1.. SPDX-License-Identifier: GPL-2.0 2 3The Virtual Video Test Driver (vivid) 4===================================== 5 6This driver emulates video4linux hardware of various types: video capture, video 7output, vbi capture and output, metadata capture and output, radio receivers and 8transmitters, touch capture and a software defined radio receiver. In addition a 9simple framebuffer device is available for testing capture and output overlays. 10 11Up to 64 vivid instances can be created, each with up to 16 inputs and 16 outputs. 12 13Each input can be a webcam, TV capture device, S-Video capture device or an HDMI 14capture device. Each output can be an S-Video output device or an HDMI output 15device. 16 17These inputs and outputs act exactly as a real hardware device would behave. This 18allows you to use this driver as a test input for application development, since 19you can test the various features without requiring special hardware. 20 21This document describes the features implemented by this driver: 22 23- Support for read()/write(), MMAP, USERPTR and DMABUF streaming I/O. 24- A large list of test patterns and variations thereof 25- Working brightness, contrast, saturation and hue controls 26- Support for the alpha color component 27- Full colorspace support, including limited/full RGB range 28- All possible control types are present 29- Support for various pixel aspect ratios and video aspect ratios 30- Error injection to test what happens if errors occur 31- Supports crop/compose/scale in any combination for both input and output 32- Can emulate up to 4K resolutions 33- All Field settings are supported for testing interlaced capturing 34- Supports all standard YUV and RGB formats, including two multiplanar YUV formats 35- Raw and Sliced VBI capture and output support 36- Radio receiver and transmitter support, including RDS support 37- Software defined radio (SDR) support 38- Capture and output overlay support 39- Metadata capture and output support 40- Touch capture support 41 42These features will be described in more detail below. 43 44Configuring the driver 45---------------------- 46 47By default the driver will create a single instance that has a video capture 48device with webcam, TV, S-Video and HDMI inputs, a video output device with 49S-Video and HDMI outputs, one vbi capture device, one vbi output device, one 50radio receiver device, one radio transmitter device and one SDR device. 51 52The number of instances, devices, video inputs and outputs and their types are 53all configurable using the following module options: 54 55- n_devs: 56 57 number of driver instances to create. By default set to 1. Up to 64 58 instances can be created. 59 60- node_types: 61 62 which devices should each driver instance create. An array of 63 hexadecimal values, one for each instance. The default is 0x1d3d. 64 Each value is a bitmask with the following meaning: 65 66 - bit 0: Video Capture node 67 - bit 2-3: VBI Capture node: 0 = none, 1 = raw vbi, 2 = sliced vbi, 3 = both 68 - bit 4: Radio Receiver node 69 - bit 5: Software Defined Radio Receiver node 70 - bit 8: Video Output node 71 - bit 10-11: VBI Output node: 0 = none, 1 = raw vbi, 2 = sliced vbi, 3 = both 72 - bit 12: Radio Transmitter node 73 - bit 16: Framebuffer for testing overlays 74 - bit 17: Metadata Capture node 75 - bit 18: Metadata Output node 76 - bit 19: Touch Capture node 77 78 So to create four instances, the first two with just one video capture 79 device, the second two with just one video output device you would pass 80 these module options to vivid: 81 82 .. code-block:: none 83 84 n_devs=4 node_types=0x1,0x1,0x100,0x100 85 86- num_inputs: 87 88 the number of inputs, one for each instance. By default 4 inputs 89 are created for each video capture device. At most 16 inputs can be created, 90 and there must be at least one. 91 92- input_types: 93 94 the input types for each instance, the default is 0xe4. This defines 95 what the type of each input is when the inputs are created for each driver 96 instance. This is a hexadecimal value with up to 16 pairs of bits, each 97 pair gives the type and bits 0-1 map to input 0, bits 2-3 map to input 1, 98 30-31 map to input 15. Each pair of bits has the following meaning: 99 100 - 00: this is a webcam input 101 - 01: this is a TV tuner input 102 - 10: this is an S-Video input 103 - 11: this is an HDMI input 104 105 So to create a video capture device with 8 inputs where input 0 is a TV 106 tuner, inputs 1-3 are S-Video inputs and inputs 4-7 are HDMI inputs you 107 would use the following module options: 108 109 .. code-block:: none 110 111 num_inputs=8 input_types=0xffa9 112 113- num_outputs: 114 115 the number of outputs, one for each instance. By default 2 outputs 116 are created for each video output device. At most 16 outputs can be 117 created, and there must be at least one. 118 119- output_types: 120 121 the output types for each instance, the default is 0x02. This defines 122 what the type of each output is when the outputs are created for each 123 driver instance. This is a hexadecimal value with up to 16 bits, each bit 124 gives the type and bit 0 maps to output 0, bit 1 maps to output 1, bit 125 15 maps to output 15. The meaning of each bit is as follows: 126 127 - 0: this is an S-Video output 128 - 1: this is an HDMI output 129 130 So to create a video output device with 8 outputs where outputs 0-3 are 131 S-Video outputs and outputs 4-7 are HDMI outputs you would use the 132 following module options: 133 134 .. code-block:: none 135 136 num_outputs=8 output_types=0xf0 137 138- vid_cap_nr: 139 140 give the desired videoX start number for each video capture device. 141 The default is -1 which will just take the first free number. This allows 142 you to map capture video nodes to specific videoX device nodes. Example: 143 144 .. code-block:: none 145 146 n_devs=4 vid_cap_nr=2,4,6,8 147 148 This will attempt to assign /dev/video2 for the video capture device of 149 the first vivid instance, video4 for the next up to video8 for the last 150 instance. If it can't succeed, then it will just take the next free 151 number. 152 153- vid_out_nr: 154 155 give the desired videoX start number for each video output device. 156 The default is -1 which will just take the first free number. 157 158- vbi_cap_nr: 159 160 give the desired vbiX start number for each vbi capture device. 161 The default is -1 which will just take the first free number. 162 163- vbi_out_nr: 164 165 give the desired vbiX start number for each vbi output device. 166 The default is -1 which will just take the first free number. 167 168- radio_rx_nr: 169 170 give the desired radioX start number for each radio receiver device. 171 The default is -1 which will just take the first free number. 172 173- radio_tx_nr: 174 175 give the desired radioX start number for each radio transmitter 176 device. The default is -1 which will just take the first free number. 