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Commit | Line | Data |
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cff4c8ac MCC |
1 | The Virtual Video Test Driver (vivid) |
2 | ===================================== | |
6a683493 HV |
3 | |
4 | This driver emulates video4linux hardware of various types: video capture, video | |
5 | output, vbi capture and output, radio receivers and transmitters and a software | |
6 | defined radio receiver. In addition a simple framebuffer device is available for | |
7 | testing capture and output overlays. | |
8 | ||
9 | Up to 64 vivid instances can be created, each with up to 16 inputs and 16 outputs. | |
10 | ||
11 | Each input can be a webcam, TV capture device, S-Video capture device or an HDMI | |
12 | capture device. Each output can be an S-Video output device or an HDMI output | |
13 | device. | |
14 | ||
15 | These inputs and outputs act exactly as a real hardware device would behave. This | |
16 | allows you to use this driver as a test input for application development, since | |
17 | you can test the various features without requiring special hardware. | |
18 | ||
19 | This document describes the features implemented by this driver: | |
20 | ||
21 | - Support for read()/write(), MMAP, USERPTR and DMABUF streaming I/O. | |
22 | - A large list of test patterns and variations thereof | |
23 | - Working brightness, contrast, saturation and hue controls | |
24 | - Support for the alpha color component | |
25 | - Full colorspace support, including limited/full RGB range | |
26 | - All possible control types are present | |
27 | - Support for various pixel aspect ratios and video aspect ratios | |
28 | - Error injection to test what happens if errors occur | |
29 | - Supports crop/compose/scale in any combination for both input and output | |
30 | - Can emulate up to 4K resolutions | |
31 | - All Field settings are supported for testing interlaced capturing | |
32 | - Supports all standard YUV and RGB formats, including two multiplanar YUV formats | |
33 | - Raw and Sliced VBI capture and output support | |
34 | - Radio receiver and transmitter support, including RDS support | |
35 | - Software defined radio (SDR) support | |
36 | - Capture and output overlay support | |
37 | ||
38 | These features will be described in more detail below. | |
39 | ||
cff4c8ac MCC |
40 | Configuring the driver |
41 | ---------------------- | |
6a683493 HV |
42 | |
43 | By default the driver will create a single instance that has a video capture | |
44 | device with webcam, TV, S-Video and HDMI inputs, a video output device with | |
45 | S-Video and HDMI outputs, one vbi capture device, one vbi output device, one | |
46 | radio receiver device, one radio transmitter device and one SDR device. | |
47 | ||
48 | The number of instances, devices, video inputs and outputs and their types are | |
49 | all configurable using the following module options: | |
50 | ||
cff4c8ac MCC |
51 | - n_devs: |
52 | ||
53 | number of driver instances to create. By default set to 1. Up to 64 | |
6a683493 HV |
54 | instances can be created. |
55 | ||
cff4c8ac MCC |
56 | - node_types: |
57 | ||
58 | which devices should each driver instance create. An array of | |
6a683493 HV |
59 | hexadecimal values, one for each instance. The default is 0x1d3d. |
60 | Each value is a bitmask with the following meaning: | |
cff4c8ac MCC |
61 | |
62 | - bit 0: Video Capture node | |
63 | - bit 2-3: VBI Capture node: 0 = none, 1 = raw vbi, 2 = sliced vbi, 3 = both | |
64 | - bit 4: Radio Receiver node | |
65 | - bit 5: Software Defined Radio Receiver node | |
66 | - bit 8: Video Output node | |
67 | - bit 10-11: VBI Output node: 0 = none, 1 = raw vbi, 2 = sliced vbi, 3 = both | |
68 | - bit 12: Radio Transmitter node | |
69 | - bit 16: Framebuffer for testing overlays | |
6a683493 HV |
70 | |
71 | So to create four instances, the first two with just one video capture | |
72 | device, the second two with just one video output device you would pass | |
73 | these module options to vivid: | |
74 | ||
cff4c8ac MCC |
75 | .. code-block:: none |
76 | ||
6a683493 HV |
77 | n_devs=4 node_types=0x1,0x1,0x100,0x100 |
78 | ||
cff4c8ac MCC |
79 | - num_inputs: |
80 | ||
81 | the number of inputs, one for each instance. By default 4 inputs | |
6a683493 HV |
82 | are created for each video capture device. At most 16 inputs can be created, |
83 | and there must be at least one. | |
84 | ||
cff4c8ac MCC |
85 | - input_types: |
86 | ||
87 | the input types for each instance, the default is 0xe4. This defines | |
6a683493 HV |
88 | what the type of each input is when the inputs are created for each driver |
89 | instance. This is a hexadecimal value with up to 16 pairs of bits, each | |
90 | pair gives the type and bits 0-1 map to input 0, bits 2-3 map to input 1, | |
91 | 30-31 map to input 15. Each pair of bits has the following meaning: | |
92 | ||
cff4c8ac MCC |
93 | - 00: this is a webcam input |
94 | - 01: this is a TV tuner input | |
95 | - 10: this is an S-Video input | |
96 | - 11: this is an HDMI input | |
6a683493 HV |
97 | |
98 | So to create a video capture device with 8 inputs where input 0 is a TV | |
99 | tuner, inputs 1-3 are S-Video inputs and inputs 4-7 are HDMI inputs you | |
100 | would use the following module options: | |
101 | ||
cff4c8ac MCC |
102 | .. code-block:: none |
103 | ||
6a683493 HV |
104 | num_inputs=8 input_types=0xffa9 |
105 | ||
cff4c8ac MCC |
106 | - num_outputs: |
107 | ||
108 | the number of outputs, one for each instance. By default 2 outputs | |
6a683493 HV |
109 | are created for each video output device. At most 16 outputs can be |
110 | created, and there must be at least one. | |
111 | ||
cff4c8ac MCC |
112 | - output_types: |
113 | ||
114 | the output types for each instance, the default is 0x02. This defines | |
6a683493 HV |
115 | what the type of each output is when the outputs are created for each |
116 | driver instance. This is a hexadecimal value with up to 16 bits, each bit | |
117 | gives the type and bit 0 maps to output 0, bit 1 maps to output 1, bit | |
118 | 15 maps to output 15. The meaning of each bit is as follows: | |
119 | ||
cff4c8ac MCC |
120 | - 0: this is an S-Video output |
121 | - 1: this is an HDMI output | |
6a683493 HV |
122 | |
123 | So to create a video output device with 8 outputs where outputs 0-3 are | |
124 | S-Video outputs and outputs 4-7 are HDMI outputs you would use the | |
125 | following module options: | |
126 | ||
cff4c8ac MCC |
127 | .. code-block:: none |
128 | ||
6a683493 HV |
129 | num_outputs=8 output_types=0xf0 |
130 | ||
cff4c8ac MCC |
131 | - vid_cap_nr: |
132 | ||
133 | give the desired videoX start number for each video capture device. | |
6a683493 HV |
134 | The default is -1 which will just take the first free number. This allows |
135 | you to map capture video nodes to specific videoX device nodes. Example: | |
136 | ||
cff4c8ac MCC |
137 | .. code-block:: none |
138 | ||
6a683493 HV |
139 | n_devs=4 vid_cap_nr=2,4,6,8 |
140 | ||
141 | This will attempt to assign /dev/video2 for the video capture device of | |
142 | the first vivid instance, video4 for the next up to video8 for the last | |
143 | instance. If it can't succeed, then it will just take the next free | |
144 | number. | |
145 | ||
cff4c8ac MCC |
146 | - vid_out_nr: |
147 | ||
148 | give the desired videoX start number for each video output device. | |
149 | The default is -1 which will just take the first free number. | |
150 | ||
151 | - vbi_cap_nr: | |
6a683493 | 152 | |
cff4c8ac MCC |
153 | give the desired vbiX start number for each vbi capture device. |
154 | The default is -1 which will just take the first free number. | |
6a683493 | 155 | |
cff4c8ac | 156 | - vbi_out_nr: |
6a683493 | 157 | |
cff4c8ac MCC |
158 | give the desired vbiX start number for each vbi output device. |
159 | The default is -1 which will just take the first free number. | |
6a683493 | 160 | |
cff4c8ac MCC |
161 | - radio_rx_nr: |
162 | ||
163 | give the desired radioX start number for each radio receiver device. | |
