| 1 | @chapter Input Devices |
| 2 | @c man begin INPUT DEVICES |
| 3 | |
| 4 | Input devices are configured elements in FFmpeg which allow to access |
| 5 | the data coming from a multimedia device attached to your system. |
| 6 | |
| 7 | When you configure your FFmpeg build, all the supported input devices |
| 8 | are enabled by default. You can list all available ones using the |
| 9 | configure option "--list-indevs". |
| 10 | |
| 11 | You can disable all the input devices using the configure option |
| 12 | "--disable-indevs", and selectively enable an input device using the |
| 13 | option "--enable-indev=@var{INDEV}", or you can disable a particular |
| 14 | input device using the option "--disable-indev=@var{INDEV}". |
| 15 | |
| 16 | The option "-devices" of the ff* tools will display the list of |
| 17 | supported input devices. |
| 18 | |
| 19 | A description of the currently available input devices follows. |
| 20 | |
| 21 | @section alsa |
| 22 | |
| 23 | ALSA (Advanced Linux Sound Architecture) input device. |
| 24 | |
| 25 | To enable this input device during configuration you need libasound |
| 26 | installed on your system. |
| 27 | |
| 28 | This device allows capturing from an ALSA device. The name of the |
| 29 | device to capture has to be an ALSA card identifier. |
| 30 | |
| 31 | An ALSA identifier has the syntax: |
| 32 | @example |
| 33 | hw:@var{CARD}[,@var{DEV}[,@var{SUBDEV}]] |
| 34 | @end example |
| 35 | |
| 36 | where the @var{DEV} and @var{SUBDEV} components are optional. |
| 37 | |
| 38 | The three arguments (in order: @var{CARD},@var{DEV},@var{SUBDEV}) |
| 39 | specify card number or identifier, device number and subdevice number |
| 40 | (-1 means any). |
| 41 | |
| 42 | To see the list of cards currently recognized by your system check the |
| 43 | files @file{/proc/asound/cards} and @file{/proc/asound/devices}. |
| 44 | |
| 45 | For example to capture with @command{ffmpeg} from an ALSA device with |
| 46 | card id 0, you may run the command: |
| 47 | @example |
| 48 | ffmpeg -f alsa -i hw:0 alsaout.wav |
| 49 | @end example |
| 50 | |
| 51 | For more information see: |
| 52 | @url{http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html} |
| 53 | |
| 54 | @section avfoundation |
| 55 | |
| 56 | AVFoundation input device. |
| 57 | |
| 58 | AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS. |
| 59 | The older QTKit framework has been marked deprecated since OSX version 10.7. |
| 60 | |
| 61 | The input filename has to be given in the following syntax: |
| 62 | @example |
| 63 | -i "[[VIDEO]:[AUDIO]]" |
| 64 | @end example |
| 65 | The first entry selects the video input while the latter selects the audio input. |
| 66 | The stream has to be specified by the device name or the device index as shown by the device list. |
| 67 | Alternatively, the video and/or audio input device can be chosen by index using the |
| 68 | @option{ |
| 69 | -video_device_index <INDEX> |
| 70 | } |
| 71 | and/or |
| 72 | @option{ |
| 73 | -audio_device_index <INDEX> |
| 74 | } |
| 75 | , overriding any |
| 76 | device name or index given in the input filename. |
| 77 | |
| 78 | All available devices can be enumerated by using @option{-list_devices true}, listing |
| 79 | all device names and corresponding indices. |
| 80 | |
| 81 | There are two device name aliases: |
| 82 | @table @code |
| 83 | |
| 84 | @item default |
| 85 | Select the AVFoundation default device of the corresponding type. |
| 86 | |
| 87 | @item none |
| 88 | Do not record the corresponding media type. |
| 89 | This is equivalent to specifying an empty device name or index. |
| 90 | |
| 91 | @end table |
| 92 | |
| 93 | @subsection Options |
| 94 | |
| 95 | AVFoundation supports the following options: |
| 96 | |
| 97 | @table @option |
| 98 | |
| 99 | @item -list_devices <TRUE|FALSE> |
| 100 | If set to true, a list of all available input devices is given showing all |
| 101 | device names and indices. |
| 102 | |
| 103 | @item -video_device_index <INDEX> |
| 104 | Specify the video device by its index. Overrides anything given in the input filename. |
| 105 | |
| 106 | @item -audio_device_index <INDEX> |
| 107 | Specify the audio device by its index. Overrides anything given in the input filename. |
| 108 | |
| 109 | @item -pixel_format <FORMAT> |
| 110 | Request the video device to use a specific pixel format. |
| 111 | If the specified format is not supported, a list of available formats is given |
| 112 | und the first one in this list is used instead. Available pixel formats are: |
| 113 | @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0, |
| 114 | bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10, |
| 115 | yuv420p, nv12, yuyv422, gray} |
| 116 | |
| 117 | @end table |
| 118 | |
| 119 | @subsection Examples |
| 120 | |
| 121 | @itemize |
| 122 | |
| 123 | @item |
| 124 | Print the list of AVFoundation supported devices and exit: |