177 178- sdr_cap_nr: 179 180 give the desired swradioX start number for each SDR capture device. 181 The default is -1 which will just take the first free number. 182 183- meta_cap_nr: 184 185 give the desired videoX start number for each metadata capture device. 186 The default is -1 which will just take the first free number. 187 188- meta_out_nr: 189 190 give the desired videoX start number for each metadata output device. 191 The default is -1 which will just take the first free number. 192 193- touch_cap_nr: 194 195 give the desired v4l-touchX start number for each touch capture device. 196 The default is -1 which will just take the first free number. 197 198- ccs_cap_mode: 199 200 specify the allowed video capture crop/compose/scaling combination 201 for each driver instance. Video capture devices can have any combination 202 of cropping, composing and scaling capabilities and this will tell the 203 vivid driver which of those is should emulate. By default the user can 204 select this through controls. 205 206 The value is either -1 (controlled by the user) or a set of three bits, 207 each enabling (1) or disabling (0) one of the features: 208 209 - bit 0: 210 211 Enable crop support. Cropping will take only part of the 212 incoming picture. 213 - bit 1: 214 215 Enable compose support. Composing will copy the incoming 216 picture into a larger buffer. 217 218 - bit 2: 219 220 Enable scaling support. Scaling can scale the incoming 221 picture. The scaler of the vivid driver can enlarge up 222 or down to four times the original size. The scaler is 223 very simple and low-quality. Simplicity and speed were 224 key, not quality. 225 226 Note that this value is ignored by webcam inputs: those enumerate 227 discrete framesizes and that is incompatible with cropping, composing 228 or scaling. 229 230- ccs_out_mode: 231 232 specify the allowed video output crop/compose/scaling combination 233 for each driver instance. Video output devices can have any combination 234 of cropping, composing and scaling capabilities and this will tell the 235 vivid driver which of those is should emulate. By default the user can 236 select this through controls. 237 238 The value is either -1 (controlled by the user) or a set of three bits, 239 each enabling (1) or disabling (0) one of the features: 240 241 - bit 0: 242 243 Enable crop support. Cropping will take only part of the 244 outgoing buffer. 245 246 - bit 1: 247 248 Enable compose support. Composing will copy the incoming 249 buffer into a larger picture frame. 250 251 - bit 2: 252 253 Enable scaling support. Scaling can scale the incoming 254 buffer. The scaler of the vivid driver can enlarge up 255 or down to four times the original size. The scaler is 256 very simple and low-quality. Simplicity and speed were 257 key, not quality. 258 259- multiplanar: 260 261 select whether each device instance supports multi-planar formats, 262 and thus the V4L2 multi-planar API. By default device instances are 263 single-planar. 264 265 This module option can override that for each instance. Values are: 266 267 - 1: this is a single-planar instance. 268 - 2: this is a multi-planar instance. 269 270- vivid_debug: 271 272 enable driver debugging info 273 274- no_error_inj: 275 276 if set disable the error injecting controls. This option is 277 needed in order to run a tool like v4l2-compliance. Tools like that 278 exercise all controls including a control like 'Disconnect' which 279 emulates a USB disconnect, making the device inaccessible and so 280 all tests that v4l2-compliance is doing will fail afterwards. 281 282 There may be other situations as well where you want to disable the 283 error injection support of vivid. When this option is set, then the 284 controls that select crop, compose and scale behavior are also 285 removed. Unless overridden by ccs_cap_mode and/or ccs_out_mode the 286 will default to enabling crop, compose and scaling. 287 288- allocators: 289 290 memory allocator selection, default is 0. It specifies the way buffers 291 will be allocated. 292 293 - 0: vmalloc 294 - 1: dma-contig 295 296Taken together, all these module options allow you to precisely customize 297the driver behavior and test your application with all sorts of permutations. 298It is also very suitable to emulate hardware that is not yet available, e.g. 299when developing software for a new upcoming device. 300 301 302Video Capture 303------------- 304 305This is probably the most frequently used feature. The video capture device 306can be configured by using the module options num_inputs, input_types and 307ccs_cap_mode (see section 1 for more detailed information), but by default 308four inputs are configured: a webcam, a TV tuner, an S-Video and an HDMI 309input, one input for each input type. Those are described in more detail 310below. 311 312Special attention has been given to the rate at which new frames become 313available. The jitter will be around 1 jiffie (that depends on the HZ 314configuration of your kernel, so usually 1/100, 1/250 or 1/1000 of a second), 315but the long-term behavior is exactly following the framerate. So a 316framerate of 59.94 Hz is really different from 60 Hz. If the framerate 317exceeds your kernel's HZ value, then you will get dropped frames, but the 318frame/field sequence counting will keep track of that so the sequence 319count will skip whenever frames are dropped. 320 321 322Webcam Input 323~~~~~~~~~~~~ 324 325The webcam input supports three framesizes: 320x180, 640x360 and 1280x720. It 326supports frames per second settings of 10, 15, 25, 30, 50 and 60 fps. Which ones 327are available depends on the chosen framesize: the larger the framesize, the 328lower the maximum frames per second. 329 330The initially selected colorspace when you switch to the webcam input will be 331sRGB. 332 333 334TV and S-Video Inputs 335~~~~~~~~~~~~~~~~~~~~~ 336 337The only difference between the TV and S-Video input is that the TV has a 338tuner. Otherwise they behave identically. 339 340These inputs support audio inputs as well: one TV and one Line-In. They 341both support all TV standards. If the standard is queried, then the Vivid 342controls 'Standard Signal Mode' and 'Standard' determine what 343the result will be. 344 345These inputs support all combinations of the field setting. Special care has 346been taken to faithfully reproduce how fields are handled for the different 347TV standards. This is particularly noticeable when generating a horizontally 348moving image so the temporal effect of using interlaced formats becomes clearly 349visible. For 50 Hz standards the top field is the oldest and the bottom field 350is the newest in time. For 60 Hz standards that is reversed: the bottom field 351is the oldest and the top field is the newest in time. 352 353When you start capturing in V4L2_FIELD_ALTERNATE mode the first buffer will 354contain the top field for 50 Hz standards and the bottom field for 60 Hz 355standards. This is what capture hardware does as well. 356 357Finally, for PAL/SECAM standards the first half of the top line contains noise. 