164 | The default is -1 which will just take the first free number. | |
165 | ||
166 | - radio_tx_nr: | |
167 | ||
168 | give the desired radioX start number for each radio transmitter | |
6a683493 HV |
169 | device. The default is -1 which will just take the first free number. |
170 | ||
cff4c8ac MCC |
171 | - sdr_cap_nr: |
172 | ||
173 | give the desired swradioX start number for each SDR capture device. | |
174 | The default is -1 which will just take the first free number. | |
175 | ||
176 | - ccs_cap_mode: | |
6a683493 | 177 | |
cff4c8ac | 178 | specify the allowed video capture crop/compose/scaling combination |
6a683493 HV |
179 | for each driver instance. Video capture devices can have any combination |
180 | of cropping, composing and scaling capabilities and this will tell the | |
181 | vivid driver which of those is should emulate. By default the user can | |
182 | select this through controls. | |
183 | ||
184 | The value is either -1 (controlled by the user) or a set of three bits, | |
185 | each enabling (1) or disabling (0) one of the features: | |
186 | ||
cff4c8ac MCC |
187 | - bit 0: |
188 | ||
189 | Enable crop support. Cropping will take only part of the | |
190 | incoming picture. | |
191 | - bit 1: | |
192 | ||
193 | Enable compose support. Composing will copy the incoming | |
194 | picture into a larger buffer. | |
195 | ||
196 | - bit 2: | |
197 | ||
198 | Enable scaling support. Scaling can scale the incoming | |
199 | picture. The scaler of the vivid driver can enlarge up | |
200 | or down to four times the original size. The scaler is | |
201 | very simple and low-quality. Simplicity and speed were | |
202 | key, not quality. | |
6a683493 HV |
203 | |
204 | Note that this value is ignored by webcam inputs: those enumerate | |
205 | discrete framesizes and that is incompatible with cropping, composing | |
206 | or scaling. | |
207 | ||
cff4c8ac MCC |
208 | - ccs_out_mode: |
209 | ||
210 | specify the allowed video output crop/compose/scaling combination | |
6a683493 HV |
211 | for each driver instance. Video output devices can have any combination |
212 | of cropping, composing and scaling capabilities and this will tell the | |
213 | vivid driver which of those is should emulate. By default the user can | |
214 | select this through controls. | |
215 | ||
216 | The value is either -1 (controlled by the user) or a set of three bits, | |
217 | each enabling (1) or disabling (0) one of the features: | |
218 | ||
cff4c8ac MCC |
219 | - bit 0: |
220 | ||
221 | Enable crop support. Cropping will take only part of the | |
222 | outgoing buffer. | |
223 | ||
224 | - bit 1: | |
225 | ||
226 | Enable compose support. Composing will copy the incoming | |
227 | buffer into a larger picture frame. | |
228 | ||
229 | - bit 2: | |
230 | ||
231 | Enable scaling support. Scaling can scale the incoming | |
232 | buffer. The scaler of the vivid driver can enlarge up | |
233 | or down to four times the original size. The scaler is | |
234 | very simple and low-quality. Simplicity and speed were | |
235 | key, not quality. | |
236 | ||
237 | - multiplanar: | |
238 | ||
239 | select whether each device instance supports multi-planar formats, | |
cba63cf8 HV |
240 | and thus the V4L2 multi-planar API. By default device instances are |
241 | single-planar. | |
6a683493 HV |
242 | |
243 | This module option can override that for each instance. Values are: | |
244 | ||
cff4c8ac MCC |
245 | - 1: this is a single-planar instance. |
246 | - 2: this is a multi-planar instance. | |
6a683493 | 247 | |
cff4c8ac | 248 | - vivid_debug: |
6a683493 | 249 | |
cff4c8ac MCC |
250 | enable driver debugging info |
251 | ||
252 | - no_error_inj: | |
253 | ||
254 | if set disable the error injecting controls. This option is | |
6a683493 HV |
255 | needed in order to run a tool like v4l2-compliance. Tools like that |
256 | exercise all controls including a control like 'Disconnect' which | |
257 | emulates a USB disconnect, making the device inaccessible and so | |
258 | all tests that v4l2-compliance is doing will fail afterwards. | |
259 | ||
260 | There may be other situations as well where you want to disable the | |
261 | error injection support of vivid. When this option is set, then the | |
262 | controls that select crop, compose and scale behavior are also | |
263 | removed. Unless overridden by ccs_cap_mode and/or ccs_out_mode the | |
264 | will default to enabling crop, compose and scaling. | |
265 | ||
8ecc5413 VA |
266 | - allocators: |
267 | ||
268 | memory allocator selection, default is 0. It specifies the way buffers | |
269 | will be allocated. | |
270 | ||
271 | - 0: vmalloc | |
272 | - 1: dma-contig | |
273 | ||
6a683493 HV |
274 | Taken together, all these module options allow you to precisely customize |
275 | the driver behavior and test your application with all sorts of permutations. | |
276 | It is also very suitable to emulate hardware that is not yet available, e.g. | |
277 | when developing software for a new upcoming device. | |
278 | ||
279 | ||
cff4c8ac MCC |
280 | Video Capture |
281 | ------------- | |
6a683493 HV |
282 | |
283 | This is probably the most frequently used feature. The video capture device | |
284 | can be configured by using the module options num_inputs, input_types and | |
285 | ccs_cap_mode (see section 1 for more detailed information), but by default | |
286 | four inputs are configured: a webcam, a TV tuner, an S-Video and an HDMI | |
287 | input, one input for each input type. Those are described in more detail | |
288 | below. | |
289 | ||
290 | Special attention has been given to the rate at which new frames become | |
291 | available. The jitter will be around 1 jiffie (that depends on the HZ | |
292 | configuration of your kernel, so usually 1/100, 1/250 or 1/1000 of a second), | |
293 | but the long-term behavior is exactly following the framerate. So a | |
294 | framerate of 59.94 Hz is really different from 60 Hz. If the framerate | |
295 | exceeds your kernel's HZ value, then you will get dropped frames, but the | |
296 | frame/field sequence counting will keep track of that so the sequence | |
297 | count will skip whenever frames are dropped. | |
298 | ||
299 | ||
cff4c8ac MCC |
300 | Webcam Input |
301 | ~~~~~~~~~~~~ | |
6a683493 HV |
302 | |
303 | The webcam input supports three framesizes: 320x180, 640x360 and 1280x720. It | |
304 | supports frames per second settings of 10, 15, 25, 30, 50 and 60 fps. Which ones | |
305 | are available depends on the chosen framesize: the larger the framesize, the | |
306 | lower the maximum frames per second. | |
307 | ||
308 | The initially selected colorspace when you switch to the webcam input will be | |
309 | sRGB. | |
310 | ||
311 | ||
cff4c8ac MCC |
312 | TV and S-Video Inputs |
313 | ~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
314 | |
315 | The only difference between the TV and S-Video input is that the TV has a | |
316 | tuner. Otherwise they behave identically. | |
317 | ||
318 | These inputs support audio inputs as well: one TV and one Line-In. They | |
319 | both support all TV standards. If the standard is queried, then the Vivid | |
320 | controls 'Standard Signal Mode' and 'Standard' determine what | |
321 | the result will be. | |
322 | ||
323 | These inputs support all combinations of the field setting. Special care has | |
324 | been taken to faithfully reproduce how fields are handled for the different | |
1a2b2c70 | 325 | TV standards. This is particularly noticeable when generating a horizontally |
6a683493 HV |
326 | moving image so the temporal effect of using interlaced formats becomes clearly |
327 | visible. For 50 Hz standards the top field is the oldest and the bottom field | |
328 | is the newest in time. For 60 Hz standards that is reversed: the bottom field | |
329 | is the oldest and the top field is the newest in time. | |
330 | ||
331 | When you start capturing in V4L2_FIELD_ALTERNATE mode the first buffer will | |
332 | contain the top field for 50 Hz standards and the bottom field for 60 Hz | |
