What is lossless bitstream? Isn't all bitstreaming the same?

[ExtremePC]

What is lossless bitstream? Isn't all bitstreaming the same?

The simple answer is lossless bitstream allows your receiver to decode HD audio formats (True HD & DTS HD MA). Lossless Bitstream is also often referred to as Raw Bitstream.

If you have a player that does lossless bitstream then receivers like the 705 will be able to decode True HD and DTS HD MA and you will see those lights turn on the display in the front of the receiver.

If your player does not have lossless bitstream then you are sending a lossy signal to your receiver and allowing your receiver to decode that lossy signal. These are not True HD and DTS HD MA these are lossy core tracks that are provided along with the Hi Def signal for people who don’t have a Hi Def audio player or a Hi Def receiver. This is less than ideal audio setting for people who own a 705.

Before the advent of Hi Definition audio formats if you owned a nice receiver bitstream was the way to make your audio shine. It allowed your receiver to decode formats that were not available if the player was set to PCM. After Hi Def audio there was a period of time that many players came out that only internally decoded these Hi Def formats and didn't allow lossless bitstream. Now only recently (with the latest players ONLY) bitstream has restored its former glory. With lossless bitstream once again you get to allow your receiver to do the decoding with no loss in audio quality when doing so. The only difference is a long time ago bitstream was the BEST way to go if you had a nice receiver. In this day and age with the latest lossless players and receivers you can pick PCM or Bitstream and not notice much of a difference either way, the end results are virtually identical.

Players that support lossless bitstream of both True HD and DTS HD MA formats:

LG BH200 [Blu-Ray & HD DVD] True HD/DTS HD MA with latest firmware update
Samsung BD-UP5000 [Blu-Ray & HD DVD] Lossless Bitstreaming of True HD/DTS HD MA with latest firmware update (1.3 or later)
Samsung BDP-1400 [Blu-Ray]
Samsung BD-P1500 [Blu-Ray]
Panasonic DMP-BD30 [Blu-Ray]
Philips BDP7200 [Blu-Ray]
Denon DVD-3800BDCI [Blu-Ray]
Denon DVD-2500BTCI [Blu-Ray]
Pioneer Elite BDP-95FD [Blu-Ray]
Pioneer BDP-LX70A [Blu-Ray]
Toshiba A35 [HD DVD]
Toshiba XA2 [HD DVD] (Only if you have firmware v2.7 or higher)
Onkyo DV-HD805 [HD DVD]

If your player is NOT on this list, then your player does not support lossless bitstream.

For these users who do not have a lossless bitstream player keep your player set to Linear PCM output when playing (Blu Ray or HD DVD movies). This allows those formats to decode in your player and be sent as lossless PCM to your receiver. You get the same benefit as the lossless bitstream crowd if you do!

The following only applies to people who DO NOT have a lossless bitstream player:

There is only 2 instances when you want to turn off PCM and switch to your lossy bitstream output setting.

A) If you are playing older Standard Definition (SD) movies, it still gives you a benefit of setting your player to bitstream so you gain ability to decode Dolby Digital and DTS on your receiver.

B) Depending on your player type it may not support certain HD audio formats (ex. DTS HD MA) and in those instances the player replaces that audio with a lossy core track instead of the HD audio track. Because of this it that may sound better to set your player to lossy bitstream.

What about Sony Playstation PS3’s?

UPDATE: As of Playstation 3 firmware version 2.30 which is out now, the PS3 can internally decode DTS HD MA tracks and this is no longer an inconvenience for PS3 owners.

For nearly all situations setting your Playstation 3 to Linear PCM output is going to be the best setting for great HD audio. When you select PCM during movie play back your receiver will likely say Multichannel on the front display (if you didn't change listening modes). Multichannel is normal and YES, you are getting TrueHD, DTS-MA or uncompressed PCM audio playback (your PS3 is doing the decoding work, not the receiver; this is why the receiver gives a generic read out.)

Turning on Linear PCM on the PS3:
To select Linear PCM on the PS3; Play a Blu Ray movie then during playback of the movie, click the "Triangle" button, then select the "AV Settings" icon from the popup menu (looks like 2 sliders), "Audio Output Options" you can select (Linear PCM) or (Bitstream).

Complete List of Audio Formats

Below I’ve attempted to summarise the current list of available audio formats on both DVD and Blu-Ray discs.

LPCM (uncompressed) 24-bit/96kHz
DTS-HD Master Audio (lossless compression) 24-bit/96kHz
Dolby TrueHD (lossless compression) 24-bit/96kHz

LPCM (uncompressed) 24-bit/48kHz
DTS-HD Master Audio (lossless compression) 24-bit/48kHz
Dolby TrueHD (lossless compression) 24-bit/48kHz
Dolby TrueHD (lossless compression) 20-bit/48kHz

LPCM (uncompressed) 16-bit/48kHz
DTS-HD Master Audio (lossless compression) 16-bit/48kHz
Dolby TrueHD (lossless compression) 16-bit/48kHz

DTS-HD High Resolution Audio (lossy compression) 24-bit/96kHz
DTS-HD High Resolution Audio (lossy compression) 24-bit/48kHz

DTS (lossy compression) 24-bit/48kHz
DTS (lossy compression) 16-bit/48kHz
Dolby Digital AC3 (lossy compression)

I hope this little article goes some way to clearing things up!

[vlad]

Good article Extreme, thanks.
It is amazing to see how long does it take for manufactures to implement proper HD Audio.
Truly amazing that Sony (maker of Blue-Ray) still cannot do loseless bitstream on PS3.

[bigdonk]

what about the Pioneer BDP-LX70A ?

QUOTE
BDP-LX70A now features bit-stream output for both Dolby TrueHD and DTS-HD Master Audio, as well as HDMI 1.3, HDMI Control (HDMI CEC).

[ExtremePC]

what about the Pioneer BDP-LX70A ?

QUOTE
BDP-LX70A now features bit-stream output for both Dolby TrueHD and DTS-HD Master Audio, as well as HDMI 1.3, HDMI Control (HDMI CEC).

I'll add it to the list