358This simulates the Wide Screen Signal that is commonly placed there. 359 360The initially selected colorspace when you switch to the TV or S-Video input 361will be SMPTE-170M. 362 363The pixel aspect ratio will depend on the TV standard. The video aspect ratio 364can be selected through the 'Standard Aspect Ratio' Vivid control. 365Choices are '4x3', '16x9' which will give letterboxed widescreen video and 366'16x9 Anamorphic' which will give full screen squashed anamorphic widescreen 367video that will need to be scaled accordingly. 368 369The TV 'tuner' supports a frequency range of 44-958 MHz. Channels are available 370every 6 MHz, starting from 49.25 MHz. For each channel the generated image 371will be in color for the +/- 0.25 MHz around it, and in grayscale for 372+/- 1 MHz around the channel. Beyond that it is just noise. The VIDIOC_G_TUNER 373ioctl will return 100% signal strength for +/- 0.25 MHz and 50% for +/- 1 MHz. 374It will also return correct afc values to show whether the frequency is too 375low or too high. 376 377The audio subchannels that are returned are MONO for the +/- 1 MHz range around 378a valid channel frequency. When the frequency is within +/- 0.25 MHz of the 379channel it will return either MONO, STEREO, either MONO | SAP (for NTSC) or 380LANG1 | LANG2 (for others), or STEREO | SAP. 381 382Which one is returned depends on the chosen channel, each next valid channel 383will cycle through the possible audio subchannel combinations. This allows 384you to test the various combinations by just switching channels.. 385 386Finally, for these inputs the v4l2_timecode struct is filled in in the 387dequeued v4l2_buffer struct. 388 389 390HDMI Input 391~~~~~~~~~~ 392 393The HDMI inputs supports all CEA-861 and DMT timings, both progressive and 394interlaced, for pixelclock frequencies between 25 and 600 MHz. The field 395mode for interlaced formats is always V4L2_FIELD_ALTERNATE. For HDMI the 396field order is always top field first, and when you start capturing an 397interlaced format you will receive the top field first. 398 399The initially selected colorspace when you switch to the HDMI input or 400select an HDMI timing is based on the format resolution: for resolutions 401less than or equal to 720x576 the colorspace is set to SMPTE-170M, for 402others it is set to REC-709 (CEA-861 timings) or sRGB (VESA DMT timings). 403 404The pixel aspect ratio will depend on the HDMI timing: for 720x480 is it 405set as for the NTSC TV standard, for 720x576 it is set as for the PAL TV 406standard, and for all others a 1:1 pixel aspect ratio is returned. 407 408The video aspect ratio can be selected through the 'DV Timings Aspect Ratio' 409Vivid control. Choices are 'Source Width x Height' (just use the 410same ratio as the chosen format), '4x3' or '16x9', either of which can 411result in pillarboxed or letterboxed video. 412 413For HDMI inputs it is possible to set the EDID. By default a simple EDID 414is provided. You can only set the EDID for HDMI inputs. Internally, however, 415the EDID is shared between all HDMI inputs. 416 417No interpretation is done of the EDID data with the exception of the 418physical address. See the CEC section for more details. 419 420There is a maximum of 15 HDMI inputs (if there are more, then they will be 421reduced to 15) since that's the limitation of the EDID physical address. 422 423 424Video Output 425------------ 426 427The video output device can be configured by using the module options 428num_outputs, output_types and ccs_out_mode (see section 1 for more detailed 429information), but by default two outputs are configured: an S-Video and an 430HDMI input, one output for each output type. Those are described in more detail 431below. 432 433Like with video capture the framerate is also exact in the long term. 434 435 436S-Video Output 437~~~~~~~~~~~~~~ 438 439This output supports audio outputs as well: "Line-Out 1" and "Line-Out 2". 440The S-Video output supports all TV standards. 441 442This output supports all combinations of the field setting. 443 444The initially selected colorspace when you switch to the TV or S-Video input 445will be SMPTE-170M. 446 447 448HDMI Output 449~~~~~~~~~~~ 450 451The HDMI output supports all CEA-861 and DMT timings, both progressive and 452interlaced, for pixelclock frequencies between 25 and 600 MHz. The field 453mode for interlaced formats is always V4L2_FIELD_ALTERNATE. 454 455The initially selected colorspace when you switch to the HDMI output or 456select an HDMI timing is based on the format resolution: for resolutions 457less than or equal to 720x576 the colorspace is set to SMPTE-170M, for 458others it is set to REC-709 (CEA-861 timings) or sRGB (VESA DMT timings). 459 460The pixel aspect ratio will depend on the HDMI timing: for 720x480 is it 461set as for the NTSC TV standard, for 720x576 it is set as for the PAL TV 462standard, and for all others a 1:1 pixel aspect ratio is returned. 463 464An HDMI output has a valid EDID which can be obtained through VIDIOC_G_EDID. 465 466There is a maximum of 15 HDMI outputs (if there are more, then they will be 467reduced to 15) since that's the limitation of the EDID physical address. See 468also the CEC section for more details. 469 470VBI Capture 471----------- 472 473There are three types of VBI capture devices: those that only support raw 474(undecoded) VBI, those that only support sliced (decoded) VBI and those that 475support both. This is determined by the node_types module option. In all 476cases the driver will generate valid VBI data: for 60 Hz standards it will 477generate Closed Caption and XDS data. The closed caption stream will 478alternate between "Hello world!" and "Closed captions test" every second. 479The XDS stream will give the current time once a minute. For 50 Hz standards 480it will generate the Wide Screen Signal which is based on the actual Video 481Aspect Ratio control setting and teletext pages 100-159, one page per frame. 482 483The VBI device will only work for the S-Video and TV inputs, it will give 484back an error if the current input is a webcam or HDMI. 485 486 487VBI Output 488---------- 489 490There are three types of VBI output devices: those that only support raw 491(undecoded) VBI, those that only support sliced (decoded) VBI and those that 492support both. This is determined by the node_types module option. 493 494The sliced VBI output supports the Wide Screen Signal and the teletext signal 495for 50 Hz standards and Closed Captioning + XDS for 60 Hz standards. 