333 | standards. This is what capture hardware does as well. | |
334 | ||
335 | Finally, for PAL/SECAM standards the first half of the top line contains noise. | |
336 | This simulates the Wide Screen Signal that is commonly placed there. | |
337 | ||
338 | The initially selected colorspace when you switch to the TV or S-Video input | |
339 | will be SMPTE-170M. | |
340 | ||
341 | The pixel aspect ratio will depend on the TV standard. The video aspect ratio | |
342 | can be selected through the 'Standard Aspect Ratio' Vivid control. | |
343 | Choices are '4x3', '16x9' which will give letterboxed widescreen video and | |
1a2b2c70 | 344 | '16x9 Anamorphic' which will give full screen squashed anamorphic widescreen |
6a683493 HV |
345 | video that will need to be scaled accordingly. |
346 | ||
347 | The TV 'tuner' supports a frequency range of 44-958 MHz. Channels are available | |
348 | every 6 MHz, starting from 49.25 MHz. For each channel the generated image | |
349 | will be in color for the +/- 0.25 MHz around it, and in grayscale for | |
350 | +/- 1 MHz around the channel. Beyond that it is just noise. The VIDIOC_G_TUNER | |
351 | ioctl will return 100% signal strength for +/- 0.25 MHz and 50% for +/- 1 MHz. | |
352 | It will also return correct afc values to show whether the frequency is too | |
353 | low or too high. | |
354 | ||
355 | The audio subchannels that are returned are MONO for the +/- 1 MHz range around | |
356 | a valid channel frequency. When the frequency is within +/- 0.25 MHz of the | |
357 | channel it will return either MONO, STEREO, either MONO | SAP (for NTSC) or | |
358 | LANG1 | LANG2 (for others), or STEREO | SAP. | |
359 | ||
360 | Which one is returned depends on the chosen channel, each next valid channel | |
361 | will cycle through the possible audio subchannel combinations. This allows | |
362 | you to test the various combinations by just switching channels.. | |
363 | ||
364 | Finally, for these inputs the v4l2_timecode struct is filled in in the | |
365 | dequeued v4l2_buffer struct. | |
366 | ||
367 | ||
cff4c8ac MCC |
368 | HDMI Input |
369 | ~~~~~~~~~~ | |
6a683493 HV |
370 | |
371 | The HDMI inputs supports all CEA-861 and DMT timings, both progressive and | |
372 | interlaced, for pixelclock frequencies between 25 and 600 MHz. The field | |
373 | mode for interlaced formats is always V4L2_FIELD_ALTERNATE. For HDMI the | |
374 | field order is always top field first, and when you start capturing an | |
375 | interlaced format you will receive the top field first. | |
376 | ||
377 | The initially selected colorspace when you switch to the HDMI input or | |
378 | select an HDMI timing is based on the format resolution: for resolutions | |
379 | less than or equal to 720x576 the colorspace is set to SMPTE-170M, for | |
380 | others it is set to REC-709 (CEA-861 timings) or sRGB (VESA DMT timings). | |
381 | ||
382 | The pixel aspect ratio will depend on the HDMI timing: for 720x480 is it | |
383 | set as for the NTSC TV standard, for 720x576 it is set as for the PAL TV | |
384 | standard, and for all others a 1:1 pixel aspect ratio is returned. | |
385 | ||
386 | The video aspect ratio can be selected through the 'DV Timings Aspect Ratio' | |
387 | Vivid control. Choices are 'Source Width x Height' (just use the | |
388 | same ratio as the chosen format), '4x3' or '16x9', either of which can | |
389 | result in pillarboxed or letterboxed video. | |
390 | ||
391 | For HDMI inputs it is possible to set the EDID. By default a simple EDID | |
392 | is provided. You can only set the EDID for HDMI inputs. Internally, however, | |
393 | the EDID is shared between all HDMI inputs. | |
394 | ||
6f8adea2 HV |
395 | No interpretation is done of the EDID data with the exception of the |
396 | physical address. See the CEC section for more details. | |
397 | ||
398 | There is a maximum of 15 HDMI inputs (if there are more, then they will be | |
399 | reduced to 15) since that's the limitation of the EDID physical address. | |
6a683493 HV |
400 | |
401 | ||
cff4c8ac MCC |
402 | Video Output |
403 | ------------ | |
6a683493 HV |
404 | |
405 | The video output device can be configured by using the module options | |
406 | num_outputs, output_types and ccs_out_mode (see section 1 for more detailed | |
407 | information), but by default two outputs are configured: an S-Video and an | |
408 | HDMI input, one output for each output type. Those are described in more detail | |
409 | below. | |
410 | ||
411 | Like with video capture the framerate is also exact in the long term. | |
412 | ||
413 | ||
cff4c8ac MCC |
414 | S-Video Output |
415 | ~~~~~~~~~~~~~~ | |
6a683493 HV |
416 | |
417 | This output supports audio outputs as well: "Line-Out 1" and "Line-Out 2". | |
418 | The S-Video output supports all TV standards. | |
419 | ||
420 | This output supports all combinations of the field setting. | |
421 | ||
422 | The initially selected colorspace when you switch to the TV or S-Video input | |
423 | will be SMPTE-170M. | |
424 | ||
425 | ||
cff4c8ac MCC |
426 | HDMI Output |
427 | ~~~~~~~~~~~ | |
6a683493 HV |
428 | |
429 | The HDMI output supports all CEA-861 and DMT timings, both progressive and | |
430 | interlaced, for pixelclock frequencies between 25 and 600 MHz. The field | |
431 | mode for interlaced formats is always V4L2_FIELD_ALTERNATE. | |
432 | ||
433 | The initially selected colorspace when you switch to the HDMI output or | |
434 | select an HDMI timing is based on the format resolution: for resolutions | |
435 | less than or equal to 720x576 the colorspace is set to SMPTE-170M, for | |
436 | others it is set to REC-709 (CEA-861 timings) or sRGB (VESA DMT timings). | |
437 | ||
438 | The pixel aspect ratio will depend on the HDMI timing: for 720x480 is it | |
439 | set as for the NTSC TV standard, for 720x576 it is set as for the PAL TV | |
440 | standard, and for all others a 1:1 pixel aspect ratio is returned. | |
441 | ||
442 | An HDMI output has a valid EDID which can be obtained through VIDIOC_G_EDID. | |
443 | ||
6f8adea2 HV |
444 | There is a maximum of 15 HDMI outputs (if there are more, then they will be |
445 | reduced to 15) since that's the limitation of the EDID physical address. See | |
446 | also the CEC section for more details. | |
6a683493 | 447 | |
cff4c8ac MCC |
448 | VBI Capture |
449 | ----------- | |
6a683493 HV |
450 | |
451 | There are three types of VBI capture devices: those that only support raw | |
452 | (undecoded) VBI, those that only support sliced (decoded) VBI and those that | |
453 | support both. This is determined by the node_types module option. In all | |
454 | cases the driver will generate valid VBI data: for 60 Hz standards it will | |
455 | generate Closed Caption and XDS data. The closed caption stream will | |
456 | alternate between "Hello world!" and "Closed captions test" every second. | |
457 | The XDS stream will give the current time once a minute. For 50 Hz standards | |
458 | it will generate the Wide Screen Signal which is based on the actual Video | |
62f28725 | 459 | Aspect Ratio control setting and teletext pages 100-159, one page per frame. |
6a683493 HV |
460 | |
461 | The VBI device will only work for the S-Video and TV inputs, it will give | |
462 | back an error if the current input is a webcam or HDMI. | |
463 | ||
464 | ||
cff4c8ac MCC |
465 | VBI Output |
466 | ---------- | |
6a683493 HV |
467 | |
468 | There are three types of VBI output devices: those that only support raw | |
469 | (undecoded) VBI, those that only support sliced (decoded) VBI and those that | |
470 | support both. This is determined by the node_types module option. | |
471 | ||
62f28725 HV |
472 | The sliced VBI output supports the Wide Screen Signal and the teletext signal |
473 | for 50 Hz standards and Closed Captioning + XDS for 60 Hz standards. | |
6a683493 HV |
474 | |
475 | The VBI device will only work for the S-Video output, it will give | |
476 | back an error if the current output is HDMI. | |
477 | ||
478 | ||
cff4c8ac MCC |
479 | Radio Receiver |
480 | -------------- | |
6a683493 HV |
