AC3 pass through

[mvallevand]

I am looking for GBPVR + NMT users with AC3 (Dolby) capable receivers or monitors to help test the next version of mpvmcx2 with AC3 2.0 and 5.1 digital pass through on SPDIF and HDMI. If you are interested please PM me with your email address.

Martin

[whurlston]

I can do it. I have a receiver with both SPDIF and HDMI. You already know my email.

[mvallevand]

Thanks whurlston, that's one test. Lindsay offered to test an AVR to so I am really looking for someone with a monitor that has built in Dolby decoding. I thought this would be common especially in North America.

Martin

[whurlston]

I haven't actually seen a monitor/tv that can decode AC-3 via an input. My Vizio 1080p LCD will decode AC-3 if it comes through the ATSC/QAM tuner but on from an input. Most TVs are the same.

[mvallevand]

Thanks whurlston, I didn't know that. I'd figure that DVD and BluRay players would be able to pass through Dolby rather than doing the decoding themselves.

Edit the more I thought about this the poorer the implementation seems. After all all lot of people hook their satellite and cable STB devices via HDMI and that means they will only have PCM.

Martin

[whurlston]

Yup. My cable STB outputs PCM and I don't have any other devices to test (DVD, BD are all in HTPC). I did test the PCH directly to the TV but there was no sound on the AC-3 test. Connecting it to the AVR worked with no settings change.

As a side (related) note, the SPDIF output on most TVs will only output 5.1 from the ATSC/QAM tuner as well. All other sources result in 2 channel PCM from the SPDIF out.

[mvallevand]

Would there be any pros or cons in turning on Dolby 7.1 decoding. The NMT actually forces 7.1 instead of 5.1 and if this smarter I can do that. Also does your AVR detect Dolby PLIIx? I am curious when the Dolby source is only 2 channel if the Pro Logic logic quicks in.

Martin

[whurlston]

For standard AC3, 5.1 is fine. I don't know of anything encoded as 7.1 AC3 and any semi-decent 7.1 AVR would be able to simulate the 2 extra channels anyway. Personally, I think it would be better to leave it to the AVR.

Also does your AVR detect Dolby PLIIx?

Yup. I've got an RX-V865 and I can decode everything but WMA basically. I'll test a 2.0 source but it might be tomorrow evening before I can.

[mvallevand]

I think 5.1 is safer for the files GBPVR records and if the PLIIx mode is in fact working it might be better than your AVR's simulation (or not nice AVR!) If it does work, I'd probably enhance this to specify PLIIx music mode for audio files.

It doesn't look like there's any rush for this, and I believe in being thorough anyway, and I appreciate both your help and your knowledge.

Martin

[whurlston]

You wouldn't happen to know where I can find a Dolby PLIIx test file would you?