| 125 | @example |
| 126 | $ ffmpeg -f avfoundation -list_devices true -i "" |
| 127 | @end example |
| 128 | |
| 129 | @item |
| 130 | Record video from video device 0 and audio from audio device 0 into out.avi: |
| 131 | @example |
| 132 | $ ffmpeg -f avfoundation -i "0:0" out.avi |
| 133 | @end example |
| 134 | |
| 135 | @item |
| 136 | Record video from video device 2 and audio from audio device 1 into out.avi: |
| 137 | @example |
| 138 | $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi |
| 139 | @end example |
| 140 | |
| 141 | @item |
| 142 | Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi: |
| 143 | @example |
| 144 | $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi |
| 145 | @end example |
| 146 | |
| 147 | @end itemize |
| 148 | |
| 149 | @section bktr |
| 150 | |
| 151 | BSD video input device. |
| 152 | |
| 153 | @section dshow |
| 154 | |
| 155 | Windows DirectShow input device. |
| 156 | |
| 157 | DirectShow support is enabled when FFmpeg is built with the mingw-w64 project. |
| 158 | Currently only audio and video devices are supported. |
| 159 | |
| 160 | Multiple devices may be opened as separate inputs, but they may also be |
| 161 | opened on the same input, which should improve synchronism between them. |
| 162 | |
| 163 | The input name should be in the format: |
| 164 | |
| 165 | @example |
| 166 | @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}] |
| 167 | @end example |
| 168 | |
| 169 | where @var{TYPE} can be either @var{audio} or @var{video}, |
| 170 | and @var{NAME} is the device's name. |
| 171 | |
| 172 | @subsection Options |
| 173 | |
| 174 | If no options are specified, the device's defaults are used. |
| 175 | If the device does not support the requested options, it will |
| 176 | fail to open. |
| 177 | |
| 178 | @table @option |
| 179 | |
| 180 | @item video_size |
| 181 | Set the video size in the captured video. |
| 182 | |
| 183 | @item framerate |
| 184 | Set the frame rate in the captured video. |
| 185 | |
| 186 | @item sample_rate |
| 187 | Set the sample rate (in Hz) of the captured audio. |
| 188 | |
| 189 | @item sample_size |
| 190 | Set the sample size (in bits) of the captured audio. |
| 191 | |
| 192 | @item channels |
| 193 | Set the number of channels in the captured audio. |
| 194 | |
| 195 | @item list_devices |
| 196 | If set to @option{true}, print a list of devices and exit. |
| 197 | |
| 198 | @item list_options |
| 199 | If set to @option{true}, print a list of selected device's options |
| 200 | and exit. |
| 201 | |
| 202 | @item video_device_number |
| 203 | Set video device number for devices with same name (starts at 0, |
| 204 | defaults to 0). |
| 205 | |
| 206 | @item audio_device_number |
| 207 | Set audio device number for devices with same name (starts at 0, |
| 208 | defaults to 0). |
| 209 | |
| 210 | @item pixel_format |
| 211 | Select pixel format to be used by DirectShow. This may only be set when |
| 212 | the video codec is not set or set to rawvideo. |
| 213 | |
| 214 | @item audio_buffer_size |
| 215 | Set audio device buffer size in milliseconds (which can directly |
| 216 | impact latency, depending on the device). |
| 217 | Defaults to using the audio device's |
| 218 | default buffer size (typically some multiple of 500ms). |
| 219 | Setting this value too low can degrade performance. |
| 220 | See also |
| 221 | @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx} |
| 222 | |
| 223 | @end table |
| 224 | |
| 225 | @subsection Examples |
| 226 | |
| 227 | @itemize |
| 228 | |
| 229 | @item |
| 230 | Print the list of DirectShow supported devices and exit: |
| 231 | @example |
| 232 | $ ffmpeg -list_devices true -f dshow -i dummy |
| 233 | @end example |
| 234 | |
| 235 | @item |
| 236 | Open video device @var{Camera}: |
| 237 | @example |
| 238 | $ ffmpeg -f dshow -i video="Camera" |
| 239 | @end example |
| 240 | |
| 241 | @item |
| 242 | Open second video device with name @var{Camera}: |
| 243 | @example |
| 244 | $ ffmpeg -f dshow -video_device_number 1 -i video="Camera" |
| 245 | @end example |
| 246 | |
| 247 | @item |
| 248 | Open video device @var{Camera} and audio device @var{Microphone}: |
| 249 | @example |
| 250 | $ ffmpeg -f dshow -i video="Camera":audio="Microphone" |
| 251 | @end example |
| 252 | |
| 253 | @item |
| 254 | Print the list of supported options in selected device and exit: |
| 255 | @example |
| 256 | $ ffmpeg -list_options true -f dshow -i video="Camera" |
| 257 | @end example |
| 258 | |
| 259 | @end itemize |
| 260 | |
| 261 | @section dv1394 |
| 262 | |
| 263 | Linux DV 1394 input device. |
| 264 | |
| 265 | @section fbdev |
| 266 | |
| 267 | Linux framebuffer input device. |
| 268 | |
| 269 | The Linux framebuffer is a graphic hardware-independent abstraction |
| 270 | layer to show graphics on a computer monitor, typically on the |