481 | |
482 | The radio receiver emulates an FM/AM/SW receiver. The FM band also supports RDS. | |
483 | The frequency ranges are: | |
484 | ||
cff4c8ac MCC |
485 | - FM: 64 MHz - 108 MHz |
486 | - AM: 520 kHz - 1710 kHz | |
487 | - SW: 2300 kHz - 26.1 MHz | |
6a683493 HV |
488 | |
489 | Valid channels are emulated every 1 MHz for FM and every 100 kHz for AM and SW. | |
490 | The signal strength decreases the further the frequency is from the valid | |
491 | frequency until it becomes 0% at +/- 50 kHz (FM) or 5 kHz (AM/SW) from the | |
492 | ideal frequency. The initial frequency when the driver is loaded is set to | |
493 | 95 MHz. | |
494 | ||
495 | The FM receiver supports RDS as well, both using 'Block I/O' and 'Controls' | |
496 | modes. In the 'Controls' mode the RDS information is stored in read-only | |
497 | controls. These controls are updated every time the frequency is changed, | |
498 | or when the tuner status is requested. The Block I/O method uses the read() | |
499 | interface to pass the RDS blocks on to the application for decoding. | |
500 | ||
501 | The RDS signal is 'detected' for +/- 12.5 kHz around the channel frequency, | |
502 | and the further the frequency is away from the valid frequency the more RDS | |
503 | errors are randomly introduced into the block I/O stream, up to 50% of all | |
504 | blocks if you are +/- 12.5 kHz from the channel frequency. All four errors | |
505 | can occur in equal proportions: blocks marked 'CORRECTED', blocks marked | |
506 | 'ERROR', blocks marked 'INVALID' and dropped blocks. | |
507 | ||
508 | The generated RDS stream contains all the standard fields contained in a | |
509 | 0B group, and also radio text and the current time. | |
510 | ||
511 | The receiver supports HW frequency seek, either in Bounded mode, Wrap Around | |
512 | mode or both, which is configurable with the "Radio HW Seek Mode" control. | |
513 | ||
514 | ||
cff4c8ac MCC |
515 | Radio Transmitter |
516 | ----------------- | |
6a683493 HV |
517 | |
518 | The radio transmitter emulates an FM/AM/SW transmitter. The FM band also supports RDS. | |
519 | The frequency ranges are: | |
520 | ||
cff4c8ac MCC |
521 | - FM: 64 MHz - 108 MHz |
522 | - AM: 520 kHz - 1710 kHz | |
523 | - SW: 2300 kHz - 26.1 MHz | |
6a683493 HV |
524 | |
525 | The initial frequency when the driver is loaded is 95.5 MHz. | |
526 | ||
527 | The FM transmitter supports RDS as well, both using 'Block I/O' and 'Controls' | |
528 | modes. In the 'Controls' mode the transmitted RDS information is configured | |
529 | using controls, and in 'Block I/O' mode the blocks are passed to the driver | |
530 | using write(). | |
531 | ||
532 | ||
cff4c8ac MCC |
533 | Software Defined Radio Receiver |
534 | ------------------------------- | |
6a683493 HV |
535 | |
536 | The SDR receiver has three frequency bands for the ADC tuner: | |
537 | ||
538 | - 300 kHz | |
539 | - 900 kHz - 2800 kHz | |
540 | - 3200 kHz | |
541 | ||
542 | The RF tuner supports 50 MHz - 2000 MHz. | |
543 | ||
544 | The generated data contains the In-phase and Quadrature components of a | |
545 | 1 kHz tone that has an amplitude of sqrt(2). | |
546 | ||
547 | ||
cff4c8ac MCC |
548 | Controls |
549 | -------- | |
6a683493 HV |
550 | |
551 | Different devices support different controls. The sections below will describe | |
552 | each control and which devices support them. | |
553 | ||
554 | ||
cff4c8ac MCC |
555 | User Controls - Test Controls |
556 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
557 | |
558 | The Button, Boolean, Integer 32 Bits, Integer 64 Bits, Menu, String, Bitmask and | |
559 | Integer Menu are controls that represent all possible control types. The Menu | |
560 | control and the Integer Menu control both have 'holes' in their menu list, | |
561 | meaning that one or more menu items return EINVAL when VIDIOC_QUERYMENU is called. | |
562 | Both menu controls also have a non-zero minimum control value. These features | |
563 | allow you to check if your application can handle such things correctly. | |
564 | These controls are supported for every device type. | |
565 | ||
566 | ||
cff4c8ac MCC |
567 | User Controls - Video Capture |
568 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
569 | |
570 | The following controls are specific to video capture. | |
571 | ||
572 | The Brightness, Contrast, Saturation and Hue controls actually work and are | |
573 | standard. There is one special feature with the Brightness control: each | |
574 | video input has its own brightness value, so changing input will restore | |
575 | the brightness for that input. In addition, each video input uses a different | |
576 | brightness range (minimum and maximum control values). Switching inputs will | |
577 | cause a control event to be sent with the V4L2_EVENT_CTRL_CH_RANGE flag set. | |
578 | This allows you to test controls that can change their range. | |
579 | ||
580 | The 'Gain, Automatic' and Gain controls can be used to test volatile controls: | |
581 | if 'Gain, Automatic' is set, then the Gain control is volatile and changes | |
582 | constantly. If 'Gain, Automatic' is cleared, then the Gain control is a normal | |
583 | control. | |
584 | ||
585 | The 'Horizontal Flip' and 'Vertical Flip' controls can be used to flip the | |
586 | image. These combine with the 'Sensor Flipped Horizontally/Vertically' Vivid | |
587 | controls. | |
588 | ||
589 | The 'Alpha Component' control can be used to set the alpha component for | |
590 | formats containing an alpha channel. | |
591 | ||
592 | ||
cff4c8ac MCC |
593 | User Controls - Audio |
594 | ~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
595 | |
596 | The following controls are specific to video capture and output and radio | |
597 | receivers and transmitters. | |
598 | ||
599 | The 'Volume' and 'Mute' audio controls are typical for such devices to | |
600 | control the volume and mute the audio. They don't actually do anything in | |
601 | the vivid driver. | |
602 | ||
603 | ||
cff4c8ac MCC |
604 | Vivid Controls |
605 | ~~~~~~~~~~~~~~ | |
6a683493 HV |
606 | |
607 | These vivid custom controls control the image generation, error injection, etc. | |
608 | ||
609 | ||
cff4c8ac MCC |
610 | Test Pattern Controls |
611 | ^^^^^^^^^^^^^^^^^^^^^ | |
6a683493 HV |
612 | |
613 | The Test Pattern Controls are all specific to video capture. | |
614 | ||
cff4c8ac MCC |
615 | - Test Pattern: |
616 | ||
617 | selects which test pattern to use. Use the CSC Colorbar for | |
6a683493 HV |
618 | testing colorspace conversions: the colors used in that test pattern |
619 | map to valid colors in all colorspaces. The colorspace conversion | |
620 | is disabled for the other test patterns. | |
621 | ||
cff4c8ac MCC |
622 | - OSD Text Mode: |
623 | ||
624 | selects whether the text superimposed on the | |
6a683493 HV |
625 | test pattern should be shown, and if so, whether only counters should |
626 | be displayed or the full text. | |
627 | ||
cff4c8ac MCC |
628 | - Horizontal Movement: |
629 | ||
630 | selects whether the test pattern should | |
6a683493 HV |
631 | move to the left or right and at what speed. |
632 | ||
cff4c8ac MCC |
633 | - Vertical Movement: |
634 | ||
635 | does the same for the vertical direction. | |
636 | ||
637 | - Show Border: | |
6a683493 | 638 | |
cff4c8ac | 639 | show a two-pixel wide border at the edge of the actual image, |
6a683493 HV |
640 | excluding letter or pillarboxing. |
641 | ||
cff4c8ac MCC |
642 | - Show Square: |
643 | ||
644 | show a square in the middle of the image. If the image is | |
6a683493 HV |
645 | displayed with the correct pixel and image aspect ratio corrections, |
646 | then the width and height of the square on the monitor should be | |
647 | the same. | |
648 | ||
cff4c8ac MCC |
649 | - Insert SAV Code in Image: |
650 | ||
651 | adds a SAV (Start of Active Video) code to the image. | |
6a683493 HV |
652 | This can be used to check if such codes in the image are inadvertently |
653 | interpreted instead of being ignored. | |
654 | ||
cff4c8ac | 655 | - Insert EAV Code in Image: |
