than 2 pass. The upshot is, you get to pick the quality while the file size is unknown, whereas with 2 pass you pick the file size/bitrate and the quality is unknown. After a bit of encoding though, most people settle on a quality setting and resolution etc which on average (they'll vary a fair bit) produces the file size they're after. The same principle applies to audio.

Anyway, I'm not trying to convert you or put you off WMV, I was just curious as to whether you settled on it for a particular reason. I've never used an Xbox so I've no idea which formats it supports.

[CasanovaFly]

The Microsoft encoder I use has a free version. The pro version just has a bunch of codecs with it and GPU-based decoding support (which I wouldn't mind, but not for $200). The encoder in question -- Expression Encoder -- has a VBR quality method for both audio and video but I don't like it, at least for audio, because I can't specify the audio bitrate and it tends to be rather random with its output (again, something I've tested). I prefer to specify a target bitrate; I like the control that way. I don't mind the time taken with the 2-pass encoding. Just upgraded the processor and overclocked it, so it's eating through videos pretty quickly.

I need the WMV, because it's the only files the Xbox can stream that plays 5.1 audio. It can play MP4's, but only stereo audio. One day I'll get an HTPC and change everything, but that's years down the road because I haven't the funds.

[DarrellS]

I would just encode to DivX/XviD with the original 5.1 audio passthrough in Virtualdub since the Xbox 360 supports it also. The DivX and XviD encoders are much faster and give a better result than WMV. The Xbox 360 supports AVI up to 720p with 5.1 ac3 in either AVI or DivX container.

There is no reason to convert to 5.1 aac or Windows Media.

[CasanovaFly]

I've actually had an incredible success rate so far since rolling back my LAVFilters. I'm content with with WMV -- I like the encoder, and I like the container. When I get my HTPC, I'll change it up; but until then, full steam ahead.