Do I need to configure mute even if the display's VCP capabilities report does not indicate it as supported?

[joevt]

I have an Acer XV273K. If I use BetterDisplay to change the volume to zero, then increase the volume again, the volume does not unmute.

I think I fixed it by disabling DDC Mute 8d in the BetterDisplay settings for the display. Why was DDC Mute enabled if VCP Capabilities does not report support for code 8d?

                VCP Capabilities = {
                    VCP string = "(prot(monitor)type(lcd)model(XV273K)cmds(01 02 03 07 0C E3 F3)vcp(02 04 05 08 0B 0C 10 12 14(05 06 08 0B 0C) 16 18 1A 52 54(00 01) 59 5A 5B 5C 5D 5E 60(03 11 0F 10) 62 9B 9C 9D 9E 9F A0 AC AE B6 C0 C6 C8 C9 CC(01 02 03 04 05 06 08 09 0A 0C 0D 0E 14 16 1E)D6(01 04 05) DF E3 E5 E6 E7(00 01 02) E8(00 01 02) )mswhql(1)asset_eep(32)mccs_ver(2.1))";
                    VCP parsed = {
                        {
                            prot = "monitor";
                            type = "lcd";
                            model = "XV273K";
                            cmds = {
                                01: VCP request
                                02: VCP reply
                                03: VCP set
                                07: Timing request
                                0C: Save current settings
                                E3: Capabilities reply
                                F3: Capabilities request
                            };
                            vcp = {
                                02: New Control Value = { RW, NC, 0100020002:{ ?New control value(s) have been changed (see FIFO 52h) }, },
                                04: Restore Factory Defaults = { WO, NC, },
                                05: Restore Factory Luminance / Contrast Defaults = { WO, NC, },
                                08: Restore Factory Color Defaults = { WO, NC, },
                                0B: User Color Temperature Increment = { RO, NC, 0100640064:{ 100°K }, },
                                0C: User Color Temperature = { RW, C, 0000550023:{ 6500°K }, },
                                10: Luminance = { RW, C, 0000640064:{ 100.0% }, },
                                12: Contrast = { RW, C, 0000640032:{ 50.0% }, },
                                14: Select Color Preset = { RW, NC, cap = { 05 06 08 0B 0C : Warmer 2, Warmer 1, Cooler 2, User 1, User 2 }, 00000B0005:{ Warmer 2 }, },
                                16: Video Gain (Drive): Red = { RW, C, 0000640032:{ 50.0% }, },
                                18: Video Gain (Drive): Green = { RW, C, 0000640032:{ 50.0% }, },
                                1A: Video Gain (Drive): Blue = { RW, C, 0000640032:{ 50.0% }, },
                                52: Active Control = { RO, NC, 0100FF0000:{ 00: FIFO is empty }, },
                                54: Performance Preservation = { RW, NC, cap = { 00 01 : }, 01FFFF0000:{ supported:{Image “orbiting” mode., Low luminance mode with “active” video mode., Slow luminance reduction when a static image is detected mode., Slow luminance reduction when no user activity is detected mode., 11?, 10?, 9?, 8?, A white vertical bar (or line) moving slowly horizontally across the screen on a black background., A white image filling the display area., A black vertical bar (or line) moving slowly horizontally across the screen on a black background., Reverse video ... the displayed image is the inverse color of the source image., Display is active but video is blanked., A gray scale pattern moving slowly horizontally across the screen., 1?, 0?, }, present:{} }, }, // (unexpected data for vcp 54: 6e8802015401ffff0000e0) 
                                59: 6 Axis Saturation Control: Red = { RW, C, 0000640032:{ 50.0% }, },
                                5A: 6 Axis Saturation Control: Yellow = { RW, C, 0000640032:{ 50.0% }, },
                                5B: 6 Axis Saturation Control: Green = { RW, C, 0000640032:{ 50.0% }, },
                                5C: 6 Axis Saturation Control: Cyan = { RW, C, 0000640032:{ 50.0% }, },
                                5D: 6 Axis Saturation Control: Blue = { RW, C, 0000640032:{ 50.0% }, },
                                5E: 6 Axis Saturation Control: Magenta = { RW, C, 0000640032:{ 50.0% }, },
                                60: Input Select = { RW, NC, cap = { 03 11 0F 10 : Digital video (TMDS) 1 DVI 1, Digital Video (TMDS) 3 HDMI 1, DisplayPort 1, DisplayPort 2 }, 0000010010:{ ?DisplayPort 2 }, },
                                62: Audio: Speaker Volume = { RW, NC, 000064003F:{ ?63.0% }, },
                                9B: 6 Axis Hue Control: Red = { RW, C, 0000640032:{ 50.0% }, },
                                9C: 6 Axis Hue Control: Yellow = { RW, C, 0000640032:{ 50.0% }, },
                                9D: 6 Axis Hue Control: Green = { RW, C, 0000640032:{ 50.0% }, },
                                9E: 6 Axis Hue Control: Cyan = { RW, C, 0000640032:{ 50.0% }, },
                                9F: 6 Axis Hue Control: Blue = { RW, C, 0000640032:{ 50.0% }, },
                                A0: 6 Axis Hue Control: Magenta = { RW, C, 0000640032:{ 50.0% }, },
                                AC: Horizontal Frequency = { RO, C, 01000208B4:{ 133.300kHz }, },
                                AE: Vertical Frequency = { RO, C, 010000176F:{ 59.99Hz }, },
                                B6: Display Technology Type = { RO, NC, 0000080003:{ Transducer: LCD (active matrix), Technology Implementation: Reserved, must be ignored }, },
                                C0: Display Usage Time = { RO, C, 01FFFF17DA:{ ?6106 hours }, },
                                C6: Application Enable Key = { RO, NC, 01FFFF0078:{ 0x0078 }, },
                                C8: Display Controller ID = { RO, NC, 01FF160005:{ Manufacturer:Mstar Semiconductor Product:0xFF1600 }, },
                                C9: Display Firmware Level = { RO, C, 01FFFF000C:{ 0.12 }, },
                                CC: OSD Language = { RW, NC, cap = { 01 02 03 04 05 06 08 09 0A 0C 0D 0E 14 16 1E : Chinese (traditional / Hantai), English, French, German, Italian, Japanese, Portuguese (Portugal), Russian, Spanish, Turkish, Chinese (simplified / Kantai), Portuguese (Brazil), Dutch, Finnish, Polish }, 0000240002:{ ?English }, },
                                D6: Power Mode = { RW, NC, cap = { 01 04 05 : }, 0100040001:{ DPM On, DPMS On }, },
                                DF: VCP Version = { RO, NC, 0100FF0201:{ 2.1 }, },
                                E3: Manufacturer Specific = { TBD, TBD, },
                                E5: Manufacturer Specific = { TBD, TBD, },
                                E6: Manufacturer Specific = { TBD, TBD, },
                                E7: Manufacturer Specific = { TBD, TBD, cap = { 00 01 02 : }, },
                                E8: Manufacturer Specific = { TBD, TBD, cap = { 00 01 02 : }, },
                            };
                            mswhql = "1";
                            asset_eep = "32";
                            mccs_ver = "2.1";
                        }
                    } // VCP parsed
                }; // VCP Capabilities

[waydabber]

Yes, the app does not really take the VCP capabilities report seriously so if DDC mute does not work, you should indeed disable it manually.

Here is how to configure mute:

#1248