User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Open any youtube video and leave it playing on one monitor
Open another youtube video and play it on the main monitor
Force interactions with the the youtube video controls.
This last step is unreliable, but I've been able to reproduce it by hovering over the video controls and moving the mouse over them, maybe alt-tabbing couple of times.
Don't really know exactly how to reproduce it reliably.

Actual results:

I see some flashes (single/couple of frames) of the video playing in another monitor over the video playing on the focused monitor

Expected results:

No frames from the non-focused video should appear on the player being focused

I've seen also this bug without taking any action, just having both videos on fullscreen.

I've found another more reliable way to repro this:

1. Open 2 videos, putting one in separate monitors (so separate windows as well)
2. Put both videos in full screen mode
3. Move the mouse from screen to screen

With these steps I've been able to reproduce the bug more easily than with the one I presented on the bug description.

Could you navigate to about:support and use one of the buttons provided to copy the information from that page and paste it onto this bug?

This is what I get from my current session:

Application Basics
------------------

Name: Firefox
Version: 76.0.1
Build ID: 20200507114007
Update Channel: release
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0
OS: Windows_NT 10.0
Launcher Process: Enabled
Multiprocess Windows: 2/2 Enabled by default
Remote Processes: 10
Enterprise Policies: Inactive
Google Location Service Key: Found
Google Safebrowsing Key: Found
Mozilla Location Service Key: Found
Safe Mode: false

Crash Reports for the Last 3 Days
---------------------------------

Firefox Features
----------------

Name: DoH Roll-Out
Version: 1.3.0
ID: doh-rollout@mozilla.org

Name: Firefox Screenshots
Version: 39.0.0
ID: screenshots@mozilla.org

Name: Form Autofill
Version: 1.0
ID: formautofill@mozilla.org

Name: Web Compat
Version: 10.1.2
ID: webcompat@mozilla.org

Name: WebCompat Reporter
Version: 1.1.0
ID: webcompat-reporter@mozilla.org

Remote Processes
----------------

Type: Web Content
Count: 8 / 8

Type: Extension
Count: 1

Type: GPU
Count: 1

Extensions
----------

Name: AdBlock — best ad blocker
Version: 4.12.0
Enabled: true
ID: jid1-NIfFY2CA8fy1tg@jetpack

Name: Amazon.com
Version: 1.1
Enabled: true
ID: amazondotcom@search.mozilla.org

Name: Bing
Version: 1.1
Enabled: true
ID: bing@search.mozilla.org

Name: Diccionario RAE
Version: 1.0
Enabled: true
ID: drae@search.mozilla.org

Name: DuckDuckGo
Version: 1.0
Enabled: true
ID: ddg@search.mozilla.org

Name: eBay
Version: 1.0
Enabled: true
ID: ebay@search.mozilla.org

Name: Google
Version: 1.0
Enabled: true
ID: google@search.mozilla.org

Name: Twitter
Version: 1.0
Enabled: true
ID: twitter@search.mozilla.org

Name: Wikipedia (en)
Version: 1.0
Enabled: true
ID: wikipedia@search.mozilla.org

Security Software
-----------------

Type: Antivirus de Microsoft Defender

Type:

