beamposition problems

Hihi,

I'm working in PTB3.0.9 on Windows 5.1 (Windows XP Professional) with a ATI Radeo HD 4550 graphics card. I've been having synchronization / beamposition problems. When I run the program, the following message appears:

AFTER RUNNING PROGRAM:

PTB-INFO: This is Psychtoolbox-3 for Microsoft Windows, under Matlab (Version 3.0.9 - Build date: Aug 23 2011).
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Some ATI graphics cards may not support proper syncing to vertical retrace when
PTB-INFO: running in windowed mode (non-fullscreen). If PTB aborts with 'Synchronization failure'
PTB-INFO: you can disable the sync test via call to Screen('Preference', 'SkipSyncTests', 1); .
PTB-INFO: You won't get proper stimulus onset timestamps though, so windowed mode may be of limited use.


OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control

PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
PTB-INFO: that i couldn't detect the duration of the vertical blank interval and won't be able to correct timestamps
PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read 'help BeampositionQueries'
PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
PTB-INFO: enable the beamposition workaround, as explained in 'help ConserveVRAM', section 'kPsychUseBeampositionQueryWorkaround'.


PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
PTB-INFO: VBL startline = 768 , VBL Endline = 768
PTB-INFO: Measured monitor refresh interval from beamposition = 13.327800 ms [75.031138 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327702 ms [75.031690 Hz]. (50 valid samples taken, stddev=0.002826 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...


PTB-ERROR: Screen('Flip'); beamposition timestamping computed an *impossible stimulus onset value* of 813788.273897 secs, which would indicate that
PTB-ERROR: stimulus onset happened *before* it was actually requested! (Earliest theoretically possible 813788.276004 secs).

PTB-ERROR: Some more diagnostic values (only for experts): rawTimestamp = 813788.287225, scanline = 767
PTB-ERROR: Some more diagnostic values (only for experts): line_pre_swaprequest = 93, line_post_swaprequest = 100, time_post_swaprequest = 813788.276125
PTB-ERROR: Some more diagnostic values (only for experts): preflip_vblcount = 0, preflip_vbltimestamp = -1.000000
PTB-ERROR: Some more diagnostic values (only for experts): postflip_vblcount = 0, postflip_vbltimestamp = -1.000000, vbltimestampquery_retrycount = 0

PTB-ERROR: This error can be due to either of the following causes (No way to discriminate):
PTB-ERROR: Either something is broken in your systems beamposition timestamping. I've disabled high precision
PTB-ERROR: timestamping for now. Returned timestamps will be less robust and accurate, but if that was the culprit it should be fixed.

PTB-ERROR: An equally likely cause would be that Synchronization of stimulus onset (buffer swap) to the
PTB-ERROR: vertical blank interval VBL is not working properly.
PTB-ERROR: Please run the script PerceptualVBLSyncTest to check this. With non-working sync to VBL, all stimulus timing
PTB-ERROR: becomes quite futile. Also read 'help SyncTrouble' !


As per suggestions in this topic http://tech.groups.yahoo.com/group/psychtoolbox/message/10703, I ran PerceptualVBLSyncTest:


AFTER RUNNING PerceptualVBLSyncTest...

OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control

PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
PTB-INFO: that i couldn't detect the duration of the vertical blank interval and won't be able to correct timestamps
PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read 'help BeampositionQueries'
PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
PTB-INFO: enable the beamposition workaround, as explained in 'help ConserveVRAM', section 'kPsychUseBeampositionQueryWorkaround'.


PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
PTB-INFO: VBL startline = 768 , VBL Endline = 768
PTB-INFO: Measured monitor refresh interval from beamposition = 13.327959 ms [75.030240 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327704 ms [75.031677 Hz]. (50 valid samples taken, stddev=0.000944 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...


From what I understand, these are considered as 'small deviations' and shouldn't be an issue? I then ran my program again with Screen('Preference','SkipSyncTests',1) and Screen('Preference','Verbosity',10)...

