User Tutorial:Testing AV Playback Tutorial - Revision history

Mellinger: /* Audio Quality Test */

2025-10-22T16:52:56Z

Audio Quality Test

← Older revision		Revision as of 16:52, 22 October 2025
Line 15:		Line 15:

	===Audio Quality Test===		===Audio Quality Test===
	Once you have inspected the rotating wheel, you may progress to a simple audio playback test. The test consists of a 1kHz permanent sine tone. It should be clearly audible, without any crackling or stuttering. Click ''Start'' to enable the audio test, and ''Suspend'' to disable it again. If you experience crackling or stuttering, open the parameter config dialog, and locate the Application->Audio Playback section. There, edit the AudioBufferDuration parameter and enter ''50ms''. Close the parameter config dialog, click ''SetConfig'' and ''Start'', and listen to the permanent sine tone again. Crackling and/or stuttering should be gone. You may now try and reduce the AudioBufferDuration parameter to find an optimal setting where latency is smaller but artifacts are still absent.		Once you have inspected the rotating wheel, you may progress to a simple audio playback test. The test consists of a 1kHz permanent sine tone. It should be clearly audible, without any crackling or stuttering. Click ''Start'' to enable the audio test, and ''Suspend'' to disable it again. If you experience crackling or stuttering, open the parameter config dialog, and locate the Application->Audio Playback section. There, edit the '''AudioBufferDuration''' parameter and enter ''50ms''. Close the parameter config dialog, click ''SetConfig'' and ''Start'', and listen to the permanent sine tone again. Crackling and/or stuttering should be gone. You may now try and reduce the '''AudioBufferDuration''' parameter to find an optimal setting where latency is smaller but artifacts are still absent.

	Take note of the AudioBufferDuration parameter and add it to your own parameter setup or batch file.		Take note of the '''AudioBufferDuration''' parameter and add it to your own parameter setup or batch file.

	==Vertical Blank Synchronization (Vsync)==		==Vertical Blank Synchronization (Vsync)==

Mellinger: /* Vertical Blank Synchronization (Vsync) */

2025-10-22T16:39:43Z

Vertical Blank Synchronization (Vsync)

← Older revision		Revision as of 16:39, 22 October 2025
Line 29:		Line 29:
	* Choose the "Driver" tab,		* Choose the "Driver" tab,
	* Click "Roll Back Driver" and confirm any prompts.		* Click "Roll Back Driver" and confirm any prompts.

			==See also==
			[[User Tutorial:P300 BCI Tutorial]], [[User Tutorial:Mu Rhythm BCI Tutorial]]

			[[Category:Tutorial]]

Mellinger at 16:38, 22 October 2025

2025-10-22T16:38:02Z

← Older revision		Revision as of 16:38, 22 October 2025
Line 1:		Line 1:
	==~~Purpose~~==		==Introduction==
	This tutorial gives you an overview how to make sure that your computer system is able to fulfill the requirements of auditory and visual stimulus playback using BCI2000.		This tutorial gives you an overview how to make sure that your computer system is able to fulfill the requirements of auditory and visual stimulus playback using BCI2000.

	~~==Introduction==~~
	BCI2000 comes with an AVTest application module that produces video and audio suited to detect playback glitches.		BCI2000 comes with an AVTest application module that produces video and audio suited to detect playback glitches.
	This is intended help you adjust system preferences in order to eliminate or minimize such glitches.		This is intended help you adjust system preferences in order to eliminate or minimize such glitches.

Mellinger: /* Video Quality Test */

2025-10-22T16:34:52Z

Video Quality Test

← Older revision		Revision as of 16:34, 22 October 2025
Line 11:		Line 11:

	===Video Quality Test===		===Video Quality Test===
	Then, after closing the parameter config dialog, click ''SetConfig''. A rotating wheel will appear on the secondary monitor. The wheel is designed to move smoothly into the left direction. Any flicker or tearing will be clearly visible against the background of this movement. Also, in the lower part of the image, text is shown that indicates some data about the visual display. Of special interest is the field "frames lost" which represents the total number of frames for which BCI2000 has missed its rendering deadline. A small number of lost frames is ok, but if the number is rapidly increasing this indicates an issue with ~~vertical blank synchronization~~ (see below).		Then, after closing the parameter config dialog, click ''SetConfig''. A rotating wheel will appear on the secondary monitor. The wheel is designed to move smoothly into the left direction. Any flicker or tearing will be clearly visible against the background of this movement. Also, in the lower part of the image, text is shown that indicates some data about the visual display. Of special interest is the field "frames lost" which represents the total number of frames for which BCI2000 has missed its rendering deadline. A small number of lost frames is ok, but if the number is rapidly increasing this indicates an issue with Vertical Blank Synchronization (see below).