6a683493 | 656 | |
cff4c8ac | 657 | does the same for the EAV (End of Active Video) code. |
6a683493 | 658 | |
cff4c8ac MCC |
659 | |
660 | Capture Feature Selection Controls | |
661 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
6a683493 HV |
662 | |
663 | These controls are all specific to video capture. | |
664 | ||
cff4c8ac MCC |
665 | - Sensor Flipped Horizontally: |
666 | ||
667 | the image is flipped horizontally and the | |
6a683493 HV |
668 | V4L2_IN_ST_HFLIP input status flag is set. This emulates the case where |
669 | a sensor is for example mounted upside down. | |
670 | ||
cff4c8ac MCC |
671 | - Sensor Flipped Vertically: |
672 | ||
673 | the image is flipped vertically and the | |
6a683493 | 674 | V4L2_IN_ST_VFLIP input status flag is set. This emulates the case where |
cff4c8ac MCC |
675 | a sensor is for example mounted upside down. |
676 | ||
677 | - Standard Aspect Ratio: | |
6a683493 | 678 | |
cff4c8ac | 679 | selects if the image aspect ratio as used for the TV or |
6a683493 HV |
680 | S-Video input should be 4x3, 16x9 or anamorphic widescreen. This may |
681 | introduce letterboxing. | |
682 | ||
cff4c8ac MCC |
683 | - DV Timings Aspect Ratio: |
684 | ||
685 | selects if the image aspect ratio as used for the HDMI | |
6a683493 HV |
686 | input should be the same as the source width and height ratio, or if |
687 | it should be 4x3 or 16x9. This may introduce letter or pillarboxing. | |
688 | ||
cff4c8ac MCC |
689 | - Timestamp Source: |
690 | ||
691 | selects when the timestamp for each buffer is taken. | |
6a683493 | 692 | |
cff4c8ac MCC |
693 | - Colorspace: |
694 | ||
695 | selects which colorspace should be used when generating the image. | |
6a683493 | 696 | This only applies if the CSC Colorbar test pattern is selected, |
64d57022 HV |
697 | otherwise the test pattern will go through unconverted. |
698 | This behavior is also what you want, since a 75% Colorbar | |
6a683493 HV |
699 | should really have 75% signal intensity and should not be affected |
700 | by colorspace conversions. | |
701 | ||
702 | Changing the colorspace will result in the V4L2_EVENT_SOURCE_CHANGE | |
703 | to be sent since it emulates a detected colorspace change. | |
704 | ||
cff4c8ac MCC |
705 | - Transfer Function: |
706 | ||
707 | selects which colorspace transfer function should be used when | |
64d57022 HV |
708 | generating an image. This only applies if the CSC Colorbar test pattern is |
709 | selected, otherwise the test pattern will go through unconverted. | |
cff4c8ac MCC |
710 | This behavior is also what you want, since a 75% Colorbar |
711 | should really have 75% signal intensity and should not be affected | |
712 | by colorspace conversions. | |
64d57022 HV |
713 | |
714 | Changing the transfer function will result in the V4L2_EVENT_SOURCE_CHANGE | |
715 | to be sent since it emulates a detected colorspace change. | |
716 | ||
cff4c8ac MCC |
717 | - Y'CbCr Encoding: |
718 | ||
719 | selects which Y'CbCr encoding should be used when generating | |
64d57022 HV |
720 | a Y'CbCr image. This only applies if the format is set to a Y'CbCr format |
721 | as opposed to an RGB format. | |
38913a5c HV |
722 | |
723 | Changing the Y'CbCr encoding will result in the V4L2_EVENT_SOURCE_CHANGE | |
724 | to be sent since it emulates a detected colorspace change. | |
725 | ||
cff4c8ac MCC |
726 | - Quantization: |
727 | ||
728 | selects which quantization should be used for the RGB or Y'CbCr | |
64d57022 | 729 | encoding when generating the test pattern. |
38913a5c HV |
730 | |
731 | Changing the quantization will result in the V4L2_EVENT_SOURCE_CHANGE | |
732 | to be sent since it emulates a detected colorspace change. | |
733 | ||
cff4c8ac MCC |
734 | - Limited RGB Range (16-235): |
735 | ||
736 | selects if the RGB range of the HDMI source should | |
6a683493 HV |
737 | be limited or full range. This combines with the Digital Video 'Rx RGB |
738 | Quantization Range' control and can be used to test what happens if | |
739 | a source provides you with the wrong quantization range information. | |
740 | See the description of that control for more details. | |
741 | ||
cff4c8ac MCC |
742 | - Apply Alpha To Red Only: |
743 | ||
744 | apply the alpha channel as set by the 'Alpha Component' | |
6a683493 HV |
745 | user control to the red color of the test pattern only. |
746 | ||
cff4c8ac MCC |
747 | - Enable Capture Cropping: |
748 | ||
749 | enables crop support. This control is only present if | |
6a683493 HV |
750 | the ccs_cap_mode module option is set to the default value of -1 and if |
751 | the no_error_inj module option is set to 0 (the default). | |
752 | ||
cff4c8ac MCC |
753 | - Enable Capture Composing: |
754 | ||
755 | enables composing support. This control is only | |
6a683493 HV |
756 | present if the ccs_cap_mode module option is set to the default value of |
757 | -1 and if the no_error_inj module option is set to 0 (the default). | |
758 | ||
cff4c8ac MCC |
759 | - Enable Capture Scaler: |
760 | ||
761 | enables support for a scaler (maximum 4 times upscaling | |
6a683493 HV |
762 | and downscaling). This control is only present if the ccs_cap_mode |
763 | module option is set to the default value of -1 and if the no_error_inj | |
764 | module option is set to 0 (the default). | |
765 | ||
cff4c8ac MCC |
766 | - Maximum EDID Blocks: |
767 | ||
768 | determines how many EDID blocks the driver supports. | |
6a683493 HV |
769 | Note that the vivid driver does not actually interpret new EDID |
770 | data, it just stores it. It allows for up to 256 EDID blocks | |
771 | which is the maximum supported by the standard. | |
772 | ||
cff4c8ac MCC |
773 | - Fill Percentage of Frame: |
774 | ||
775 | can be used to draw only the top X percent | |
6a683493 HV |
776 | of the image. Since each frame has to be drawn by the driver, this |
777 | demands a lot of the CPU. For large resolutions this becomes | |
778 | problematic. By drawing only part of the image this CPU load can | |
779 | be reduced. | |
780 | ||
781 | ||
cff4c8ac MCC |
782 | Output Feature Selection Controls |
783 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
6a683493 HV |
784 | |
785 | These controls are all specific to video output. | |
786 | ||
cff4c8ac MCC |
787 | - Enable Output Cropping: |
788 | ||
789 | enables crop support. This control is only present if | |
6a683493 HV |
790 | the ccs_out_mode module option is set to the default value of -1 and if |
791 | the no_error_inj module option is set to 0 (the default). | |
792 | ||
cff4c8ac MCC |
793 | - Enable Output Composing: |
794 | ||
795 | enables composing support. This control is only | |
6a683493 HV |
796 | present if the ccs_out_mode module option is set to the default value of |
797 | -1 and if the no_error_inj module option is set to 0 (the default). | |
798 | ||
cff4c8ac MCC |
799 | - Enable Output Scaler: |
800 | ||
801 | enables support for a scaler (maximum 4 times upscaling | |
6a683493 HV |
802 | and downscaling). This control is only present if the ccs_out_mode |
803 | module option is set to the default value of -1 and if the no_error_inj | |
804 | module option is set to 0 (the default). | |
805 | ||
806 | ||
cff4c8ac MCC |
807 | Error Injection Controls |
808 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
6a683493 HV |
809 | |
810 | The following two controls are only valid for video and vbi capture. | |
811 | ||
cff4c8ac MCC |
812 | - Standard Signal Mode: |
813 | ||
814 | selects the behavior of VIDIOC_QUERYSTD: what should it return? | |
6a683493 HV |
815 | |
816 | Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE | |
817 | to be sent since it emulates a changed input condition (e.g. a cable | |
818 | was plugged in or out). | |
819 | ||
cff4c8ac MCC |
820 | - Standard: |
821 | ||
822 | selects the standard that VIDIOC_QUERYSTD should return if the | |
6a683493 HV |
823 | previous control is set to "Selected Standard". |
824 | ||
825 | Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE | |
826 | to be sent since it emulates a changed input standard. | |
827 | ||
828 | ||