AFTER RUNNING PROGRAM WITH Screen('Preference','SkipSyncTests',1) and Screen('Preference','Verbosity',10)

PTB-DEBUG: PsychOSOpenOnscreenWindow: Entering Win32 specific window setup...
PTB-DEBUG: Checking for DWM Aero desktop compositor support... ... DWM Aero desktop compositing window manager unsupported. Running on a Pre-Vista system.
PTB-DEBUG: PsychOSOpenOnscreenWindow: Window parameters computed, display switch to fullscreen done (if needed). Registering window class...
PTB-DEBUG: Window enumeration done. Our hostwindow is HWND=013E034A, Name: 'MATLAB 7.9.0 (R2009b)'

PTB-DEBUG: PsychOSOpenOnscreenWindow: Window class registered - Creating GDI window...
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: Created onscreen window has position -4 x -30 and a size of 108 x 134.
PTB-DEBUG: PsychOSOpenOnscreenWindow: Window created - Pixelformat selection...
PTB-DEBUG: PsychOSOpenOnscreenWindow: ChoosePixelFormat(), SetPixelFormat() done... Creating OpenGL context...
PTB-DEBUG: PsychOSOpenOnscreenWindow: Context created - Activating and binding context...
PTB-DEBUG: PsychOSOpenOnscreenWindow: Online - glewInit()...
PTB-INFO: Using GLEW version 1.5.3 for automatic detection of OpenGL extensions...
PTB-DEBUG: PsychOSOpenOnscreenWindow: Mastercontext created, activated and bound - Enabling multisampling if needed...
PTB-DEBUG: Window and master OpenGL context creation finished.
PTB-DEBUG: Before slaveWindow context sharing: glGetString reports 1E667038 pointer...
PTB-DEBUG: After slaveWindow context sharing: glGetString reports 1E667038 pointer...
PTB-DEBUG: Final low-level window setup: ShowWindow(), SetCapture(), diagnostics...
PTB-DEBUG: OpenGL initialization of all master-/slave-/shared-/userspace contexts finished...
PTB-DEBUG: Final low-level window setup: ShowWindow(), SetCapture(), diagnostics...
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): WM_SIZE!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: No call to SetForegroundWindow() and SetFocus() on window, because trigger-conditions not satisfied.
PTB-INFO: Some ATI graphics cards may not support proper syncing to vertical retrace when
PTB-INFO: running in windowed mode (non-fullscreen). If PTB aborts with 'Synchronization failure'
PTB-INFO: you can disable the sync test via call to Screen('Preference', 'SkipSyncTests', 1); .
PTB-INFO: You won't get proper stimulus onset timestamps though, so windowed mode may be of limited use.
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): Called!
PTB-DEBUG: WndProc(): WM_PAINT!
PTB-DEBUG: Final low-level window setup finished. Continuing with OS-independent setup.


OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control

PTB-DEBUG: Interrogating Low-level renderer capabilities for onscreen window with handle 10:
Indicator variables: FBO's 1, ATI_texture_float 1, ARB_texture_float 1, Vendor ATI Technologies Inc., Renderer ATI Radeon HD 4550.
Indicator variables: maxcolorattachments = 8, maxrectangletexturesize = 8192, maxnativealuinstructions = 2147483647.
Basic framebuffer objects with rectangle texture rendertargets supported --> RGBA8 rendertargets with blending.
Framebuffer objects support fast blitting between each other.
Framebuffer objects support anti-aliasing via multisampling.
Hardware supports floating point textures of 16bpc and 32bpc float format.
Assuming ATI R300 core or later: Hardware supports basic floating point framebuffers of 16bpc and 32bpc float format.
Assuming ATI R500 or later (maxtexsize=8192): Hardware supports floating point blending on 16bpc float format.
Hardware supports full 32 bit floating point precision shading.
Assuming ATI R600 or later (Matching namestring): Hardware supports floating point blending and filtering on 16bpc and 32bpc float formats.
No compiled in support for OpenML OML_sync_control extension. Using standard implementation.
PTB-DEBUG: Interrogation done.

PTB-INFO: Threshold Settings for successfull video refresh calibration are: maxStdDev = 1.000000 msecs, maxDeviation = 10.000000 %, minSamples = 50, maxDuration = 5.000000 secs.

WARNING: Querying rasterbeam-position doesn't work on your setup! (Returns a constant value 96)

WARNING: Couldn't determine end-line of vertical blanking interval for your display! Trouble with beamposition queries?!?

WARNING: Detected end-line is -1, which is either lower or more than 25% higher than vbl startline 768 --> Out of sane range!


