LAV Filters - DirectShow Media Splitter and Decoders

[LigH]

"When It's Done" ™

good.

[foxyshadis]

Originally Posted by KoD

@nevcariel

I've been using LAVFilters-0.70.2-83 for a long time now. I just updated to LAVFilters-0.71.0-30, but started noticing right away random audio pops and cracks. They're not loud, but they're there. Very easy to notice on dtshd-ma 24 bit integer 48KHz BluRay soundtracks which decode to 24bit integer 48Khz, but it's there on AC3 that decodes to 32 bit float too. Tried LAVFilters-0.71.0-35, and it's the same. Tried playing on both an external audio receiver (digital optical out), as well as over HDMI, and it's the same. Went back to LAVFilters-0.70.2-83 again and the sound is free of these cracks and pops. I have not tried any intermediate versions.

Later edit: well, I just noticed the cracks are there with LAVFilters-0.70.2-83 too.

Even later edit: yes, they're in LAVFilters-0.70.2-83 too, but not as often than in LAVFilters-0.71.0-35; with the latest version of the filters it's so often it's impossible not to notice it and is very distracting.

Later later edit: forgot to say that the cracks and pops are not there when playing the same m2ts or mkv file with PowerDVD and letting it decode the audio.

USB audio? That's the biggest culprit for pops and crackles; Win10 is a huge improvement for USB audio dropouts (as in, I've never had them) compared to Win7. Aside from that, the only thing you can do is keep your audio and video drivers updated, increase audio buffers in applications, and experiment. Unfortunately, MPC-BE is pretty limited in audio options; even BE doesn't give you control over audio buffers. You could try an ASIO driver, which will give you more knobs to twiddle, or ffdshow, with did expose buffer size, iirc. Aside from that, changing applications, as you have, is the only way to go.

[gfxnow]

Which players use LAV filters as default internal filters? I know kodi dsplayer uses it. I am currently using mpc-hc but would prefer switching to a player that is being actively developed/updated. I don't think mpc-be is using LAV.

[ryrynz]

It doesn't need to be "using LAV" because you simply disable the internal filters and install LAV filters. You don't need any player to come with LAV for it to be up to date or run perfectly the same as if it came built with LAV.

[clsid]

As long as MPC-HC does what you need, then there is no reason to switch. And there still are minor updates for it occasionally.

[jkauff]

Kudos to clsid for building those minor updates. He tries to keep current with stable LAV filters releases, so no reason to shy away from MPC-HC.

[gfxnow]

Thanks guys, happily installed MPC-HC v1.7.16. Kudos to clsid indeed!

[Orf]

@nevcariel
I want also to report that despite of what read-me says that it was fixed, LAV video decoder (D3D11 mode only, other modes are not affected) often stops working after media type changes. This is not happens always, occasionally it might work once or several times, but in most cases it didn't. After that point decoder starts sending frames with garbage content to renderer, and any further media type changes didn't work too

[Thunderbolt8]

I want to get the best possible sound from my internal sound card, using LAV audio and the mpc-hc internal audio render (without the ability to use bitstreaming). Im trying to play a 5.1 96kHz 24-bit TrueHD file using a 2 speaker setup. so I know the playback cant be 100% bit-perfect anyway due to channel mixing, but I want it to be as perfect as it can get aside from that.

in windows settings I ticked the box for allowing apps to take exclusive mode (and also the priority box) and set the default format to 24/96.

in the internal audio renderer of mpc-hc settings device is set to system default, the box for exclusive mode is ticked as well as the "ignore system channel mixer" box.

in LAV audio decoder settings, I enabled mixing with output configuration set to stereo, changed LFE mix level to 0 (dont want heavy bass in the night) and also ticked the box for clipping protection. status box says TrueHD --> PCM; 6 channels --> 2 channels; 24-bit integer --> 32-bit float.

now, when I play back the file, the internal audio renderer status tab says format: float --> PCM-24 (padded) and Processors: limiter.

when I untick the boxes 32-bit integer and 32-bit float in LAV, then LAV status says 24-bit int --> 24-bit int and internal audio renderer status PCM-24 --> PCM-24 (padded) and processors: -

so Im wondering whether keeping the 32-bit boxes in LAV ticked gives me the better/more original sound presentation or unticking the boxes. the input format is only 24-bit and not 32-bit. does channel changing from 6 --> 2 need some float headroom/dithering for sound quality? in LAV audio it says "enabling all formats will allow untouched/bitexact output" and "the best format is used automatically". what does "best" here mean? best quality? most fitting/suitable format?

[lvqcl]

It doesn't matter IMHO.

[Asmodian]

Originally Posted by Thunderbolt8

does channel changing from 6 --> 2 need some float headroom/dithering for sound quality? in LAV audio it says "enabling all formats will allow untouched/bitexact output" and "the best format is used automatically". what does "best" here mean? best quality? most fitting/suitable format?

Yes, channel muxing from 6 -> 2 generates 32-bit float. Do not disable any formats in LAV, it will pick the optimal format for quality.