			If Vertical Blank Synchronization is not the cause of tearing and lost frames, it is possible that your machine's computing power is not sufficient to produce an image of the requested size within the duration of a frame. Especially, this may be the case with modern 4k displays and high frame rates. Try reducing frame rate and/or resolution of the second monitor.

	===Audio Quality Test===		===Audio Quality Test===

Mellinger: /* Vertical Blank Synchronization (Vsync) */

2025-10-22T16:23:51Z

Vertical Blank Synchronization (Vsync)

← Older revision		Revision as of 16:23, 22 October 2025
Line 19:		Line 19:

	==Vertical Blank Synchronization (Vsync)==		==Vertical Blank Synchronization (Vsync)==
	To avoid tearing and flicker, BCI2000 uses Vertical Blank Synchronization, i.e. it synchronizes its rendering loop with the graphic card's monitor frame rate. This way, it ensures that frames are fully rendered before being displayed on screen. Many graphic cards come with configuration tools that allow to disable Vertical Blank Synchronization. This is not a desired setting for use with BCI2000. If you experience tearing but have difficulties locating the Vsync setting, you may also try to "roll back" your graphics card driver to a previous version:		To avoid tearing and flicker, BCI2000 uses Vertical Blank Synchronization, i.e. it synchronizes its rendering loop with the graphic card's monitor frame rate. This way, it ensures that frames are fully rendered before being displayed on screen.

			Many graphic cards come with configuration tools that allow to disable Vertical Blank Synchronization. This is not a desired setting for use with BCI2000. If you experience tearing but have difficulties locating the Vsync setting, you may also try to "roll back" your graphics card driver to a previous version:
	* Right-click the start menu,		* Right-click the start menu,
	* Choose "Device Manager",		* Choose "Device Manager",

Mellinger: /* Running AVTest with SignalGenerator */

2025-10-22T16:22:42Z

Running AVTest with SignalGenerator

← Older revision		Revision as of 16:22, 22 October 2025
Line 6:		Line 6:
	This is intended help you adjust system preferences in order to eliminate or minimize such glitches.		This is intended help you adjust system preferences in order to eliminate or minimize such glitches.

	==Running AVTest ~~with SignalGenerator~~==		==Running AVTest==
	To run the AVTest application module with the SignalGenerator source module, simply double-click on the AVTest_SignalGenerator batch file in the BCI2000 batch directory.		To run the AVTest application module with the SignalGenerator source module, simply double-click on the AVTest_SignalGenerator batch file in the BCI2000 batch directory.
	Click ''Config'' to open the parameter config dialog, and navigate to the Application->Window section. There, enter your second monitor's left and top coordinate, and height and width (for more information about how to configure a dual monitor setup for use with BCI2000, see [[User_Tutorial:Preparing_your_BCI2000_system_for_P300_BCI_experiments_for_the_first_time#Preparing_for_Configuration\|this description]].		Click ''Config'' to open the parameter config dialog, and navigate to the Application->Window section. There, enter your second monitor's left and top coordinate, and height and width (for more information about how to configure a dual monitor setup for use with BCI2000, see [[User_Tutorial:Preparing_your_BCI2000_system_for_P300_BCI_experiments_for_the_first_time#Preparing_for_Configuration\|this description]].

			===Video Quality Test===
	Then, after closing the parameter config dialog, click ''SetConfig''. A rotating wheel will appear on the secondary monitor. The wheel is designed to move smoothly into the left direction. Any flicker or tearing will be clearly visible against the background of this movement. Also, in the lower part of the image, text is shown that indicates some data about the visual display. Of special interest is the field "frames lost" which represents the total number of frames for which BCI2000 has missed its rendering deadline. A small number of lost frames is ok, but if the number is rapidly increasing this indicates an issue with vertical blank synchronization (see below).		Then, after closing the parameter config dialog, click ''SetConfig''. A rotating wheel will appear on the secondary monitor. The wheel is designed to move smoothly into the left direction. Any flicker or tearing will be clearly visible against the background of this movement. Also, in the lower part of the image, text is shown that indicates some data about the visual display. Of special interest is the field "frames lost" which represents the total number of frames for which BCI2000 has missed its rendering deadline. A small number of lost frames is ok, but if the number is rapidly increasing this indicates an issue with vertical blank synchronization (see below).