PTB-DEBUG: Output of all acquired samples of calibration run follows:
PTB-DEBUG: Sample 0: 0.000000
PTB-DEBUG: Sample 1: 0.013323
PTB-DEBUG: Sample 2: 0.013327
PTB-DEBUG: Sample 3: 0.013342
PTB-DEBUG: Sample 4: 0.013314
PTB-DEBUG: Sample 5: 0.013328
PTB-DEBUG: Sample 6: 0.013328
PTB-DEBUG: Sample 7: 0.013329
PTB-DEBUG: Sample 8: 0.013327
PTB-DEBUG: Sample 9: 0.013327
PTB-DEBUG: Sample 10: 0.013329
PTB-DEBUG: Sample 11: 0.013336
PTB-DEBUG: Sample 12: 0.013319
PTB-DEBUG: Sample 13: 0.013341
PTB-DEBUG: Sample 14: 0.013315
PTB-DEBUG: Sample 15: 0.013328
PTB-DEBUG: Sample 16: 0.013328
PTB-DEBUG: Sample 17: 0.013327
PTB-DEBUG: Sample 18: 0.013337
PTB-DEBUG: Sample 19: 0.013318
PTB-DEBUG: Sample 20: 0.013327
PTB-DEBUG: Sample 21: 0.013329
PTB-DEBUG: Sample 22: 0.013328
PTB-DEBUG: Sample 23: 0.013329
PTB-DEBUG: Sample 24: 0.013326
PTB-DEBUG: Sample 25: 0.013328
PTB-DEBUG: Sample 26: 0.013328
PTB-DEBUG: Sample 27: 0.013327
PTB-DEBUG: Sample 28: 0.013328
PTB-DEBUG: Sample 29: 0.013328
PTB-DEBUG: Sample 30: 0.013327
PTB-DEBUG: Sample 31: 0.013329
PTB-DEBUG: Sample 32: 0.013327
PTB-DEBUG: Sample 33: 0.013328
PTB-DEBUG: Sample 34: 0.013327
PTB-DEBUG: Sample 35: 0.013329
PTB-DEBUG: Sample 36: 0.013327
PTB-DEBUG: Sample 37: 0.013328
PTB-DEBUG: Sample 38: 0.013328
PTB-DEBUG: Sample 39: 0.013328
PTB-DEBUG: Sample 40: 0.013329
PTB-DEBUG: Sample 41: 0.013327
PTB-DEBUG: Sample 42: 0.013328
PTB-DEBUG: Sample 43: 0.013327
PTB-DEBUG: Sample 44: 0.013329
PTB-DEBUG: Sample 45: 0.013328
PTB-DEBUG: Sample 46: 0.013327
PTB-DEBUG: Sample 47: 0.013329
PTB-DEBUG: Sample 48: 0.013327
PTB-DEBUG: Sample 49: 0.013328
PTB-DEBUG: Sample 50: 0.013329
PTB-DEBUG: End of calibration data for this run...



PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
PTB-INFO: VBL startline = 768 , VBL Endline = -1
PTB-INFO: Beamposition queries unsupported or defective on this system. Using basic timestamping as fallback: Timestamps returned by Screen('Flip') will be less robust and accurate.
PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327716 ms [75.031612 Hz]. (50 valid samples taken, stddev=0.004758 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...


----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----

One or more internal checks (see Warnings above) indicate that
queries of rasterbeam position are not properly working for your setup.

Psychtoolbox will work around this by using a different timing algorithm,
but it will cause Screen('Flip') to report less accurate/robust timestamps
for stimulus timing.
Read 'help BeampositionQueries' for more info and troubleshooting tips.


PTB-DEBUG: Allocated unicode string: 69.000000 110.000000 100.000000 32.000000 111.000000 102.000000 32.000000 66.000000 108.000000 111.000000 99.000000 107.000000 32.000000 48.000000 32.000000 111.000000 102.000000 32.000000 49.000000 32.000000 98.000000 108.000000 111.000000 99.000000 107.000000 115.000000 46.000000
PTB-DEBUG: In DrawTextGDI: Rebuilding font due to window switch or rebuild request: needit = 1 , oldwin = 00000000 vs. newwin = 1A1DD060
PTB-DEBUG: Allocated unicode string: 69.000000 110.000000 100.000000 32.000000 111.000000 102.000000 32.000000 66.000000 108.000000 111.000000 99.000000 107.000000 32.000000 48.000000 32.000000 111.000000 102.000000 32.000000 49.000000 32.000000 98.000000 108.000000 111.000000 99.000000 107.000000 115.000000 46.000000
PTB-DEBUG: Allocated unicode string: 40.000000 112.000000 114.000000 101.000000 115.000000 115.000000 32.000000 69.000000 78.000000 84.000000 69.000000 82.000000 32.000000 116.000000 111.000000 32.000000 99.000000 111.000000 110.000000 116.000000 105.000000 110.000000 117.000000 101.000000 41.000000
PTB-DEBUG: Allocated unicode string: 40.000000 112.000000 114.000000 101.000000 115.000000 115.000000 32.000000 69.000000 78.000000 84.000000 69.000000 82.000000 32.000000 116.000000 111.000000 32.000000 99.000000 111.000000 110.000000 116.000000 105.000000 110.000000 117.000000 101.000000 41.000000



Please let me know if you have any suggestions.