496 497The VBI device will only work for the S-Video output, it will give 498back an error if the current output is HDMI. 499 500 501Radio Receiver 502-------------- 503 504The radio receiver emulates an FM/AM/SW receiver. The FM band also supports RDS. 505The frequency ranges are: 506 507 - FM: 64 MHz - 108 MHz 508 - AM: 520 kHz - 1710 kHz 509 - SW: 2300 kHz - 26.1 MHz 510 511Valid channels are emulated every 1 MHz for FM and every 100 kHz for AM and SW. 512The signal strength decreases the further the frequency is from the valid 513frequency until it becomes 0% at +/- 50 kHz (FM) or 5 kHz (AM/SW) from the 514ideal frequency. The initial frequency when the driver is loaded is set to 51595 MHz. 516 517The FM receiver supports RDS as well, both using 'Block I/O' and 'Controls' 518modes. In the 'Controls' mode the RDS information is stored in read-only 519controls. These controls are updated every time the frequency is changed, 520or when the tuner status is requested. The Block I/O method uses the read() 521interface to pass the RDS blocks on to the application for decoding. 522 523The RDS signal is 'detected' for +/- 12.5 kHz around the channel frequency, 524and the further the frequency is away from the valid frequency the more RDS 525errors are randomly introduced into the block I/O stream, up to 50% of all 526blocks if you are +/- 12.5 kHz from the channel frequency. All four errors 527can occur in equal proportions: blocks marked 'CORRECTED', blocks marked 528'ERROR', blocks marked 'INVALID' and dropped blocks. 529 530The generated RDS stream contains all the standard fields contained in a 5310B group, and also radio text and the current time. 532 533The receiver supports HW frequency seek, either in Bounded mode, Wrap Around 534mode or both, which is configurable with the "Radio HW Seek Mode" control. 535 536 537Radio Transmitter 538----------------- 539 540The radio transmitter emulates an FM/AM/SW transmitter. The FM band also supports RDS. 541The frequency ranges are: 542 543 - FM: 64 MHz - 108 MHz 544 - AM: 520 kHz - 1710 kHz 545 - SW: 2300 kHz - 26.1 MHz 546 547The initial frequency when the driver is loaded is 95.5 MHz. 548 549The FM transmitter supports RDS as well, both using 'Block I/O' and 'Controls' 550modes. In the 'Controls' mode the transmitted RDS information is configured 551using controls, and in 'Block I/O' mode the blocks are passed to the driver 552using write(). 553 554 555Software Defined Radio Receiver 556------------------------------- 557 558The SDR receiver has three frequency bands for the ADC tuner: 559 560 - 300 kHz 561 - 900 kHz - 2800 kHz 562 - 3200 kHz 563 564The RF tuner supports 50 MHz - 2000 MHz. 565 566The generated data contains the In-phase and Quadrature components of a 5671 kHz tone that has an amplitude of sqrt(2). 568 569 570Metadata Capture 571---------------- 572 573The Metadata capture generates UVC format metadata. The PTS and SCR are 574transmitted based on the values set in vivid contols. 575 576The Metadata device will only work for the Webcam input, it will give 577back an error for all other inputs. 578 579 580Metadata Output 581--------------- 582 583The Metadata output can be used to set brightness, contrast, saturation and hue. 584 585The Metadata device will only work for the Webcam output, it will give 586back an error for all other outputs. 587 588 589Touch Capture 590------------- 591 592The Touch capture generates touch patterns simulating single tap, double tap, 593triple tap, move from left to right, zoom in, zoom out, palm press (simulating 594a large area being pressed on a touchpad), and simulating 16 simultaneous 595touch points. 596 597Controls 598-------- 599 600Different devices support different controls. The sections below will describe 601each control and which devices support them. 602 603 604User Controls - Test Controls 605~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 606 607The Button, Boolean, Integer 32 Bits, Integer 64 Bits, Menu, String, Bitmask and 608Integer Menu are controls that represent all possible control types. The Menu 609control and the Integer Menu control both have 'holes' in their menu list, 610meaning that one or more menu items return EINVAL when VIDIOC_QUERYMENU is called. 611Both menu controls also have a non-zero minimum control value. These features 612allow you to check if your application can handle such things correctly. 613These controls are supported for every device type. 614 615 616User Controls - Video Capture 617~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 618 619The following controls are specific to video capture. 620 621The Brightness, Contrast, Saturation and Hue controls actually work and are 622standard. There is one special feature with the Brightness control: each 623video input has its own brightness value, so changing input will restore 624the brightness for that input. In addition, each video input uses a different 625brightness range (minimum and maximum control values). Switching inputs will 626cause a control event to be sent with the V4L2_EVENT_CTRL_CH_RANGE flag set. 627This allows you to test controls that can change their range. 628 629The 'Gain, Automatic' and Gain controls can be used to test volatile controls: 630if 'Gain, Automatic' is set, then the Gain control is volatile and changes 631constantly. If 'Gain, Automatic' is cleared, then the Gain control is a normal 632control. 633 634The 'Horizontal Flip' and 'Vertical Flip' controls can be used to flip the 635image. These combine with the 'Sensor Flipped Horizontally/Vertically' Vivid 636controls. 637 638The 'Alpha Component' control can be used to set the alpha component for 639formats containing an alpha channel. 640 641 642User Controls - Audio 643~~~~~~~~~~~~~~~~~~~~~ 644 645The following controls are specific to video capture and output and radio 646receivers and transmitters. 647 648The 'Volume' and 'Mute' audio controls are typical for such devices to 649control the volume and mute the audio. They don't actually do anything in 650the vivid driver. 651 652 653Vivid Controls 654~~~~~~~~~~~~~~ 655 656These vivid custom controls control the image generation, error injection, etc. 657 658 659Test Pattern Controls 660^^^^^^^^^^^^^^^^^^^^^ 661 662The Test Pattern Controls are all specific to video capture. 663 664- Test Pattern: 665 666 selects which test pattern to use. Use the CSC Colorbar for 667 testing colorspace conversions: the colors used in that test pattern 668 map to valid colors in all colorspaces. The colorspace conversion 669 is disabled for the other test patterns. 670 671- OSD Text Mode: 672 673 selects whether the text superimposed on the 674 test pattern should be shown, and if so, whether only counters should 675 be displayed or the full text. 676 677- Horizontal Movement: 678 679 selects whether the test pattern should 680 move to the left or right and at what speed. 