Playback Issues - Audio/Video & Power

[FX4]

"All DD+ streams must contain at least one independent substream or legacy substream, which contains the first (or only) 5.1 channels of the primary audio program."

https://en.wikipedia.org/wiki/Dolby_Digital_Plus

[Heyitsrick]

"FX4" wrote:
"All DD+ streams must contain at least one independent substream or legacy substream, which contains the first (or only) 5.1 channels of the primary audio program."

https://en.wikipedia.org/wiki/Dolby_Digital_Plus

It is enclosed in the stream, but if it's in a DD+ wrapper and your receiver has no idea what DD+ is, it can't pick it off.

[FX4]

Per the Dolby Standard it is backwards compatible. I didn't design the system, just read the spec. Apparently they were forward thinking when the designed the Dolby Digital specifications.

[RokuDale]

From the aforementioned wiki link.
Dolby Digital Plus bitstreams are not directly backward compatible with legacy Dolby Digital decoders.

Dolby Digital Plus streams may contain a core DD stream, however most DD players are not able to parse a DD+ stream to get to the DD core stream. By most definitions of "backwards compatible", DD+ is actually NOT backwards compatible with DD. If it was we wouldn't have DD only audio receivers unable to do anything with DD+.

dale

[FX4]

But Dale, Dolby in their own literature specifically cites that it is backwards compatible. Since they are the author of their own specifications I'm going with what they say over Wikipedia. I know ATV sure sucks the 5.1 out of higher encodes. I am not certain about the technical aspects but it works as Dolby describes. The Wikipedia also says DD+ can be sent down TosLink and the Dolby Standard says HDMI 1.3 is required.

[Heyitsrick]

"FX4" wrote:
But Dale, Dolby in their own literature specifically cites that it is backwards compatible. Since they are the author of their own specifications I'm going with what they say over Wikipedia. I know ATV sure sucks the 5.1 out of higher encodes. I am not certain about the technical aspects but it works as Dolby describes. The Wikipedia also says DD+ can be sent down TosLink and the Dolby Standard says HDMI 1.3 is required.

If it is the way you describe, then where's the standard Dolby Digital stream when using a Roku when the source is DD+? Roku is merely passing it through to the end device. So again...where is it? Are you saying/implying they are stripping it out?

You have to have a Dolby audio chipset that in the box that can handle various streams. The Dolby MS11 Decoder is one such chip. Here's a snippet of what it does (but remember - you have to have this decoder and not just pass through audio - big difference):

http://www.dolby.com/us/en/professional ... -sheet.pdf

For maximum compatibility with the
worldwide installed base of home theater
systems that incorporate Dolby technologies,
and for connectivity over S/PDIF interfaces,
the decoder also generates a standard Dolby
Digital bitstream output (up to 5.1 channels)
from any incoming audio coding format,
which can also be an encode of the 5.1 mix
from dual 5.1 decoders, all contained within
the one Multistream Decoder package.

I don't know what you mean about ATV - unless you mean Amazon Fire TV. In that case, they have a license for offering the DD stream. My LG HDTV has a Dolby Digital Plus license, so I get standard Dolby via optical from DD+ streams to my non-DD+ receiver. But other people who have LG TV's that don't have a DD+ license and instead have just a regular DD license can't get the DD stream from a DD+ source with a Roku box.

[FX4]

Apple TV, commonly referred to as ATV. DD+ streams are as they should be out the HDMI port, DD streams are sent the TosLink connector. Been doing it for years and the Audio issues with Roku is why I bought an ATV, so I could watch movies in 5.1 surround from my old and very expensive Onkyo receiver.

[Heyitsrick]

"FX4" wrote:
Apple TV, commonly referred to as ATV. DD+ streams are as they should be out the HDMI port, DD streams are sent the TosLink connector. Been doing it for years and the Audio issues with Roku is why I bought an ATV, so I could watch movies in 5.1 surround from my old and very expensive Onkyo receiver.

Right, because they most likely have a decoder chipset and a license to go along with it to do that - just like my LG TV. Seems like the Roku 4 has the required chipset, as all of this would be moot if it didn't. In the case of the R4, it seems like it may be a license-cost issue and firmware update to enable this feature, as RokuDale has implied that the technical capability to offer the stream is in the R4. Or perhaps the licensing comes with the chipset and it's just a matter of enabling; I don't know.

And I guess I blanked on the Apple TV / ATV, lol.

Edit: My guess is correct. This snippet is directly from Dolby regarding the Apple TV's handling of Dolby streams:

DECODING AUDIO STREAMS


Apple TV includes a built-in decoder for Dolby Digital Plus and Dolby Digital audio. This means that the Apple TV is able to decode Dolby audio rather than simply pass the compressed bitstream to another device (such as an audio/video receiver [AVR] or a sound bar).

Decoding the audio inside of the Apple TV enables Apple to support several features such as mixing of other sounds from the system, Siri® voice input, and so on.

When a user plays media with stereo or multichannel audio (including Dolby Digital Plus and Dolby Digital audio), the audio soundtrack is decoded to two or more PCM channels (uncompressed digital audio) before it is sent to the AVR or other downstream device.

Dolby Surround – This setting is intended to force the Apple TV to output a Dolby Digital (also known as “AC3”) compressed bitstream. This may be required with certain legacy devices or sound bars that support the older Dolby Digital format but do not yet support Dolby Digital Plus or multichannel PCM audio. Remember that Dolby Digital is only capable of up to 5.1 channels of audio, so this option will never be able to send 7.1 channel audio to the connected HDMI device.

When this setting is selected, the audio is first decoded (although constrained to 5.1 channels) and mixed with other system sounds, and is then reencoded to the legacy Dolby Digital format just prior to the HDMI output. The connected device (TV, sound bar or AVR) will then receive a Dolby Digital bitstream.

http://developer.dolby.com/News/Dolby_A ... le_TV.aspx

On older ATV's, there's a chance that Netflix, et al., is/was offering standard DD 5.1 dedicated streams vs. DD+ - or has a similar/older decoder.

This post suggests that the Netflix stream on ATV - as of a year and a half ago, anyway - was standard Dolby:

http://www.idownloadblog.com/2014/05/27 ... n-5-1-fix/

[FX4]

No doubt Heystack. I actually think they are just peeling off the DD stream. I have never seen an audio sync issue with the ATV. In fact it has been to date the most stable streamer I have ever owned. It has its issues like a crappy remote and limited channel selection but streaming and audio have always been rock solid. If stability was someone's benchmark, ATV wins hands down.

[AnClar]

Please do this.