Some typos in V4L2_FMT_FLAG symbols were fixed. struct v4l2_clip was changed for compatibility with v4l. (1999-08-30)

V4L2_TUNER_SUB_LANG1 was added. (1999-09-05)

All ioctl() commands that used an integer argument now take a pointer to an integer. Where it makes sense, ioctls will return the actual new value in the integer pointed to by the argument, a common convention in the V4L2 API. The affected ioctls are: VIDIOC_PREVIEW, VIDIOC_STREAMON, VIDIOC_STREAMOFF, VIDIOC_S_FREQ, VIDIOC_S_INPUT, VIDIOC_S_OUTPUT, VIDIOC_S_EFFECT. For example

err = ioctl (fd, VIDIOC_XXX, V4L2_XXX);

becomes

int a = V4L2_XXX; err = ioctl(fd, VIDIOC_XXX, &a);

All the different get- and set-format commands were swept into one VIDIOC_G_FMT and VIDIOC_S_FMT ioctl taking a union and a type field selecting the union member as parameter. Purpose is to simplify the API by eliminating several ioctls and to allow new and driver private data streams without adding new ioctls.

This change obsoletes the following ioctls: VIDIOC_S_INFMT, VIDIOC_G_INFMT, VIDIOC_S_OUTFMT, VIDIOC_G_OUTFMT, VIDIOC_S_VBIFMT and VIDIOC_G_VBIFMT. The image format structure v4l2_format was renamed to struct v4l2_pix_format, while struct v4l2_format is now the envelopping structure for all format negotiations.

Similar to the changes above, the VIDIOC_G_PARM and VIDIOC_S_PARM ioctls were merged with VIDIOC_G_OUTPARM and VIDIOC_S_OUTPARM. A type field in the new struct v4l2_streamparm selects the respective union member.

This change obsoletes the VIDIOC_G_OUTPARM and VIDIOC_S_OUTPARM ioctls.

Control enumeration was simplified, and two new control flags were introduced and one dropped. The catname field was replaced by a group field.

Drivers can now flag unsupported and temporarily unavailable controls with V4L2_CTRL_FLAG_DISABLED and V4L2_CTRL_FLAG_GRABBED respectively. The group name indicates a possibly narrower classification than the category. In other words, there may be multiple groups within a category. Controls within a group would typically be drawn within a group box. Controls in different categories might have a greater separation, or may even appear in separate windows.

The struct v4l2_buffer timestamp was changed to a 64 bit integer, containing the sampling or output time of the frame in nanoseconds. Additionally timestamps will be in absolute system time, not starting from zero at the beginning of a stream. The data type name for timestamps is stamp_t, defined as a signed 64-bit integer. Output devices should not send a buffer out until the time in the timestamp field has arrived. I would like to follow SGI's lead, and adopt a multimedia timestamping system like their UST (Unadjusted System Time). See http://web.archive.org/web/*/http://reality.sgi.com /cpirazzi_engr/lg/time/intro.html. UST uses timestamps that are 64-bit signed integers (not struct timeval's) and given in nanosecond units. The UST clock starts at zero when the system is booted and runs continuously and uniformly. It takes a little over 292 years for UST to overflow. There is no way to set the UST clock. The regular Linux time-of-day clock can be changed periodically, which would cause errors if it were being used for timestamping a multimedia stream. A real UST style clock will require some support in the kernel that is not there yet. But in anticipation, I will change the timestamp field to a 64-bit integer, and I will change the v4l2_masterclock_gettime() function (used only by drivers) to return a 64-bit integer.

A sequence field was added to struct v4l2_buffer. The sequence field counts captured frames, it is ignored by output devices. When a capture driver drops a frame, the sequence number of that frame is skipped.

Figures clarifying the line numbering scheme were added to the V4L2 API specification. The start[0] and start[1] fields no longer count line numbers beginning at zero. Rationale: a) The previous definition was unclear. b) The start[] values are ordinal numbers. c) There is no point in inventing a new line numbering scheme. We now use line number as defined by ITU-R, period. Compatibility: Add one to the start values. Applications depending on the previous semantics may not function correctly.

