Dolby Digital Audio bit depth = 16 bits??? Why?

[Bonie81]

Even after trying to encode ac-3 with a professional encoder, I am getting bit depth = 16 most of time in some cases 20 with 4 extra bits, why?

Raw WAV (PCM)

Audio
Format : PCM
Bit rate : 1534 Kbps
Channel(s) : 6 channels
Sampling rate : 48.0 KHz
Bit depth : 24 bits

DTS

Audio
Format : Digital Theatre System
Format/Info : DTS
Bit rate mode : Constant
Bit rate : 1534 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits

Dolby Digital AC-3

Audio
Format : AC-3
Format/Info : Audio Coding 3
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits

I have gone thru' collection of my original DVDs n BDs, but could not find DD AC3 audio with bit depth = 24.
Why DD AC3 Bit depth = 16 bits??? Why not 24?
Is there any technical limitation on ac-3 format?

[aedipuss]

because ac-3 specs say so. only Dolby TrueHD can be up to 24 bit.

[Bonie81]

because ac-3 specs say so. only can be up to 24 bit.

Thanks for the response.
yeah u r right Dolby TrueHD supports bit depth up to 24 bits.
but, Dolby TrueHD can only be supported in HD DVD or BD.
anyways...has to stick with 16 bits for a while!
Thanks!


PS: its seems like LibA52 (aften) ATSC development team has gone on long summer vacation while i am looking for Free DD AC3 TrueHD encoder coz i do not have $$$$$$$$$ for TrueHD professional encoder.

[jman98]

PS: its seems like LibA52 (aften) ATSC development team has gone on long summer vacation while i am looking for Free DD AC3 TrueHD encoder coz i do not have $$$$$$$$$ for TrueHD professional encoder.

You may be waiting a LONG time. I'm sure that Dolby Lossless/True HD is covered by patents.

[Bonie81]

You may be waiting a LONG time. I'm sure that Dolby Lossless/True HD is covered by patents.

yeaaaaah..., and that is the main reason DTS started leading in Blu-Rays : DTS-HD Master Audio Becoming the Blu-ray Standard
anyway keep smiling with 640 16bits.
Just in case anyone wants to go thru' "Digital Audio Compression Standard (AC-3, E-AC-3) PDF from the ATSC website"

[El Heggunte]

Why Lossless Audio Codecs generally suck


http://codecs.multimedia.cx/?p=313

[jagabo]

PS: its seems like LibA52 (aften) ATSC development team has gone on long summer vacation while i am looking for Free DD AC3 TrueHD encoder coz i do not have $$$$$$$$$ for TrueHD professional encoder.

You may be waiting a LONG time. I'm sure that Dolby Lossless/True HD is covered by patents.

So are AC3, AAC, MP3, MPEG 2, MPEG 4 part 2 (divx), MPEG 2 part 4 (h.264)... That doesn't stop open source versions from appearing.