681 682- Vertical Movement: 683 684 does the same for the vertical direction. 685 686- Show Border: 687 688 show a two-pixel wide border at the edge of the actual image, 689 excluding letter or pillarboxing. 690 691- Show Square: 692 693 show a square in the middle of the image. If the image is 694 displayed with the correct pixel and image aspect ratio corrections, 695 then the width and height of the square on the monitor should be 696 the same. 697 698- Insert SAV Code in Image: 699 700 adds a SAV (Start of Active Video) code to the image. 701 This can be used to check if such codes in the image are inadvertently 702 interpreted instead of being ignored. 703 704- Insert EAV Code in Image: 705 706 does the same for the EAV (End of Active Video) code. 707 708 709Capture Feature Selection Controls 710^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 711 712These controls are all specific to video capture. 713 714- Sensor Flipped Horizontally: 715 716 the image is flipped horizontally and the 717 V4L2_IN_ST_HFLIP input status flag is set. This emulates the case where 718 a sensor is for example mounted upside down. 719 720- Sensor Flipped Vertically: 721 722 the image is flipped vertically and the 723 V4L2_IN_ST_VFLIP input status flag is set. This emulates the case where 724 a sensor is for example mounted upside down. 725 726- Standard Aspect Ratio: 727 728 selects if the image aspect ratio as used for the TV or 729 S-Video input should be 4x3, 16x9 or anamorphic widescreen. This may 730 introduce letterboxing. 731 732- DV Timings Aspect Ratio: 733 734 selects if the image aspect ratio as used for the HDMI 735 input should be the same as the source width and height ratio, or if 736 it should be 4x3 or 16x9. This may introduce letter or pillarboxing. 737 738- Timestamp Source: 739 740 selects when the timestamp for each buffer is taken. 741 742- Colorspace: 743 744 selects which colorspace should be used when generating the image. 745 This only applies if the CSC Colorbar test pattern is selected, 746 otherwise the test pattern will go through unconverted. 747 This behavior is also what you want, since a 75% Colorbar 748 should really have 75% signal intensity and should not be affected 749 by colorspace conversions. 750 751 Changing the colorspace will result in the V4L2_EVENT_SOURCE_CHANGE 752 to be sent since it emulates a detected colorspace change. 753 754- Transfer Function: 755 756 selects which colorspace transfer function should be used when 757 generating an image. This only applies if the CSC Colorbar test pattern is 758 selected, otherwise the test pattern will go through unconverted. 759 This behavior is also what you want, since a 75% Colorbar 760 should really have 75% signal intensity and should not be affected 761 by colorspace conversions. 762 763 Changing the transfer function will result in the V4L2_EVENT_SOURCE_CHANGE 764 to be sent since it emulates a detected colorspace change. 765 766- Y'CbCr Encoding: 767 768 selects which Y'CbCr encoding should be used when generating 769 a Y'CbCr image. This only applies if the format is set to a Y'CbCr format 770 as opposed to an RGB format. 771 772 Changing the Y'CbCr encoding will result in the V4L2_EVENT_SOURCE_CHANGE 773 to be sent since it emulates a detected colorspace change. 774 775- Quantization: 776 777 selects which quantization should be used for the RGB or Y'CbCr 778 encoding when generating the test pattern. 779 780 Changing the quantization will result in the V4L2_EVENT_SOURCE_CHANGE 781 to be sent since it emulates a detected colorspace change. 782 783- Limited RGB Range (16-235): 784 785 selects if the RGB range of the HDMI source should 786 be limited or full range. This combines with the Digital Video 'Rx RGB 787 Quantization Range' control and can be used to test what happens if 788 a source provides you with the wrong quantization range information. 789 See the description of that control for more details. 790 791- Apply Alpha To Red Only: 792 793 apply the alpha channel as set by the 'Alpha Component' 794 user control to the red color of the test pattern only. 795 796- Enable Capture Cropping: 797 798 enables crop support. This control is only present if 799 the ccs_cap_mode module option is set to the default value of -1 and if 800 the no_error_inj module option is set to 0 (the default). 801 802- Enable Capture Composing: 803 804 enables composing support. This control is only 805 present if the ccs_cap_mode module option is set to the default value of 806 -1 and if the no_error_inj module option is set to 0 (the default). 807 808- Enable Capture Scaler: 809 810 enables support for a scaler (maximum 4 times upscaling 811 and downscaling). This control is only present if the ccs_cap_mode 812 module option is set to the default value of -1 and if the no_error_inj 813 module option is set to 0 (the default). 814 815- Maximum EDID Blocks: 816 817 determines how many EDID blocks the driver supports. 818 Note that the vivid driver does not actually interpret new EDID 819 data, it just stores it. It allows for up to 256 EDID blocks 820 which is the maximum supported by the standard. 821 822- Fill Percentage of Frame: 823 824 can be used to draw only the top X percent 825 of the image. Since each frame has to be drawn by the driver, this 826 demands a lot of the CPU. For large resolutions this becomes 827 problematic. By drawing only part of the image this CPU load can 828 be reduced. 829 830 831Output Feature Selection Controls 832^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 833 834These controls are all specific to video output. 835 836- Enable Output Cropping: 837 838 enables crop support. This control is only present if 839 the ccs_out_mode module option is set to the default value of -1 and if 840 the no_error_inj module option is set to 0 (the default). 841 842- Enable Output Composing: 843 844 enables composing support. This control is only 845 present if the ccs_out_mode module option is set to the default value of 846 -1 and if the no_error_inj module option is set to 0 (the default). 847 848- Enable Output Scaler: 849 850 enables support for a scaler (maximum 4 times upscaling 851 and downscaling). This control is only present if the ccs_out_mode 852 module option is set to the default value of -1 and if the no_error_inj 853 module option is set to 0 (the default). 854 855 856Error Injection Controls 857^^^^^^^^^^^^^^^^^^^^^^^^ 858 859The following two controls are only valid for video and vbi capture. 860 861- Standard Signal Mode: 862 863 selects the behavior of VIDIOC_QUERYSTD: what should it return? 864 865 Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE 866 to be sent since it emulates a changed input condition (e.g. a cable 867 was plugged in or out). 868 869- Standard: 870 871 selects the standard that VIDIOC_QUERYSTD should return if the 872 previous control is set to "Selected Standard". 