The restriction "count[0] > 0 and count[1] > 0" has been relaxed to "(count[0] + count[1]) > 0". Rationale: Drivers may allocate resources at scan line granularity and some data services are transmitted only on the first field. The comment that both count values will usually be equal is misleading and pointless and has been removed. This change breaks compatibility with earlier versions: Drivers may return EINVAL, applications may not function correctly.

Drivers are again permitted to return negative (unknown) start values as proposed earlier. Why this feature was dropped is unclear. This change may break compatibility with applications depending on the start values being positive. The use of EBUSY and EINVAL error codes with the VIDIOC_S_FMT ioctl was clarified. The EBUSY error code was finally documented, and the reserved2 field which was previously mentioned only in the videodev.h header file.

New buffer types V4L2_TYPE_VBI_INPUT and V4L2_TYPE_VBI_OUTPUT were added. The former is an alias for the old V4L2_TYPE_VBI, the latter was missing in the videodev.h file.

As specified in the section called “Related Devices”, drivers must make related device functions available under all minor device numbers.

The open() function requires access mode O_RDWR regardless of the device type. All V4L2 drivers exchanging data with applications must support the O_NONBLOCK flag. The O_NOIO flag, a V4L2 symbol which aliased the meaningless O_TRUNC to indicate accesses without data exchange (panel applications) was dropped. Drivers must stay in "panel mode" until the application attempts to initiate a data exchange, see the section called “Opening and Closing Devices”.

The struct v4l2_capability changed dramatically. Note that also the size of the structure changed, which is encoded in the ioctl request code, thus older V4L2 devices will respond with an EINVAL error code to the new VIDIOC_QUERYCAP ioctl.

There are new fields to identify the driver, a new RDS device function V4L2_CAP_RDS_CAPTURE, the V4L2_CAP_AUDIO flag indicates if the device has any audio connectors, another I/O capability V4L2_CAP_ASYNCIO can be flagged. In response to these changes the type field became a bit set and was merged into the flags field. V4L2_FLAG_TUNER was renamed to V4L2_CAP_TUNER, V4L2_CAP_VIDEO_OVERLAY replaced V4L2_FLAG_PREVIEW and V4L2_CAP_VBI_CAPTURE and V4L2_CAP_VBI_OUTPUT replaced V4L2_FLAG_DATA_SERVICE. V4L2_FLAG_READ and V4L2_FLAG_WRITE were merged into V4L2_CAP_READWRITE.

The redundant fields inputs, outputs and audios were removed. These properties can be determined as described in the section called “Video Inputs and Outputs” and the section called “Audio Inputs and Outputs”.

The somewhat volatile and therefore barely useful fields maxwidth, maxheight, minwidth, minheight, maxframerate were removed. This information is available as described in the section called “Data Formats” and the section called “Video Standards”.

V4L2_FLAG_SELECT was removed. We believe the select() function is important enough to require support of it in all V4L2 drivers exchanging data with applications. The redundant V4L2_FLAG_MONOCHROME flag was removed, this information is available as described in the section called “Data Formats”.

In struct v4l2_input the assoc_audio field and the capability field and its only flag V4L2_INPUT_CAP_AUDIO was replaced by the new audioset field. Instead of linking one video input to one audio input this field reports all audio inputs this video input combines with.

New fields are tuner (reversing the former link from tuners to video inputs), std and status.

Accordingly struct v4l2_output lost its capability and assoc_audio fields. audioset, modulator and std where added instead.

The struct v4l2_audio field audio was renamed to index, for consistency with other structures. A new capability flag V4L2_AUDCAP_STEREO was added to indicated if the audio input in question supports stereo sound. V4L2_AUDCAP_EFFECTS and the corresponding V4L2_AUDMODE flags where removed. This can be easily implemented using controls. (However the same applies to AVL which is still there.)

Again for consistency the struct v4l2_audioout field audio was renamed to index.