			===Audio Quality Test===
	Once you have inspected the rotating wheel, you may progress to a simple audio playback test. The test consists of a 1kHz permanent sine tone. It should be clearly audible, without any crackling or stuttering. Click ''Start'' to enable the audio test, and ''Suspend'' to disable it again. If you experience crackling or stuttering, open the parameter config dialog, and locate the Application->Audio Playback section. There, edit the AudioBufferDuration parameter and enter ''50ms''. Close the parameter config dialog, click ''SetConfig'' and ''Start'', and listen to the permanent sine tone again. Crackling and/or stuttering should be gone. You may now try and reduce the AudioBufferDuration parameter to find an optimal setting where latency is smaller but artifacts are still absent.		Once you have inspected the rotating wheel, you may progress to a simple audio playback test. The test consists of a 1kHz permanent sine tone. It should be clearly audible, without any crackling or stuttering. Click ''Start'' to enable the audio test, and ''Suspend'' to disable it again. If you experience crackling or stuttering, open the parameter config dialog, and locate the Application->Audio Playback section. There, edit the AudioBufferDuration parameter and enter ''50ms''. Close the parameter config dialog, click ''SetConfig'' and ''Start'', and listen to the permanent sine tone again. Crackling and/or stuttering should be gone. You may now try and reduce the AudioBufferDuration parameter to find an optimal setting where latency is smaller but artifacts are still absent.

			Take note of the AudioBufferDuration parameter and add it to your own parameter setup or batch file.

			==Vertical Blank Synchronization (Vsync)==
			To avoid tearing and flicker, BCI2000 uses Vertical Blank Synchronization, i.e. it synchronizes its rendering loop with the graphic card's monitor frame rate. This way, it ensures that frames are fully rendered before being displayed on screen. Many graphic cards come with configuration tools that allow to disable Vertical Blank Synchronization. This is not a desired setting for use with BCI2000. If you experience tearing but have difficulties locating the Vsync setting, you may also try to "roll back" your graphics card driver to a previous version:
			* Right-click the start menu,
			* Choose "Device Manager",
			* Open the "Display Adapters" section,
			* Double-click your graphics card,
			* Choose the "Driver" tab,
			* Click "Roll Back Driver" and confirm any prompts.

Mellinger: Created page with "==Purpose== This tutorial gives you an overview how to make sure that your computer system is able to fulfill the requirements of auditory and visual stimulus playback using BCI2000. ==Introduction== BCI2000 comes with an AVTest application module that produces video and audio suited to detect playback glitches. This is intended help you adjust system preferences in order to eliminate or minimize such glitches. ==Running AVTest with SignalGenerator== To run the AVTest..."

2025-10-22T16:05:56Z

Created page with "==Purpose== This tutorial gives you an overview how to make sure that your computer system is able to fulfill the requirements of auditory and visual stimulus playback using BCI2000. ==Introduction== BCI2000 comes with an AVTest application module that produces video and audio suited to detect playback glitches. This is intended help you adjust system preferences in order to eliminate or minimize such glitches. ==Running AVTest with SignalGenerator== To run the AVTest..."

New page

==Purpose==
This tutorial gives you an overview how to make sure that your computer system is able to fulfill the requirements of auditory and visual stimulus playback using BCI2000.

==Introduction==
BCI2000 comes with an AVTest application module that produces video and audio suited to detect playback glitches.
This is intended help you adjust system preferences in order to eliminate or minimize such glitches.

==Running AVTest with SignalGenerator==
To run the AVTest application module with the SignalGenerator source module, simply double-click on the AVTest_SignalGenerator batch file in the BCI2000 batch directory.
Click ''Config'' to open the parameter config dialog, and navigate to the Application->Window section. There, enter your second monitor's left and top coordinate, and height and width (for more information about how to configure a dual monitor setup for use with BCI2000, see [[User_Tutorial:Preparing_your_BCI2000_system_for_P300_BCI_experiments_for_the_first_time#Preparing_for_Configuration|this description]].

Then, after closing the parameter config dialog, click ''SetConfig''. A rotating wheel will appear on the secondary monitor. The wheel is designed to move smoothly into the left direction. Any flicker or tearing will be clearly visible against the background of this movement. Also, in the lower part of the image, text is shown that indicates some data about the visual display. Of special interest is the field "frames lost" which represents the total number of frames for which BCI2000 has missed its rendering deadline. A small number of lost frames is ok, but if the number is rapidly increasing this indicates an issue with vertical blank synchronization (see below).

Once you have inspected the rotating wheel, you may progress to a simple audio playback test. The test consists of a 1kHz permanent sine tone. It should be clearly audible, without any crackling or stuttering. Click ''Start'' to enable the audio test, and ''Suspend'' to disable it again. If you experience crackling or stuttering, open the parameter config dialog, and locate the Application->Audio Playback section. There, edit the AudioBufferDuration parameter and enter ''50ms''. Close the parameter config dialog, click ''SetConfig'' and ''Start'', and listen to the permanent sine tone again. Crackling and/or stuttering should be gone. You may now try and reduce the AudioBufferDuration parameter to find an optimal setting where latency is smaller but artifacts are still absent.