| 271 | console. It is accessed through a file device node, usually |
| 272 | @file{/dev/fb0}. |
| 273 | |
| 274 | For more detailed information read the file |
| 275 | Documentation/fb/framebuffer.txt included in the Linux source tree. |
| 276 | |
| 277 | To record from the framebuffer device @file{/dev/fb0} with |
| 278 | @command{ffmpeg}: |
| 279 | @example |
| 280 | ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi |
| 281 | @end example |
| 282 | |
| 283 | You can take a single screenshot image with the command: |
| 284 | @example |
| 285 | ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg |
| 286 | @end example |
| 287 | |
| 288 | See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1). |
| 289 | |
| 290 | @section gdigrab |
| 291 | |
| 292 | Win32 GDI-based screen capture device. |
| 293 | |
| 294 | This device allows you to capture a region of the display on Windows. |
| 295 | |
| 296 | There are two options for the input filename: |
| 297 | @example |
| 298 | desktop |
| 299 | @end example |
| 300 | or |
| 301 | @example |
| 302 | title=@var{window_title} |
| 303 | @end example |
| 304 | |
| 305 | The first option will capture the entire desktop, or a fixed region of the |
| 306 | desktop. The second option will instead capture the contents of a single |
| 307 | window, regardless of its position on the screen. |
| 308 | |
| 309 | For example, to grab the entire desktop using @command{ffmpeg}: |
| 310 | @example |
| 311 | ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg |
| 312 | @end example |
| 313 | |
| 314 | Grab a 640x480 region at position @code{10,20}: |
| 315 | @example |
| 316 | ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg |
| 317 | @end example |
| 318 | |
| 319 | Grab the contents of the window named "Calculator" |
| 320 | @example |
| 321 | ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg |
| 322 | @end example |
| 323 | |
| 324 | @subsection Options |
| 325 | |
| 326 | @table @option |
| 327 | @item draw_mouse |
| 328 | Specify whether to draw the mouse pointer. Use the value @code{0} to |
| 329 | not draw the pointer. Default value is @code{1}. |
| 330 | |
| 331 | @item framerate |
| 332 | Set the grabbing frame rate. Default value is @code{ntsc}, |
| 333 | corresponding to a frame rate of @code{30000/1001}. |
| 334 | |
| 335 | @item show_region |
| 336 | Show grabbed region on screen. |
| 337 | |
| 338 | If @var{show_region} is specified with @code{1}, then the grabbing |
| 339 | region will be indicated on screen. With this option, it is easy to |
| 340 | know what is being grabbed if only a portion of the screen is grabbed. |
| 341 | |
| 342 | Note that @var{show_region} is incompatible with grabbing the contents |
| 343 | of a single window. |
| 344 | |
| 345 | For example: |
| 346 | @example |
| 347 | ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg |
| 348 | @end example |
| 349 | |
| 350 | @item video_size |
| 351 | Set the video frame size. The default is to capture the full screen if @file{desktop} is selected, or the full window size if @file{title=@var{window_title}} is selected. |
| 352 | |
| 353 | @item offset_x |
| 354 | When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop. |
| 355 | |
| 356 | Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative @var{offset_x} value to move the region to that monitor. |
| 357 | |
| 358 | @item offset_y |
| 359 | When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop. |
| 360 | |
| 361 | Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative @var{offset_y} value to move the region to that monitor. |
| 362 | |
| 363 | @end table |
| 364 | |
| 365 | @section iec61883 |
| 366 | |
| 367 | FireWire DV/HDV input device using libiec61883. |
| 368 | |
| 369 | To enable this input device, you need libiec61883, libraw1394 and |
| 370 | libavc1394 installed on your system. Use the configure option |
| 371 | @code{--enable-libiec61883} to compile with the device enabled. |
| 372 | |
| 373 | The iec61883 capture device supports capturing from a video device |
| 374 | connected via IEEE1394 (FireWire), using libiec61883 and the new Linux |
| 375 | FireWire stack (juju). This is the default DV/HDV input method in Linux |
| 376 | Kernel 2.6.37 and later, since the old FireWire stack was removed. |
| 377 | |
| 378 | Specify the FireWire port to be used as input file, or "auto" |
| 379 | to choose the first port connected. |
| 380 | |
| 381 | @subsection Options |
| 382 | |
| 383 | @table @option |
| 384 | |
| 385 | @item dvtype |
| 386 | Override autodetection of DV/HDV. This should only be used if auto |
| 387 | detection does not work, or if usage of a different device type |
| 388 | should be prohibited. Treating a DV device as HDV (or vice versa) will |
| 389 | not work and result in undefined behavior. |
| 390 | The values @option{auto}, @option{dv} and @option{hdv} are supported. |
| 391 | |
| 392 | @item dvbuffer |
