Audio syncing and DTS pulldown

[Colek]

Hello,

I am nearly done with thing I am doing, and last step is to get audio going. Now, the problem is that I have several different sources:

Source 1 - the one which I used to make video, has AC3 and AAC - but my output file is not in sync with this (needs delay of few seconds, but I'd like to get it perfect).
Source 2 - this one is DVD, which has DTS audio - but DVD is PAL, therefore it's speedup. I want to pull it down to proper speed and keep DTS. Any ideas? Eac3to outputs me with .wav files.
Source 3 - DVD, which has one AC3 audio - needs pulldown and proper syncing.

Got any tips for beginner? How should I start syncing audios to video?

[hello_hello]

Video pulldown removal from NTSC 29.970 to 23.976fps doesn't change the duration so you can use the AC3 audio from the DVD as-is if your current file is 23.976 (assuming the video is edited exactly the same and it matches).

eac3to can re-encode while changing the duration (PAL slowdown). The command line option is -slowdown or there's a GUI dedicated to using eac3to for audio encoding here. http://www.afterdawn.com/software/audio_video/convert_audio/eac3to_conversion_utility.cfm
I think it converts to AC3 by default but you can change the output to another format by changing extension for the output file name (it's been a while since I've used it).

Or MeGUI's audio converter can be configured for slowdown and it'll convert to several different formats.

Both MeGUI and eac3to can add a specified amount of silence to the beginning when re-encoding. In the case of eac3to, if the output format is the same as the input format it'll add silence without re-encoding.

[Colek]

Video pulldown removal from NTSC 29.970 to 23.976fps doesn't change the duration so you can use the AC3 audio from the DVD as-is if your current file is 23.976 (assuming the video is edited exactly the same and it matches).

eac3to can re-encode while changing the duration (PAL slowdown). The command line option is -slowdown or there's a GUI dedicated to using eac3to for audio encoding here. http://www.afterdawn.com/software/audio_video/convert_audio/eac3to_conversion_utility.cfm
I think it converts to AC3 by default but you can change the output to another format by changing extension for the output file name (it's been a while since I've used it).

Or MeGUI's audio converter can be configured for slowdown and it'll convert to several different formats.

Both MeGUI and eac3to can add a specified amount of silence to the beginning when re-encoding. In the case of eac3to, if the output format is the same as the input format it'll add silence without re-encoding.

eac3to worked great for AC3 tracks, but when I use it for .DTS, it outputs me with six .wav files, is there way to mux it back into .dts now? If not, what other codec would you recommend for Bluray disc?

[Colek]

Okay, maybe not so well.

There is some mess things here, as I did the math and turns out that DVD is running 1,041680312377888 faster than my video. How can I deal with that? I only see slowdown option in eac3to, and using simply this makes it go out of sync with time.

[hello_hello]

eac3to worked great for AC3 tracks, but when I use it for .DTS, it outputs me with six .wav files, is there way to mux it back into .dts now? If not, what other codec would you recommend for Bluray disc?

If you specify dts as the output extension (I tested using EAC3to Conversion utility) you can add silence to the beginning by specifying a delay, but if you specify a bitrate (or probably any other option that'd require the audio to be re-encoded) you get six wave files. I assume that's because the dts encoder requires the individual wave file as input so without the dts encoder the process stops there.

I tried that, and the log file confirmed it.

DTS-ES, 5.1 channels, 2:11:43, 1509kbps, 48kHz
Decoding with libDcaDec DTS Decoder...
Applying RAW/PCM delay...
Writing WAVs...
Creating file "E:\movie.LFE.wav"...
Creating file "E:\movie.C.wav"...
Creating file "E:\movie.SR.wav"...
Creating file "E:\movie.L.wav"...
Creating file "E:\movie.SL.wav"...
Creating file "E:\movie.R.wav"...
Encoding DTS <1536kbps> with Surcode...
Surcode DTS Encoder doesn't seem to be installed. <ERROR>

The dts encoder required by eac3to isn't free. I don't think there is a free one. There's nothing stopping you converting to AC3 or AAC though, or even flac, but AC3 would be 100% compatible with all Bluray plyers.

Okay, maybe not so well.

There is some mess things here, as I did the math and turns out that DVD is running 1,041680312377888 faster than my video. How can I deal with that? I only see slowdown option in eac3to, and using simply this makes it go out of sync with time.

25/24 = 1.0416666666666666666666666666667

Is your finished video 23.976fps or 24fps? If it's 24fps I don't think eac3to can apply that sort of slowdown. MeGUI's audio encoder configuration can. Or you could use the eac3to -slowdown option and when you mux the encoded audio with the video, change the video frame rate to 23.976fps (assuming it's currently 24fps).

It's possible the DVD versions were edited slightly differently, even if the DVD has the same frame rate as your source. All it takes is a missing frame or two at the end of a scene now and then and the audio might appear to be gradually losing sync but's really losing sync in distinct steps. I've seen that happen several times and the only way to fix it would be to edit the audio as required, but I can only guess as to what's happening.

[El Heggunte]

......
The dts encoder required by eac3to isn't free. I don't think there is a free one.

You think wrong There exists ffdcaenc, which accepts mono .WAVs as input.

Surcode is outdated AND rather limited.
DTS itself is not limited to only 2 bitrates, 2 sampling frequencies and 6 channels.
ffdcaenc is the closest thing to a full-featured DTS encoder that we have until now.

[hello_hello]

You learn something new every day. I didn't know ffdcaenc existed. So why is it such a secret? It's not listed in VideoHelp's software section (I couldn't find dcaenc either) and no encoder GUIs I know of use it. That doesn't mean none do, just that I'm not aware of any.

Using the command line here I got it working in foobar2000 easily enough.

Cheers.

Edit: You might need to explain to the OP how to input multiple mono wave files. I haven't got that far yet.