829 | The following two controls are only valid for video capture. | |
830 | ||
cff4c8ac | 831 | - DV Timings Signal Mode: |
a28ee884 | 832 | |
cff4c8ac | 833 | selects the behavior of VIDIOC_QUERY_DV_TIMINGS: what |
6a683493 HV |
834 | should it return? |
835 | ||
836 | Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE | |
837 | to be sent since it emulates a changed input condition (e.g. a cable | |
838 | was plugged in or out). | |
839 | ||
cff4c8ac MCC |
840 | - DV Timings: |
841 | ||
842 | selects the timings the VIDIOC_QUERY_DV_TIMINGS should return | |
6a683493 HV |
843 | if the previous control is set to "Selected DV Timings". |
844 | ||
845 | Changing this control will result in the V4L2_EVENT_SOURCE_CHANGE | |
846 | to be sent since it emulates changed input timings. | |
847 | ||
848 | ||
849 | The following controls are only present if the no_error_inj module option | |
850 | is set to 0 (the default). These controls are valid for video and vbi | |
851 | capture and output streams and for the SDR capture device except for the | |
852 | Disconnect control which is valid for all devices. | |
853 | ||
cff4c8ac MCC |
854 | - Wrap Sequence Number: |
855 | ||
856 | test what happens when you wrap the sequence number in | |
6a683493 HV |
857 | struct v4l2_buffer around. |
858 | ||
cff4c8ac MCC |
859 | - Wrap Timestamp: |
860 | ||
861 | test what happens when you wrap the timestamp in struct | |
6a683493 HV |
862 | v4l2_buffer around. |
863 | ||
cff4c8ac MCC |
864 | - Percentage of Dropped Buffers: |
865 | ||
866 | sets the percentage of buffers that | |
6a683493 HV |
867 | are never returned by the driver (i.e., they are dropped). |
868 | ||
cff4c8ac MCC |
869 | - Disconnect: |
870 | ||
871 | emulates a USB disconnect. The device will act as if it has | |
6a683493 HV |
872 | been disconnected. Only after all open filehandles to the device |
873 | node have been closed will the device become 'connected' again. | |
874 | ||
cff4c8ac MCC |
875 | - Inject V4L2_BUF_FLAG_ERROR: |
876 | ||
877 | when pressed, the next frame returned by | |
6a683493 HV |
878 | the driver will have the error flag set (i.e. the frame is marked |
879 | corrupt). | |
880 | ||
cff4c8ac MCC |
881 | - Inject VIDIOC_REQBUFS Error: |
882 | ||
883 | when pressed, the next REQBUFS or CREATE_BUFS | |
6a683493 HV |
884 | ioctl call will fail with an error. To be precise: the videobuf2 |
885 | queue_setup() op will return -EINVAL. | |
886 | ||
cff4c8ac MCC |
887 | - Inject VIDIOC_QBUF Error: |
888 | ||
889 | when pressed, the next VIDIOC_QBUF or | |
6a683493 HV |
890 | VIDIOC_PREPARE_BUFFER ioctl call will fail with an error. To be |
891 | precise: the videobuf2 buf_prepare() op will return -EINVAL. | |
892 | ||
cff4c8ac MCC |
893 | - Inject VIDIOC_STREAMON Error: |
894 | ||
895 | when pressed, the next VIDIOC_STREAMON ioctl | |
6a683493 HV |
896 | call will fail with an error. To be precise: the videobuf2 |
897 | start_streaming() op will return -EINVAL. | |
898 | ||
cff4c8ac MCC |
899 | - Inject Fatal Streaming Error: |
900 | ||
901 | when pressed, the streaming core will be | |
6a683493 HV |
902 | marked as having suffered a fatal error, the only way to recover |
903 | from that is to stop streaming. To be precise: the videobuf2 | |
904 | vb2_queue_error() function is called. | |
905 | ||
906 | ||
cff4c8ac MCC |
907 | VBI Raw Capture Controls |
908 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
909 | ||
910 | - Interlaced VBI Format: | |
6a683493 | 911 | |
cff4c8ac | 912 | if set, then the raw VBI data will be interlaced instead |
6a683493 HV |
913 | of providing it grouped by field. |
914 | ||
915 | ||
cff4c8ac MCC |
916 | Digital Video Controls |
917 | ~~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 | 918 | |
cff4c8ac MCC |
919 | - Rx RGB Quantization Range: |
920 | ||
921 | sets the RGB quantization detection of the HDMI | |
6a683493 HV |
922 | input. This combines with the Vivid 'Limited RGB Range (16-235)' |
923 | control and can be used to test what happens if a source provides | |
924 | you with the wrong quantization range information. This can be tested | |
925 | by selecting an HDMI input, setting this control to Full or Limited | |
926 | range and selecting the opposite in the 'Limited RGB Range (16-235)' | |
927 | control. The effect is easy to see if the 'Gray Ramp' test pattern | |
928 | is selected. | |
929 | ||
cff4c8ac MCC |
930 | - Tx RGB Quantization Range: |
931 | ||
932 | sets the RGB quantization detection of the HDMI | |
6a683493 HV |
933 | output. It is currently not used for anything in vivid, but most HDMI |
934 | transmitters would typically have this control. | |
935 | ||
cff4c8ac MCC |
936 | - Transmit Mode: |
937 | ||
938 | sets the transmit mode of the HDMI output to HDMI or DVI-D. This | |
6a683493 HV |
939 | affects the reported colorspace since DVI_D outputs will always use |
940 | sRGB. | |
941 | ||
942 | ||
cff4c8ac MCC |
943 | FM Radio Receiver Controls |
944 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
945 | ||
946 | - RDS Reception: | |
947 | ||
948 | set if the RDS receiver should be enabled. | |
949 | ||
950 | - RDS Program Type: | |
951 | ||
952 | ||
953 | - RDS PS Name: | |
954 | ||
6a683493 | 955 | |
cff4c8ac | 956 | - RDS Radio Text: |
6a683493 | 957 | |
cff4c8ac MCC |
958 | |
959 | - RDS Traffic Announcement: | |
960 | ||
961 | ||
962 | - RDS Traffic Program: | |
963 | ||
964 | ||
965 | - RDS Music: | |
966 | ||
967 | these are all read-only controls. If RDS Rx I/O Mode is set to | |
6a683493 | 968 | "Block I/O", then they are inactive as well. If RDS Rx I/O Mode is set |
cff4c8ac MCC |
969 | to "Controls", then these controls report the received RDS data. |
970 | ||
971 | .. note:: | |
972 | The vivid implementation of this is pretty basic: they are only | |
6a683493 HV |
973 | updated when you set a new frequency or when you get the tuner status |
974 | (VIDIOC_G_TUNER). | |
975 | ||
cff4c8ac MCC |
976 | - Radio HW Seek Mode: |
977 | ||
978 | can be one of "Bounded", "Wrap Around" or "Both". This | |
6a683493 HV |
979 | determines if VIDIOC_S_HW_FREQ_SEEK will be bounded by the frequency |
980 | range or wrap-around or if it is selectable by the user. | |
981 | ||
cff4c8ac MCC |
982 | - Radio Programmable HW Seek: |
983 | ||
984 | if set, then the user can provide the lower and | |
6a683493 HV |
985 | upper bound of the HW Seek. Otherwise the frequency range boundaries |
986 | will be used. | |
987 | ||
cff4c8ac MCC |
988 | - Generate RBDS Instead of RDS: |
989 | ||
990 | if set, then generate RBDS (the US variant of | |
6a683493 HV |
991 | RDS) data instead of RDS (European-style RDS). This affects only the |
992 | PICODE and PTY codes. | |
993 | ||
cff4c8ac MCC |
994 | - RDS Rx I/O Mode: |
995 | ||
996 | this can be "Block I/O" where the RDS blocks have to be read() | |
6a683493 HV |
997 | by the application, or "Controls" where the RDS data is provided by |
998 | the RDS controls mentioned above. | |
999 | ||
1000 | ||
cff4c8ac MCC |
1001 | FM Radio Modulator Controls |
1002 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
1003 | ||
1004 | - RDS Program ID: | |
1005 | ||
1006 | ||
1007 | - RDS Program Type: | |
1008 | ||
1009 | ||
1010 | - RDS PS Name: | |
1011 | ||
1012 | ||
1013 | - RDS Radio Text: | |
1014 | ||
1015 | ||
1016 | - RDS Stereo: | |
1017 | ||
1018 | ||
1019 | - RDS Artificial Head: | |
1020 | ||
1021 | ||
1022 | - RDS Compressed: | |
1023 | ||
1024 | ||
1025 | - RDS Dynamic PTY: | |
1026 | ||
1027 | ||
1028 | - RDS Traffic Announcement: | |
1029 | ||
1030 | ||
1031 | - RDS Traffic Program: | |
1032 | ||
1033 | ||
1034 | - RDS Music: | |
1035 | ||
1036 | these are all controls that set the RDS data that is transmitted by | |
6a683493 HV |
1037 | the FM modulator. |
1038 | ||
cff4c8ac | 1039 | - RDS Tx I/O Mode: |
6a683493 | 1040 | |
cff4c8ac MCC |
1041 | this can be "Block I/O" where the application has to use write() |
1042 | to pass the RDS blocks to the driver, or "Controls" where the RDS data | |
1043 | is Provided by the RDS controls mentioned above. | |
6a683493 | 1044 | |
