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[Q] Possible to get SPDIF audio without a TV attached?

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lunkhound
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Default [Q] Possible to get SPDIF audio without a TV attached?

I have an Amazon Fire TV which I was hoping I could turn into a headless music streamer. I've sideloaded XBMC and got it streaming music over my network (controlled via remote) outputting audio via optical SPDIF to my receiver.
However, if there is no TV connected to the HDMI port (at least briefly) since booting, I get no sound on SPDIF.

I checked out the system log while XBMC is failing to play a track and I see this:

Quote:
W/AudioTrack( 2210): obtainBuffer timed out (is the CPU pegged?) 0x5b990420 name=0user=0001d400, server=0001c800
W/AudioTrack( 2210): obtainBuffer timed out (is the CPU pegged?) 0x5b990420 name=0user=0001d400, server=0001c800
W/AudioTrack( 2210): obtainBuffer timed out (is the CPU pegged?) 0x5b990420 name=0user=0001d400, server=0001c800
E/AudioHardwareALSA( 277): error pcm_write returned -5
E/AudioStreamOutALSA( 277): pcm_write returned n < 0
W/AudioFlinger( 277): write blocked for 40004 msecs, 120 delayed writes, thread 0x419ba5f0
W/AudioTrack( 2210): obtainBuffer timed out (is the CPU pegged?) 0x5b990420 name=0user=0001d400, server=0001cc00
W/AudioTrack( 2210): obtainBuffer timed out (is the CPU pegged?) 0x5b990420 name=0user=0001d800, server=0001cc00
If I hotplug a TV into the HDMI port while this is happening, those lines stop appearing in the log and music starts to play (on SPDIF).
I can then unplug the TV from HDMI and the music continues to play fine--until the next reboot. It seems that the FTV needs to see *something* on the HDMI port before initializing the audio system.

I bought a "fit headless 4k" HDMI display emulator, hoping that it would make the FTV happy. It didn't.

Any ideas? I'm open to any workaround, software or hardware that is easy and cheap (and doesn't require having a bulky thing attached to the FTV's HDMI port)...
 
wunderdrug
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Quote:
Originally Posted by lunkhound View Post
I have an Amazon Fire TV which I was hoping I could turn into a headless music streamer. I've sideloaded XBMC and got it streaming music over my network (controlled via remote) outputting audio via optical SPDIF to my receiver.
However, if there is no TV connected to the HDMI port (at least briefly) since booting, I get no sound on SPDIF.

I checked out the system log while XBMC is failing to play a track and I see this:



If I hotplug a TV into the HDMI port while this is happening, those lines stop appearing in the log and music starts to play (on SPDIF).
I can then unplug the TV from HDMI and the music continues to play fine--until the next reboot. It seems that the FTV needs to see *something* on the HDMI port before initializing the audio system.

I bought a "fit headless 4k" HDMI display emulator, hoping that it would make the FTV happy. It didn't.

Any ideas? I'm open to any workaround, software or hardware that is easy and cheap (and doesn't require having a bulky thing attached to the FTV's HDMI port)...
There is information on this in the Fire TV thread on the XBMC.org forums.
Basically, optical audio out will not work without a connected HDMI device
which supports HDCP. People have tried using devices such as HDMI
splitters with varied success. I ran into the same issue using a DVI monitor
(with an HDMI to DVI adapter). The monitor is supposed to support HDCP,
but did not work -- so has to be an HDCP compatible HDMI monitor.
 
lunkhound
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Quote:
Originally Posted by wunderdrug View Post
There is information on this in the Fire TV thread on the XBMC.org forums.
Basically, optical audio out will not work without a connected HDMI device
which supports HDCP. People have tried using devices such as HDMI
splitters with varied success. I ran into the same issue using a DVI monitor
(with an HDMI to DVI adapter). The monitor is supposed to support HDCP,
but did not work -- so has to be an HDCP compatible HDMI monitor.
Thanks for the reply. I've scanned (and posted in) the XBMC forum thread on this, but since it seems to be more of an OS level issue rather than an XBMC issue I think this forum is better suited. Also, last I checked, there were only some suggestions of devices that MIGHT work, but nothing yet on anything that actually DID work.

One device that did work is my Denon 3311ci AV receiver. When the FTV is attached to one of the HDMI inputs on the AVR (and with the AVR not connected to any TV), FTV would output SPDIF audio.

Perhaps the reason for the failure of the fit-Headless-4k HDMI display emulator, is lack of HDCP support. But that's just a guess.
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