873 874 Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE 875 to be sent since it emulates a changed input standard. 876 877 878The following two controls are only valid for video capture. 879 880- DV Timings Signal Mode: 881 882 selects the behavior of VIDIOC_QUERY_DV_TIMINGS: what 883 should it return? 884 885 Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE 886 to be sent since it emulates a changed input condition (e.g. a cable 887 was plugged in or out). 888 889- DV Timings: 890 891 selects the timings the VIDIOC_QUERY_DV_TIMINGS should return 892 if the previous control is set to "Selected DV Timings". 893 894 Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE 895 to be sent since it emulates changed input timings. 896 897 898The following controls are only present if the no_error_inj module option 899is set to 0 (the default). These controls are valid for video and vbi 900capture and output streams and for the SDR capture device except for the 901Disconnect control which is valid for all devices. 902 903- Wrap Sequence Number: 904 905 test what happens when you wrap the sequence number in 906 struct v4l2_buffer around. 907 908- Wrap Timestamp: 909 910 test what happens when you wrap the timestamp in struct 911 v4l2_buffer around. 912 913- Percentage of Dropped Buffers: 914 915 sets the percentage of buffers that 916 are never returned by the driver (i.e., they are dropped). 917 918- Disconnect: 919 920 emulates a USB disconnect. The device will act as if it has 921 been disconnected. Only after all open filehandles to the device 922 node have been closed will the device become 'connected' again. 923 924- Inject V4L2_BUF_FLAG_ERROR: 925 926 when pressed, the next frame returned by 927 the driver will have the error flag set (i.e. the frame is marked 928 corrupt). 929 930- Inject VIDIOC_REQBUFS Error: 931 932 when pressed, the next REQBUFS or CREATE_BUFS 933 ioctl call will fail with an error. To be precise: the videobuf2 934 queue_setup() op will return -EINVAL. 935 936- Inject VIDIOC_QBUF Error: 937 938 when pressed, the next VIDIOC_QBUF or 939 VIDIOC_PREPARE_BUFFER ioctl call will fail with an error. To be 940 precise: the videobuf2 buf_prepare() op will return -EINVAL. 941 942- Inject VIDIOC_STREAMON Error: 943 944 when pressed, the next VIDIOC_STREAMON ioctl 945 call will fail with an error. To be precise: the videobuf2 946 start_streaming() op will return -EINVAL. 947 948- Inject Fatal Streaming Error: 949 950 when pressed, the streaming core will be 951 marked as having suffered a fatal error, the only way to recover 952 from that is to stop streaming. To be precise: the videobuf2 953 vb2_queue_error() function is called. 954 955 956VBI Raw Capture Controls 957^^^^^^^^^^^^^^^^^^^^^^^^ 958 959- Interlaced VBI Format: 960 961 if set, then the raw VBI data will be interlaced instead 962 of providing it grouped by field. 963 964 965Digital Video Controls 966~~~~~~~~~~~~~~~~~~~~~~ 967 968- Rx RGB Quantization Range: 969 970 sets the RGB quantization detection of the HDMI 971 input. This combines with the Vivid 'Limited RGB Range (16-235)' 972 control and can be used to test what happens if a source provides 973 you with the wrong quantization range information. This can be tested 974 by selecting an HDMI input, setting this control to Full or Limited 975 range and selecting the opposite in the 'Limited RGB Range (16-235)' 976 control. The effect is easy to see if the 'Gray Ramp' test pattern 977 is selected. 978 979- Tx RGB Quantization Range: 980 981 sets the RGB quantization detection of the HDMI 982 output. It is currently not used for anything in vivid, but most HDMI 983 transmitters would typically have this control. 984 985- Transmit Mode: 986 987 sets the transmit mode of the HDMI output to HDMI or DVI-D. This 988 affects the reported colorspace since DVI_D outputs will always use 989 sRGB. 990 991- Display Present: 992 993 sets the presence of a "display" on the HDMI output. This affects 994 the tx_edid_present, tx_hotplug and tx_rxsense controls. 995 996 997FM Radio Receiver Controls 998~~~~~~~~~~~~~~~~~~~~~~~~~~ 999 1000- RDS Reception: 1001 1002 set if the RDS receiver should be enabled. 1003 1004- RDS Program Type: 1005 1006 1007- RDS PS Name: 1008 1009 1010- RDS Radio Text: 1011 1012 1013- RDS Traffic Announcement: 1014 1015 1016- RDS Traffic Program: 1017 1018 1019- RDS Music: 1020 1021 these are all read-only controls. If RDS Rx I/O Mode is set to 1022 "Block I/O", then they are inactive as well. If RDS Rx I/O Mode is set 1023 to "Controls", then these controls report the received RDS data. 1024 1025.. note:: 1026 The vivid implementation of this is pretty basic: they are only 1027 updated when you set a new frequency or when you get the tuner status 1028 (VIDIOC_G_TUNER). 1029 1030- Radio HW Seek Mode: 1031 1032 can be one of "Bounded", "Wrap Around" or "Both". This 1033 determines if VIDIOC_S_HW_FREQ_SEEK will be bounded by the frequency 1034 range or wrap-around or if it is selectable by the user. 1035 1036- Radio Programmable HW Seek: 1037 1038 if set, then the user can provide the lower and 1039 upper bound of the HW Seek. Otherwise the frequency range boundaries 1040 will be used. 1041 1042- Generate RBDS Instead of RDS: 1043 1044 if set, then generate RBDS (the US variant of 1045 RDS) data instead of RDS (European-style RDS). This affects only the 1046 PICODE and PTY codes. 1047 1048- RDS Rx I/O Mode: 1049 1050 this can be "Block I/O" where the RDS blocks have to be read() 1051 by the application, or "Controls" where the RDS data is provided by 1052 the RDS controls mentioned above. 1053 1054 1055FM Radio Modulator Controls 1056~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1057 1058- RDS Program ID: 1059 1060 1061- RDS Program Type: 1062 1063 1064- RDS PS Name: 1065 1066 1067- RDS Radio Text: 1068 1069 1070- RDS Stereo: 1071 1072 1073- RDS Artificial Head: 1074 1075 1076- RDS Compressed: 1077 1078 1079- RDS Dynamic PTY: 1080 1081 1082- RDS Traffic Announcement: 1083 1084 1085- RDS Traffic Program: 1086 1087 1088- RDS Music: 1089 1090 these are all controls that set the RDS data that is transmitted by 1091 the FM modulator. 1092 1093- RDS Tx I/O Mode: 1094 1095 this can be "Block I/O" where the application has to use write() 1096 to pass the RDS blocks to the driver, or "Controls" where the RDS data 1097 is Provided by the RDS controls mentioned above. 1098 1099Metadata Capture Controls 1100~~~~~~~~~~~~~~~~~~~~~~~~~~ 1101 1102- Generate PTS 1103 1104 if set, then the generated metadata stream contains Presentation timestamp. 1105 1106- Generate SCR 1107 1108 if set, then the generated metadata stream contains Source Clock information. 