LAV Filters - DirectShow Media Splitter and Decoders

[nevcairiel]

Originally Posted by aufkrawall

It doesn't occur with ffdshow, only with LAV.
So it may be more accurate to post this here, or not?

Its either an Intel driver bug or a bug in the QS decoder.
The QS decoder outputs 60 frames, but outputs the frames with timestamps for 30fps, and then occasionally there is a huge gap in the timestamps when it re-syncs to the actual time - which causes the drops.

Overall, i'm really not happy with how the QS DI performs so far, i'll probably disable it again soon until its working properly, or Intel finally decides to release a fixed driver.

[egur]

Originally Posted by nevcairiel

Its either an Intel driver bug or a bug in the QS decoder.
The QS decoder outputs 60 frames, but outputs the frames with timestamps for 30fps, and then occasionally there is a huge gap in the timestamps when it re-syncs to the actual time - which causes the drops.

I've committed r62 which fixes some (hopefully all) of stalls/crashes related to the DI.

As for the time stamps, per your request I don't calculate them, the new (extra) frames do not have time stamps. If you have an idea to improve this, let me know.

[jakmal]

At the outset, I am not sure whether this is the right thread to report this issue (where do I report avcodec decoding problems?), but here it is:

Sample file: Original MP4 version of this YouTube clip: www.youtube.com/watch?v=t56ooXC9VmY [ Size : ~252 MB ]

Playback system: Core i7-3770K + GT 640. Using LAV Filters 0.50.5 (from 1f0.de, downloaded couple of days back) and MPC-HC 1.6.2.4902 x86 version, display on to 1080p monitor with EVR-CP renderer.

With Video Decoder set to avcodec, there are blocking artifacts when the words 'Peter Jackson' swivels across the middle of the screen.

With Video Decoder set to cuvid or DXVA2 CB, playback is flawless.

[nussman]

Originally Posted by STaRGaZeR

I don't know what that option does, but since it works with it it should be a good starting point.

Then DVBViewer waits for more video format informations.
This slows down channel switching, but some decoders need this informations.

In Graphstudio you should see the differences.

P.S. For fileplayback its always on - so you have to test it with LiveTV!

[CiNcH]

I don't know what that option does, but since it works with it it should be a good starting point.

Check the connection format between DVBSource and the decoder with GraphStudio for example. In case the detection is disabled, the DVBSource will propagate some default values on the video pin and the decoder has to detect the correct values by parsing the bitstream.

I have no clue however, why it works with standard EVR, but not with the EVR custom presenter.

[meetajhu]

hi nevcairiel, will be adding support for Windows Media Audio 9.2?

[dansrfe]

@ nevcairiel

Is I/O and copy/transfer from HDD -> RAM -> CPU -> RAM -> VIDEO RAM streamed or buffered?

[nevcairiel]

Both.

You should ask more specific questions if you want specific answers.

[CruNcher]

@nev
Decodinerror.ts is now falling back from Quicksync to libavcodec what is the detection reason for the fallback or is it out of your hands ?

[nevcairiel]

Originally Posted by CruNcher

@nev
Decodinerror.ts is now falling back from Quicksync to libavcodec what is the detection reason for the fallback, or is it out of your hands ?

Half my files are named "decodingerror.ts" and the other half is named "sample.ts", so either link to the file you are referring to, or don't expect any answers.

[CruNcher]

This one http://www.mediafire.com/?rld8gnlh52f03ud that intel wanted to look into fixing which works on the Nvidia DSP just fine, now the fix seems to be a fallback to Software Decoding which though doesn't fix the main problem which would be Microsofts DTV Decoder (Intels Driver 2761) there the issue is still apparent

[nevcairiel]

The Media SDK just fails when decoding the SPS/PPS of that file. Maybe egur can look more into that, but it looks like they just blocked it - maybe temporarily until it can be fixed for realz.

[CruNcher]

Thx i see so they seem to block it entirely and fallback by that to libavcodec instead of their own Software Decoder which i think would produce the same problematic result in this case thus also most probably why they cant fix it for Microsofts Decoder they have no libavcodec fallback possibility from there only their Software Decoder which most probably is also affected then by this SPS/PPS Decoding issue so a very Generic parsing Bug that affects both of their Decoder currently

I see also nothing changed on the Lav and Videolan DXVA crash state of

720p.mpg
test-720p cuda.mkv

on the Intel Driver i still wonder how long it will take till someone exploits this.

[egur]

I've confirmed the regression for this clip in driver 2752 though 2778, using older MSDK DLLs returns the old behavior - decode header passes and decoding produces artifacts.
With the above MSDK DLLs, the H264 header decode fails, don't know why, and thus my compatibility check fails too.
I'll report this bug tomorrow.

[ipanema]

I'm just trying LAV for the first time today, and I'm getting occasional crashes when seeking. I'm using the Microsoft MPEG-2 Demultiplexer which works well for all of the decoder's I've tried in the past (Mainconcept, Elecard, ffdshow etc).

It's been ages since I've had to tinker with the Microsoft MPEG-2 Demultiplexer, but as far as I recall it passes samples with a maximum size of 8192 bytes, so frames may be split into several output samples with the last one being smaller than 8192. Only the first sample for a frame carries a time stamp, the continuation samples have no time stamp. I mention this in case it helps.

The decoder seems to start streaming OK, but when I try to seek I sometimes get a crash in avcodec-lav-54.dll, exception code c0000005, and it is always at offset 00218b4f.

This is just with the default (no hardware accel) settings of LAV.

[nevcairiel]

As far as i know, you can't just use the MS Demultiplexer, you need an application to properly configure it for usage, so i cannot really test it unless you tell me which application you're using specifically.
While you're at it, providing a sample file that causes such a crash will greatly help to analyse and fix the problem.

[wanezhiling]

@nev

For some WMP users (some of my friends), a tray is really useful when using lav splitter to play back mkv files which integrate several audio tracks.

I know you have no that plan, but don't close the door please.

[sneaker_ger]

ftp://ftp.heise.de/pub/ct/spezial/shuttle.mpg
Crashes LAV Splitter 0.50.5 stable.

[nevcairiel]

Originally Posted by sneaker_ger

ftp://ftp.heise.de/pub/ct/spezial/shuttle.mpg
Crashes LAV Splitter 0.50.5 stable.

No crash on latest Git for me.

[sneaker_ger]

Yes, seems to be working. No more crash with this:
https://forum.doom9.org/showpost.php...ostcount=11285