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  1. I am still testing but this seems to be working, for all who are interested.

    Have Motorola Digital Cable box with RCA Coax SPDIF. When menu is set to Digital Surround, connectid to SPDIF In on sound card, I get a pulsing static. This is apparently standard for AC-3 sound, but I tried several methods and could not get either SoftEncode or BeSweet to recognize the file, as a WAV or AC-3. Zilch.

    But, when Motorola menu is set to Surround (NOT Digital), thru the SPDIF I get what sounds like normal audio, which SoftEncode recognizes and creates a usable AC-3 audio file, and WinDVD plays it. I have recorded as mono thru Total Recorder, Mono thru Vdub, and Stereo thru Vdub and so far all were accepted. Trimming wave and frameserving with Vdub seemed to work OK.

    This only works on transmissions stated to have Surround Sound.

    Using DVD player set to PCM rather than Dolby Digital gave similar results.

    Time Warner just told me that my cable only provides Dolby 3.1 and NOT Dolby 5.1, although SoftEncode indicates all five channels plus LFE. Am currently in process of clarifying this discrepancy.

    The AC-3 can either be translated to Prologic II for SVCD or used as AC-3 on DVD or mini-DVD, so far I haven't burnt a disk though I have played a 1-hour MPG with AC-3 and seems OK.

    My testing equipment is very limited as my amp is Prologic I only and I only have 2.1 and headphones on the PC, although the card and WinDVD do handle AC-3, anyone else testing this please supply their results.
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  2. Member
    Join Date
    Aug 2000
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    Upstate NY
    Search Comp PM
    You are capturing a downconverted PCM stream. If you only captures mono it will end up mono.

    You are not capturing the ac3 as it's transmitted.
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  3. But I think that PCM file is a 6-channel wave, at least from the DVD I'm pretty sure it was. Although my main indicator was the fact that SoftEncode seemed to identify it as such, now I'm not so sure.

    I was able to create six wave files using BeSweet, but that may not mean anything. Do you know of any program which will identify the number of channels in a wave file?

    My confirmation is kinda circular as I can only confirm a valid AC-3 by playing what SoftEncode creates, and I am now uncertain how many channels I am feeding it.

    Docs on the Cable Box and DVD seem to indicate that the PCM file, at least from the DVD player, is a decoded AC-3, although this is somewhat unclear.

    That pulsing static is apparently an AC-3, although I couldn't get anything to accept it, headac3e, besweet, added wav header, ac3fix, nada. Post any success you get, and I am going to test the PCM some more and see what I get. Good Luck!
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  4. you can actually send a decoder a pulsing wav file and have it be decoded into AC-3 or dts. i've seen this done with regular CDs. basically, the idea is to record all the sync signals along with the data, and play it back verbatim. the dvd player may be aware that it's only a cd track and not ac-3, but the reciever only sees the digital bitstream with all the ac-3 info, and can play it back as 5.1. however, i've never used besweet, and i don't know how to get this wav file into a ac3 file, or how you could encode it as .mp2 and get this same effect.
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  5. The pulsing wav is apparently missing something. The only playback I have is Phillips Acoustic Edge with WinDVD 4 and it won't recognize the stream as AC-3. Neither will BeSweet break it down into 6 waves, tried adding WAV header and fixing AC-3, get data chunk missing or some such.

    Have confirmed that SoftEncode is not identifying 6 tracks in the PCM wave but is just telling me the encoding method. It makes a VALID AC-3 as opposed to a CORRECT one.

    Original idea was to convert AC-3 to 6-wave and encode to Prologic 2, and/or to use AC-3 for miniDVD or DVD.

    Have tried recording with Total Recorder, Vdub, and some others. Close but no cigar. ANY ideas welcome, I think it's doable.

    PatrickM, how EXACTLY was the wave that worked recorded?
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  6. can't tell you how it was encoded because i didn't do it (it was a sample i downloaded somewhere a year or so ago) and i can't find it now. but basically, it was a standard 44.1 WAV that played back as static, but if the stream was run as PCM to a AC-3 decoder, you got 5.1 AC-3. fyi, when you looked at the waveform, it looked more like digital pulses than analog info ...
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  7. Thanks for any and all info.

    I can use Besweet or SoftEncode on downloaded samples, to which my recorded/captured Wave files seem similar. Mine just won't be accepted.
    SFAIK, the samples were ripped from DVD.

    My thinking is that there is some sort of header or timing info missing.

    Any other softwares known which will accept an AC-3 PCM wave file and do ANYTHING with it, preferably repair, verify, or convert?

    Had given up on this for a while, will have to re-do some experiments and post the error messages. I know there are a few others looking into this question.
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