Issues with Camera CommandMode set to noWait

RVMedia support and discussion (components for displaying and controlling IP cameras, webcams, video conferencing, video chats, recording audio and video files)
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atshurelov
Posts: 3
Joined: Tue Jan 25, 2022 9:01 am

Issues with Camera CommandMode set to noWait

Post by atshurelov »

Hello,

I have a USB camera - ELP-USBFHD06H-L36.
The application is built with Embarcadero C++ Builder 10.3 Version 26.0.33219.4899

Using the TRVCamera components (version 8.2) I can start a video stream by invoking the TrvCamera->PlayVideoStream().
I use TRVCamView to view the stream.
The camera component CommandMode is set to rvsmNoWait.
To end the stream, TRVCamera->Abort() is called - this is where I observe some issues.

After the Abort() method is called the application freezes for certain amount of time, depending on the resolution set in the video mode. (Subtype is MJPEG, color depth 24 for all resolutions)
if set to 320x240 - almost instant return from Abort()
if set to 640x480 - returns after about a second.
if set to 1920x1080 - more than a minute to return

dfm:
object RVCamera1: TRVCamera
Agent = 'IP Camera'
CameraSearchTimeOut = 1000
CommandMode = rvsmNoWait
DeviceType = rvdtWebCamera
Left = 352
Top = 376
end

object RVCamView1: TRVCamView
Left = 11
Top = 11
Width = 1121
Height = 554
Align = alClient
CaptionFont.Charset = DEFAULT_CHARSET
CaptionFont.Color = clWindowText
CaptionFont.Height = -11
CaptionFont.Name = 'Segoe UI'
CaptionFont.Style = []
Color = clBtnFace
DoubleBuffered = False
TabOrder = 0
AllowEmptyGUID = False
CaptionColor = clBtnShadow
HoverLineColor = clBtnShadow
ShowCaption = False
ShowFrameRect = False
IsInFocus = False
end

According to RVMedia help file description of noWait mode - operations are performed in background threads, without waiting.
Is there a reason Abort() would return after a long time, increasing with higher resolutions? I would expect it to return instantly in all cases.
All operations are executed from VCL main thread.

Thanks,
Atanas
Sergey Tkachenko
Site Admin
Posts: 17236
Joined: Sat Aug 27, 2005 10:28 am
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Re: Issues with Camera CommandMode set to noWait

Post by Sergey Tkachenko »

Wait/nowait mode is related to commands to IP cameras, not to web cameras.
And there is a good chance that this problem is solved in RVMedia 9.3, please update.
atshurelov
Posts: 3
Joined: Tue Jan 25, 2022 9:01 am

Re: Issues with Camera CommandMode set to noWait

Post by atshurelov »

Hi Sergey,

Thanks for the reply.
I only see trial versions in the download link https://www.trichview.com/download/.
Where can I download non trial version?

Thanks
Sergey Tkachenko
Site Admin
Posts: 17236
Joined: Sat Aug 27, 2005 10:28 am
Contact:

Re: Issues with Camera CommandMode set to noWait

Post by Sergey Tkachenko »

I opened private section of this forum for you.
New version is here: viewtopic.php?t=9282
You can also check for updates by right clicking any RVMedia component at designtime and choose "Check for RVMedia update" in the context menu
(RVMedia can also check for updates when Delphi IDE starts; probably you disabled this feature)
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