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  1. Member
    Join Date: Apr 2008
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    I converted an .mkv with FAVC and it kept the original AC3 file (640 bitrate), I stuck the resulting output onto an -rw and threw it into the dvd player and the sound and picture were great. The problem now is when I try to give it a menu and re-author it, neither of my re-authoring progs will allow me to use this AC3 track as it is *not standard*. Does anybody know of any authoring progs that will allow me to keep this bitrate and not have to downsample it? I know how to downsample and have frequently done so in the past, but now I know my DVD player will play this higher quality AC3 track I would like to keep it.
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  2. Always Watching guns1inger's Avatar
    Join Date: Apr 2004
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    The maximum allowable bitrate for DVD is 448 kbps for AC3. Only BluRay allows for 640 kbps.
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  3. Member DB83's Avatar
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    If indeed you were hearing ac3 audio.

    As gunslinger says, that is beyond the dvd spec for ac3 audio.

    However, you can go up to 640 kbps for mpeg-2 audio and that may well be what you are hearing.
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  4. Always Watching guns1inger's Avatar
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    An MKV sourced from a BluRay disc could well have the original 640 kbps AC3 audio - you just can't use it for DVD is all.
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  5. Member
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    I know what the rules for DVD are - all I'm saying is that when I put the dvd in my player (no menus just what was output from FAVC) both sound and picture were great. My amp told me I was playing a Dolby Digital track. When I demuxed the output to make menus in DVD-Lab it threw up an error, same when I pulled the vobs into TMPGenc DVD Author. I could live without a menu and chapter selection etc., it would just be nice if I could keep the original AC3 without downsampling and create my own menus.
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  6. Member DB83's Avatar
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    If you know the rules then you know it cannot be done.

    So why hear it from a dvd-rw ?. I can only assume that the player treats what is effectively a data disk differently.

    I am no audiophile(sp?) but would there be a vast difference in quality to resample the audio to 448 kbps ?
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  7. Member
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    I am no audiophile(sp?) but would there be a vast difference in quality to resample the audio to 448 kbps ?
    About 30% difference. That's like asking if there's a difference between 192 kbps mp3's and 128 kbps mp3's, to those that care it matters greatly

    I guess I'm not going to be able to keep this bitrate AND create menus, my new dvd player must just like to break the rules...
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  8. Member
    Join Date: Oct 2004
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    Yes, it is quite possible that your DVD player supports things that are invalid for DVD when you use it in file play mode. That's a good thing.

    I don't know of any DVD authoring application that will let you use 640 Kbps AC3. DVD Lab Pro will let you do things that technically violate the standards, but if it won't allow it, I guess you are out of luck.

    Your MP3 example is a poor one because I think I could make a strong case that perhaps as many as 99 people out of 100 would not be able to tell a difference between 640 Kbps AC3 and 448. A better analogy would be could most people tell the difference between 320 Kbps MP3 and 224 Kbps MP3. Studies have shown that to the vast majority of listeners, 192 Kbps MP3 is indistinguishable from the original audio, so you can imagine that very very few people could tell a difference between 320 and 224. I'm finding it hard to believe that most people could a difference between 640 Kbps AC3 and 448 Kbps AC3. Even you might not really be able to tell a difference. Or perhaps you are one of those rare people with very sensitive hearing who can tell a difference. Anyway, I'd say you're spot on with your comment that either you keep the bitrate and lose the menus or you lower the bitrate and make a DVD with menus.
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  9. Member
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    Thanks for the comments jman, I see your point - guess I'm just fussy. I just like the richer, fuller sound of a higher bitrate. Next time maybe I'll encode for DL and leave enough room to change the 640 AC3 to a 768 DTS track - that way I shouldn't lose any of the original quality and still be able to build my own menus.
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  10. Banned
    Join Date: Jun 2007
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    Slimbo69 wrote:

    Next time maybe I'll encode for DL and leave enough room to change the
    640 AC3 to a 768 DTS track - that way I shouldn't lose any of the original
    quality
    and still be able to build my own menus.
    LPCM --> AC3 == lossy compression

    LPCM --> DTS == lossy compression

    AC3 --> DTS == double lossy compression (a.k.a. double loss of quality)


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  11. Member
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    AC3 --> DTS == double lossy compression (a.k.a. double loss of quality)
    Yes, I should think before typing nonsense. It's like WAV to MP3 to WAV to WMA, double the damage.
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  12. I would disagree that the vast majority of listeners cannot tell the difference between 192k mp3 and the original audio.. to me there is a great deal of quality lost (minimum acceptable 256k pref 320k). I might agree that in most portable listening devices and situations it would be hard to tell...A lot would depend on the type of music.. classical and instrumental would be most likely to show the difference. I agree that every time you convert you lose some quality, even if it is to a "higher" quality format. 5.1ch sound to DTS hmmmm?
    I would agree that 99% of people couldn't tell the diff between 640k ac3 and 448k ac3.
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