The struct v4l2_tuner input field was replaced by an index field, permitting devices with multiple tuners. The link between video inputs and tuners is now reversed, inputs point to their tuner. The std substructure became a simple set (more about this below) and moved into struct v4l2_input. A type field was added.

Accordingly in struct v4l2_modulator the output was replaced by an index field.

In struct v4l2_frequency the port field was replaced by a tuner field containing the respective tuner or modulator index number. A tuner type field was added and the reserved field became larger for future extensions (satellite tuners in particular).

The idea of completely transparent video standards was dropped. Experience showed that applications must be able to work with video standards beyond presenting the user a menu. Instead of enumerating supported standards with an ioctl applications can now refer to standards by v4l2_std_id and symbols defined in the videodev2.h header file. For details see the section called “Video Standards”. The VIDIOC_G_STD and VIDIOC_S_STD now take a pointer to this type as argument. VIDIOC_QUERYSTD was added to autodetect the received standard, if the hardware has this capability. In struct v4l2_standard an index field was added for VIDIOC_ENUMSTD. A v4l2_std_id field named id was added as machine readable identifier, also replacing the transmission field. The misleading framerate field was renamed to frameperiod. The now obsolete colorstandard information, originally needed to distguish between variations of standards, were removed.

Struct v4l2_enumstd ceased to be. VIDIOC_ENUMSTD now takes a pointer to a struct v4l2_standard directly. The information which standards are supported by a particular video input or output moved into struct v4l2_input and struct v4l2_output fields named std, respectively.

The struct v4l2_queryctrl fields category and group did not catch on and/or were not implemented as expected and therefore removed.

The VIDIOC_TRY_FMT ioctl was added to negotiate data formats as with VIDIOC_S_FMT, but without the overhead of programming the hardware and regardless of I/O in progress.

In struct v4l2_format the fmt union was extended to contain struct v4l2_window. All image format negotiations are now possible with VIDIOC_G_FMT, VIDIOC_S_FMT and VIDIOC_TRY_FMT; ioctl. The VIDIOC_G_WIN and VIDIOC_S_WIN ioctls to prepare for a video overlay were removed. The type field changed to type enum v4l2_buf_type and the buffer type names changed as follows.

In struct v4l2_fmtdesc a enum v4l2_buf_type field named type was added as in struct v4l2_format. The VIDIOC_ENUM_FBUFFMT ioctl is no longer needed and was removed. These calls can be replaced by VIDIOC_ENUM_FMT with type V4L2_BUF_TYPE_VIDEO_OVERLAY.

In struct v4l2_pix_format the depth field was removed, assuming applications which recognize the format by its four-character-code already know the color depth, and others do not care about it. The same rationale lead to the removal of the V4L2_FMT_FLAG_COMPRESSED flag. The V4L2_FMT_FLAG_SWCONVECOMPRESSED flag was removed because drivers are not supposed to convert images in kernel space. A user library of conversion functions should be provided instead. The V4L2_FMT_FLAG_BYTESPERLINE flag was redundant. Applications can set the bytesperline field to zero to get a reasonable default. Since the remaining flags were replaced as well, the flags field itself was removed.

The interlace flags were replaced by a enum v4l2_field value in a newly added field field.

The color space flags were replaced by a enum v4l2_colorspace value in a newly added colorspace field, where one of V4L2_COLORSPACE_SMPTE170M, V4L2_COLORSPACE_BT878, V4L2_COLORSPACE_470_SYSTEM_M or V4L2_COLORSPACE_470_SYSTEM_BG replaces V4L2_FMT_CS_601YUV.

In struct v4l2_requestbuffers the type field was properly defined as enum v4l2_buf_type. Buffer types changed as mentioned above. A new memory field of type enum v4l2_memory was added to distinguish between I/O methods using buffers allocated by the driver or the application. See Chapter 3, Input/Output for details.

