LAV Filters - DirectShow Media Splitter and Decoders

[MokrySedeS]

Sorry, it works now... I had to reset the settings. Though it's still a mystery to me why 0.50.1 worked without a reset

[e-t172]

Originally Posted by bugmen0t

Yes, therefore i didn't asked about that. Applying the +10dB to the LFE is just multiplying it by sqrt(10) (states a table of your link).

However when routing one channel to n others you need to compensate for loudness change by applying a 1/sqrt(n) factor (from ac3filter site). That's where the 1/sqrt(2) ~= 0.7071 comes from when downmixing the center level from e.g. 5.1 to stereo.
So for LFE it should be the sqrt(10) factor for applying +10dB and 1/sqrt(2) because of routing one channel to two, giving sqrt(10)*1/sqrt(2) = sqrt(5). However what they seem to use is sqrt(10)*1/sqrt(4) = sqrt(10)/2 ~= 1.5811 which essentially means compensating for four channels i.e. doubling the actual two.

So here you say one needs +6dB instead of +3dB, i.e. doubling the latter. That seems to be mathematically equivalent to compensate for four channels instead of two as said above.
I guess this is because of the coherence but i don't understand why it is like that and how to compute that. Routing to one speaker (mono) doesn't need any compensation (states ITU) because of missing coherence, i guess. But e.g. routing LFE to four channels, will it need a sqrt(10)*1/sqrt(2*4) = sqrt(5)/2 factor because the speakers bass will add up pairwise? How does that work?

Either I'm not understanding you, or you're really making things more complicated that they really are. The fact that sqrt(10) = +10dB is a pure coincidence. I don't know why ac3filter uses the sqrt(2) notation instead of just saying +3dB (which is the same thing) like a sane person. Maybe that's because they're looking at it from the sound *power* perspective (as opposed to the sound *pressure*, which is not the same thing), and they're trying to equalize power instead of pressure, which is a weird way of doing it (and AFAIK invalid, because power summing is only valid for incoherent signals). So let's just forget about sqrt() notations and just use decibels to avoid confusion.

Basically, I'm postulating that in the bass range (and only in the bass range), the same signal coming from two equidistant acoustic sources in a typical room will be coherent at the listening position, meaning that they will add up to +6dB, not +3dB. You seem skeptical, and it is true that right now I only have my microphone measurements to back that up. I should probably search for some authoritative reference to put an end to the speculation.

One thing I'm 100% sure, however, is that +6dB *is* the right number if you're using a 2.1 system with bass management: indeed, in such a system bass from the two channels are summed electrically (as opposed to acoustically), and electric (voltage) sum of two identical signals definitely *is* +6dB.

[turbojet]

Considering LAV fixed a crash when moving to extended display. Could the problem of MPC-BE >1596 auto pausing when a video is opened on an extended display when LAV and madvr 85.x is used?

Changing one of those things makes it play like it should. Reporting it to madvr and mpc-be has led to dead ends.

[JMGNYC]

I'm having a odd problem. I've got a DVD rip into an .mkv via MakeMKV. It's MPEG video.

Using the latest LAV with MPC-HC and madVR it does not play using None as the Hardware Decoder but does play using Intel QuickSync (HD4000 graphics). Anything I can look at to see why this would be the case?

[sneaker_ger]

You could upload a sample for starters.

[supercoolman]

I have a problem when using LAV Splitter playing one MKV file as shown below. LAV Splitter loads both audio and play both of them at the same time... how do I select just the audio track from mka and disable audio track in the mkv file?

a.mkv (video+mp3)
a.mka (flac)

[nevcairiel]

LAV Splitter has no such feature, it is your player loading both files.

[supercoolman]

unfortunately, MPC-HC doesn't see any audio track, but I got two instance of LAV Splitter. one loads the mkv file, the other loads just the mka file. would be good to be able to disable audio in one of the LAV Splitter instance.

[namaiki]

Do you have the Audio Switcher enabled in MPC-HC? (View-> Options-> Audio Switcher)

[supercoolman]

it's disabled.

I tried another mkv file with one video stream and two audio track. MPC-HC can only see one video stream and the audio track I selected with LAV Splitter.

[CiNcH]

LAV Splitters outputs several different types for AAC, one being that one, but also an official Microsoft one (MEDIASUBTYPE_AAC). DVBViewer should be looking at all media types offered for a pin, and not only the first (which is really a special format just for LAV Audio, but needs to be the first so its actually used over the others)

You also propagate the proprietary media subtype GUID...

MEDIASUBTYPE_ADTS_FOURCC = '{53544441-0000-0010-8000-00AA00389B71}'; //ADTS LAV Splitter

... via ppmt, when looking at the available audio tracks via 'IAMStreamSelect.Info'. This method does not provide the possibility to cycle through the media subtypes, right? So the application has to know this specific media subtype GUID in this case.

[nevcairiel]

TBH, IAMStreamSelect.Info is hardly the correct function to try to probe for a media subtype, especially because it doesn't let you provide more then one, which is a very common use-case to support different filters that expect different things.

In any case, i cannot change this without sacrificing some functionality in LAV Audio, so i will not.

[mastrboy]

Will the LAV Splitter support MKV Segment linking/Ordered chapters sometime in 2013?
It's the only feature I miss before I can uninstall the Haali splitter.

Or is this a feature that you nevcairiel will never work on, and it's up to someone else to write the code for this to be implemented?

[MokrySedeS]

@masterboy
http://forum.doom9.org/showpost.php?...ostcount=13700

[mastrboy]

Originally Posted by MokrySedeS

@masterboy
http://forum.doom9.org/showpost.php?...ostcount=13700

Awesome, i tried searching this post after "segment" and "segment linking", but didn't try "ordered chapter".

Thanks... no need to reply to my other post then.

[filler56789]

Hmmm, only today I noticed that the option "Enable Video Stream Parsing" does not exist anymore.
Could someone please explain why?

[nevcairiel]

Originally Posted by filler56789

Hmmm, only today I noticed that the option "Enable Video Stream Parsing" does not exist anymore.
Could someone please explain why?

Because turning it off should never be required, or its a bug.

[dansrfe]

LAV Filters (x86) does not work with the 1CL3 builds (or at least the latest 1CL3 builds) of MPC-HC x86.

[nevcairiel]

Then don't use ICL builds.

If it works everywhere except in one specific build of one player, maybe you should look there and not here?

[wanezhiling]

Whats the benefit of ICL builds? Any faster?