| 393 | Set maxiumum size of buffer for incoming data, in frames. For DV, this |
| 394 | is an exact value. For HDV, it is not frame exact, since HDV does |
| 395 | not have a fixed frame size. |
| 396 | |
| 397 | @item dvguid |
| 398 | Select the capture device by specifying it's GUID. Capturing will only |
| 399 | be performed from the specified device and fails if no device with the |
| 400 | given GUID is found. This is useful to select the input if multiple |
| 401 | devices are connected at the same time. |
| 402 | Look at /sys/bus/firewire/devices to find out the GUIDs. |
| 403 | |
| 404 | @end table |
| 405 | |
| 406 | @subsection Examples |
| 407 | |
| 408 | @itemize |
| 409 | |
| 410 | @item |
| 411 | Grab and show the input of a FireWire DV/HDV device. |
| 412 | @example |
| 413 | ffplay -f iec61883 -i auto |
| 414 | @end example |
| 415 | |
| 416 | @item |
| 417 | Grab and record the input of a FireWire DV/HDV device, |
| 418 | using a packet buffer of 100000 packets if the source is HDV. |
| 419 | @example |
| 420 | ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg |
| 421 | @end example |
| 422 | |
| 423 | @end itemize |
| 424 | |
| 425 | @section jack |
| 426 | |
| 427 | JACK input device. |
| 428 | |
| 429 | To enable this input device during configuration you need libjack |
| 430 | installed on your system. |
| 431 | |
| 432 | A JACK input device creates one or more JACK writable clients, one for |
| 433 | each audio channel, with name @var{client_name}:input_@var{N}, where |
| 434 | @var{client_name} is the name provided by the application, and @var{N} |
| 435 | is a number which identifies the channel. |
| 436 | Each writable client will send the acquired data to the FFmpeg input |
| 437 | device. |
| 438 | |
| 439 | Once you have created one or more JACK readable clients, you need to |
| 440 | connect them to one or more JACK writable clients. |
| 441 | |
| 442 | To connect or disconnect JACK clients you can use the @command{jack_connect} |
| 443 | and @command{jack_disconnect} programs, or do it through a graphical interface, |
| 444 | for example with @command{qjackctl}. |
| 445 | |
| 446 | To list the JACK clients and their properties you can invoke the command |
| 447 | @command{jack_lsp}. |
| 448 | |
| 449 | Follows an example which shows how to capture a JACK readable client |
| 450 | with @command{ffmpeg}. |
| 451 | @example |
| 452 | # Create a JACK writable client with name "ffmpeg". |
| 453 | $ ffmpeg -f jack -i ffmpeg -y out.wav |
| 454 | |
| 455 | # Start the sample jack_metro readable client. |
| 456 | $ jack_metro -b 120 -d 0.2 -f 4000 |
| 457 | |
| 458 | # List the current JACK clients. |
| 459 | $ jack_lsp -c |
| 460 | system:capture_1 |
| 461 | system:capture_2 |
| 462 | system:playback_1 |
| 463 | system:playback_2 |
| 464 | ffmpeg:input_1 |
| 465 | metro:120_bpm |
| 466 | |
| 467 | # Connect metro to the ffmpeg writable client. |
| 468 | $ jack_connect metro:120_bpm ffmpeg:input_1 |
| 469 | @end example |
| 470 | |
| 471 | For more information read: |
| 472 | @url{http://jackaudio.org/} |
| 473 | |
| 474 | @section lavfi |
| 475 | |
| 476 | Libavfilter input virtual device. |
| 477 | |
| 478 | This input device reads data from the open output pads of a libavfilter |
| 479 | filtergraph. |
| 480 | |
| 481 | For each filtergraph open output, the input device will create a |
| 482 | corresponding stream which is mapped to the generated output. Currently |
| 483 | only video data is supported. The filtergraph is specified through the |
| 484 | option @option{graph}. |
| 485 | |
| 486 | @subsection Options |
| 487 | |
| 488 | @table @option |
| 489 | |
| 490 | @item graph |
| 491 | Specify the filtergraph to use as input. Each video open output must be |
| 492 | labelled by a unique string of the form "out@var{N}", where @var{N} is a |
| 493 | number starting from 0 corresponding to the mapped input stream |
| 494 | generated by the device. |
| 495 | The first unlabelled output is automatically assigned to the "out0" |
| 496 | label, but all the others need to be specified explicitly. |
| 497 | |
| 498 | If not specified defaults to the filename specified for the input |
| 499 | device. |
| 500 | |
| 501 | @item graph_file |
| 502 | Set the filename of the filtergraph to be read and sent to the other |
| 503 | filters. Syntax of the filtergraph is the same as the one specified by |
| 504 | the option @var{graph}. |
| 505 | |
| 506 | @end table |
| 507 | |
| 508 | @subsection Examples |
| 509 | |
| 510 | @itemize |
| 511 | @item |
| 512 | Create a color video stream and play it back with @command{ffplay}: |
| 513 | @example |
| 514 | ffplay -f lavfi -graph "color=c=pink [out0]" dummy |
| 515 | @end example |
| 516 | |
| 517 | @item |
| 518 | As the previous example, but use filename for specifying the graph |
| 519 | description, and omit the "out0" label: |
| 520 | @example |
| 521 | ffplay -f lavfi color=c=pink |
