The patch number 8216 was added via Thierry MERLE <[EMAIL PROTECTED]>
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
[EMAIL PROTECTED]
------
From: Hans de Goede <j.w.r.degoede at hhs.nl>
v4l2-library: global files
Global files to make the libv4l compile, install and exported into a tar.gz file
Signed-off-by: Hans de Goede <j.w.r.degoede at hhs.nl>
Signed-off-by: Thierry MERLE <[EMAIL PROTECTED]>
---
v4l2-apps/lib/libv4l/ChangeLog | 107 ++++++++++++++++
v4l2-apps/lib/libv4l/INSTALL | 4
v4l2-apps/lib/libv4l/Makefile | 16 ++
v4l2-apps/lib/libv4l/README | 129 ++++++++++++++++++++
v4l2-apps/lib/libv4l/README.multi-threading | 12 +
v4l2-apps/lib/libv4l/TODO | 26 ++++
6 files changed, 294 insertions(+)
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/ChangeLog
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/ChangeLog Tue Jul 01 21:18:23 2008 +0200
@@ -0,0 +1,107 @@
+libv4l-0.3
+----------
+* add extern "C" magic to public header files for c++ usage (Gregor Jasny)
+* Make libv4l1 and libv4l2 multithread use safe, see README.multi-threading
+* Add v4lx_dup() calls (and intercept dup() from the wrappers) this fixes
+ use with gstreamer's v4l2 plugin (tested with cheese)
+* Hopefully definitely fix compile errors on systems with a broken videodev2.h
+
+libv4l-0.2
+----------
+*** API change ***
+* Change v4lconvert api so that the v4lconvert struct always gets allocated
+ by the library, this to make it opaque, so that we can avoid future API
+ and ABI changes
+* Add support for yuv420 -> bgr24 conversion
+* When converting from v4l2 pixelformat to v4l12 palette return
+ VIDEO_PALETTE_YUV420P instead of VIDEO_PALETTE_YUV420 for
+ V4L2_PIX_FMT_YUV420 as that is what most apps seem to expect
+* override kernel v4l1 compat min / max size with our own more accurate values
+* fix v4l1 munmap bug where it didn't recognise the buffer being unmapped was
+ our fake buffer (fixes gstreamer v4l1 support, checked with cheese)
+* add support for reporting the emulated pixelformats with ENUM_FMT, this
+ defaults to off, and can be activated by passing a flag to enable it to
+ v4l2_fd_open. This gets enabled by default the wrappers.
+* v4l2: mmap the real device buffers before doing conversion when DQBUF gets
+ called before the application has called mmap (avoid crash).
+
+
+libv4l-0.1
+----------
+* major shuffle / rewrite now split into libv4l1, libv4l2, libv4lconvert
+ and 2 wrappers for binary compatibility
+* rewritten LGPL bayer decoding
+* many many other changes and fixes
+
+
+v4l1-compat-0.6 (V4L2 apps stay working)
+----------------------------------------
+* Do not go into emulation mode of rgb24 immediately, but only after a
+ GPICT ioctl which has not been preceded by a SPICT ioctl, AKA do not get
+ in the way of V4L2 read calls by doing conversion on them
+* Do not get in the way of mmap calls made by V4L2 applications
+* Fix swapping of red and blue in bayer -> bgr24 decode routine
+* Remember the v4l1 palette asked for with SPICT and return that, as
+ otherwise we loose information when going v4l1 -> v4l2 -> v4l1, for example
+ YUV420P becomes YUV420, which are separate in v4l1.
+
+
+v4l1-compat-0.5 (perfect camorama)
+----------------------------------
+* Allow changing of format after the buffers have been mapped, by tearing
+ down the entire house, changing the fundament and then rebuilding it.
+ Now changing the capture resolution in camorama works!
+* Fix jpeg decoding error reporting
+* Allow jpeg's with a height which is a multiple of 8 (was 16)
+* Remove a number of pretty new VIDIOCXXX -> string mappings from log.c,
+ fixing compiling with somewhat older kernels
+
+
+v4l1-compat 0.4
+---------------
+* Do not even try to change the format in v4l1_compat_set_format(), unless
+ _really_ necessary.
