[neil.j1983]

THIS APPLIES FOR ANALOG CONNECTIONS ONLY (or if you are using a dolby digital live or dts interactive card!)

i have a direct rip of my ironman bluray into .m2ts with the core DD taken out from the Dolby TrueHD track.

the explosion at about 2:30 played with MPC-HC using ffdshows AC3 decoder is really nice sounding.

the same explosion played through XBMC sounds like some real heavy DRC is being applied, it doesnt really wake the sub up. i think 'flat' might be the right word. i have tried the disc in my ps3 and ffdshow outputs very similar to the ps3, but xbmc unfortunately doesnt sound as dynamic

i am decoding with output set to "analog" and then my sound card based on a CMI8768+ (dolby digital live) sends it to my amp. i do this so i can have reclock in MPCHC or the 'sync playback to screen' turned on in dvdplayer.

there are no logs for this, and its like it for all files, DTS less so. any tips?

running one of yesterdays SVN. windows vista 32bit, q6600, nvidia 7800gt (HDMI video output to onkyo606), CMI8768+ card (Toslink dolby digital live)

edit - i tried a test dvd and all channels are being sent through correctly.

[paco]

No offense, but considering you have an amp, why not bitstream the AC3?

[neil.j1983]

no offence taken, i like to use the "sync to display" and i dont think you can do both at the same time (bitstream and sync to display).

i understand there is a master audio branch in development, is this likely to offer decoding options?

i listened again to a few bits in movies, and it is like the volume has a limit, what should be a really loud noise is limited and sounds less dramatic.

i'm currently trying out the externalplayer partof xbmc, which is working, but i love the interface of xbmc.

[natethomas]

The curious thing about this is the fact that I'm relatively certain that XBMC is USING ffmpeg's AC3 decoder. To my knowledge, there should be no additional DRC or any other kind of post processing occurring, unless sync to display itself is having an effect.

[neil.j1983]

thats what i thought, but i'm not as clued up as others, so i wasnt sure. i will try later with sync t odisplay disabled and let you know.

its a real shame, i tried media portal and its nowhere near xbmc. its got a bunch of plugins that sound cool, but xbmc just works! its got an interface that has never required me to use a keyboard and...........i'll stop singing its praises now!

[theophile]

Seems to me that this is exactly what would happen since you're essentially downmixing to analog stereo. You lose the discrete sub channel and instead rely on the amp to do some sort of frequency filtering. This will always result in a less dynamic soundtrack.

[neil.j1983]

Seems to me that this is exactly what would happen since you're essentially downmixing to analog stereo. You lose the discrete sub channel and instead rely on the amp to do some sort of frequency filtering. This will always result in a less dynamic soundtrack.

even though i have windows set to 5.1 speakers, and dolby digital live turned on, xbmc will always downmix it? i ran a dvd test disc and all channels are being sent to the correct ones, sub included. i am not running in 2 channel PCM mode via spdif.

below is an admitedly stereo graph of the same explosion section played with ffdshow and with xbmc. but ffdshow sounds almost identical to my amp decoding, but xbmc has the muted sounds (top graph). you can see the ffdshow has higher volume after the peak explosion (especially around 3seconds), this has a real negative impact and happens whenever xbmc is doing the decoding. with "sync playback to display" on or off.

2009-07-12_150723.jpg (842 KB)

[natethomas]

Seems to me that this is exactly what would happen since you're essentially downmixing to analog stereo. You lose the discrete sub channel and instead rely on the amp to do some sort of frequency filtering. This will always result in a less dynamic soundtrack.

So long as the setting is not set to downmix, XBMC should not downmix. It should simply decode and spit out all 5.1 channels, then let the sound card figure out what to do with them. I'm still at a loss.

Edit: BTW, you should submit a log in which you play a 5.1 channel video. It probably wouldn't help me, but any wandering devs may find it useful.

[neil.j1983]

here is a log for opening xbmc, playing a file for a few seconds, stopping, and exitting xbmc

http://pastebin.com/m25819ecb

i hope it is of some use.

edit - is this (http://forum.xbmc.org/showthread.php?tid=54476) something i should do for my setup?

[natethomas]

Alright, neil, it looks like I've been giving you some bad info. Turns out, we do not use the FFmpeg decoder, but rather use liba52. And not only that, but you have the ear to discover that we currently have the DRC set to always on.

The devs are currently looking into this and may add an advancedsetting function to manually turn it on and off. I'll let you know if I hear more.

[neil.j1983]

thanks for the info. i appreciate the time you took to find that out,

if you could keep me updated if you hear anymore, i would be very grateful.

[snuffy1pro]

I would also like to know if/when the advanced settings are added for audio. I knew something was wrong, and now know it is not my setup (HT Omega Claro Plus+/toslink to recv.) but XBMC using DRC. DRC is poo turn it off.... and give the users with "gear" or dedicated theaters (me) advanced options please.....begging...on knees.... kissing feet....

[natethomas]

snuffy, the advancedsettings we're talking about here is not a dedicated advanced settings for audio; it's the advancedsettings for all of xbmc and can be found in the wiki. However, what you are looking for is being worked on currently. If you do a search for "master audio," you should find a few things.

[ashlar]

Hi NateThomas, are you saying that by default there's somesort of "Night Mode" a la Dolby Digital?

[neil.j1983]

Hi NateThomas, are you saying that by default there's somesort of "Night Mode" a la Dolby Digital?

that is what it sounds like. all loud noises are reduced in volume.

but i did add:

<advancedsettings>
<audio>
<analogmultichannel>true</analogmultichannel>
</audio>
</advancedsettings>

to my advancedsettings.xml and it did make an audible difference (still has DRC though), not sure about it, i'm still not sure what it actually does (can't find it on the wiki). i havent done any qualitative tests yet.

giving a search, i have found ticke #67 (http://trac.xbmc.org/ticket/67), just wondering if any progress has been made since that was last updated?