[KoD]

@nevcariel, @foxyshadis

I am using Win10, indeed. It's build 1703 (so, April last year I guess) with all updates until now, as I have the Pro version and can delay feature updates, and there were quite a few people complaining about issues with the nvidia drivers in 1709. 1803 also seems to be having teething problems, so I'm not eager to update to it either.

I am playing audio using either:
- motherboard optical out (external DAC + amplifier)
- or via HDMI (on the TV audio speakers)

I either case:
- having LAVaudio decode audio: random (but quite seldom) pops and clicks;
- using PowerDVD to play: no audio issue;
- using the Microsoft audio decoder (even for AC3 audio): no audio issue.

Once upon a time, the Cyberlink PowerDVD decoders were also available as DirectShow filters and could be used by players like MPC-HC, but this does not seem to be the case anymore, neither as 32bit nor as 64bit filters, so I can't use them in 3rd party media players to test this scenario as well.

I've switched between several video drivers (nvidia), and audio (realtek), and there was no difference.
I'm playing using either MPC-HC (with internal filters disabled), or ZoomPlayer. Tried all audio options: DirectSound wrapper around the audio device, or directly the audio device (I guess WaveOut ?). It makes no difference.

Regardind the pops and clicks I'm having when using LAVaudio decode audio, if I rewind back and play the same fragment again, the pop does not happen again. I guess it's either an issue of some errors that accumulate in time and then you get the click, or maybe some sync issue where lav filters try to keep the video and audio in sync and this happens? I don't experience audio and video getting out of sync in time, though. I toggled the "Auto A/V Sync correction" on and off in the Lav audio filter configuration, but it did not have any effect. The pop/click resembles what one would get when "normalize matrix" is enabled in the Mixer, but I don't have the Mixer enabled in LAV audio, so it's not that. And with it enabled to mix audio to stereo, I still got the pops and clicks.

These issues did not happen in the past, but I could not say when they started. There was quite a long stretch of time where my HTPC was left unused due to lack of time.
At this point, I don't know what else it could be. Since out of three audio decoders, it only happens with LAV audio, my guess was that LAV audio must have something to do with it.

Unfortunately, for some audio formats there is no option other than LAV audio, so using something else is not possible.

[e-t172]

Originally Posted by Thunderbolt8

I want to get the best possible sound from my internal sound card, using LAV audio and the mpc-hc internal audio render (without the ability to use bitstreaming). Im trying to play a 5.1 96kHz 24-bit TrueHD file using a 2 speaker setup. so I know the playback cant be 100% bit-perfect anyway due to channel mixing, but I want it to be as perfect as it can get aside from that.

You would be better off spending your time on other things. There is no evidence whatsoever that a "perfect" "bit-perfect" audio pipeline will make any kind of audible difference compared to a normal audio pipeline using default options. It will be more trouble than it's worth. If it does make a difference, it just means that your audio system is broken.

(Also, trying to build a "perfect" pipeline while downmixing to stereo and setting LFE to zero is a bit nonsensical.)

[Thunderbolt8]

Originally Posted by e-t172

(Also, trying to build a "perfect" pipeline while downmixing to stereo and setting LFE to zero is a bit nonsensical.)

as perfect as possible considering the given conditions

Originally Posted by Asmodian

Yes, channel muxing from 6 -> 2 generates 32-bit float. Do not disable any formats in LAV, it will pick the optimal format for quality.

so basically audio would be truncated if I choose to output at 32-bit float? apparently the 32-bit float then get changed to 24-bit padded by the MPC audio renderer afterwards. is this done via dithering?

[lvqcl]

Originally Posted by Thunderbolt8

as perfect as possible considering the given conditions

Two things that can really affect audio are:
1) surround -> stereo downmixing
2) no LFE channel

[el Filou]

Originally Posted by Thunderbolt8

so basically audio would be truncated if I choose to output at 32-bit float? apparently the 32-bit float then get changed to 24-bit padded by the MPC audio renderer afterwards. is this done via dithering?

No, 32-bit float can represent 24-bit int without losing precision.
Anyway if you uncheck 32-bit float in LAV's output formats, the conversion from it back to 24 int is going to be done by LAV itself instead of MPC's renderer.

[gfxnow]

Posted this in MadVR but realized it might be more relevant here, should I force enable my onboard Intel GPU (HD Graphics 630) in BIOS to use it as a D3D11 CB device in LAV? The logic being that it might free up resources on my GTX 1070 allowing me to further crank up MadVR settings.

[mclingo]

i'd be interested to know what difference this would make as I could set LAV to software and use my CPU for LAV and GPU for MADVR.

Although, I doubt my CPU could handle HEVC.

[sneaker_ger]

Systems and files are so different it's best if you simply give it a try and compare. Note that video decoding is usually on an extra part of the chip not used by madvr and that copying uncompressed frames via PCIe has overhead so often D3D11 native should have the performance advantage (without quality loss DXVA2 native may introduce).