In struct v4l2_buffer the type field was properly defined as enum v4l2_buf_type. Buffer types changed as mentioned above. A field field of type enum v4l2_field was added to indicate if a buffer contains a top or bottom field. The old field flags were removed. Since no unadjusted system time clock was added to the kernel as planned, the timestamp field changed back from type stamp_t, an unsigned 64 bit integer expressing the sample time in nanoseconds, to struct timeval. With the addition of a second memory mapping method the offset field moved into union m, and a new memory field of type enum v4l2_memory was added to distinguish between I/O methods. See Chapter 3, Input/Output for details.

The V4L2_BUF_REQ_CONTIG flag was used by the V4L compatibility layer, after changes to this code it was no longer needed. The V4L2_BUF_ATTR_DEVICEMEM flag would indicate if the buffer was indeed allocated in device memory rather than DMA-able system memory. It was barely useful and so was removed.

In struct v4l2_framebuffer the base[3] array anticipating double- and triple-buffering in off-screen video memory, however without defining a synchronization mechanism, was replaced by a single pointer. The V4L2_FBUF_CAP_SCALEUP and V4L2_FBUF_CAP_SCALEDOWN flags were removed. Applications can determine this capability more accurately using the new cropping and scaling interface. The V4L2_FBUF_CAP_CLIPPING flag was replaced by V4L2_FBUF_CAP_LIST_CLIPPING and V4L2_FBUF_CAP_BITMAP_CLIPPING.

In struct v4l2_clip the x, y, width and height field moved into a c substructure of type struct v4l2_rect. The x and y fields were renamed to left and top, i. e. offsets to a context dependent origin.

In struct v4l2_window the x, y, width and height field moved into a w substructure as above. A field field of type %v4l2-field; was added to distinguish between field and frame (interlaced) overlay.

The digital zoom interface, including struct v4l2_zoomcap, struct v4l2_zoom, V4L2_ZOOM_NONCAP and V4L2_ZOOM_WHILESTREAMING was replaced by a new cropping and scaling interface. The previously unused struct v4l2_cropcap and v4l2_crop where redefined for this purpose. See the section called “Image Cropping, Insertion and Scaling” for details.

In struct v4l2_vbi_format the SAMPLE_FORMAT field now contains a four-character-code as used to identify video image formats and V4L2_PIX_FMT_GREY replaces the V4L2_VBI_SF_UBYTE define. The reserved field was extended.

In struct v4l2_captureparm the type of the timeperframe field changed from unsigned long to struct v4l2_fract. This allows the accurate expression of multiples of the NTSC-M frame rate 30000 / 1001. A new field readbuffers was added to control the driver behaviour in read I/O mode.

Similar changes were made to struct v4l2_outputparm.

The struct v4l2_performance and VIDIOC_G_PERF ioctl were dropped. Except when using the read/write I/O method, which is limited anyway, this information is already available to applications.

The example transformation from RGB to YCbCr color space in the old V4L2 documentation was inaccurate, this has been corrected in Chapter 2, Image Formats.

A new capability flag V4L2_CAP_RADIO was added for radio devices. Prior to this change radio devices would identify solely by having exactly one tuner whose type field reads V4L2_TUNER_RADIO.

An optional driver access priority mechanism was added, see the section called “Application Priority” for details.

The audio input and output interface was found to be incomplete.

Previously the VIDIOC_G_AUDIO ioctl would enumerate the available audio inputs. An ioctl to determine the current audio input, if more than one combines with the current video input, did not exist. So VIDIOC_G_AUDIO was renamed to VIDIOC_G_AUDIO_OLD, this ioctl was removed on Kernel 2.6.39. The VIDIOC_ENUMAUDIO ioctl was added to enumerate audio inputs, while VIDIOC_G_AUDIO now reports the current audio input.

The same changes were made to VIDIOC_G_AUDOUT and VIDIOC_ENUMAUDOUT.

Until further the "videodev" module will automatically translate between the old and new ioctls, but drivers and applications must be updated to successfully compile again.

The VIDIOC_OVERLAY ioctl was incorrectly defined with write-read parameter. It was changed to write-only, while the write-read version was renamed to VIDIOC_OVERLAY_OLD. The old ioctl was removed on Kernel 2.6.39. Until further the "videodev" kernel module will automatically translate to the new version, so drivers must be recompiled, but not applications.

the section called “Video Overlay Interface” incorrectly stated that clipping rectangles define regions where the video can be seen. Correct is that clipping rectangles define regions where no video shall be displayed and so the graphics surface can be seen.