Thank you for your help!
--- In psychtoolbox@yahoogroups.com, "thenekonaut" <nekonaut@...> wrote:
>
> Hihi,
>
> I'm working in PTB3.0.9 on Windows 5.1 (Windows XP Professional) with a ATI Radeo HD 4550 graphics card. I've been having synchronization / beamposition problems. When I run the program, the following message appears:
>
> AFTER RUNNING PROGRAM:

...

> PTB-INFO: Some ATI graphics cards may not support proper syncing to vertical retrace when
> PTB-INFO: running in windowed mode (non-fullscreen). If PTB aborts with

...

-> Your script uses a non-fullscreen window, so timing trouble is expected. It actually can also apply to other graphics cards. Windowed presentation on any operating system can cause wildly inaccurate or wrong timestamps and wrong timing for stimulus onset. It is a design limitation of all existing operating systems and graphics drivers.

-> Disable the synctests and 'vbltimestampingmode' to get rid of the warnings, but be aware that visual timing (the actual one and the reported one) can be off by dozens of milliseconds.

Other than that, looks good as far as i can see.
-mario


'Synchronization failure'
> PTB-INFO: you can disable the sync test via call to Screen('Preference', 'SkipSyncTests', 1); .
> PTB-INFO: You won't get proper stimulus onset timestamps though, so windowed mode may be of limited use.
>
>
> OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control
>
> PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
> PTB-INFO: that i couldn't detect the duration of the vertical blank interval and won't be able to correct timestamps
> PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read 'help BeampositionQueries'
> PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
> PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
> PTB-INFO: enable the beamposition workaround, as explained in 'help ConserveVRAM', section 'kPsychUseBeampositionQueryWorkaround'.
>
>
> PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
> PTB-INFO: VBL startline = 768 , VBL Endline = 768
> PTB-INFO: Measured monitor refresh interval from beamposition = 13.327800 ms [75.031138 Hz].
> PTB-INFO: Will use beamposition query for accurate Flip time stamping.
> PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327702 ms [75.031690 Hz]. (50 valid samples taken, stddev=0.002826 ms.)
> PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
> PTB-INFO: Small deviations between reported values are normal and no reason to worry.
> PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...
>
>
> PTB-ERROR: Screen('Flip'); beamposition timestamping computed an *impossible stimulus onset value* of 813788.273897 secs, which would indicate that
> PTB-ERROR: stimulus onset happened *before* it was actually requested! (Earliest theoretically possible 813788.276004 secs).
>
> PTB-ERROR: Some more diagnostic values (only for experts): rawTimestamp = 813788.287225, scanline = 767
> PTB-ERROR: Some more diagnostic values (only for experts): line_pre_swaprequest = 93, line_post_swaprequest = 100, time_post_swaprequest = 813788.276125
> PTB-ERROR: Some more diagnostic values (only for experts): preflip_vblcount = 0, preflip_vbltimestamp = -1.000000
> PTB-ERROR: Some more diagnostic values (only for experts): postflip_vblcount = 0, postflip_vbltimestamp = -1.000000, vbltimestampquery_retrycount = 0
>
> PTB-ERROR: This error can be due to either of the following causes (No way to discriminate):
> PTB-ERROR: Either something is broken in your systems beamposition timestamping. I've disabled high precision
> PTB-ERROR: timestamping for now. Returned timestamps will be less robust and accurate, but if that was the culprit it should be fixed.
>
> PTB-ERROR: An equally likely cause would be that Synchronization of stimulus onset (buffer swap) to the
> PTB-ERROR: vertical blank interval VBL is not working properly.
> PTB-ERROR: Please run the script PerceptualVBLSyncTest to check this. With non-working sync to VBL, all stimulus timing
> PTB-ERROR: becomes quite futile. Also read 'help SyncTrouble' !
>
>
> As per suggestions in this topic http://tech.groups.yahoo.com/group/psychtoolbox/message/10703, I ran PerceptualVBLSyncTest:
