•   
  • 1
  • 2(current)
  • 3
  • 4
  • 5
  • 7
  •   
Req How to boost center channel when downmixing
#16
(2014-06-09, 08:50)Fraludio Wrote: Any news?.
I doubt anything will happen quickly in relation to this - its a new feature not a bug fix, so it wouldn't go into Gotham, which is bug fixes only now.

That means that at the earliest it wouldn't appear until Helix is released next year, assuming someone decided to actually start working on it.
Kodi 18.3 - Mid 2007 Mac Mini, 4GB, 2TB HD, Windows 7 SP1
Kodi 18.3 - Vero4k, Raspberry Pi 2. OSMC.
Reply
#17
Not even a temporarily boost to the center channel in the downmix matrix for the rpi?. It should'nt be very difficult to change just this one parameter in the event of a 5.1 -> 2.0 downmix.
Reply
#18
Yesterday I tried to watch "Escape Plan" at night and it was impossible, I had to turn up and down the volume all the time as the voices were very very soft even with normalize levels on downmix disabled.
Reply
#19
(2014-05-30, 12:47)popcornmix Wrote: @da-anda @FernetMenta

On Frodo, where the Pi has it's own mixing matrix generation code I added a new settings option "boost centre channel on downmix".
This added 3dB to centre channel after the mixing matrix was calculated.
This tends to make dialogue more audible amongst loud sound effects/background music.

On Gotham I use exactly the same mixing matrix as xbmc does on other platforms and this feature has been dropped.

So no, "normalise on downmix" is not related to the option I added, and so this issue is not solved.

This is becomes even stranger... if rpi has the same matrix like for example linux build then why on linux center channel is more "clear" and "audible than on rpi? i use same settings on both and it is definetely different...
Reply
#20
Any news?. It's impossible to confortably watch a film using the tv speakers.
Reply
#21
Thats not true btw - i watched a blueray rip (gravity) on my girl friends rbpi last week which has DTS track and i was able to watch it without issues. (samsung tv - stereo output).
AppleTV4/iPhone/iPod/iPad: HowTo find debug logs and everything else which the devs like so much: click here
HowTo setup NFS for Kodi: NFS (wiki)
HowTo configure avahi (zeroconf): Avahi_Zeroconf (wiki)
READ THE IOS FAQ!: iOS FAQ (wiki)
Reply
#22
(2014-09-08, 10:59)Memphiz Wrote: Thats not true btw - i watched a blueray rip (gravity) on my girl friends rbpi last week which has DTS track and i was able to watch it without issues. (samsung tv - stereo output).

Maybe your tv was decoding the ac3 stream. If you let the pi do it you will have this problem.
Reply
#23
No its DTS and the TV doesn't decode DTS ... (and no - the rbpi is not configured to transcode dts to ac3...)
AppleTV4/iPhone/iPod/iPad: HowTo find debug logs and everything else which the devs like so much: click here
HowTo setup NFS for Kodi: NFS (wiki)
HowTo configure avahi (zeroconf): Avahi_Zeroconf (wiki)
READ THE IOS FAQ!: iOS FAQ (wiki)
Reply
#24
(2014-05-30, 13:46)Milhouse Wrote: I agree multichannel music is rare but I've got some examples that play well on the Pi and if centre channel boosting is ever added to core it should take multichannel music into consideration (ie no boost).
I was reminded of this when trying to play an ISO rip of Pink Floyd's pulse DVD's... they're encoded as normal Stereo and Dolby Digital 5.1 audio tracks and my default volume amplification setting (6dB) was sucking out all the dynamic range of the music...as soon as I realised I reset volume amplification to 0dB (remembered automatically for that particular file) and all was well...
Kodi 18.3 - Mid 2007 Mac Mini, 4GB, 2TB HD, Windows 7 SP1
Kodi 18.3 - Vero4k, Raspberry Pi 2. OSMC.
Reply
#25
I also noticed low volume on a downmixed stream, but I was using analogue out. In my case it was a 2ch AC3. 5.1 AC3 or DTS is much louder. Haven't tested that particular movie on my HTPC though, so can't tell if the audio track itself has a very low volume.
Reply
#26
(2014-09-09, 10:51)da-anda Wrote: I also noticed low volume on a downmixed stream, but I was using analogue out. In my case it was a 2ch AC3. 5.1 AC3 or DTS is much louder. Haven't tested that particular movie on my HTPC though, so can't tell if the audio track itself has a very low volume.
The analogue output jack on the model B Pi is considerably (about 6-10dB) lower than normal "line level" audio sources such as a CD player, see my comments here:

http://forum.xbmc.org/showthread.php?tid...pid1791955

From what I've read the low analogue output level has been addressed on the B+ but I'm yet to try one to see if this is true.

This is over and above the fundamental issue of either losing volume or having to compress dynamic range when downmixing to 2 channels, and the inability to boost the centre channel in the downmix relative to other channels...
Kodi 18.3 - Mid 2007 Mac Mini, 4GB, 2TB HD, Windows 7 SP1
Kodi 18.3 - Vero4k, Raspberry Pi 2. OSMC.
Reply
#27
I know that analogue out has a lower output level, but still 2c AC3 had a by far lower volume than 5.1 AC3 when downmixed - at least on the tested movie.
Reply
#28
(2014-09-08, 10:59)Memphiz Wrote: Thats not true btw - i watched a blueray rip (gravity) on my girl friends rbpi last week which has DTS track and i was able to watch it without issues. (samsung tv - stereo output).

It might be dependent on the film though. A few weeks ago I was watching the latest Captain America with 5.1 AAC. It was a bit frustrating because I had to constantly turn the volume up to hear dialogue scenes and then turn it back down during action scenes (they caused an earthquake in my apartment!)

I tinkered around with lots of audio settings (including ones not available in the GUI) but to no avail. I think we really need an option to allow the user to selectively boost the middle channel. Even better if we could do that with a slider, that way we could find the best setting per film.
Reply
#29
I've had a go at this:
https://github.com/popcornmix/xbmc/commi...b0a27d9787

Quote:This allows a dB volume increase to be added to centre channel.
This can help improve dialgue in the presence of background music/effects.
It can go up to 30dB for testing purposes, but value of 6 is probably more reasonable.
It is recommended to ensure "Normalise levels on downmix" is enabled when boosting by large values to avoid clipping.

Should work with Pi Sink (dvdplayer/paplayer) and omxplayer

Should be in next Milhouse/miappa builds.
Reply
#30
(2014-09-25, 00:18)popcornmix Wrote: I've had a go at this:
https://github.com/popcornmix/xbmc/commi...b0a27d9787

Quote:This allows a dB volume increase to be added to centre channel.
This can help improve dialgue in the presence of background music/effects.
It can go up to 30dB for testing purposes, but value of 6 is probably more reasonable.
It is recommended to ensure "Normalise levels on downmix" is enabled when boosting by large values to avoid clipping.

Should work with Pi Sink (dvdplayer/paplayer) and omxplayer

Should be in next Milhouse/miappa builds.

I love you Laugh
Reply
  •   
  • 1
  • 2(current)
  • 3
  • 4
  • 5
  • 7
  •   



Logout Mark Read Team Forum Stats Members Help
How to boost center channel when downmixing3
This forum uses Lukasz Tkacz MyBB addons.