Type: Firewall de Windows

Graphics
--------

Features
Compositing: WebRender
Asynchronous Pan/Zoom: wheel input enabled; scrollbar drag enabled; keyboard enabled; autoscroll enabled
WebGL 1 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000a83b) EGL_VERSION: 1.4 (ANGLE 2.1.0.3885ee272685) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable EGL_ANGLE_image_d3d11_texture EGL_ANGLE_create_context_backwards_compatible EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_KHR_debug EGL_ANGLE_explicit_context EGL_ANGLE_feature_control
WebGL 1 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 1060 6GB Direct3D11 vs_5_0 ps_5_0)
WebGL 1 Driver Version: OpenGL ES 2.0.0 (ANGLE 2.1.0.3885ee272685)
WebGL 1 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_multiview_multisample GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_lose_context GL_CHROMIUM_sync_query GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_bptc GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_parallel_shader_compile GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_depth24 GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_3D GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object OES_compressed_EAC_R11_signed_texture OES_compressed_EAC_R11_unsigned_texture OES_compressed_EAC_RG11_signed_texture OES_compressed_EAC_RG11_unsigned_texture OES_compressed_ETC2_RGB8_texture OES_compressed_ETC2_RGBA8_texture OES_compressed_ETC2_punchthroughA_RGBA8_texture OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture OES_compressed_ETC2_sRGB8_alpha8_texture OES_compressed_ETC2_sRGB8_texture
WebGL 1 Extensions: ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_float_blend EXT_frag_depth EXT_shader_texture_lod EXT_sRGB EXT_texture_compression_bptc EXT_texture_filter_anisotropic MOZ_debug OES_element_index_uint OES_standard_derivatives OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_vertex_array_object WEBGL_color_buffer_float WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_depth_texture WEBGL_draw_buffers WEBGL_lose_context
WebGL 2 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000a83b) EGL_VERSION: 1.4 (ANGLE 2.1.0.3885ee272685) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable EGL_ANGLE_image_d3d11_texture EGL_ANGLE_create_context_backwards_compatible EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_KHR_debug EGL_ANGLE_explicit_context EGL_ANGLE_feature_control
WebGL 2 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 1060 6GB Direct3D11 vs_5_0 ps_5_0)
WebGL 2 Driver Version: OpenGL ES 3.0.0 (ANGLE 2.1.0.3885ee272685)
WebGL 2 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_copy_texture_3d GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_multiview_multisample GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_multisample GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_lose_context GL_CHROMIUM_sync_query GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_bptc GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_norm16 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_parallel_shader_compile GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_EGL_image_external_essl3 GL_OES_depth24 GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_3D GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object GL_OVR_multiview GL_OVR_multiview2 OES_compressed_EAC_R11_signed_texture OES_compressed_EAC_R11_unsigned_texture OES_compressed_EAC_RG11_signed_texture OES_compressed_EAC_RG11_unsigned_texture OES_compressed_ETC2_RGB8_texture OES_compressed_ETC2_RGBA8_texture OES_compressed_ETC2_punchthroughA_RGBA8_texture OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture OES_compressed_ETC2_sRGB8_alpha8_texture OES_compressed_ETC2_sRGB8_texture
WebGL 2 Extensions: EXT_color_buffer_float EXT_float_blend EXT_texture_compression_bptc EXT_texture_filter_anisotropic MOZ_debug OES_texture_float_linear OVR_multiview2 WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_lose_context
Direct2D: true
Uses Tiling (Content): true
Off Main Thread Painting Enabled: true
Off Main Thread Painting Worker Count: 4
Target Frame Rate: 144
DirectWrite: true (10.0.19041.264)
GPU #1
Active: Yes
Description: NVIDIA GeForce GTX 1060 6GB
Vendor ID: 0x10de
Device ID: 0x1c03
Driver Version: 26.21.14.4120
Driver Date: 11-6-2019
Drivers: C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumdx.dll C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_c54903cb687d7726\nvldumd.dll
Subsys ID: 00000000
RAM: 6144
GPU #2
Active: No
RAM: 0
Diagnostics
AzureCanvasBackend: direct2d 1.1
AzureCanvasBackend (UI Process): skia
AzureContentBackend: skia
AzureContentBackend (UI Process): skia
AzureFallbackCanvasBackend (UI Process): none
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Display0: 1920x1080@144Hz
Display1: 1920x1080@60Hz
DisplayCount: 2
GPUProcessPid: 4336
ClearType Parameters: \\.\DISPLAY1 [ Gamma: 1,8 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50 ] \\.\DISPLAY2 [ Gamma: 1,8 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50 ]
Decision Log
WEBRENDER:
opt-in by default: WebRender is an opt-in feature
available by user: Qualified in release
WEBRENDER_PARTIAL:
available by user: Enabled
ADVANCED_LAYERS:
blocked by env: Blocked from fallback candidate by WebRender usage
WEBGPU:
disabled by default: Disabled by default
blocked by runtime: WebGPU can only be enabled in nightly
Crash Guard Disabled Features
WMF VPX Video Decoder: Reset on Next Restart

Failure Log
(#0) Error: WMF VPX video decoding is disabled due to a previous crash.
(#1): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#2) Error: WMF VPX video decoding is disabled due to a previous crash.
(#3): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#4) Error: WMF VPX video decoding is disabled due to a previous crash.
(#5): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#6) Error: WMF VPX video decoding is disabled due to a previous crash.
(#7): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#8) Error: WMF VPX video decoding is disabled due to a previous crash.
(#9): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#10) Error: WMF VPX video decoding is disabled due to a previous crash.
(#11): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#12) Error: WMF VPX video decoding is disabled due to a previous crash.
(#13): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#14) Error: WMF VPX video decoding is disabled due to a previous crash.
(#15): CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.

