The VideoLAN Forums

Just for the record, concerning that link: https://forum.videolan.org/viewtopic.php?f=32&t=136452 We are unable to start several vlc instances using vdpau within the same application.. we have also tried with nvidia quadro series, that is supposed to handle unlimited number of h264 streams with ...

Final thanks Remi,

So, nvdec and vdpau both use the underlying special circuits for hw acceleration.. it just depends on the graphics card. ok. thanks.

Kind Regards,

Sampsa

Dear Remi, Thanks for the great explanation. I totally get it now .. With the more "professional"/modern cards I guess the way to go is the "nvidia video decoder api", i.e. with NVDEC and that VPDAU is kind of obsolete, right? What might be the status of NVDEC in in VLC? Regards,...

in modules/hw/vdpau/instance.c

It says ..

/** Finds an existing VDPAU instance for the given X11 display and screen.
* If not found, (try to) create a new one.
...

So it seems that vdpau instances are on "ration cards". That would explain the problem maybe..

Important Note! Remi, it seems you didn't read the question carefully: As I said in the original question, we CAN use several vdpau "threads" simultaneously, by launching several different, independent vlc clients. .. in that case there is no problem. VLC uses 4+ vpdau "threads" ...

Dear Remi, Thanks for the answer. The weird thing is that, we are running into this problem already with n=3..4. I thought that a modern nvidia gpu could handle quite many (say, like .. ten?) vdpau "threads". Said that, I have to take this opportunity to ask your opinion / experience (you ...

Hi Olivier,

Thank you for your reply. Silly me, being a swig-person I didn't think with ctypes. Your solution is indeed much simpler.

What do you think about this one..?

https://forum.videolan.org/viewtopic.php?f=32&t=136452

(did you get my test program..?

Regards,

Sampsa

Hi (Remi), I have a problem when my application is using several vlc instances, all taking advantage of the vpdau hw acceleration. In detail, I do the following: 1) I call XInitThreads() 2) I get an instance of libvlc_new() 3) I create a media player from that instance [media_player_new()] 4) I crea...

Dear Remi, Thanks for the .. reply. If the python bindings dont work with vdpau/x11 as expected / suggested in the python bindings documentation, I think it's worth asking. Luckily, I was able to solve this: all we need is a swig wrapped enclosing the XInitThreads() [filename: "pyx11.i"]: ...

Hi, First of all thanks to Olivier for writing the python binding. It's great! However, I have never managed to run vdpau with it, because of .. [00007f008404b8d8] vdpau_avcodec generic error: Xlib not initialized for threads [00007f008404b8d8] vdpau_avcodec generic error: Xlib is required for VDPAU...

I don't have this problem in linux, vlc version 2.2.1 (maybe it's windows specific problem) ?

have you tried ?

--no-qt-video-autoresize

I guess not.. if in both videos, the first frame does not correspond exactly to the same time instant.

You might need to add lag / extra frames to your streams "by hand". No idea how that can be achieved, though..

Hi, i think my recent post is a bit related: https://forum.videolan.org/viewtopic.php?f=2&t=130841 I have had these problems ("buffering 0%" or "video 5 secs too late") for a long time in a number of situations. I think it is because of corrupted RTCP timestamps (you did not ...

I end this monologue here (I found the solution). Correct ffmpeg command is: ffmpeg -y -f x11grab -s 1920x1080 -r 25 -i :0.0 -vf "scale=960x540" -vcodec h264 -tune zerolatency -preset ultrafast -pix_fmt yuv420p -vprofile main -x264opts keyint=25:min-keyint=25 -maxrate 2000k -bufsize 2000k ...

Thanks for the reply. - So, if vlc comes to the conclusion that it's unable to decode the (i) frames at the required pace it gives up. Makes sense. - .. but I am convinced that it's not the problem here (ffplay does ok job in decoding ffmpeg rtp muxed streams) - .. could such behaviour ("more t...

Hello, This question is about broken interoperability between ffmpeg and vlc. In our system, we send live screencasts using ffmpeg and receive them with vlc. Their compatibility has been degrading continuously as new versions of vlc roll out, namely, vlc is unable to read streams send by ffmpeg (not...

I guess it was because I had forgotten the "DefaultDuration" ebml tag from the matroska file that defines the framerate.

Now it seems to seek far better ..

Hello, I have a h264 video stream in a Matroska container. The container has cue information for each cluster. Cluster are organized in such a way, that there is only one I frame per cluster and the rest are P frames. Now, is it possible to seek the video outside I frames..? When seeking, I get this...

Different video in each vlc player .. Here the trick is to have homogeneous video files, with exactly the same number of frames, but that is a bit of a long story .. (I achieve that with some custom software).

nope

Hello, I get problematic (buggy?) behaviour when telling vlc to read media streams as instructed in a session description protocol (sdp) file. I don't get the same problems when using the "rtsp://" protocol, even when having exactly the same parameters for the media streams as in the sdp f...

Dear libvlc people, I have several videos in a window grid and I need to play the videos in sync. I am using python to achieve this. Works like a charm. However, the vlc instances / players are asynchronous beasts and this creates some problems. I have enumerated these problems below with more detai...

Live555, file "MediaSession.cpp" has the following line .. if (protocolIsRTP && !fMultiplexRTCPWithRTP) { fClientPortNum = fClientPortNum&~1; // use an even-numbered port for RTP, and the next (odd-numbered) port for RTCP } I changed in the above examples, the port number to ev...

Dear Remi, The bug (and the data) is trivial to reproduce as I demoed in the original question - did you give it a try..? I'm just wondering if I should .. 1) File a VLC bug report with the example producing the bug 2) Compile latest VLC from the source and figure the bug out by myself 3) Do both (1...

.. and if I go to the live555 forum, they will tell me that it is VLC's fault, right?

It could actually be that VLC does not pass the information correctly to live555.

.. so, should I file a bug report to VLC, to live555 or both?