| 522 | @end example |
| 523 | |
| 524 | @item |
| 525 | Create three different video test filtered sources and play them: |
| 526 | @example |
| 527 | ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3 |
| 528 | @end example |
| 529 | |
| 530 | @item |
| 531 | Read an audio stream from a file using the amovie source and play it |
| 532 | back with @command{ffplay}: |
| 533 | @example |
| 534 | ffplay -f lavfi "amovie=test.wav" |
| 535 | @end example |
| 536 | |
| 537 | @item |
| 538 | Read an audio stream and a video stream and play it back with |
| 539 | @command{ffplay}: |
| 540 | @example |
| 541 | ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]" |
| 542 | @end example |
| 543 | |
| 544 | @end itemize |
| 545 | |
| 546 | @section libcdio |
| 547 | |
| 548 | Audio-CD input device based on cdio. |
| 549 | |
| 550 | To enable this input device during configuration you need libcdio |
| 551 | installed on your system. Requires the configure option |
| 552 | @code{--enable-libcdio}. |
| 553 | |
| 554 | This device allows playing and grabbing from an Audio-CD. |
| 555 | |
| 556 | For example to copy with @command{ffmpeg} the entire Audio-CD in /dev/sr0, |
| 557 | you may run the command: |
| 558 | @example |
| 559 | ffmpeg -f libcdio -i /dev/sr0 cd.wav |
| 560 | @end example |
| 561 | |
| 562 | @section libdc1394 |
| 563 | |
| 564 | IIDC1394 input device, based on libdc1394 and libraw1394. |
| 565 | |
| 566 | Requires the configure option @code{--enable-libdc1394}. |
| 567 | |
| 568 | @section openal |
| 569 | |
| 570 | The OpenAL input device provides audio capture on all systems with a |
| 571 | working OpenAL 1.1 implementation. |
| 572 | |
| 573 | To enable this input device during configuration, you need OpenAL |
| 574 | headers and libraries installed on your system, and need to configure |
| 575 | FFmpeg with @code{--enable-openal}. |
| 576 | |
| 577 | OpenAL headers and libraries should be provided as part of your OpenAL |
| 578 | implementation, or as an additional download (an SDK). Depending on your |
| 579 | installation you may need to specify additional flags via the |
| 580 | @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build |
| 581 | system to locate the OpenAL headers and libraries. |
| 582 | |
| 583 | An incomplete list of OpenAL implementations follows: |
| 584 | |
| 585 | @table @strong |
| 586 | @item Creative |
| 587 | The official Windows implementation, providing hardware acceleration |
| 588 | with supported devices and software fallback. |
| 589 | See @url{http://openal.org/}. |
| 590 | @item OpenAL Soft |
| 591 | Portable, open source (LGPL) software implementation. Includes |
| 592 | backends for the most common sound APIs on the Windows, Linux, |
| 593 | Solaris, and BSD operating systems. |
| 594 | See @url{http://kcat.strangesoft.net/openal.html}. |
| 595 | @item Apple |
| 596 | OpenAL is part of Core Audio, the official Mac OS X Audio interface. |
| 597 | See @url{http://developer.apple.com/technologies/mac/audio-and-video.html} |
| 598 | @end table |
| 599 | |
| 600 | This device allows one to capture from an audio input device handled |
| 601 | through OpenAL. |
| 602 | |
| 603 | You need to specify the name of the device to capture in the provided |
| 604 | filename. If the empty string is provided, the device will |
| 605 | automatically select the default device. You can get the list of the |
| 606 | supported devices by using the option @var{list_devices}. |
| 607 | |
| 608 | @subsection Options |
| 609 | |
| 610 | @table @option |
| 611 | |
| 612 | @item channels |
| 613 | Set the number of channels in the captured audio. Only the values |
| 614 | @option{1} (monaural) and @option{2} (stereo) are currently supported. |
| 615 | Defaults to @option{2}. |
| 616 | |
| 617 | @item sample_size |
| 618 | Set the sample size (in bits) of the captured audio. Only the values |
| 619 | @option{8} and @option{16} are currently supported. Defaults to |
| 620 | @option{16}. |
| 621 | |
| 622 | @item sample_rate |
| 623 | Set the sample rate (in Hz) of the captured audio. |
| 624 | Defaults to @option{44.1k}. |
| 625 | |
| 626 | @item list_devices |
| 627 | If set to @option{true}, print a list of devices and exit. |
| 628 | Defaults to @option{false}. |
| 629 | |
| 630 | @end table |
| 631 | |
| 632 | @subsection Examples |
| 633 | |
| 634 | Print the list of OpenAL supported devices and exit: |
| 635 | @example |
| 636 | $ ffmpeg -list_devices true -f openal -i dummy out.ogg |
| 637 | @end example |
| 638 | |
| 639 | Capture from the OpenAL device @file{DR-BT101 via PulseAudio}: |
| 640 | @example |
| 641 | $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg |
| 642 | @end example |
| 643 | |
| 644 | Capture from the default device (note the empty string '' as filename): |
| 645 | @example |
| 646 | $ ffmpeg -f openal -i '' out.ogg |
| 647 | @end example |
| 648 | |