Media
-----

Audio Backend: wasapi
Max Channels: 8
Preferred Sample Rate: 48000
Output Devices
Name: Group
Altavoces (Logitech G935/G933s Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&8b2e543&0&0000
DigitalOutput (NVIDIA High Definition Audio):
S24C350 (NVIDIA High Definition Audio):
Altavoces (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
26W_LCD_TV (NVIDIA High Definition Audio):
Altavoces (2- Logitech G935/G933s Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&2a4c05d2&0&0000
XG2405 (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
Altavoces (G935 Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&2e26468d&0&0000
S24C350 (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
XG2405 (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
Realtek Digital Output (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
S24C350 (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
Input Devices
Name: Group
Conector AUX interno (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
Micrófono (G935 Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&2e26468d&0&0000
Micrófono (2- Logitech G935/G933s Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&2a4c05d2&0&0000
Subwoofer (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Mezcla estéreo (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Micrófono (Logitech G935/G933s Gaming Headset): USB\VID_046D&PID_0A87&MI_00\6&8b2e543&0&0000
Línea de entrada (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Rear (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Front (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Center (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Micrófono (VF0700 Live! Cam Chat HD): USB\VID_041E&PID_4088&MI_02\6&2af04ba&0&0002
Front Pink In (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Rear Blue In (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Conector AUX interno (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0084&SUBSYS_104385A6&REV_1001\5&357d2e93&0&0001
Side (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Micrófono (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001
Micrófono (Realtek High Definition Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1168&SUBSYS_10438723&REV_1000\4&292560ce&0&0001

Enumerate database

Important Modified Preferences
------------------------------

accessibility.typeaheadfind.flashBar: 0
browser.cache.disk.amount_written: 1789790
browser.cache.disk.capacity: 1048576
browser.cache.disk.filesystem_reported: 1
browser.cache.disk.hashstats_reported: 1
browser.contentblocking.category: standard
browser.sessionstore.upgradeBackup.latestBuildID: 20200507114007
browser.startup.homepage: https://www.google.es/
browser.startup.homepage_override.buildID: 20200507114007
browser.startup.homepage_override.mstone: 76.0.1
browser.urlbar.placeholderName: Google
browser.urlbar.placeholderName.private: Google
browser.urlbar.tipShownCount.searchTip_onboard: 4
browser.urlbar.tipShownCount.searchTip_redirect: 4
dom.push.userAgentID: 67e883d1f952423aaedc1767a1ee4d32
extensions.lastAppVersion: 76.0.1
gfx.crash-guard.status.wmfvpxvideo: 3
gfx.crash-guard.wmfvpxvideo.appVersion: 76.0.1
gfx.crash-guard.wmfvpxvideo.deviceID: 0x1c03
gfx.crash-guard.wmfvpxvideo.driverVersion: 26.21.14.4120
idle.lastDailyNotification: 1591129815
layers.mlgpu.sanity-test-failed: true
media.gmp-gmpopenh264.abi: x86_64-msvc-x64
media.gmp-gmpopenh264.lastUpdate: 1590186327
media.gmp-gmpopenh264.version: 1.8.1.1
media.gmp-manager.buildID: 20200507114007
media.gmp-manager.lastCheck: 1591084593
media.gmp-widevinecdm.abi: x86_64-msvc-x64
media.gmp-widevinecdm.lastUpdate: 1590186328
media.gmp-widevinecdm.version: 4.10.1582.2
media.gmp.storage.version.observed: 1
media.hardware-video-decoding.failed: false
places.database.lastMaintenance: 1590870433
places.history.expiration.transient_current_max_pages: 101870
privacy.purge_trackers.date_in_cookie_database: 0
privacy.sanitize.pending: [{"id":"newtab-container","itemsToClear":[],"options":{}}]
security.remote_settings.crlite_filters.checked: 1591090715
security.remote_settings.intermediates.checked: 1591090715
security.sandbox.content.tempDirSuffix: {390b5f1b-f59f-43c6-bc33-e4cb62f50887}
security.sandbox.plugin.tempDirSuffix: {3b157bbf-8c29-4cce-b242-374730d33463}
services.sync.declinedEngines: tabs
services.sync.engine.prefs.modified: false
services.sync.engine.tabs: false
services.sync.lastPing: 1591092808
services.sync.lastSync: Wed Jun 03 2020 01:31:33 GMT+0200 (Central European Summer Time)
signon.importedFromSqlite: true
storage.vacuum.last.index: 1
storage.vacuum.last.places.sqlite: 1590228788
ui.osk.debug.keyboardDisplayReason: IKPOS: Touch screen not found.

