How to Record SPDIF Dolby Digital Input

[pandy]

Originally Posted by sebus

Cannot detect file format

Audio must be recorded without any modification - bit exact copy mode

http://www.hydrogenaudio.org/forums/index.php?showtopic=91655

[Ghitulescu]

Some American told me long time ago that all HD receivers have to have the firewire-interface enabled. I would suggest trying to copy them 1:1 via firewire (there is a software used for D-VHS once in the internet).
The best solution would be to copy them natively directly from the HDD.
The third best option (and the first for me) would be to buy the set on BD (it's cheaper now). It think the price is lower than any other solution involving hardware you don't have or that doesn't work (and requiring to buy additional gear).
In Germany the PayTV providers try to force people into getting their own boxes, which generally are not only nuttered in terms of functionality but also have of a very bad quality, both constructional and reliability. I own my own STB and I could always recover the recordings from the HDD. Movies I don't record, as usually they have various issues (senders' logo, less channels, lower A/V quality, lack of subtitles, lack of the original audio). This is what I recommend to you, too. It will be a good future investment, a movie can be remuxed and authored (chapters, subtitles etc) within one hour, if needed, in original broadcasting quality.

Coming back to your question, S/P-DIF should be in theory possible with all soundcards having digital in. The software has to bypass windows (ie it has to be ASIO based) for best results (or any results at all ). Many freeware and payware can do this. You can even create a graph to save the digital stream to a file.

[Music Fan]

I recorded ac3 5.1 a few years ago with the optical input of an Audigy 2 ZS and its original drivers on Windows XP.
I had to ;
-tick "enable bit accurate recording" in Device Controls
-put REC on SPDIF in Creative's volume window
-put REC's volume on 0db (50 %)
-record in stereo 48/16 with Cool Edit Pro (became Adobe Audition) ; of course, it's better to begin recording before to play the stream to record and finish after recording to avoid missing parts
-save in Windows PCM (Wav extension)
-use BeSplit to clean the stream and create an .ac3 file with this command ;

C:\BeSplit.exe -core( -input "F:\ac3 file 448k.wav" -prefix P:\track -type ddwav -fix )

P:\track will become P:\track01.ac3
It also removes the potential blank parts at the beginning and end (if done how I suggested with Cool Edit Pro).

eac3to can maybe also clean the stream.
Anyway eac3to can be used after BeSplit to remove the possible dialog norm (IIRC BeSplit didn't do this) with this simple command ;

"C:\Program Files\eac3to\eac3to.exe" "P:\input file.ac3" "F:\output file.ac3"

This also works to remove dialog norm of dts files (replace .ac3 by .dts).

[astraub]

Hi,

I found that recording an AC-3 track using SPDIF and post-processing it with besplit destroys the audio/video sync. The AC-3 file is shorter than the video. Could this be a problem when recording in 16 instead of 24Bit mode?

I also tried AC3REC and this showed a lot of CRC errors and frame drops, which could explain the missing audio time?

I will get another SPDIF interface, capable of 24 bit mode. Hopefully this improves the situation.

Any additional comments / ideas?.

Greetings
Andreas

[goemon]

what spdif interface are you using?

[wonkey_monkey]

What version of Windows are you using? I used a SoundBlaster SPDIF box ages ago - it worked fine under Windows XP, but on Windows 7 the Windows Mixer got in the way and added noise/resampling to the recording. You have to make sure whatever's recording is exclusively and directly access the SPDIF interface, I think.

[Bruno202]

What software to use?