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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/userspace-api/media/v4l/v4l2.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/userspace-api/media/v4l/v4l2.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/v4l2.rst | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/v4l2.rst b/Documentation/userspace-api/media/v4l/v4l2.rst new file mode 100644 index 000000000..ad7a2bf0c --- /dev/null +++ b/Documentation/userspace-api/media/v4l/v4l2.rst @@ -0,0 +1,418 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. include:: <isonum.txt> + +.. _v4l2spec: + +############################ +Part I - Video for Linux API +############################ + +This part describes the Video for Linux API version 2 (V4L2 API) specification. + +**Revision 4.5** + +.. only:: html + + .. class:: toc-title + + Table of Contents + +.. toctree:: + :numbered: + :maxdepth: 5 + + common + pixfmt + io + devices + libv4l + compat + user-func + common-defs + videodev + capture-example + v4l2grab-example + biblio + + +********************** +Revision and Copyright +********************** + +Authors, in alphabetical order: + +- Ailus, Sakari <sakari.ailus@iki.fi> + + - Subdev selections API. + +- Carvalho Chehab, Mauro <mchehab+samsung@kernel.org> + + - Documented libv4l, designed and added v4l2grab example, Remote Controller chapter. + +- Dirks, Bill + + - Original author of the V4L2 API and documentation. + +- Figa, Tomasz <tfiga@chromium.org> + + - Documented the memory-to-memory decoder interface. + - Documented the memory-to-memory encoder interface. + +- H Schimek, Michael <mschimek@gmx.at> + + - Original author of the V4L2 API and documentation. + +- Karicheri, Muralidharan <m-karicheri2@ti.com> + + - Documented the Digital Video timings API. + +- Osciak, Pawel <posciak@chromium.org> + + - Documented the memory-to-memory decoder interface. + - Documented the memory-to-memory encoder interface. + +- Osciak, Pawel <pawel@osciak.com> + + - Designed and documented the multi-planar API. + +- Palosaari, Antti <crope@iki.fi> + + - SDR API. + +- Ribalda, Ricardo + + - Introduce HSV formats and other minor changes. + +- Rubli, Martin + + - Designed and documented the VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS ioctls. + +- Walls, Andy <awalls@md.metrocast.net> + + - Documented the fielded V4L2_MPEG_STREAM_VBI_FMT_IVTV MPEG stream embedded, sliced VBI data format in this specification. + +- Verkuil, Hans <hverkuil@xs4all.nl> + + - Designed and documented the VIDIOC_LOG_STATUS ioctl, the extended control ioctls, major parts of the sliced VBI API, the MPEG encoder and decoder APIs and the DV Timings API. + +**Copyright** |copy| 1999-2018: Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab, Pawel Osciak, Sakari Ailus & Antti Palosaari, Tomasz Figa + +Except when explicitly stated as GPL, programming examples within this +part can be used and distributed without restrictions. + +**************** +Revision History +**************** + +:revision: 4.10 / 2016-07-15 (*rr*) + +Introduce HSV formats. + + +:revision: 4.5 / 2015-10-29 (*rr*) + +Extend VIDIOC_G_EXT_CTRLS;. Replace ctrl_class with a new union with +ctrl_class and which. Which is used to select the current value of the +control or the default value. + + +:revision: 4.4 / 2015-05-26 (*ap*) + +Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR. Added +V4L2_CID_RF_TUNER_RF_GAIN control. Added transmitter support for +Software Defined Radio (SDR) Interface. + + +:revision: 4.1 / 