Important Locked Preferences
----------------------------

dom.ipc.processCount.webIsolated: 1
fission.autostart: false

Places Database
---------------

JavaScript
----------

Incremental GC: true

Accessibility
-------------

Activated: false
Prevent Accessibility: 0
Accessible Handler Used: true
Accessibility Instantiator:

Library Versions
----------------

NSPR
Expected minimum version: 4.25
Version in use: 4.25

NSS
Expected minimum version: 3.51.1
Version in use: 3.51.1

NSSSMIME
Expected minimum version: 3.51.1
Version in use: 3.51.1

NSSSSL
Expected minimum version: 3.51.1
Version in use: 3.51.1

NSSUTIL
Expected minimum version: 3.51.1
Version in use: 3.51.1

Sandbox
-------

Content Process Sandbox Level: 6
Effective Content Process Sandbox Level: 6

Startup Cache
-------------

Disk Cache Path: C:\Users\Alvaro\AppData\Local\Mozilla\Firefox\Profiles\1az6dzv5.default-release\startupCache\startupCache.8.little
Ignore Disk Cache: false
Found Disk Cache on Init: true
Wrote to Disk Cache: false

Internationalization & Localization
-----------------------------------

Application Settings
Requested Locales: ["en-US","es-ES"]
Available Locales: ["es-ES","en-US"]
App Locales: ["en-US","es-ES"]
Regional Preferences: ["en-US","es-ES"]
Default Locale: "es-ES"
Operating System
System Locales: ["es-ES"]
Regional Preferences: ["es-ES"]

If you navigate to about:config and set the gfx.webrender.force-disabled to true then restart, does that have any impact on the bug (you can set the pref back after checking)?

It seems that with gfx.webrender.force-disabled = true the bug is gone, at least I have not seen it for the last hour I checked.
For now I will keep the setting like that and if I see the glithes appear again I will comment back here.

Hi, I tried to reproduce this issue on 2 different Machines (one with Intel HD 620 and one with Nvidia GeForce GTX 1050 ) with a normal 1080p monitor attached to them but also with a 4k monitor instead and I was unable to reproduce this issue.

I used the Steps from the Description as well as the Steps from Comment 1 while using the 4k resolution on the videos and played with the video controls just to stress the GPU's a bit but it wouldnt reproduce.

I tried this on Windows 10 with the Firefox Release 77.0.1, Beta 78.0b6 and our latest Nightly version.

Does this happen with a fresh profile as well ? does it happen right away or only after a few hours of surfing the web ? what resolution does the monitor have ? is it 144Hz ?

Does this happen with a fresh profile as well?

Yes, I noticed this happening since I installed Firefox

does it happen right away or only after few hours of surfing the web?

I think that it happens pretty much right away, although I could not tell 100% for sure

what resolution does the monitor have? is it 144Hz?

Yes! That's right! I probably should have mentioned it before, I notice this on a 144Hz monitor

Also, it is worth pointing out that I was able to see the same visual artifacts even with gfx.webrender.force-disabled = true, although it only happened once since I changed that setting. Unfortunately I did not save the about:support output from that session.

Do the newer 451.xx series help with this? Is HW-Accelerated GPU Scheduling enabled?

NI-ing the reporter so they see the questions in Comment 8

(In reply to Arthur K. from comment #8)

Do the newer 451.xx series help with this? Is HW-Accelerated GPU Scheduling enabled?

Haven't tried this. I will update the drivers and enable HW-Accelerated GPU Scheduling and report.

However, I haven't been noticing this bug lately, don't know if some udpate may have reduced the frequency/removed it completely.

Has this gone away since FF80 or with NVidia 452.06 drivers or after the most recent August Windows Update?

(In reply to Arthur K. from comment #11)

Has this gone away since FF80 or with NVidia 452.06 drivers or after the most recent August Windows Update?

Looks like it, haven't seen this happening in some time.

(In reply to clemente.varo from comment #12)

(In reply to Arthur K. from comment #11)

Has this gone away since FF80 or with NVidia 452.06 drivers or after the most recent August Windows Update?

Looks like it, haven't seen this happening in some time.

This is good to hear. Maybe the latest Windows Updates fixed it? I remember reading that August update contained a lot of fixes for GFX related issues. Of course, it could be something fixed between your original FF 76 post and FF 80.

If you're thinking the latter, please close this as Works for Me after you're sure it's gone using the recent FF and note that if you could please.