| 649 | Capture from two devices simultaneously, writing to two different files, |
| 650 | within the same @command{ffmpeg} command: |
| 651 | @example |
| 652 | $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg |
| 653 | @end example |
| 654 | Note: not all OpenAL implementations support multiple simultaneous capture - |
| 655 | try the latest OpenAL Soft if the above does not work. |
| 656 | |
| 657 | @section oss |
| 658 | |
| 659 | Open Sound System input device. |
| 660 | |
| 661 | The filename to provide to the input device is the device node |
| 662 | representing the OSS input device, and is usually set to |
| 663 | @file{/dev/dsp}. |
| 664 | |
| 665 | For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the |
| 666 | command: |
| 667 | @example |
| 668 | ffmpeg -f oss -i /dev/dsp /tmp/oss.wav |
| 669 | @end example |
| 670 | |
| 671 | For more information about OSS see: |
| 672 | @url{http://manuals.opensound.com/usersguide/dsp.html} |
| 673 | |
| 674 | @section pulse |
| 675 | |
| 676 | PulseAudio input device. |
| 677 | |
| 678 | To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}. |
| 679 | |
| 680 | The filename to provide to the input device is a source device or the |
| 681 | string "default" |
| 682 | |
| 683 | To list the PulseAudio source devices and their properties you can invoke |
| 684 | the command @command{pactl list sources}. |
| 685 | |
| 686 | More information about PulseAudio can be found on @url{http://www.pulseaudio.org}. |
| 687 | |
| 688 | @subsection Options |
| 689 | @table @option |
| 690 | @item server |
| 691 | Connect to a specific PulseAudio server, specified by an IP address. |
| 692 | Default server is used when not provided. |
| 693 | |
| 694 | @item name |
| 695 | Specify the application name PulseAudio will use when showing active clients, |
| 696 | by default it is the @code{LIBAVFORMAT_IDENT} string. |
| 697 | |
| 698 | @item stream_name |
| 699 | Specify the stream name PulseAudio will use when showing active streams, |
| 700 | by default it is "record". |
| 701 | |
| 702 | @item sample_rate |
| 703 | Specify the samplerate in Hz, by default 48kHz is used. |
| 704 | |
| 705 | @item channels |
| 706 | Specify the channels in use, by default 2 (stereo) is set. |
| 707 | |
| 708 | @item frame_size |
| 709 | Specify the number of bytes per frame, by default it is set to 1024. |
| 710 | |
| 711 | @item fragment_size |
| 712 | Specify the minimal buffering fragment in PulseAudio, it will affect the |
| 713 | audio latency. By default it is unset. |
| 714 | @end table |
| 715 | |
| 716 | @subsection Examples |
| 717 | Record a stream from default device: |
| 718 | @example |
| 719 | ffmpeg -f pulse -i default /tmp/pulse.wav |
| 720 | @end example |
| 721 | |
| 722 | @section qtkit |
| 723 | |
| 724 | QTKit input device. |
| 725 | |
| 726 | The filename passed as input is parsed to contain either a device name or index. |
| 727 | The device index can also be given by using -video_device_index. |
| 728 | A given device index will override any given device name. |
| 729 | If the desired device consists of numbers only, use -video_device_index to identify it. |
| 730 | The default device will be chosen if an empty string or the device name "default" is given. |
| 731 | The available devices can be enumerated by using -list_devices. |
| 732 | |
| 733 | @example |
| 734 | ffmpeg -f qtkit -i "0" out.mpg |
| 735 | @end example |
| 736 | |
| 737 | @example |
| 738 | ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg |
| 739 | @end example |
| 740 | |
| 741 | @example |
| 742 | ffmpeg -f qtkit -i "default" out.mpg |
| 743 | @end example |
| 744 | |
| 745 | @example |
| 746 | ffmpeg -f qtkit -list_devices true -i "" |
| 747 | @end example |
| 748 | |
| 749 | @section sndio |
| 750 | |
| 751 | sndio input device. |
| 752 | |
| 753 | To enable this input device during configuration you need libsndio |
| 754 | installed on your system. |
| 755 | |
| 756 | The filename to provide to the input device is the device node |
| 757 | representing the sndio input device, and is usually set to |
| 758 | @file{/dev/audio0}. |
| 759 | |
| 760 | For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the |
| 761 | command: |
| 762 | @example |
| 763 | ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav |
| 764 | @end example |
| 765 | |
| 766 | @section video4linux2, v4l2 |
| 767 | |
| 768 | Video4Linux2 input video device. |
| 769 | |
| 770 | "v4l2" can be used as alias for "video4linux2". |
| 771 | |
| 772 | If FFmpeg is built with v4l-utils support (by using the |
| 773 | @code{--enable-libv4l2} configure option), it is possible to use it with the |
| 774 | @code{-use_libv4l2} input device option. |
| 775 | |
| 776 | The name of the device to grab is a file device node, usually Linux |
| 777 | systems tend to automatically create such nodes when the device |
| 778 | (e.g. an USB webcam) is plugged into the system, and has a name of the |
