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View Full Version : where is spec of LPCM used in blu-ray and HDVD?


fancolumn
19th November 2007, 04:23
Hi, people
I'm developing an audio decoder of blu-ray audio. But I can't find the specification of LPCM. For example, the format header of it, sampling frequency, bit/sample, channnel configuration and so on.

Could anybody give me a hint?

Thank you very much!
Sen.

ACrowley
19th November 2007, 09:42
HDDVD use no LPCM

HDDVD : TrueHD/ DTSHD/ EAC3
BluRay : TrueHD/DTS(HD)/ AC3/ LPCM

fancolumn
19th November 2007, 10:08
ok.

Where is the spec of LPCM used in blu-ray?

tebasuna51
19th November 2007, 11:28
Can someone verify/complete this specs?

- Raw data (without header)
- Samplerate: 48000, 96000, 192000
- Bitdepth: 16, 24
- Sample format: Integer Big Endian
- Channels: 2.0, 5.1, 7.1
- Channel mapping: FL, FR, [C, BL, [SL, SR,] BR, LFE]

All correct now?

Edit: Adding inputs

Shakey_Jake33
19th November 2007, 21:47
Can someone verify/complete this specs?

- Raw data (without header)
- Samplerate: 48000, ... (more ?)
- Bitdepth: 16, 24, ... (more ?)
- Sample format: Integer Big Endian
- Channel mapping: FL, FR, C, SL, SR, LFE (more ?)
I have a Japanese Blu-Ray that has 2.0 LPCM 24-bit 96KHz, I think it supports that up to 7.1 too.

killa_kid
20th November 2007, 01:37
HDDVD use no LPCM

I don't know the specs, but from what I've read HDDVD requires all players to be able to decode LPCM, and the only reason we haven't seen it is because the size wasn't feasible on the 30gb dual layers or the bandwidth wasn't high enough. Now that triple layers have been approved at 51gb, we may see them now (unless the bandwidth is the problem, then who knows).

xkodi
20th November 2007, 12:18
@fancolumn

here:

http://www.rarewares.org/files/others/lpcm24.zip

you can find the source code in C of an open-source LPCM decoder and as you will see from that source, the LPCM decoding is pretty simple.

i'm using the code above to decode 96kHz/24bit/stereo LPCM (used on some DVD discs) to stereo WAV files, but probably it will work with multichannel LPCM too, after some modification, like writing of correct multichannel WAV header, etc.

madshi
21st November 2007, 17:50
- Raw data (without header)
- Samplerate: 48000, 96000 ... (more ?)
- Bitdepth: 16, 24, ... (more ?)
- Sample format: Integer Big Endian
According to a german home cinema magazine I'm reading it's:

Blu-Ray:
max 8 x 96kHz
max 6 x 192kHz

HD-DVD:
max 8 x 96kHz
max 2 x 192kHz

The rest of your list above is correct. Max bitdepth is 24 bit integer.

- Channel mapping: FL, FR, [C, SL, SR, [BL, BR,] LFE] (correct ?)
No, IIRC it should be: L, R, C, BL, SL, SR, BR, LFE