The VIDIOC_S_PARM and VIDIOC_S_CTRL ioctls were defined with write-only parameter, inconsistent with other ioctls modifying their argument. They were changed to write-read, while a _OLD suffix was added to the write-only versions. The old ioctls were removed on Kernel 2.6.39. Drivers and applications assuming a constant parameter need an update.

In the section called “RGB Formats” the following pixel formats were incorrectly transferred from Bill Dirks' V4L2 specification. Descriptions below refer to bytes in memory, in ascending address order.

The V4L2_PIX_FMT_BGR24 example was always correct.

In the section called “Image Properties” the mapping of the V4L VIDEO_PALETTE_RGB24 and VIDEO_PALETTE_RGB32 formats to V4L2 pixel formats was accordingly corrected.

Unrelated to the fixes above, drivers may still interpret some V4L2 RGB pixel formats differently. These issues have yet to be addressed, for details see the section called “RGB Formats”.

The VIDIOC_CROPCAP ioctl was incorrectly defined with read-only parameter. It is now defined as write-read ioctl, while the read-only version was renamed to VIDIOC_CROPCAP_OLD. The old ioctl was removed on Kernel 2.6.39.

A new field input (former reserved[0]) was added to the struct v4l2_buffer structure. Purpose of this field is to alternate between video inputs (e. g. cameras) in step with the video capturing process. This function must be enabled with the new V4L2_BUF_FLAG_INPUT flag. The flags field is no longer read-only.

The return value of the V4L2 open()(2) function was incorrectly documented.

Audio output ioctls end in -AUDOUT, not -AUDIOOUT.

In the Current Audio Input example the VIDIOC_G_AUDIO ioctl took the wrong argument.

The documentation of the VIDIOC_QBUF and VIDIOC_DQBUF ioctls did not mention the struct v4l2_buffer memory field. It was also missing from examples. Also on the VIDIOC_DQBUF page the EIO error code was not documented.

A new sliced VBI interface was added. It is documented in the section called “Sliced VBI Data Interface” and replaces the interface first proposed in V4L2 specification 0.8.

The VIDIOC_LOG_STATUS ioctl was added.

New video standards V4L2_STD_NTSC_443, V4L2_STD_SECAM_LC, V4L2_STD_SECAM_DK (a set of SECAM D, K and K1), and V4L2_STD_ATSC (a set of V4L2_STD_ATSC_8_VSB and V4L2_STD_ATSC_16_VSB) were defined. Note the V4L2_STD_525_60 set now includes V4L2_STD_NTSC_443. See also Table A.48, “typedef v4l2_std_id”.

The VIDIOC_G_COMP and VIDIOC_S_COMP ioctl were renamed to VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP respectively. Their argument was replaced by a struct v4l2_mpeg_compression pointer. (The VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP ioctls where removed in Linux 2.6.25.)

The V4L2_IN_ST_COLOR_KILL flag in struct v4l2_input not only indicates if the color killer is enabled, but also if it is active. (The color killer disables color decoding when it detects no color in the video signal to improve the image quality.)

VIDIOC_S_PARM is a write-read ioctl, not write-only as stated on its reference page. The ioctl changed in 2003 as noted above.

In struct v4l2_captureparm and struct v4l2_outputparm the timeperframe field gives the time in seconds, not microseconds.

The clips field in struct v4l2_window must point to an array of struct v4l2_clip, not a linked list, because drivers ignore the struct v4l2_clip.next pointer.

New video standard macros were added: V4L2_STD_NTSC_M_KR (NTSC M South Korea), and the sets V4L2_STD_MN, V4L2_STD_B, V4L2_STD_GH and V4L2_STD_DK. The V4L2_STD_NTSC and V4L2_STD_SECAM sets now include V4L2_STD_NTSC_M_KR and V4L2_STD_SECAM_LC respectively.

