BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  How to read TJPEGImage faster?          BorlandTalk.com Forum Index -> C++ Builder (Graphics) View previous topic :: View next topic   Author Message PC Hua Guest Posted: Mon Jan 05, 2004 12:10 am    Post subject: How to read TJPEGImage faster? I put LoadFromFile in a TThread and running some actions with TTimer. I'm having the problem that the TTimer routine is delayed if the JPEG file is too huge. I was hoping that TThread could run independently. If I use timeSetEvent() instead of TTimer would this help? Any trick to load the JPEG file faster if I can't do it in background? thanks PC HUA -- _/__/__/__/__/__/_ www.folksfun.com Back to top Detlef Guest Posted: Mon Jan 05, 2004 10:33 am    Post subject: Re: How to read TJPEGImage faster? Hi PC HUA, If I understand your problem, you read in the thread the image and you somewhere else in your program, you are waiting for a timer. And the timer does not occur. What is the delay of the timer? Do you test it with different priorities ( Priority is a property of TThread) on the thread? Use the value tpLower for the thread. At this time only some hints Detlef "PC Hua" <home-at-huaonline.dot.com> schrieb im Newsbeitrag news:opr09z31jleb6hof (AT) newsgroups (DOT) borland.com... Quote: I put LoadFromFile in a TThread and running some actions with TTimer. I'm having the problem that the TTimer routine is delayed if the JPEG file is too huge. I was hoping that TThread could run independently. If I use timeSetEvent() instead of TTimer would this help? Any trick to load the JPEG file faster if I can't do it in background? thanks PC HUA -- _/__/__/__/__/__/_ www.folksfun.com Back to top PC Hua Guest Posted: Mon Jan 05, 2004 10:00 pm    Post subject: Re: How to read TJPEGImage faster? On Mon, 5 Jan 2004 11:33:33 +0100, Detlef <detlef.stute (AT) seatec-gmbh (DOT) com> wrote: Quote: Hi PC HUA, If I understand your problem, you read in the thread the image and you somewhere else in your program, you are waiting for a timer. And the timer does not occur. It does occur. The timer event come regularly (for updating the screen). When the JPEG file is too huge you can see the delay (or skip) like video missing frames. Quote: What is the delay of the timer? Do you test it with different priorities ( Priority is a property of TThread) on the thread? Use the value tpLower for the thread. It's already set to tpIdle. Phuoc Can HUA -- _/__/__/__/__/__/_ www.folksfun.com Back to top Dennis Jones Guest Posted: Thu Jan 08, 2004 4:33 am    Post subject: Re: How to read TJPEGImage faster? "PC Hua" <home-at-huaonline.dot.com> wrote Quote: On Mon, 5 Jan 2004 11:33:33 +0100, Detlef wrote: Hi PC HUA, If I understand your problem, you read in the thread the image and you somewhere else in your program, you are waiting for a timer. And the timer does not occur. It does occur. The timer event come regularly (for updating the screen). When the JPEG file is too huge you can see the delay (or skip) like video missing frames. What is the delay of the timer? Do you test it with different priorities ( Priority is a property of TThread) on the thread? Use the value tpLower for the thread. It's already set to tpIdle. Your thread is probably executing a tight loop that is hogging all the CPU time. You may need to modify (or re-design) your thread function so that it gives up CPU time periodically so that other events, messages, etc., get a chance to be processed by the OS while the thread is executing. - Dennis Back to top Fishface Guest Posted: Thu Jan 08, 2004 4:44 pm    Post subject: Re: How to read TJPEGImage faster? Dennis Jones wrote: Quote: Your thread is probably executing a tight loop that is hogging all the CPU time. You may need to modify (or re-design) your thread function so that it gives up CPU time periodically so that other events, messages, etc., get a chance to be processed by the OS while the thread is executing. I could envision using a TMemoryStream, setting the Size, getting a pointer to the buffer, and using an asynchronous (overlapped) API ReadFile() to fill the buffer. The thread could then wait for the the event to be signalled. Meanwhile, the main thread can run normally. I'm not sure how much that would save, though. Probably much of the time is spent decompressing the JPEG. The Intel library that Sergio mentioned in the "Fast JPEG writing" thread might be faster, as well... Back to top PC Hua Guest Posted: Thu Jan 08, 2004 11:23 pm    Post subject: Re: How to read TJPEGImage faster? On Thu, 8 Jan 2004 08:44:41 -0800, Fishface <invalid (AT) ddress (DOT) ok?> wrote: Quote: Dennis Jones wrote: I could envision using a TMemoryStream, setting the Size, getting a pointer to the buffer, and using an asynchronous (overlapped) API asynchronous (overlapped), what does that mean? Quote: ReadFile() to fill the buffer. The thread could then wait for the the event to be signalled. Meanwhile, the main thread can run normally. I'm not sure how much that would save, though. Probably much of the time is spent decompressing the JPEG. The Intel library that I think you are right because nowadays the HD is that fast and for <1MB it shouldn't be a problem I only hoped that I could get a bit improvement But then what other trick can I use if my TJPEGImage::LoadFromFile is already running in TThread (with tpIdle)? I have tried to replace my TTimer (refreshing screen) with timeSetEvent. It seems a little bit better (less interruptions by loading of image). But it caused another problem. It interrupts another TThread which is running music. Quote: Sergio mentioned in the "Fast JPEG writing" thread might be faster, as well... I was following that thread as well, but I think Sergio said that Borland is faster. By the way, how do I use Intel's one? I assume TJPEGImage is using Borland. PC HUA -- _/__/__/__/__/__/_ www.folksfun.com Back to top Fishface Guest Posted: Fri Jan 09, 2004 6:41 pm    Post subject: Re: How to read TJPEGImage faster? PC Hua wrote: Quote: I think you are right because nowadays the HD is that fast and for 1MB it shouldn't be a problem I only hoped that I could get a bit improvement But then what other trick can I use if my TJPEGImage::LoadFromFile is already running in TThread (with tpIdle)? I think it's still worth a try. How fast is the computer on which you are testing and how quickly do you need to switch the images? What does your screen refresh actually do? Are you using TImage to display? Sounds like a slideshow or something... Quote: I was following that thread as well, but I think Sergio said that Borland is faster. By the way, how do I use Intel's one? I assume TJPEGImage is using Borland. I thought he said Intel's was faster, but I'm not familiar with it. I think Borland just used code from the IJG libraries. www.ijg.org Back to top PC Hua Guest Posted: Mon Jan 12, 2004 12:06 am    Post subject: Re: How to read TJPEGImage faster? On Fri, 9 Jan 2004 10:41:22 -0800, Fishface <invalid (AT) ddress (DOT) ok?> wrote: Quote: But then what other trick can I use if my TJPEGImage::LoadFromFile is already running in TThread (with tpIdle)? I think it's still worth a try. How fast is the computer on which you I'm think of an easier way to try, instead of modifying my codes, I want to configure a RAM disk (Win98SE) just for testing. Do you know how to do that? Quote: are testing and how quickly do you need to switch the images? What does your screen refresh actually do? Are you using TImage to display? Sounds like a slideshow or something... Yes, it's a kind of slide show (see [url]www.folksfun.com)[/url]. The refresh is drawing text on the image which i don't want to be interrupted by the loading of the next image. I don't mind to have a very slow image changing rate if I can make sure that the text can be drawn smoothly. I tried with TThread. But it doesn't seem to work as I want :-( PC HUA -- _/__/__/__/__/__/_ www.folksfun.com Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder (Graphics) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.