cff4c8ac MCC |
1045 | |
1046 | Video, VBI and RDS Looping | |
1047 | -------------------------- | |
6a683493 HV |
1048 | |
1049 | The vivid driver supports looping of video output to video input, VBI output | |
1050 | to VBI input and RDS output to RDS input. For video/VBI looping this emulates | |
1051 | as if a cable was hooked up between the output and input connector. So video | |
1052 | and VBI looping is only supported between S-Video and HDMI inputs and outputs. | |
1053 | VBI is only valid for S-Video as it makes no sense for HDMI. | |
1054 | ||
1055 | Since radio is wireless this looping always happens if the radio receiver | |
1056 | frequency is close to the radio transmitter frequency. In that case the radio | |
1057 | transmitter will 'override' the emulated radio stations. | |
1058 | ||
1059 | Looping is currently supported only between devices created by the same | |
1060 | vivid driver instance. | |
1061 | ||
1062 | ||
cff4c8ac MCC |
1063 | Video and Sliced VBI looping |
1064 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
1065 | |
1066 | The way to enable video/VBI looping is currently fairly crude. A 'Loop Video' | |
1067 | control is available in the "Vivid" control class of the video | |
63344b65 | 1068 | capture and VBI capture devices. When checked the video looping will be enabled. |
6a683493 HV |
1069 | Once enabled any video S-Video or HDMI input will show a static test pattern |
1070 | until the video output has started. At that time the video output will be | |
1071 | looped to the video input provided that: | |
1072 | ||
1073 | - the input type matches the output type. So the HDMI input cannot receive | |
1074 | video from the S-Video output. | |
1075 | ||
1076 | - the video resolution of the video input must match that of the video output. | |
1077 | So it is not possible to loop a 50 Hz (720x576) S-Video output to a 60 Hz | |
1078 | (720x480) S-Video input, or a 720p60 HDMI output to a 1080p30 input. | |
1079 | ||
1080 | - the pixel formats must be identical on both sides. Otherwise the driver would | |
1081 | have to do pixel format conversion as well, and that's taking things too far. | |
1082 | ||
1083 | - the field settings must be identical on both sides. Same reason as above: | |
1084 | requiring the driver to convert from one field format to another complicated | |
1085 | matters too much. This also prohibits capturing with 'Field Top' or 'Field | |
1086 | Bottom' when the output video is set to 'Field Alternate'. This combination, | |
1087 | while legal, became too complicated to support. Both sides have to be 'Field | |
1088 | Alternate' for this to work. Also note that for this specific case the | |
1089 | sequence and field counting in struct v4l2_buffer on the capture side may not | |
1090 | be 100% accurate. | |
1091 | ||
ba24b442 HV |
1092 | - field settings V4L2_FIELD_SEQ_TB/BT are not supported. While it is possible to |
1093 | implement this, it would mean a lot of work to get this right. Since these | |
1094 | field values are rarely used the decision was made not to implement this for | |
1095 | now. | |
1096 | ||
6a683493 HV |
1097 | - on the input side the "Standard Signal Mode" for the S-Video input or the |
1098 | "DV Timings Signal Mode" for the HDMI input should be configured so that a | |
1099 | valid signal is passed to the video input. | |
1100 | ||
1101 | The framerates do not have to match, although this might change in the future. | |
1102 | ||
1103 | By default you will see the OSD text superimposed on top of the looped video. | |
1104 | This can be turned off by changing the "OSD Text Mode" control of the video | |
1105 | capture device. | |
1106 | ||
1107 | For VBI looping to work all of the above must be valid and in addition the vbi | |
1108 | output must be configured for sliced VBI. The VBI capture side can be configured | |
62f28725 HV |
1109 | for either raw or sliced VBI. Note that at the moment only CC/XDS (60 Hz formats) |
1110 | and WSS (50 Hz formats) VBI data is looped. Teletext VBI data is not looped. | |
6a683493 HV |
1111 | |
1112 | ||
cff4c8ac MCC |
1113 | Radio & RDS Looping |
1114 | ~~~~~~~~~~~~~~~~~~~ | |
6a683493 HV |
1115 | |
1116 | As mentioned in section 6 the radio receiver emulates stations are regular | |
1117 | frequency intervals. Depending on the frequency of the radio receiver a | |
1118 | signal strength value is calculated (this is returned by VIDIOC_G_TUNER). | |
1119 | However, it will also look at the frequency set by the radio transmitter and | |
1120 | if that results in a higher signal strength than the settings of the radio | |
1121 | transmitter will be used as if it was a valid station. This also includes | |
1122 | the RDS data (if any) that the transmitter 'transmits'. This is received | |
1123 | faithfully on the receiver side. Note that when the driver is loaded the | |
1124 | frequencies of the radio receiver and transmitter are not identical, so | |
1125 | initially no looping takes place. | |
1126 | ||
1127 | ||
cff4c8ac MCC |
1128 | Cropping, Composing, Scaling |
1129 | ---------------------------- | |
6a683493 HV |
1130 | |
1131 | This driver supports cropping, composing and scaling in any combination. Normally | |
1132 | which features are supported can be selected through the Vivid controls, | |
1133 | but it is also possible to hardcode it when the module is loaded through the | |
1134 | ccs_cap_mode and ccs_out_mode module options. See section 1 on the details of | |
1135 | these module options. | |
1136 | ||
1137 | This allows you to test your application for all these variations. | |
1138 | ||
1139 | Note that the webcam input never supports cropping, composing or scaling. That | |
1140 | only applies to the TV/S-Video/HDMI inputs and outputs. The reason is that | |
1141 | webcams, including this virtual implementation, normally use | |
1142 | VIDIOC_ENUM_FRAMESIZES to list a set of discrete framesizes that it supports. | |
1143 | And that does not combine with cropping, composing or scaling. This is | |
1144 | primarily a limitation of the V4L2 API which is carefully reproduced here. | |
1145 | ||
1146 | The minimum and maximum resolutions that the scaler can achieve are 16x16 and | |
1147 | (4096 * 4) x (2160 x 4), but it can only scale up or down by a factor of 4 or | |
1148 | less. So for a source resolution of 1280x720 the minimum the scaler can do is | |
1149 | 320x180 and the maximum is 5120x2880. You can play around with this using the | |
1150 | qv4l2 test tool and you will see these dependencies. | |
1151 | ||
1152 | This driver also supports larger 'bytesperline' settings, something that | |
1153 | VIDIOC_S_FMT allows but that few drivers implement. | |
1154 | ||
1155 | The scaler is a simple scaler that uses the Coarse Bresenham algorithm. It's | |
1156 | designed for speed and simplicity, not quality. | |
1157 | ||
1158 | If the combination of crop, compose and scaling allows it, then it is possible | |
1159 | to change crop and compose rectangles on the fly. | |
1160 | ||
1161 | ||
cff4c8ac MCC |
1162 | Formats |
1163 | ------- | |
6a683493 | 1164 | |
64d57022 HV |
1165 | The driver supports all the regular packed and planar 4:4:4, 4:2:2 and 4:2:0 |
1166 | YUYV formats, 8, 16, 24 and 32 RGB packed formats and various multiplanar | |
1167 | formats. | |
6a683493 HV |
1168 | |
1169 | The alpha component can be set through the 'Alpha Component' User control | |
1170 | for those formats that support it. If the 'Apply Alpha To Red Only' control | |
1171 | is set, then the alpha component is only used for the color red and set to | |
1172 | 0 otherwise. | |
1173 | ||
1174 | The driver has to be configured to support the multiplanar formats. By default | |
cba63cf8 HV |
1175 | the driver instances are single-planar. This can be changed by setting the |
1176 | multiplanar module option, see section 1 for more details on that option. | |
6a683493 HV |
1177 | |
1178 | If the driver instance is using the multiplanar formats/API, then the first | |
1179 | single planar format (YUYV) and the multiplanar NV16M and NV61M formats the | |