A new V4L2_TUNER_MODE_LANG1_LANG2 was defined to record both languages of a bilingual program. The use of V4L2_TUNER_MODE_STEREO for this purpose is deprecated now. See the VIDIOC_G_TUNER section for details.

In various places V4L2_BUF_TYPE_SLICED_VBI_CAPTURE and V4L2_BUF_TYPE_SLICED_VBI_OUTPUT of the sliced VBI interface were not mentioned along with other buffer types.

In ioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO(2) it was clarified that the struct v4l2_audio mode field is a flags field.

ioctl VIDIOC_QUERYCAP(2) did not mention the sliced VBI and radio capability flags.

In ioctl VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY(2) it was clarified that applications must initialize the tuner type field of struct v4l2_frequency before calling VIDIOC_S_FREQUENCY.

The reserved array in struct v4l2_requestbuffers has 2 elements, not 32.

In the section called “Video Output Interface” and the section called “Raw VBI Data Interface” the device file names /dev/vout which never caught on were replaced by /dev/video.

With Linux 2.6.15 the possible range for VBI device minor numbers was extended from 224-239 to 224-255. Accordingly device file names /dev/vbi0 to /dev/vbi31 are possible now.

New ioctls VIDIOC_G_EXT_CTRLS, VIDIOC_S_EXT_CTRLS and VIDIOC_TRY_EXT_CTRLS were added, a flag to skip unsupported controls with VIDIOC_QUERYCTRL, new control types V4L2_CTRL_TYPE_INTEGER64 and V4L2_CTRL_TYPE_CTRL_CLASS (Table A.98, “enum v4l2_ctrl_type”), and new control flags V4L2_CTRL_FLAG_READ_ONLY, V4L2_CTRL_FLAG_UPDATE, V4L2_CTRL_FLAG_INACTIVE and V4L2_CTRL_FLAG_SLIDER (Table A.99, “Control Flags”). See the section called “Extended Controls” for details.

In struct v4l2_sliced_vbi_cap a buffer type field was added replacing a reserved field. Note on architectures where the size of enum types differs from int types the size of the structure changed. The VIDIOC_G_SLICED_VBI_CAP ioctl was redefined from being read-only to write-read. Applications must initialize the type field and clear the reserved fields now. These changes may break the compatibility with older drivers and applications.

The ioctls VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS were added.

A new pixel format V4L2_PIX_FMT_RGB444 (Table 2.16, “Packed RGB Image Formats”) was added.

V4L2_PIX_FMT_HM12 (Table 2.20, “Reserved Image Formats”) is a YUV 4:2:0, not 4:2:2 format.

The videodev2.h header file is now dual licensed under GNU General Public License version two or later, and under a 3-clause BSD-style license.

Two new field orders V4L2_FIELD_INTERLACED_TB and V4L2_FIELD_INTERLACED_BT were added. See Table 3.9, “enum v4l2_field” for details.

Three new clipping/blending methods with a global or straight or inverted local alpha value were added to the video overlay interface. See the description of the VIDIOC_G_FBUF and VIDIOC_S_FBUF ioctls for details.

A new global_alpha field was added to v4l2_window, extending the structure. This may break compatibility with applications using a struct v4l2_window directly. However the VIDIOC_G/S/TRY_FMT ioctls, which take a pointer to a v4l2_format parent structure with padding bytes at the end, are not affected.

The format of the chromakey field in struct v4l2_window changed from "host order RGB32" to a pixel value in the same format as the framebuffer. This may break compatibility with existing applications. Drivers supporting the "host order RGB32" format are not known.

The pixel formats V4L2_PIX_FMT_PAL8, V4L2_PIX_FMT_YUV444, V4L2_PIX_FMT_YUV555, V4L2_PIX_FMT_YUV565 and V4L2_PIX_FMT_YUV32 were added.

The pixel formats V4L2_PIX_FMT_Y16 and V4L2_PIX_FMT_SBGGR16 were added.