| 779 | kind @file{/dev/video@var{N}}, where @var{N} is a number associated to |
| 780 | the device. |
| 781 | |
| 782 | Video4Linux2 devices usually support a limited set of |
| 783 | @var{width}x@var{height} sizes and frame rates. You can check which are |
| 784 | supported using @command{-list_formats all} for Video4Linux2 devices. |
| 785 | Some devices, like TV cards, support one or more standards. It is possible |
| 786 | to list all the supported standards using @command{-list_standards all}. |
| 787 | |
| 788 | The time base for the timestamps is 1 microsecond. Depending on the kernel |
| 789 | version and configuration, the timestamps may be derived from the real time |
| 790 | clock (origin at the Unix Epoch) or the monotonic clock (origin usually at |
| 791 | boot time, unaffected by NTP or manual changes to the clock). The |
| 792 | @option{-timestamps abs} or @option{-ts abs} option can be used to force |
| 793 | conversion into the real time clock. |
| 794 | |
| 795 | Some usage examples of the video4linux2 device with @command{ffmpeg} |
| 796 | and @command{ffplay}: |
| 797 | @itemize |
| 798 | @item |
| 799 | Grab and show the input of a video4linux2 device: |
| 800 | @example |
| 801 | ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0 |
| 802 | @end example |
| 803 | |
| 804 | @item |
| 805 | Grab and record the input of a video4linux2 device, leave the |
| 806 | frame rate and size as previously set: |
| 807 | @example |
| 808 | ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg |
| 809 | @end example |
| 810 | @end itemize |
| 811 | |
| 812 | For more information about Video4Linux, check @url{http://linuxtv.org/}. |
| 813 | |
| 814 | @subsection Options |
| 815 | |
| 816 | @table @option |
| 817 | @item standard |
| 818 | Set the standard. Must be the name of a supported standard. To get a |
| 819 | list of the supported standards, use the @option{list_standards} |
| 820 | option. |
| 821 | |
| 822 | @item channel |
| 823 | Set the input channel number. Default to -1, which means using the |
| 824 | previously selected channel. |
| 825 | |
| 826 | @item video_size |
| 827 | Set the video frame size. The argument must be a string in the form |
| 828 | @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation. |
| 829 | |
| 830 | @item pixel_format |
| 831 | Select the pixel format (only valid for raw video input). |
| 832 | |
| 833 | @item input_format |
| 834 | Set the preferred pixel format (for raw video) or a codec name. |
| 835 | This option allows one to select the input format, when several are |
| 836 | available. |
| 837 | |
| 838 | @item framerate |
| 839 | Set the preferred video frame rate. |
| 840 | |
| 841 | @item list_formats |
| 842 | List available formats (supported pixel formats, codecs, and frame |
| 843 | sizes) and exit. |
| 844 | |
| 845 | Available values are: |
| 846 | @table @samp |
| 847 | @item all |
| 848 | Show all available (compressed and non-compressed) formats. |
| 849 | |
| 850 | @item raw |
| 851 | Show only raw video (non-compressed) formats. |
| 852 | |
| 853 | @item compressed |
| 854 | Show only compressed formats. |
| 855 | @end table |
| 856 | |
| 857 | @item list_standards |
| 858 | List supported standards and exit. |
| 859 | |
| 860 | Available values are: |
| 861 | @table @samp |
| 862 | @item all |
| 863 | Show all supported standards. |
| 864 | @end table |
| 865 | |
| 866 | @item timestamps, ts |
| 867 | Set type of timestamps for grabbed frames. |
| 868 | |
| 869 | Available values are: |
| 870 | @table @samp |
| 871 | @item default |
| 872 | Use timestamps from the kernel. |
| 873 | |
| 874 | @item abs |
| 875 | Use absolute timestamps (wall clock). |
| 876 | |
| 877 | @item mono2abs |
| 878 | Force conversion from monotonic to absolute timestamps. |
| 879 | @end table |
| 880 | |
| 881 | Default value is @code{default}. |
| 882 | @end table |
| 883 | |
| 884 | @section vfwcap |
| 885 | |
| 886 | VfW (Video for Windows) capture input device. |
| 887 | |
| 888 | The filename passed as input is the capture driver number, ranging from |
| 889 | 0 to 9. You may use "list" as filename to print a list of drivers. Any |
| 890 | other filename will be interpreted as device number 0. |
| 891 | |
| 892 | @section x11grab |
| 893 | |
| 894 | X11 video input device. |
| 895 | |
| 896 | Depends on X11, Xext, and Xfixes. Requires the configure option |
| 897 | @code{--enable-x11grab}. |
| 898 | |
| 899 | This device allows one to capture a region of an X11 display. |
| 900 | |
| 901 | The filename passed as input has the syntax: |
| 902 | @example |
| 903 | [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}] |
| 904 | @end example |
| 905 | |
| 906 | @var{hostname}:@var{display_number}.@var{screen_number} specifies the |
| 907 | X11 display name of the screen to grab from. @var{hostname} can be |