1109 1110Video, VBI and RDS Looping 1111-------------------------- 1112 1113The vivid driver supports looping of video output to video input, VBI output 1114to VBI input and RDS output to RDS input. For video/VBI looping this emulates 1115as if a cable was hooked up between the output and input connector. So video 1116and VBI looping is only supported between S-Video and HDMI inputs and outputs. 1117VBI is only valid for S-Video as it makes no sense for HDMI. 1118 1119Since radio is wireless this looping always happens if the radio receiver 1120frequency is close to the radio transmitter frequency. In that case the radio 1121transmitter will 'override' the emulated radio stations. 1122 1123Looping is currently supported only between devices created by the same 1124vivid driver instance. 1125 1126 1127Video and Sliced VBI looping 1128~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1129 1130The way to enable video/VBI looping is currently fairly crude. A 'Loop Video' 1131control is available in the "Vivid" control class of the video 1132capture and VBI capture devices. When checked the video looping will be enabled. 1133Once enabled any video S-Video or HDMI input will show a static test pattern 1134until the video output has started. At that time the video output will be 1135looped to the video input provided that: 1136 1137- the input type matches the output type. So the HDMI input cannot receive 1138 video from the S-Video output. 1139 1140- the video resolution of the video input must match that of the video output. 1141 So it is not possible to loop a 50 Hz (720x576) S-Video output to a 60 Hz 1142 (720x480) S-Video input, or a 720p60 HDMI output to a 1080p30 input. 1143 1144- the pixel formats must be identical on both sides. Otherwise the driver would 1145 have to do pixel format conversion as well, and that's taking things too far. 1146 1147- the field settings must be identical on both sides. Same reason as above: 1148 requiring the driver to convert from one field format to another complicated 1149 matters too much. This also prohibits capturing with 'Field Top' or 'Field 1150 Bottom' when the output video is set to 'Field Alternate'. This combination, 1151 while legal, became too complicated to support. Both sides have to be 'Field 1152 Alternate' for this to work. Also note that for this specific case the 1153 sequence and field counting in struct v4l2_buffer on the capture side may not 1154 be 100% accurate. 1155 1156- field settings V4L2_FIELD_SEQ_TB/BT are not supported. While it is possible to 1157 implement this, it would mean a lot of work to get this right. Since these 1158 field values are rarely used the decision was made not to implement this for 1159 now. 1160 1161- on the input side the "Standard Signal Mode" for the S-Video input or the 1162 "DV Timings Signal Mode" for the HDMI input should be configured so that a 1163 valid signal is passed to the video input. 1164 1165The framerates do not have to match, although this might change in the future. 1166 1167By default you will see the OSD text superimposed on top of the looped video. 1168This can be turned off by changing the "OSD Text Mode" control of the video 1169capture device. 1170 1171For VBI looping to work all of the above must be valid and in addition the vbi 1172output must be configured for sliced VBI. The VBI capture side can be configured 1173for either raw or sliced VBI. Note that at the moment only CC/XDS (60 Hz formats) 1174and WSS (50 Hz formats) VBI data is looped. Teletext VBI data is not looped. 1175 1176 1177Radio & RDS Looping 1178~~~~~~~~~~~~~~~~~~~ 1179 1180As mentioned in section 6 the radio receiver emulates stations are regular 1181frequency intervals. Depending on the frequency of the radio receiver a 1182signal strength value is calculated (this is returned by VIDIOC_G_TUNER). 1183However, it will also look at the frequency set by the radio transmitter and 1184if that results in a higher signal strength than the settings of the radio 1185transmitter will be used as if it was a valid station. This also includes 1186the RDS data (if any) that the transmitter 'transmits'. This is received 1187faithfully on the receiver side. Note that when the driver is loaded the 1188frequencies of the radio receiver and transmitter are not identical, so 1189initially no looping takes place. 1190 1191 1192Cropping, Composing, Scaling 1193---------------------------- 1194 1195This driver supports cropping, composing and scaling in any combination. Normally 1196which features are supported can be selected through the Vivid controls, 1197but it is also possible to hardcode it when the module is loaded through the 1198ccs_cap_mode and ccs_out_mode module options. See section 1 on the details of 1199these module options. 1200 1201This allows you to test your application for all these variations. 1202 1203Note that the webcam input never supports cropping, composing or scaling. That 1204only applies to the TV/S-Video/HDMI inputs and outputs. The reason is that 1205webcams, including this virtual implementation, normally use 1206VIDIOC_ENUM_FRAMESIZES to list a set of discrete framesizes that it supports. 1207And that does not combine with cropping, composing or scaling. This is 1208primarily a limitation of the V4L2 API which is carefully reproduced here. 1209 1210The minimum and maximum resolutions that the scaler can achieve are 16x16 and 1211(4096 * 4) x (2160 x 4), but it can only scale up or down by a factor of 4 or 1212less. So for a source resolution of 1280x720 the minimum the scaler can do is 1213320x180 and the maximum is 5120x2880. You can play around with this using the 1214qv4l2 test tool and you will see these dependencies. 1215 1216This driver also supports larger 'bytesperline' settings, something that 1217VIDIOC_S_FMT allows but that few drivers implement. 1218 1219The scaler is a simple scaler that uses the Coarse Bresenham algorithm. It's 1220designed for speed and simplicity, not quality. 1221 1222If the combination of crop, compose and scaling allows it, then it is possible 1223to change crop and compose rectangles on the fly. 1224 1225 1226Formats 1227------- 1228 1229The driver supports all the regular packed and planar 4:4:4, 4:2:2 and 4:2:0 1230YUYV formats, 8, 16, 24 and 32 RGB packed formats and various multiplanar 1231formats. 1232 1233The alpha component can be set through the 'Alpha Component' User control 1234for those formats that support it. If the 'Apply Alpha To Red Only' control 1235is set, then the alpha component is only used for the color red and set to 12360 otherwise. 1237 1238The driver has to be configured to support the multiplanar formats. By default 1239the driver instances are single-planar. This can be changed by setting the 1240multiplanar module option, see section 1 for more details on that option. 