>
>
> AFTER RUNNING PerceptualVBLSyncTest...
>
> OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control
>
> PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
> PTB-INFO: that i couldn't detect the duration of the vertical blank interval and won't be able to correct timestamps
> PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read 'help BeampositionQueries'
> PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
> PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
> PTB-INFO: enable the beamposition workaround, as explained in 'help ConserveVRAM', section 'kPsychUseBeampositionQueryWorkaround'.
>
>
> PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
> PTB-INFO: VBL startline = 768 , VBL Endline = 768
> PTB-INFO: Measured monitor refresh interval from beamposition = 13.327959 ms [75.030240 Hz].
> PTB-INFO: Will use beamposition query for accurate Flip time stamping.
> PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327704 ms [75.031677 Hz]. (50 valid samples taken, stddev=0.000944 ms.)
> PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
> PTB-INFO: Small deviations between reported values are normal and no reason to worry.
> PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...
>
>
> From what I understand, these are considered as 'small deviations' and shouldn't be an issue? I then ran my program again with Screen('Preference','SkipSyncTests',1) and Screen('Preference','Verbosity',10)...
>
> AFTER RUNNING PROGRAM WITH Screen('Preference','SkipSyncTests',1) and Screen('Preference','Verbosity',10)
>
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Entering Win32 specific window setup...
> PTB-DEBUG: Checking for DWM Aero desktop compositor support... ... DWM Aero desktop compositing window manager unsupported. Running on a Pre-Vista system.
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Window parameters computed, display switch to fullscreen done (if needed). Registering window class...
> PTB-DEBUG: Window enumeration done. Our hostwindow is HWND=013E034A, Name: 'MATLAB 7.9.0 (R2009b)'
>
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Window class registered - Creating GDI window...
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: Created onscreen window has position -4 x -30 and a size of 108 x 134.
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Window created - Pixelformat selection...
> PTB-DEBUG: PsychOSOpenOnscreenWindow: ChoosePixelFormat(), SetPixelFormat() done... Creating OpenGL context...
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Context created - Activating and binding context...
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Online - glewInit()...
> PTB-INFO: Using GLEW version 1.5.3 for automatic detection of OpenGL extensions...
> PTB-DEBUG: PsychOSOpenOnscreenWindow: Mastercontext created, activated and bound - Enabling multisampling if needed...
> PTB-DEBUG: Window and master OpenGL context creation finished.
> PTB-DEBUG: Before slaveWindow context sharing: glGetString reports 1E667038 pointer...
> PTB-DEBUG: After slaveWindow context sharing: glGetString reports 1E667038 pointer...
> PTB-DEBUG: Final low-level window setup: ShowWindow(), SetCapture(), diagnostics...
> PTB-DEBUG: OpenGL initialization of all master-/slave-/shared-/userspace contexts finished...
> PTB-DEBUG: Final low-level window setup: ShowWindow(), SetCapture(), diagnostics...
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): WM_SIZE!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: No call to SetForegroundWindow() and SetFocus() on window, because trigger-conditions not satisfied.
> PTB-INFO: Some ATI graphics cards may not support proper syncing to vertical retrace when
> PTB-INFO: running in windowed mode (non-fullscreen). If PTB aborts with 'Synchronization failure'
> PTB-INFO: you can disable the sync test via call to Screen('Preference', 'SkipSyncTests', 1); .
> PTB-INFO: You won't get proper stimulus onset timestamps though, so windowed mode may be of limited use.
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): Called!
> PTB-DEBUG: WndProc(): WM_PAINT!
> PTB-DEBUG: Final low-level window setup finished. Continuing with OS-independent setup.