1180 | will have a plane that has a non-zero data_offset of 128 bytes. It is rare for | |
1181 | data_offset to be non-zero, so this is a useful feature for testing applications. | |
1182 | ||
1183 | Video output will also honor any data_offset that the application set. | |
1184 | ||
1185 | ||
cff4c8ac MCC |
1186 | Capture Overlay |
1187 | --------------- | |
6a683493 HV |
1188 | |
1189 | Note: capture overlay support is implemented primarily to test the existing | |
1190 | V4L2 capture overlay API. In practice few if any GPUs support such overlays | |
1191 | anymore, and neither are they generally needed anymore since modern hardware | |
1192 | is so much more capable. By setting flag 0x10000 in the node_types module | |
1193 | option the vivid driver will create a simple framebuffer device that can be | |
1194 | used for testing this API. Whether this API should be used for new drivers is | |
1195 | questionable. | |
1196 | ||
1197 | This driver has support for a destructive capture overlay with bitmap clipping | |
1198 | and list clipping (up to 16 rectangles) capabilities. Overlays are not | |
1199 | supported for multiplanar formats. It also honors the struct v4l2_window field | |
1200 | setting: if it is set to FIELD_TOP or FIELD_BOTTOM and the capture setting is | |
1201 | FIELD_ALTERNATE, then only the top or bottom fields will be copied to the overlay. | |
1202 | ||
1203 | The overlay only works if you are also capturing at that same time. This is a | |
1204 | vivid limitation since it copies from a buffer to the overlay instead of | |
1205 | filling the overlay directly. And if you are not capturing, then no buffers | |
1206 | are available to fill. | |
1207 | ||
1208 | In addition, the pixelformat of the capture format and that of the framebuffer | |
1209 | must be the same for the overlay to work. Otherwise VIDIOC_OVERLAY will return | |
1210 | an error. | |
1211 | ||
1212 | In order to really see what it going on you will need to create two vivid | |
1213 | instances: the first with a framebuffer enabled. You configure the capture | |
1214 | overlay of the second instance to use the framebuffer of the first, then | |
1215 | you start capturing in the second instance. For the first instance you setup | |
1216 | the output overlay for the video output, turn on video looping and capture | |
1217 | to see the blended framebuffer overlay that's being written to by the second | |
1218 | instance. This setup would require the following commands: | |
1219 | ||
cff4c8ac MCC |
1220 | .. code-block:: none |
1221 | ||
cba63cf8 | 1222 | $ sudo modprobe vivid n_devs=2 node_types=0x10101,0x1 |
6a683493 HV |
1223 | $ v4l2-ctl -d1 --find-fb |
1224 | /dev/fb1 is the framebuffer associated with base address 0x12800000 | |
1225 | $ sudo v4l2-ctl -d2 --set-fbuf fb=1 | |
1226 | $ v4l2-ctl -d1 --set-fbuf fb=1 | |
1227 | $ v4l2-ctl -d0 --set-fmt-video=pixelformat='AR15' | |
1228 | $ v4l2-ctl -d1 --set-fmt-video-out=pixelformat='AR15' | |
1229 | $ v4l2-ctl -d2 --set-fmt-video=pixelformat='AR15' | |
1230 | $ v4l2-ctl -d0 -i2 | |
1231 | $ v4l2-ctl -d2 -i2 | |
1232 | $ v4l2-ctl -d2 -c horizontal_movement=4 | |
1233 | $ v4l2-ctl -d1 --overlay=1 | |
1234 | $ v4l2-ctl -d1 -c loop_video=1 | |
1235 | $ v4l2-ctl -d2 --stream-mmap --overlay=1 | |
1236 | ||
1237 | And from another console: | |
1238 | ||
cff4c8ac MCC |
1239 | .. code-block:: none |
1240 | ||
6a683493 HV |
1241 | $ v4l2-ctl -d1 --stream-out-mmap |
1242 | ||
1243 | And yet another console: | |
1244 | ||
cff4c8ac MCC |
1245 | .. code-block:: none |
1246 | ||
6a683493 HV |
1247 | $ qv4l2 |
1248 | ||
1249 | and start streaming. | |
1250 | ||
1251 | As you can see, this is not for the faint of heart... | |
1252 | ||
1253 | ||
cff4c8ac MCC |
1254 | Output Overlay |
1255 | -------------- | |
6a683493 HV |
1256 | |
1257 | Note: output overlays are primarily implemented in order to test the existing | |
1258 | V4L2 output overlay API. Whether this API should be used for new drivers is | |
1259 | questionable. | |
1260 | ||
1261 | This driver has support for an output overlay and is capable of: | |
1262 | ||
1263 | - bitmap clipping, | |
1264 | - list clipping (up to 16 rectangles) | |
1265 | - chromakey | |
1266 | - source chromakey | |
1267 | - global alpha | |
1268 | - local alpha | |
1269 | - local inverse alpha | |
1270 | ||
1271 | Output overlays are not supported for multiplanar formats. In addition, the | |
1272 | pixelformat of the capture format and that of the framebuffer must be the | |
1273 | same for the overlay to work. Otherwise VIDIOC_OVERLAY will return an error. | |
1274 | ||
1275 | Output overlays only work if the driver has been configured to create a | |
1276 | framebuffer by setting flag 0x10000 in the node_types module option. The | |
1277 | created framebuffer has a size of 720x576 and supports ARGB 1:5:5:5 and | |
1278 | RGB 5:6:5. | |
1279 | ||
1280 | In order to see the effects of the various clipping, chromakeying or alpha | |
1281 | processing capabilities you need to turn on video looping and see the results | |
1282 | on the capture side. The use of the clipping, chromakeying or alpha processing | |
1283 | capabilities will slow down the video loop considerably as a lot of checks have | |
1284 | to be done per pixel. | |
1285 | ||
1286 | ||
cff4c8ac MCC |
1287 | CEC (Consumer Electronics Control) |
1288 | ---------------------------------- | |
6f8adea2 HV |
1289 | |
1290 | If there are HDMI inputs then a CEC adapter will be created that has | |
1291 | the same number of input ports. This is the equivalent of e.g. a TV that | |
1292 | has that number of inputs. Each HDMI output will also create a | |
1293 | CEC adapter that is hooked up to the corresponding input port, or (if there | |
1294 | are more outputs than inputs) is not hooked up at all. In other words, | |
1295 | this is the equivalent of hooking up each output device to an input port of | |
1296 | the TV. Any remaining output devices remain unconnected. | |
1297 | ||
1298 | The EDID that each output reads reports a unique CEC physical address that is | |
1299 | based on the physical address of the EDID of the input. So if the EDID of the | |
1300 | receiver has physical address A.B.0.0, then each output will see an EDID | |
1301 | containing physical address A.B.C.0 where C is 1 to the number of inputs. If | |
1302 | there are more outputs than inputs then the remaining outputs have a CEC adapter | |
1303 | that is disabled and reports an invalid physical address. | |
1304 | ||
1305 | ||
cff4c8ac MCC |
1306 | Some Future Improvements |
1307 | ------------------------ | |
6a683493 HV |
1308 | |
1309 | Just as a reminder and in no particular order: | |
1310 | ||
1311 | - Add a virtual alsa driver to test audio | |
1312 | - Add virtual sub-devices and media controller support | |
1313 | - Some support for testing compressed video | |
1314 | - Add support to loop raw VBI output to raw VBI input | |
62f28725 | 1315 | - Add support to loop teletext sliced VBI output to VBI input |
6a683493 HV |
1316 | - Fix sequence/field numbering when looping of video with alternate fields |
1317 | - Add support for V4L2_CID_BG_COLOR for video outputs | |
1318 | - Add ARGB888 overlay support: better testing of the alpha channel | |
6a683493 HV |
1319 | - Improve pixel aspect support in the tpg code by passing a real v4l2_fract |
1320 | - Use per-queue locks and/or per-device locks to improve throughput | |
1321 | - Add support to loop from a specific output to a specific input across | |
1322 | vivid instances | |
6a683493 HV |
1323 | - The SDR radio should use the same 'frequencies' for stations as the normal |
1324 | radio receiver, and give back noise if the frequency doesn't match up with | |
1325 | a station frequency | |
6a683493 HV |
1326 | - Make a thread for the RDS generation, that would help in particular for the |
1327 | "Controls" RDS Rx I/O Mode as the read-only RDS controls could be updated | |
1328 | in real-time. | |
6f8adea2 | 1329 | - Changing the EDID should cause hotplug detect emulation to happen. |