+* Cleanup ambigious use of src_format (no functional changes)
+* Drop the mmap hack for zerocopy access under certain conditions, one of them
+ that the cam can deliver the requested format. Although avoiding the
+ memcpy in this scenarios is a good thing todo, there were several issues
+ with the 0.3 implementation of this, fixing all these means adding lots of
+ special cases all over the code. So instead we just drop support and
+ always do atleast a memcpy (or a conversion). If an application cannot
+ live with the speed penalty this imposes it should be ported to v4l2.
+* Now that we've gotten rid of the zerocopy mmap hack, we can safely allow
+ mixing read and mmap based IO.
+* Explictly include linux/ioctl.h, to fix compile with kernel headers where
+ linux/videodev.h doesn't.
+
+
+v4l1-compat 0.3
+---------------
+* Don't allow multiple opens, in theory our code can handle it, but not all
+ v4l2 devices like it (ekiga does it and uvc doesn't like it).
+
+
+v4l1-compat 0.2
+---------------
+* When mmap gets passed an fd of -1 (anonymous map) don't look for it in our
+ list of managed fds, as we use -1 to mark unused entries (fixes ekiga
+ crashing). Also check for an fd of -1 in the other calls we intercept.
+* In close() start with removing the fd from our list of managed fds, this must
+ be done first, because as soon as we've done the actual close syscall, the
+ fd maybe returned by an open in another thread and we don't want to intercept
+ calls to this new fd.
+* Make unknown v4l1 palette types a normal level log messages instead of an
+ error.
+* When an applicaiton changes the width / height through the CMCAPTURE ioctl
+ remember the new width and height.
+* If the devices initial v4l2 pixformat has no corresponding v4l1 palette, try
+ setting a format which does (and which we emulate when necessary) so that
+ applicactions which just query the current format (GPICT) and then take
+ whatever they get will work (partially fixes camorama)
+* Implement our own SWIN instead of using kernel compat layer, for more
+ flexibility and better error checking
+
+
+v4l1-compat 0.1
+---------------
+* Initial public release.
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/INSTALL
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/INSTALL Tue Jul 01 21:18:23 2008 +0200
@@ -0,0 +1,4 @@
+To compile simply type "make" after that you can find the compiled libraries
+and wrappers under the lib dir, public headers are under the include dir.
+
+Sorry no make install target for now.
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/Makefile
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/Makefile Tue Jul 01 21:18:23 2008 +0200
@@ -0,0 +1,16 @@
+LIB_RELEASE=0
+V4L2_LIB_VERSION=$(LIB_RELEASE).3
+
+all clean install:
+ $(MAKE) -C libv4lconvert $@
+ $(MAKE) -C libv4l2 $@
+ $(MAKE) -C libv4l1 $@
+
+export: clean
+ mkdir /tmp/libv4l-$(V4L2_LIB_VERSION)
+ cp -a . /tmp/libv4l-$(V4L2_LIB_VERSION)/
+ cd /tmp/ && \
+ tar cvf /tmp/libv4l-$(V4L2_LIB_VERSION).tar\
+ libv4l-$(V4L2_LIB_VERSION)
+ gzip /tmp/libv4l-$(V4L2_LIB_VERSION).tar
+ rm -rf /tmp/libv4l-$(V4L2_LIB_VERSION)
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/README
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/README Tue Jul 01 21:18:23 2008 +0200
@@ -0,0 +1,129 @@
+Introduction
+------------
+
+libv4l is a collection of libraries which adds a thin abstraction layer on
+top of video4linux2 devices. The purpose of this (thin) layer is to make it
+easy for application writers to support a wide variety of devices without
+having to write seperate code for different devices in the same class.
+
+All libv4l components are licensed under the GNU Library General Publishing
+License version 2 or (at your option) any later version.