New controls V4L2_CID_POWER_LINE_FREQUENCY, V4L2_CID_HUE_AUTO, V4L2_CID_WHITE_BALANCE_TEMPERATURE, V4L2_CID_SHARPNESS and V4L2_CID_BACKLIGHT_COMPENSATION were added. The controls V4L2_CID_BLACK_LEVEL, V4L2_CID_WHITENESS, V4L2_CID_HCENTER and V4L2_CID_VCENTER were deprecated.

A Camera controls class was added, with the new controls V4L2_CID_EXPOSURE_AUTO, V4L2_CID_EXPOSURE_ABSOLUTE, V4L2_CID_EXPOSURE_AUTO_PRIORITY, V4L2_CID_PAN_RELATIVE, V4L2_CID_TILT_RELATIVE, V4L2_CID_PAN_RESET, V4L2_CID_TILT_RESET, V4L2_CID_PAN_ABSOLUTE, V4L2_CID_TILT_ABSOLUTE, V4L2_CID_FOCUS_ABSOLUTE, V4L2_CID_FOCUS_RELATIVE and V4L2_CID_FOCUS_AUTO.

The VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP ioctls, which were superseded by the extended controls interface in Linux 2.6.18, where finally removed from the videodev2.h header file.

The pixel formats V4L2_PIX_FMT_Y16 and V4L2_PIX_FMT_SBGGR16 were added.

Added user controls V4L2_CID_CHROMA_AGC and V4L2_CID_COLOR_KILLER.

The VIDIOC_S_HW_FREQ_SEEK ioctl and the V4L2_CAP_HW_FREQ_SEEK capability were added.

The pixel formats V4L2_PIX_FMT_YVYU, V4L2_PIX_FMT_PCA501, V4L2_PIX_FMT_PCA505, V4L2_PIX_FMT_PCA508, V4L2_PIX_FMT_PCA561, V4L2_PIX_FMT_SGBRG8, V4L2_PIX_FMT_PAC207 and V4L2_PIX_FMT_PJPG were added.

Added V4L2_MPEG_AUDIO_ENCODING_AAC and V4L2_MPEG_AUDIO_ENCODING_AC3 MPEG audio encodings.

Added V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC MPEG video encoding.

The pixel formats V4L2_PIX_FMT_SGRBG10 and V4L2_PIX_FMT_SGRBG10DPCM8 were added.

The VIDIOC_G_CHIP_IDENT ioctl was renamed to VIDIOC_G_CHIP_IDENT_OLD and VIDIOC_DBG_G_CHIP_IDENT was introduced in its place. The old struct v4l2_chip_ident was renamed to v4l2_chip_ident_old.

The pixel formats V4L2_PIX_FMT_VYUY, V4L2_PIX_FMT_NV16 and V4L2_PIX_FMT_NV61 were added.

Added camera controls V4L2_CID_ZOOM_ABSOLUTE, V4L2_CID_ZOOM_RELATIVE, V4L2_CID_ZOOM_CONTINUOUS and V4L2_CID_PRIVACY.

New control flag V4L2_CTRL_FLAG_WRITE_ONLY was added.

New control V4L2_CID_COLORFX was added.

In order to be easier to compare a V4L2 API and a kernel version, now V4L2 API is numbered using the Linux Kernel version numeration.

Finalized the RDS capture API. See the section called “RDS Interface” for more information.

Added new capabilities for modulators and RDS encoders.

Add description for libv4l API.

Added support for string controls via new type V4L2_CTRL_TYPE_STRING.

Added V4L2_CID_BAND_STOP_FILTER documentation.

Added FM Modulator (FM TX) Extended Control Class: V4L2_CTRL_CLASS_FM_TX and their Control IDs.

Added FM Receiver (FM RX) Extended Control Class: V4L2_CTRL_CLASS_FM_RX and their Control IDs.

Added Remote Controller chapter, describing the default Remote Controller mapping for media devices.

Added support for Digital Video timings in order to support HDTV receivers and transmitters.

Added V4L2_CID_IRIS_ABSOLUTE and V4L2_CID_IRIS_RELATIVE controls to the Camera controls class.

