[Spice-devel] Is the data after USB camera redirection compressed?

[lx]

Frediano Ziglio <freddy77 at gmail.com> 于2021年2月4日周四 下午9:47写道：

> Il giorno gio 4 feb 2021 alle ore 12:56 lx <lxlenovostar at gmail.com> ha
> scritto:
> >
> >
> >
> > Uri Lublin <uril at redhat.com> 于2021年2月2日周二 下午10:32写道：
> >>
> >> On 2/2/21 2:50 PM, lx wrote:
> >> >
> >> >
> >> > Uri Lublin <uril at redhat.com <mailto:uril at redhat.com>> 于2021年1月31日周
> >> > 日 下午9:48写道：
> >> >
> >> >     On 1/30/21 1:25 PM, lx wrote:
> >> >      > Frediano Ziglio <freddy77 at gmail.com <mailto:freddy77 at gmail.com
> >>
> >> >     于2021年1月29日周五 下午6:39写道：
> >> >      >
> >> >      >> Il giorno gio 28 gen 2021 alle ore 01:45 lx
> >> >     <lxlenovostar at gmail.com <mailto:lxlenovostar at gmail.com>> ha
> >> >      >> scritto:
> >> >      >>>
> >> >      >>>
> >> >      >>> Uri Lublin <uril at redhat.com <mailto:uril at redhat.com>>
> 于2021年1
> >> >     月27日周三 下午11:47写道：
> >> >      >>>>
> >> >      >>>> On 1/27/21 4:22 AM, lx wrote:
> >> >      >>>>> Hi all:
> >> >      >>>>>          If I redirect USB camera to virtual machine, I
> think
> >> >     we send
> >> >      >>>>> original URB to virtual machine by USB channel.
> >> >      >>>>> Is this understanding correct? If we want to improve the
> user
> >> >      >> experience,
> >> >      >>>>> we need to compress URB data?
> >> >      >>>>
> >> >      >>>> Hi,
> >> >      >>>>
> >> >      >>>> If you build with lz4 enabled (both client and server),
> >> >      >>>> then it should use lz4 to compress the data.
> >> >      >>>>
> >> >      >>>> There is no functionality to create
> >> >      >>>> a video stream out of raw data.
> >> >      >>>>
> >> >      >>>> Can the USB camera be configured to send a compress stream?
> >> >      >>>>
> >> >      >>>> Uri.
> >> >      >>>>
> >> >      >>>
> >> >      >>>    Hi:
> >> >      >>>     USB camera can support MJPG and YUV.   I think H264 is
> >> >     better than
> >> >      >> MJPG. So Can we
> >> >      >>> let spice support H264 ? Is this feasible?
> >> >      >>>
> >> >      >>
> >> >      >> This is independent from SPICE, if the camera send compressed
> data
> >> >      >> already SPICE will just
> >> >      >> forward compressed data in whatever format is in USB.
> >> >      >> If the camera supports MJPEG and YUV choose MJPEG, YUV is not
> >> >      >> compressed (just a different color
> >> >      >> space than RGB, often taking less bits but still not
> compressed).
> >> >      >>
> >> >      >> Frediano
> >> >      >>
> >> >      >
> >> >      > If the camera chooses YUV, can we encode it to H264 in SPICE?
> Is this
> >> >      > feasible?
> >> >
> >> >     Currently, SPICE does not do look at USB data.
> >> >
> >> >
> >> > Hi:
> >> >
> >> > What do you mean spice just forward USB protocol data?
> >>
> >> SPICE does look at USB headers, configurations, etc.
> >>
> >> I meant that SPICE does not look at data that is
> >> being transferred. So for example, it does
> >> not know if the data coming from the camera is YUV,
> >> RGB, MJPEG or other.
> >>
> >> To answer your question above more clearly:
> >> Currently it's not possible to H264-encode the
> >> YUV data coming from the camera.
> >> It is feasible to add code that does it.
> >> If possible, it's best if the camera sends an encoded video stream.
> >>
> >> Uri.
> >>
> > Hi all:
> >         I know ICA/RDP is better than spice, when they redirect the USB
> camera devices. This is beacuse
> >  ICA/RDP encode video stream, so the effect is so good? Or how can we
> optimize spice to achieve their results?
> >
> > Thank you
> >
> > btw: I know ICA/RDP support few devices.
> >
>
> Hi,
>    what exactly do you mean by "I know ICA/RDP is better than spice",
> I mean, did you
> personally try and works better? Did you do some measurement? Is just
> some comments
> on Internet?
>
Hi :
I get some inforamtion from this page:
https://forum.huawei.com/enterprise/zh/thread-324721.html
ICA/RDP complete USB redirection through virtual USB device driver. And
SPICE complete USB redirection
through virtual USB host controller driver. SPICE client read/write URB by
libusb.

I will test RDP and perform analysis betwwen RDP and SPICE.



> I didn't try personally (I don't have ICA solution installed) but you
> could run a test to check for
> compression:
> - run a program in the VM to record camera video without showing on the
> screen
> - start monitoring traffic (like tcpdump, or just some network
> statistic program)
> - let the recording goes for a predefined amount of time
> - stop monitoring.
> - look at the amount of traffic generated.
> If the amount of traffic is less they are compressing (not said they
> are video compressing,
> maybe only as raw data better than us). If they are compressing A LOT
> (like 5 times)
> probably they are using video compression (unless they found a way to
> reduce frame rate).
>
> It could be that they detect camera and optimize specifically the
> dialog with the VM.
>
> Other reasons could be less pipeline having a lower latency or some
> sort of QoS for the
> network.
>
> Frediano
>
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