>
>
> OpenGL-Extensions are: GL_AMDX_name_gen_delete GL_AMDX_vertex_shader_tessellator GL_AMD_draw_buffers_blend GL_AMD_performance_monitor GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_AMD_texture_cube_map_array GL_AMD_texture_texture4 GL_AMD_vertex_shader_tessellator GL_ARB_color_buffer_float GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced GL_ARB_fragment_coord_conventions GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_provoking_vertex GL_ARB_seamless_cube_map GL_ARB_shader_objects GL_ARB_shader_texture_lod GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_shadow_ambient GL_ARB_sync GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object GL_ARB_texture_compression GL_ARB_texture_compression_rgtc GL_ARB_texture_cube_map GL_ARB_texture_cube_map_array GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample GL_ARB_texture_non_power_of_two GL_ARB_texture_query_lod GL_ARB_texture_rectangle GL_ARB_texture_rg GL_ARB_texture_snorm GL_ARB_transpose_matrix GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_envmap_bumpmap GL_ATI_fragment_shader GL_ATI_meminfo GL_ATI_separate_stencil GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_ATI_texture_mirror_once GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array GL_EXT_copy_buffer GL_EXT_copy_texture GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_histogram GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_point_parameters GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texgen_reflection GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object GL_EXT_texture_buffer_object_rgb32 GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_EXT_texture_snorm GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_transform_feedback GL_EXT_vertex_array GL_EXT_vertex_array_bgra GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_explicit_multisample GL_NV_primitive_restart GL_NV_texgen_reflection GL_SGIS_generate_mipmap GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint WGL_EXT_swap_control
>
> PTB-DEBUG: Interrogating Low-level renderer capabilities for onscreen window with handle 10:
> Indicator variables: FBO's 1, ATI_texture_float 1, ARB_texture_float 1, Vendor ATI Technologies Inc., Renderer ATI Radeon HD 4550.
> Indicator variables: maxcolorattachments = 8, maxrectangletexturesize = 8192, maxnativealuinstructions = 2147483647.
> Basic framebuffer objects with rectangle texture rendertargets supported --> RGBA8 rendertargets with blending.
> Framebuffer objects support fast blitting between each other.
> Framebuffer objects support anti-aliasing via multisampling.
> Hardware supports floating point textures of 16bpc and 32bpc float format.
> Assuming ATI R300 core or later: Hardware supports basic floating point framebuffers of 16bpc and 32bpc float format.
> Assuming ATI R500 or later (maxtexsize=8192): Hardware supports floating point blending on 16bpc float format.
> Hardware supports full 32 bit floating point precision shading.
> Assuming ATI R600 or later (Matching namestring): Hardware supports floating point blending and filtering on 16bpc and 32bpc float formats.
> No compiled in support for OpenML OML_sync_control extension. Using standard implementation.
> PTB-DEBUG: Interrogation done.
>
> PTB-INFO: Threshold Settings for successfull video refresh calibration are: maxStdDev = 1.000000 msecs, maxDeviation = 10.000000 %, minSamples = 50, maxDuration = 5.000000 secs.
>
> WARNING: Querying rasterbeam-position doesn't work on your setup! (Returns a constant value 96)
>
> WARNING: Couldn't determine end-line of vertical blanking interval for your display! Trouble with beamposition queries?!?
>
> WARNING: Detected end-line is -1, which is either lower or more than 25% higher than vbl startline 768 --> Out of sane range!
>
>
> PTB-DEBUG: Output of all acquired samples of calibration run follows:
> PTB-DEBUG: Sample 0: 0.000000
> PTB-DEBUG: Sample 1: 0.013323
> PTB-DEBUG: Sample 2: 0.013327
> PTB-DEBUG: Sample 3: 0.013342
> PTB-DEBUG: Sample 4: 0.013314
> PTB-DEBUG: Sample 5: 0.013328
> PTB-DEBUG: Sample 6: 0.013328
> PTB-DEBUG: Sample 7: 0.013329