Remove the vtx (videotext/teletext) API. This API was no longer used and no hardware exists to verify the API. Nor were any userspace applications found that used it. It was originally scheduled for removal in 2.6.35.

The old VIDIOC_*_OLD symbols and V4L1 support were removed.

Multi-planar API added. Does not affect the compatibility of current drivers and applications. See multi-planar API for details.

VIDIOC_QUERYCAP now returns a per-subsystem version instead of a per-driver one.

Standardize an error code for invalid ioctl.

Added V4L2_CTRL_TYPE_BITMASK.

V4L2_CTRL_FLAG_VOLATILE was added to signal volatile controls to userspace.

Add selection API for extended control over cropping and composing. Does not affect the compatibility of current drivers and applications. See selection API for details.

Added V4L2_CID_ALPHA_COMPONENT control to the User controls class.

Added the device_caps field to struct v4l2_capabilities and added the new V4L2_CAP_DEVICE_CAPS capability.

Added JPEG compression control class.

Extended the DV Timings API: VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and VIDIOC_DV_TIMINGS_CAP.

Added integer menus, the new type will be V4L2_CTRL_TYPE_INTEGER_MENU.

Added selection API for V4L2 subdev interface: VIDIOC_SUBDEV_G_SELECTION and VIDIOC_SUBDEV_S_SELECTION.

Added V4L2_COLORFX_ANTIQUE, V4L2_COLORFX_ART_FREEZE, V4L2_COLORFX_AQUA, V4L2_COLORFX_SILHOUETTE, V4L2_COLORFX_SOLARIZATION, V4L2_COLORFX_VIVID and V4L2_COLORFX_ARBITRARY_CBCR menu items to the V4L2_CID_COLORFX control.

Added V4L2_CID_COLORFX_CBCR control.

Added camera controls V4L2_CID_AUTO_EXPOSURE_BIAS, V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE, V4L2_CID_IMAGE_STABILIZATION, V4L2_CID_ISO_SENSITIVITY, V4L2_CID_ISO_SENSITIVITY_AUTO, V4L2_CID_EXPOSURE_METERING, V4L2_CID_SCENE_MODE, V4L2_CID_3A_LOCK, V4L2_CID_AUTO_FOCUS_START, V4L2_CID_AUTO_FOCUS_STOP, V4L2_CID_AUTO_FOCUS_STATUS and V4L2_CID_AUTO_FOCUS_RANGE.

Replaced input in v4l2_buffer by reserved2 and removed V4L2_BUF_FLAG_INPUT.

Added V4L2_CAP_VIDEO_M2M and V4L2_CAP_VIDEO_M2M_MPLANE capabilities.

Added support for frequency band enumerations: VIDIOC_ENUM_FREQ_BANDS.

Added timestamp types to flags field in v4l2_buffer. See Table 3.4, “Buffer Flags”.

Added V4L2_EVENT_CTRL_CH_RANGE control event changes flag. See Table A.19, “Control Changes”.

Removed obsolete and unused DV_PRESET ioctls VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET, VIDIOC_QUERY_DV_PRESET and VIDIOC_ENUM_DV_PRESET. Remove the related v4l2_input/output capability flags V4L2_IN_CAP_PRESETS and V4L2_OUT_CAP_PRESETS.

Added new debugging ioctl VIDIOC_DBG_G_CHIP_INFO.

Remove obsolete VIDIOC_DBG_G_CHIP_IDENT ioctl.

In struct v4l2_rect, the type of width and height fields changed from _s32 to _u32.

Added Software Defined Radio (SDR) Interface.

Added event V4L2_EVENT_SOURCE_CHANGE.

Extended struct v4l2_pix_format. Added format flags.

Added compound control types and VIDIOC_QUERY_EXT_CTRL.

Added V4L2_CID_PAN_SPEED and V4L2_CID_TILT_SPEED camera controls.

Rewrote Colorspace chapter, added new enum v4l2_ycbcr_encoding and enum v4l2_quantization fields to struct v4l2_pix_format, struct v4l2_pix_format_mplane and struct v4l2_mbus_framefmt.