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barberio · 2012-09-08, 15:48

I'd like it if XBMC could pre-flight playback with a quater of a second of near silent white noise.

Some Audio receivers that 'autodetect' their inputs have a tiny bit of lag in waking up. (ex. Teufal Decoderstation 5) This only affects decoded audio, as bitstream/transcoded will of course have a handshake that wakes the decoder, but analogue sound needs to be detected.

The idea would be for XBMC to output a barely noticable amount of white noise to 'wake up' any autodetecting audio decoders as part of the pre-flight on playback of decoded audio.

DDDamian · (This post was last modified: 2012-09-08, 15:55 by DDDamian.)

Have you tried the nightlies with AE? It streams silence to try keep connections alive. Note that you would have to add:

Code:
<audio>

  <streamsilence>1</streamsilence>

</audio>

to your advancedsettings.xml file.

barberio · 2012-09-08, 16:02

Is that streaming a silent digital stream? Might not work with stereo analogue detection. I'll give it a test when I can.

DDDamian · 2012-09-08, 16:18

Yes it is silent, and all streams are digital - we cannot output "analogue". If you mean PCM then yes, that's what you'll get.

barberio · (This post was last modified: 2012-09-08, 16:46 by barberio.)

Doesn't work on the latest Monthly on my ATV2. The setting appears to do nothing. (And yes, I meant to type PCM because it's over optical connection, but brainstupids and only had one cup of coffee today.)

DDDamian · 2012-09-08, 16:52

Ahhh sorry barberio - that feature is only for Win/Linux - didn't realize you were on an ATV2

barberio · 2012-09-08, 17:40

Is it going to be ported to ATV2, or are there issues with that?

DDDamian · 2012-09-08, 17:58

Really up to a couple of devs who have been handling the CoreAudio side of things - will canvas them.

tismon · 2012-09-14, 17:17

To add onto this question, do you possibly know if it outputs a near-silent stream for analog devices or completely silent that technically doesn't actually produce a sound, but rather does something else to trick the soundcard?
Basically, would this work for analog connections (composite/headphone)?

Thanks

davilla · 2012-09-15, 04:22

"near silent white noise" ?

tismon · 2012-09-17, 17:46

Near silent as in an actual signal would come out through the speakers, but that is too quiet for anyone to hear. Such as a 15-20Hz at a very low volume. Something that most speakers with their own timeout function could detect and then not go to standby, but that wouldn't be actually audible by anyone around.

~~Ned Scott~~ · 2012-09-17, 17:49

"Honey, why is the dog barking?"

tismon · 2012-09-17, 18:05

...um, I think is only high frequencies (20-40KHz). Though it does seem that <20Hz can still be heard by some people and with my luck, I'll be one of them.

barberio · 2013-06-20, 19:56

This needs to be re-examined as it's been apparently decided not to port AE to embedded platforms, so the individual players need to pre-flight audio themselves. This is very much apparent on the RaspberryPi platform, where the audio hardware isn't initialised till the player starts outputting content. Currently I'm getting a little over a second of silence at the start of all media playback while using HDMI audio out to a Philips TV.

I suspect that this may even be solvable if the audio output was just kept open with zero packing to keep decoders awake when there's no playback.

davilla · 2013-06-21, 17:10

RaspberryPi platform is just one of many embedded platforms that xbmc runs under, AE might not be running under RaspberryPi platform but it is a mistake to apply that logic to all embedded platforms.