2015-02-13 (*mcc*) + +Fix documentation for media controller device nodes and add support for +DVB device nodes. Add support for Tuner sub-device. + + +:revision: 3.19 / 2014-12-05 (*hv*) + +Rewrote Colorspace chapter, added new enum +:c:type:`v4l2_ycbcr_encoding` and enum +:c:type:`v4l2_quantization` fields to struct +:c:type:`v4l2_pix_format`, struct +:c:type:`v4l2_pix_format_mplane` and struct +:c:type:`v4l2_mbus_framefmt`. + + +:revision: 3.17 / 2014-08-04 (*lp, hv*) + +Extended struct :c:type:`v4l2_pix_format`. Added +format flags. Added compound control types and VIDIOC_QUERY_EXT_CTRL. + + +:revision: 3.15 / 2014-02-03 (*hv, ap*) + +Update several sections of "Common API Elements": "Opening and Closing +Devices" "Querying Capabilities", "Application Priority", "Video Inputs +and Outputs", "Audio Inputs and Outputs" "Tuners and Modulators", "Video +Standards" and "Digital Video (DV) Timings". Added SDR API. + + +:revision: 3.14 / 2013-11-25 (*rr*) + +Set width and height as unsigned on v4l2_rect. + + +:revision: 3.11 / 2013-05-26 (*hv*) + +Remove obsolete VIDIOC_DBG_G_CHIP_IDENT ioctl. + + +:revision: 3.10 / 2013-03-25 (*hv*) + +Remove 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 VIDIOC_DBG_G_CHIP_INFO. + + +:revision: 3.9 / 2012-12-03 (*sa, sn*) + +Added timestamp types to v4l2_buffer. Added +V4L2_EVENT_CTRL_CH_RANGE control event changes flag. + + +:revision: 3.6 / 2012-07-02 (*hv*) + +Added VIDIOC_ENUM_FREQ_BANDS. + + +:revision: 3.5 / 2012-05-07 (*sa, sn, hv*) + +Added V4L2_CTRL_TYPE_INTEGER_MENU and V4L2 subdev selections API. +Improved the description of 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. Added +VIDIOC_ENUM_DV_TIMINGS, VIDIOC_QUERY_DV_TIMINGS and +VIDIOC_DV_TIMINGS_CAP. + + +:revision: 3.4 / 2012-01-25 (*sn*) + +Added :ref:`JPEG compression control class. <jpeg-controls>` + + +:revision: 3.3 / 2012-01-11 (*hv*) + +Added device_caps field to struct v4l2_capabilities. + + +:revision: 3.2 / 2011-08-26 (*hv*) + +Added V4L2_CTRL_FLAG_VOLATILE. + + +:revision: 3.1 / 2011-06-27 (*mcc, po, hv*) + +Documented that 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. + + +:revision: 2.6.39 / 2011-03-01 (*mcc, po*) + +Removed VIDIOC_*_OLD from videodev2.h header and update it to reflect +latest changes. Added the :ref:`multi-planar API <planar-apis>`. + + +:revision: 2.6.37 / 2010-08-06 (*hv*) + +Removed obsolete vtx (videotext) API. + + +:revision: 2.6.33 / 2009-12-03 (*mk*) + +Added documentation for the Digital Video timings API. + + +:revision: 2.6.32 / 2009-08-31 (*mcc*) + +Now, revisions will match the kernel version where the V4L2 API changes +will be used by the Linux Kernel. Also added Remote Controller chapter. + + +:revision: 0.29 / 2009-08-26 (*ev*) + +Added documentation for string controls and for FM Transmitter controls. + + +:revision: 0.28 / 2009-08-26 (*gl*) + +Added V4L2_CID_BAND_STOP_FILTER documentation. + + +:revision: 0.27 / 2009-08-15 (*mcc*) + +Added libv4l and Remote Controller documentation; added v4l2grab and +keytable application examples. + + +:revision: 0.26 / 2009-07-23 (*hv*) + +Finalized the RDS capture API. Added modulator and RDS encoder +capabilities. Added support for string controls. + + +:revision: 0.25 / 2009-01-18 (*hv*) + +Added pixel formats VYUY, NV16 and NV61, and changed the debug ioctls +VIDIOC_DBG_G/S_REGISTER and VIDIOC_DBG_G_CHIP_IDENT. Added camera +controls V4L2_CID_ZOOM_ABSOLUTE, V4L2_CID_ZOOM_RELATIVE, +V4L2_CID_ZOOM_CONTINUOUS and V4L2_CID_PRIVACY. + + +:revision: 0.24 / 2008-03-04 (*mhs*) + +Added