| 908 | omitted, and defaults to "localhost". The environment variable |
| 909 | @env{DISPLAY} contains the default display name. |
| 910 | |
| 911 | @var{x_offset} and @var{y_offset} specify the offsets of the grabbed |
| 912 | area with respect to the top-left border of the X11 screen. They |
| 913 | default to 0. |
| 914 | |
| 915 | Check the X11 documentation (e.g. man X) for more detailed information. |
| 916 | |
| 917 | Use the @command{dpyinfo} program for getting basic information about the |
| 918 | properties of your X11 display (e.g. grep for "name" or "dimensions"). |
| 919 | |
| 920 | For example to grab from @file{:0.0} using @command{ffmpeg}: |
| 921 | @example |
| 922 | ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg |
| 923 | @end example |
| 924 | |
| 925 | Grab at position @code{10,20}: |
| 926 | @example |
| 927 | ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg |
| 928 | @end example |
| 929 | |
| 930 | @subsection Options |
| 931 | |
| 932 | @table @option |
| 933 | @item draw_mouse |
| 934 | Specify whether to draw the mouse pointer. A value of @code{0} specify |
| 935 | not to draw the pointer. Default value is @code{1}. |
| 936 | |
| 937 | @item follow_mouse |
| 938 | Make the grabbed area follow the mouse. The argument can be |
| 939 | @code{centered} or a number of pixels @var{PIXELS}. |
| 940 | |
| 941 | When it is specified with "centered", the grabbing region follows the mouse |
| 942 | pointer and keeps the pointer at the center of region; otherwise, the region |
| 943 | follows only when the mouse pointer reaches within @var{PIXELS} (greater than |
| 944 | zero) to the edge of region. |
| 945 | |
| 946 | For example: |
| 947 | @example |
| 948 | ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg |
| 949 | @end example |
| 950 | |
| 951 | To follow only when the mouse pointer reaches within 100 pixels to edge: |
| 952 | @example |
| 953 | ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg |
| 954 | @end example |
| 955 | |
| 956 | @item framerate |
| 957 | Set the grabbing frame rate. Default value is @code{ntsc}, |
| 958 | corresponding to a frame rate of @code{30000/1001}. |
| 959 | |
| 960 | @item show_region |
| 961 | Show grabbed region on screen. |
| 962 | |
| 963 | If @var{show_region} is specified with @code{1}, then the grabbing |
| 964 | region will be indicated on screen. With this option, it is easy to |
| 965 | know what is being grabbed if only a portion of the screen is grabbed. |
| 966 | |
| 967 | For example: |
| 968 | @example |
| 969 | ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg |
| 970 | @end example |
| 971 | |
| 972 | With @var{follow_mouse}: |
| 973 | @example |
| 974 | ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg |
| 975 | @end example |
| 976 | |
| 977 | @item video_size |
| 978 | Set the video frame size. Default value is @code{vga}. |
| 979 | |
| 980 | @item use_shm |
| 981 | Use the MIT-SHM extension for shared memory. Default value is @code{1}. |
| 982 | It may be necessary to disable it for remote displays. |
| 983 | @end table |
| 984 | |
| 985 | @section decklink |
| 986 | |
| 987 | The decklink input device provides capture capabilities for Blackmagic |
| 988 | DeckLink devices. |
| 989 | |
| 990 | To enable this input device, you need the Blackmagic DeckLink SDK and you |
| 991 | need to configure with the appropriate @code{--extra-cflags} |
| 992 | and @code{--extra-ldflags}. |
| 993 | On Windows, you need to run the IDL files through @command{widl}. |
| 994 | |
| 995 | DeckLink is very picky about the formats it supports. Pixel format is always |
| 996 | uyvy422, framerate and video size must be determined for your device with |
| 997 | @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number |
| 998 | of channels currently is limited to 2 (stereo). |
| 999 | |
| 1000 | @subsection Options |
| 1001 | |
| 1002 | @table @option |
| 1003 | |
| 1004 | @item list_devices |
| 1005 | If set to @option{true}, print a list of devices and exit. |
| 1006 | Defaults to @option{false}. |
| 1007 | |
| 1008 | @item list_formats |
| 1009 | If set to @option{true}, print a list of supported formats and exit. |
| 1010 | Defaults to @option{false}. |
| 1011 | |
| 1012 | @end table |
| 1013 | |
| 1014 | @subsection Examples |
| 1015 | |
| 1016 | @itemize |
| 1017 | |
| 1018 | @item |
| 1019 | List input devices: |
| 1020 | @example |
| 1021 | ffmpeg -f decklink -list_devices 1 -i dummy |
| 1022 | @end example |
| 1023 | |
| 1024 | @item |
| 1025 | List supported formats: |
| 1026 | @example |
| 1027 | ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro' |
| 1028 | @end example |
| 1029 | |
| 1030 | @item |
| 1031 | Capture video clip at 1080i50 (format 11): |
| 1032 | @example |
| 1033 | ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi |
| 1034 | @end example |
| 1035 | |
| 1036 | @end itemize |
| 1037 | |
| 1038 | |
| 1039 | @c man end INPUT DEVICES |