> PTB-DEBUG: Sample 8: 0.013327
> PTB-DEBUG: Sample 9: 0.013327
> PTB-DEBUG: Sample 10: 0.013329
> PTB-DEBUG: Sample 11: 0.013336
> PTB-DEBUG: Sample 12: 0.013319
> PTB-DEBUG: Sample 13: 0.013341
> PTB-DEBUG: Sample 14: 0.013315
> PTB-DEBUG: Sample 15: 0.013328
> PTB-DEBUG: Sample 16: 0.013328
> PTB-DEBUG: Sample 17: 0.013327
> PTB-DEBUG: Sample 18: 0.013337
> PTB-DEBUG: Sample 19: 0.013318
> PTB-DEBUG: Sample 20: 0.013327
> PTB-DEBUG: Sample 21: 0.013329
> PTB-DEBUG: Sample 22: 0.013328
> PTB-DEBUG: Sample 23: 0.013329
> PTB-DEBUG: Sample 24: 0.013326
> PTB-DEBUG: Sample 25: 0.013328
> PTB-DEBUG: Sample 26: 0.013328
> PTB-DEBUG: Sample 27: 0.013327
> PTB-DEBUG: Sample 28: 0.013328
> PTB-DEBUG: Sample 29: 0.013328
> PTB-DEBUG: Sample 30: 0.013327
> PTB-DEBUG: Sample 31: 0.013329
> PTB-DEBUG: Sample 32: 0.013327
> PTB-DEBUG: Sample 33: 0.013328
> PTB-DEBUG: Sample 34: 0.013327
> PTB-DEBUG: Sample 35: 0.013329
> PTB-DEBUG: Sample 36: 0.013327
> PTB-DEBUG: Sample 37: 0.013328
> PTB-DEBUG: Sample 38: 0.013328
> PTB-DEBUG: Sample 39: 0.013328
> PTB-DEBUG: Sample 40: 0.013329
> PTB-DEBUG: Sample 41: 0.013327
> PTB-DEBUG: Sample 42: 0.013328
> PTB-DEBUG: Sample 43: 0.013327
> PTB-DEBUG: Sample 44: 0.013329
> PTB-DEBUG: Sample 45: 0.013328
> PTB-DEBUG: Sample 46: 0.013327
> PTB-DEBUG: Sample 47: 0.013329
> PTB-DEBUG: Sample 48: 0.013327
> PTB-DEBUG: Sample 49: 0.013328
> PTB-DEBUG: Sample 50: 0.013329
> PTB-DEBUG: End of calibration data for this run...
>
>
>
> PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 4550 :: 3.2.9704 Compatibility Profile Context
> PTB-INFO: VBL startline = 768 , VBL Endline = -1
> PTB-INFO: Beamposition queries unsupported or defective on this system. Using basic timestamping as fallback: Timestamps returned by Screen('Flip') will be less robust and accurate.
> PTB-INFO: Measured monitor refresh interval from VBLsync = 13.327716 ms [75.031612 Hz]. (50 valid samples taken, stddev=0.004758 ms.)
> PTB-INFO: Reported monitor refresh interval from operating system = 13.333333 ms [75.000000 Hz].
> PTB-INFO: Small deviations between reported values are normal and no reason to worry.
> PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for efficient high-performance texture mapping...
>
>
> ----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----
>
> One or more internal checks (see Warnings above) indicate that
> queries of rasterbeam position are not properly working for your setup.
>
> Psychtoolbox will work around this by using a different timing algorithm,
> but it will cause Screen('Flip') to report less accurate/robust timestamps
> for stimulus timing.
> Read 'help BeampositionQueries' for more info and troubleshooting tips.
>
>
> PTB-DEBUG: Allocated unicode string: 69.000000 110.000000 100.000000 32.000000 111.000000 102.000000 32.000000 66.000000 108.000000 111.000000 99.000000 107.000000 32.000000 48.000000 32.000000 111.000000 102.000000 32.000000 49.000000 32.000000 98.000000 108.000000 111.000000 99.000000 107.000000 115.000000 46.000000
> PTB-DEBUG: In DrawTextGDI: Rebuilding font due to window switch or rebuild request: needit = 1 , oldwin = 00000000 vs. newwin = 1A1DD060
> PTB-DEBUG: Allocated unicode string: 69.000000 110.000000 100.000000 32.000000 111.000000 102.000000 32.000000 66.000000 108.000000 111.000000 99.000000 107.000000 32.000000 48.000000 32.000000 111.000000 102.000000 32.000000 49.000000 32.000000 98.000000 108.000000 111.000000 99.000000 107.000000 115.000000 46.000000
> PTB-DEBUG: Allocated unicode string: 40.000000 112.000000 114.000000 101.000000 115.000000 115.000000 32.000000 69.000000 78.000000 84.000000 69.000000 82.000000 32.000000 116.000000 111.000000 32.000000 99.000000 111.000000 110.000000 116.000000 105.000000 110.000000 117.000000 101.000000 41.000000
> PTB-DEBUG: Allocated unicode string: 40.000000 112.000000 114.000000 101.000000 115.000000 115.000000 32.000000 69.000000 78.000000 84.000000 69.000000 82.000000 32.000000 116.000000 111.000000 32.000000 99.000000 111.000000 110.000000 116.000000 105.000000 110.000000 117.000000 101.000000 41.000000
>
>
>
> Please let me know if you have any suggestions.
>
> Thank you for your help!
>