1241 1242If the driver instance is using the multiplanar formats/API, then the first 1243single planar format (YUYV) and the multiplanar NV16M and NV61M formats the 1244will have a plane that has a non-zero data_offset of 128 bytes. It is rare for 1245data_offset to be non-zero, so this is a useful feature for testing applications. 1246 1247Video output will also honor any data_offset that the application set. 1248 1249 1250Capture Overlay 1251--------------- 1252 1253Note: capture overlay support is implemented primarily to test the existing 1254V4L2 capture overlay API. In practice few if any GPUs support such overlays 1255anymore, and neither are they generally needed anymore since modern hardware 1256is so much more capable. By setting flag 0x10000 in the node_types module 1257option the vivid driver will create a simple framebuffer device that can be 1258used for testing this API. Whether this API should be used for new drivers is 1259questionable. 1260 1261This driver has support for a destructive capture overlay with bitmap clipping 1262and list clipping (up to 16 rectangles) capabilities. Overlays are not 1263supported for multiplanar formats. It also honors the struct v4l2_window field 1264setting: if it is set to FIELD_TOP or FIELD_BOTTOM and the capture setting is 1265FIELD_ALTERNATE, then only the top or bottom fields will be copied to the overlay. 1266 1267The overlay only works if you are also capturing at that same time. This is a 1268vivid limitation since it copies from a buffer to the overlay instead of 1269filling the overlay directly. And if you are not capturing, then no buffers 1270are available to fill. 1271 1272In addition, the pixelformat of the capture format and that of the framebuffer 1273must be the same for the overlay to work. Otherwise VIDIOC_OVERLAY will return 1274an error. 1275 1276In order to really see what it going on you will need to create two vivid 1277instances: the first with a framebuffer enabled. You configure the capture 1278overlay of the second instance to use the framebuffer of the first, then 1279you start capturing in the second instance. For the first instance you setup 1280the output overlay for the video output, turn on video looping and capture 1281to see the blended framebuffer overlay that's being written to by the second 1282instance. This setup would require the following commands: 1283 1284.. code-block:: none 1285 1286 $ sudo modprobe vivid n_devs=2 node_types=0x10101,0x1 1287 $ v4l2-ctl -d1 --find-fb 1288 /dev/fb1 is the framebuffer associated with base address 0x12800000 1289 $ sudo v4l2-ctl -d2 --set-fbuf fb=1 1290 $ v4l2-ctl -d1 --set-fbuf fb=1 1291 $ v4l2-ctl -d0 --set-fmt-video=pixelformat='AR15' 1292 $ v4l2-ctl -d1 --set-fmt-video-out=pixelformat='AR15' 1293 $ v4l2-ctl -d2 --set-fmt-video=pixelformat='AR15' 1294 $ v4l2-ctl -d0 -i2 1295 $ v4l2-ctl -d2 -i2 1296 $ v4l2-ctl -d2 -c horizontal_movement=4 1297 $ v4l2-ctl -d1 --overlay=1 1298 $ v4l2-ctl -d1 -c loop_video=1 1299 $ v4l2-ctl -d2 --stream-mmap --overlay=1 1300 1301And from another console: 1302 1303.. code-block:: none 1304 1305 $ v4l2-ctl -d1 --stream-out-mmap 1306 1307And yet another console: 1308 1309.. code-block:: none 1310 1311 $ qv4l2 1312 1313and start streaming. 1314 1315As you can see, this is not for the faint of heart... 1316 1317 1318Output Overlay 1319-------------- 1320 1321Note: output overlays are primarily implemented in order to test the existing 1322V4L2 output overlay API. Whether this API should be used for new drivers is 1323questionable. 1324 1325This driver has support for an output overlay and is capable of: 1326 1327 - bitmap clipping, 1328 - list clipping (up to 16 rectangles) 1329 - chromakey 1330 - source chromakey 1331 - global alpha 1332 - local alpha 1333 - local inverse alpha 1334 1335Output overlays are not supported for multiplanar formats. In addition, the 1336pixelformat of the capture format and that of the framebuffer must be the 1337same for the overlay to work. Otherwise VIDIOC_OVERLAY will return an error. 1338 1339Output overlays only work if the driver has been configured to create a 1340framebuffer by setting flag 0x10000 in the node_types module option. The 1341created framebuffer has a size of 720x576 and supports ARGB 1:5:5:5 and 1342RGB 5:6:5. 1343 1344In order to see the effects of the various clipping, chromakeying or alpha 1345processing capabilities you need to turn on video looping and see the results 1346on the capture side. The use of the clipping, chromakeying or alpha processing 1347capabilities will slow down the video loop considerably as a lot of checks have 1348to be done per pixel. 1349 1350 1351CEC (Consumer Electronics Control) 1352---------------------------------- 1353 1354If there are HDMI inputs then a CEC adapter will be created that has 1355the same number of input ports. This is the equivalent of e.g. a TV that 1356has that number of inputs. Each HDMI output will also create a 1357CEC adapter that is hooked up to the corresponding input port, or (if there 1358are more outputs than inputs) is not hooked up at all. In other words, 1359this is the equivalent of hooking up each output device to an input port of 1360the TV. Any remaining output devices remain unconnected. 1361 1362The EDID that each output reads reports a unique CEC physical address that is 1363based on the physical address of the EDID of the input. So if the EDID of the 1364receiver has physical address A.B.0.0, then each output will see an EDID 1365containing physical address A.B.C.0 where C is 1 to the number of inputs. If 1366there are more outputs than inputs then the remaining outputs have a CEC adapter 1367that is disabled and reports an invalid physical address. 1368 1369 1370Some Future Improvements 1371------------------------ 1372 1373Just as a reminder and in no particular order: 1374 1375- Add a virtual alsa driver to test audio 1376- Add virtual sub-devices and media controller support 1377- Some support for testing compressed video 1378- Add support to loop raw VBI output to raw VBI input 1379- Add support to loop teletext sliced VBI output to VBI input 1380- Fix sequence/field numbering when looping of video with alternate fields 1381- Add support for V4L2_CID_BG_COLOR for video outputs 1382- Add ARGB888 overlay support: better testing of the alpha channel 1383- Improve pixel aspect support in the tpg code by passing a real v4l2_fract 1384- Use per-queue locks and/or per-device locks to improve throughput 1385- Add support to loop from a specific output to a specific input across 1386 vivid instances 1387- The SDR radio should use the same 'frequencies' for stations as the normal 1388 radio receiver, and give back noise if the frequency doesn't match up with 1389 a station frequency 1390- Make a thread for the RDS generation, that would help in particular for the 1391 "Controls" RDS Rx I/O Mode as the read-only RDS controls could be updated 1392 in real-time. 1393- Changing the EDID should cause hotplug detect emulation to happen. 1394