<html><head></head><body>Hi,<br><br>Indeed we did agree that some old and crappy API's may require memory copying if they have no sane ways to allocate and reference picture buffers, including but not limited to old OpenGL versions.<br><br><div class="gmail_quote">Le 9 août 2019 16:11:55 GMT+03:00, Steve Lhomme <robux4@ycbcr.xyz> a écrit :<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">Did we agree that MMAL will get extra copies due to our design decisions ?<br><br>On 2019-08-09 13:55, Rémi Denis-Courmont wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;">No, it is not my opinion. It is what was agreed collectively. Unlike your opinion, which engages only you.<br><br>I am very fed up with people misconstruing earlier decisions as my opinion. You can not have it both ways.<br><br>Le 9 août 2019 12:57:53 GMT+03:00, Steve Lhomme <robux4@ycbcr.xyz> a écrit :<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ad7fa8; padding-left: 1ex;">On 2019-08-09 10:16, Rémi Denis-Courmont wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"> Hi,<br><br> The MMAL plugins are unmaintained. By definition, if the<br></blockquote>implementation that actually sees users and updates is another one,<br>then ours is unmaintained.<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;">And the point is that I don't want to change the core for a<br></blockquote>misdesigned plugin. I have not seen any technically valid justification<br>for adding yet another way to allocate pictures, nor how this would<br>work.<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;">You cannot expect software decoders and filters to allocate pictures<br></blockquote>from decoder device or video context. That's complete denial of<br> everything that was agreed upon, and reintroduces a whole lot of<br> problems that push was supposed to fix.<br><br> That's your opinion and I don't share it. We made some design choices<br> but until they were implemented we had no idea if all use cases were<br> covered. And it turns out not all use cases are covered. With MMAL (be<br> it the old module or the new module) the design we have is not good<br> enough. We are forcing copies where they didn't exist before.<br><br> And what I propose is still push design. It's still the decoder that<br> creates a video context and pushes it forward. It just may not be aware<br><br> it's using it at all.<br><br> And as I experienced with this idea, for D3D11 it would make perfect<br> sense to allow the decoder device be the creator of video context. They<br><br> are highly related and one doesn't really exist without the other.<br><br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;">Le 9 août 2019 08:50:43 GMT+03:00, Steve Lhomme <robux4@ycbcr.xyz> a<br></blockquote>écrit :<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">On 2019-08-08 18:27, Rémi Denis-Courmont wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">Le torstaina 8. elokuuta 2019, 15.29.30 EEST Steve Lhomme a écrit :<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ccc; padding-left: 1ex;">Any opinion ?<br></blockquote>I don't see why we should mess the architecture for a<br></blockquote>hardware-specific<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">implementation-specific unmaintained module.<br></blockquote> It's not unmaintained, I was planning to revive it to make sure that<br> the<br> default player on Raspberry Pi remains VLC when we release 4.0. It<br> seems<br> there's a different implementation so I'll adapt that one.<br><br> One reason for that is to make sure our new push architecture is<br></blockquote></blockquote>sound<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;"> and can adapt to many use cases. Supporting SoC architectures should<br> still be possible with the new architecture. Allocating all buffers<br> once<br> in the display was making this easy and efficient (in terms of copy,<br> not<br> memory usage). We should aim for the same level of efficiency.<br><br> Also let me remind you the VLC motto: "VLC plays everything and runs<br> everywhere".<br><br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">Even when the GPU uses the same RAM as the CPU, it typically uses<br></blockquote>different<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">pixel format, tile format and/or memory coherency protocol, or it<br></blockquote>might simply<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">not have a suitable IOMMU. As such, VLC cannot render directly in<br></blockquote></blockquote></blockquote>it.<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">And if it could, then by definition, it implies that the decoder<br></blockquote></blockquote></blockquote>and<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">filters can<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">allocate and *reference* picture buffers as they see fit,<br></blockquote></blockquote></blockquote>regardless<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">of the<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">hardware. Which means the software on CPU side is doing the<br></blockquote>allocation. If so,<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">then there are no good technical reasons why push cannot work -<br></blockquote>misdesigning<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #e9b96e; padding-left: 1ex;">the display plugin is not a good reason.<br></blockquote>I haven't proposed any design change to the display plugin, other<br></blockquote></blockquote>than<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;"> already discussed. What I proposed is a way to allocate CPU pictures<br>from the GPU. My current solution involves creating a video context <br> optionally when the decoder doesn't provide one.<br><br> It could even be used on desktop. For example on Intel platform it's<br> possible to do it without much performance penalty. I used to do it<br></blockquote></blockquote>in<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">D3D11 until I realized it sucked for separate GPU memory. But I had<br></blockquote></blockquote>no<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">way to know exactly the impact of the switch because the code was<br></blockquote></blockquote>quite<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">different. Now it might be possible to tell. I have a feeling on<br></blockquote></blockquote>Intel<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">it may actually be better to decode in "GPU" buffers directly. The<br>driver can take shortcuts that we can't. It may do the copy more<br>efficiently if it needs one (or maybe it doesn't need one). It can<br></blockquote></blockquote>do<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #fcaf3e; padding-left: 1ex;">the copy asynchronously (as every command sent to a<br>ID3D11DeviceContext)<br>as long as it's ready when it needs to be displayed.<hr>vlc-devel mailing list<br>To unsubscribe or modify your subscription options:<br><a href="https://mailman.videolan.org/listinfo/vlc-devel">https://mailman.videolan.org/listinfo/vlc-devel</a><br></blockquote>-- <br>Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez<br></blockquote>excuser ma brièveté.<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #8ae234; padding-left: 1ex;"><hr> vlc-devel mailing list<br> To unsubscribe or modify your subscription options:<br> <a href="https://mailman.videolan.org/listinfo/vlc-devel">https://mailman.videolan.org/listinfo/vlc-devel</a><br><br></blockquote><hr>vlc-devel mailing list<br>To unsubscribe or modify your subscription options:<br><a href="https://mailman.videolan.org/listinfo/vlc-devel">https://mailman.videolan.org/listinfo/vlc-devel</a><br></blockquote>-- <br>Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.<hr>vlc-devel mailing list<br>To unsubscribe or modify your subscription options:<br><a href="https://mailman.videolan.org/listinfo/vlc-devel">https://mailman.videolan.org/listinfo/vlc-devel</a><br><br></blockquote><hr>vlc-devel mailing list<br>To unsubscribe or modify your subscription options:<br><a href="https://mailman.videolan.org/listinfo/vlc-devel">https://mailman.videolan.org/listinfo/vlc-devel</a></pre></blockquote></div><br>-- <br>Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.</body></html>