pixel formats Y16 and SBGGR16, new controls and a camera controls +class. Removed VIDIOC_G/S_MPEGCOMP. + + +:revision: 0.23 / 2007-08-30 (*mhs*) + +Fixed a typo in VIDIOC_DBG_G/S_REGISTER. Clarified the byte order of +packed pixel formats. + + +:revision: 0.22 / 2007-08-29 (*mhs*) + +Added the Video Output Overlay interface, new MPEG controls, +V4L2_FIELD_INTERLACED_TB and V4L2_FIELD_INTERLACED_BT, +VIDIOC_DBG_G/S_REGISTER, VIDIOC\_(TRY\_)ENCODER_CMD, +VIDIOC_G_CHIP_IDENT, VIDIOC_G_ENC_INDEX, new pixel formats. +Clarifications in the cropping chapter, about RGB pixel formats, the +mmap(), poll(), select(), read() and write() functions. Typographical +fixes. + + +:revision: 0.21 / 2006-12-19 (*mhs*) + +Fixed a link in the VIDIOC_G_EXT_CTRLS section. + + +:revision: 0.20 / 2006-11-24 (*mhs*) + +Clarified the purpose of the audioset field in struct v4l2_input and +v4l2_output. + + +:revision: 0.19 / 2006-10-19 (*mhs*) + +Documented V4L2_PIX_FMT_RGB444. + + +:revision: 0.18 / 2006-10-18 (*mhs*) + +Added the description of extended controls by Hans Verkuil. Linked +V4L2_PIX_FMT_MPEG to V4L2_CID_MPEG_STREAM_TYPE. + + +:revision: 0.17 / 2006-10-12 (*mhs*) + +Corrected V4L2_PIX_FMT_HM12 description. + + +:revision: 0.16 / 2006-10-08 (*mhs*) + +VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS are now part +of the API. + + +:revision: 0.15 / 2006-09-23 (*mhs*) + +Cleaned up the bibliography, added BT.653 and BT.1119. +capture.c/start_capturing() for user pointer I/O did not initialize the +buffer index. Documented the V4L MPEG and MJPEG VID_TYPEs and +V4L2_PIX_FMT_SBGGR8. Updated the list of reserved pixel formats. See +the history chapter for API changes. + + +:revision: 0.14 / 2006-09-14 (*mr*) + +Added VIDIOC_ENUM_FRAMESIZES and VIDIOC_ENUM_FRAMEINTERVALS proposal +for frame format enumeration of digital devices. + + +:revision: 0.13 / 2006-04-07 (*mhs*) + +Corrected the description of struct v4l2_window clips. New V4L2_STD\_ +and V4L2_TUNER_MODE_LANG1_LANG2 defines. + + +:revision: 0.12 / 2006-02-03 (*mhs*) + +Corrected the description of struct v4l2_captureparm and +v4l2_outputparm. + + +:revision: 0.11 / 2006-01-27 (*mhs*) + +Improved the description of struct v4l2_tuner. + + +:revision: 0.10 / 2006-01-10 (*mhs*) + +VIDIOC_G_INPUT and VIDIOC_S_PARM clarifications. + + +:revision: 0.9 / 2005-11-27 (*mhs*) + +Improved the 525 line numbering diagram. Hans Verkuil and I rewrote the +sliced VBI section. He also contributed a VIDIOC_LOG_STATUS page. +Fixed VIDIOC_S_STD call in the video standard selection example. +Various updates. + + +:revision: 0.8 / 2004-10-04 (*mhs*) + +Somehow a piece of junk slipped into the capture example, removed. + + +:revision: 0.7 / 2004-09-19 (*mhs*) + +Fixed video standard selection, control enumeration, downscaling and +aspect example. Added read and user pointer i/o to video capture +example. + + +:revision: 0.6 / 2004-08-01 (*mhs*) + +v4l2_buffer changes, added video capture example, various corrections. + + +:revision: 0.5 / 2003-11-05 (*mhs*) + +Pixel format erratum. + + +:revision: 0.4 / 2003-09-17 (*mhs*) + +Corrected source and Makefile to generate a PDF. SGML fixes. Added +latest API changes. Closed gaps in the history chapter. + + +:revision: 0.3 / 2003-02-05 (*mhs*) + +Another draft, more corrections. + + +:revision: 0.2 / 2003-01-15 (*mhs*) + +Second draft, with corrections pointed out by Gerd Knorr. + + +:revision: 0.1 / 2002-12-01 (*mhs*) + +First draft, based on documentation by Bill Dirks and discussions on the +V4L mailing list. |