+
+libv4l consists of 3 different libraries:
+
+
+libv4lconvert
+-------------
+
+libv4lconvert offers functions to convert from any (known) pixelformat
+to V4l2_PIX_FMT_BGR24 or V4l2_PIX_FMT_YUV420.
+
+Currently the following source formats are supported:
+jpeg, mjpeg, bayer (all 4 variants: bggr, rggb, gbrg, grbg),
+spca501 (chip specific yuv 420 with interlaced components),
+spca561 (chip specific compressed gbrg bayer)
+For more details on the v4lconvert_ functions see libv4lconvert.h .
+
+
+libv4l1
+-------
+
+This offers functions like v4l1_open, v4l1_ioctl, etc. which can by used to
+quickly make v4l1 applications work with v4l2 devices. These functions work
+exactly like the normal open/close/etc, except that libv4l1 does full emulation
+of the v4l1 api on top of v4l2 drivers, in case of v4l1 drivers it will just
+pass calls through. For more details on the v4l1_ functions see libv4l1.h .
+
+
+libv4l2
+-------
+
+This offers functions like v4l2_open, v4l2_ioctl, etc. which can by used to
+quickly make v4l2 applications work with v4l2 devices with weird formats.
+libv4l2 mostly passes calls directly through to the v4l2 driver. When the
+app does a TRY_FMT / S_FMT with a not supported format libv4l2 will get in
+the middle and emulate the format (if an app wants to know which formats the
+hardware can _really_ do it should use ENUM_FMT, not randomly try a bunch of
+S_FMT's). For more details on the v4l2_ functions see libv4l2.h .
+
+
+wrappers
+--------
+
+The functionality provided by libv4l1 for v4l1 apps and libv4l2 for v4l2 apps
+can also be used by existing apps without modifying them. For this purpose
+2 wrapper libraries are provided which can be preloaded before starting the
+application using the LD_PRELOAD environment variable. These wrappers will
+then intercept calls to open/close/ioctl/etc. and if these calls directed
+towards a video device the wrapper will redirect the call to the libv4lX
+counterparts.
+
+The preloadable libv4l1 wrapper which adds v4l2 device compatibility to v4l1
+applications is called v4l1compat.so. The preloadable libv4l1 wrapper which
+adds v4l2 device compatibility to v4l1 applications is called v4l2convert.so
+
+Example usage:
+$ export LD_LIBRARY_PATH=`pwd`/lib
+$ export LD_PRELOAD=`pwd`/lib/v4l1compat.so
+$ camorama
+
+
+FAQ
+---
+
+Q: Why libv4l, whats wrong with directly accessing v4l2 devices ?
+Q: Do we really need yet another library ?
+A: Current webcam using applications like ekiga contain code to handle many
+different specific pixelformats webcam's use, but that code only supports a
+small subset of all native webcam (compressed) pixelformats. Other current
+v4l2 applications do not support anything but rgb pixelformats (xawtv for
+example) and this will not work with most webcams at all.
+
+With gspca being ported to v4l2 and thus decoding to normal formats being
+removed from the device driver as this really belongs in userspace, ekiga
+would need to be extended with many more often chip dependent formats, like
+the bayer compression used by the spca561 and the (different) compression used
+by the pac207 and the (again different) compression used by the sn9c102. Adding
+support for all these formats should not be done at the application level, as
+then it needs to be written for each application seperately. Licensing issues
+with the decompressors will then also become a problem as just cut and pasting
+from one application to another is bound to hit license incompatibilities.
+
+So clearly this belongs in a library, and in a library with a license which
+allows this code to be used from as many different applications as possible.
+Hence libv4l was born.
+
+Q: Under which license may I use and distribute libv4l?
+A: All libv4l components are licensed under the GNU Library General Publishing
+License version 2 or (at your option) any later version. See the included
+COPYING.LIB file.
+
+Q: Okay so I get the use of having a libv4lconvert, but why libv4l1 ?
+A: Many v4l2 drivers do not offer full v4l1 compatibility. They often do not
+implemented the CGMBUF ioctl and v4l1 style mmap call. Adding support to all
+these drivers for this is a lot of work and more importantly unnecessary
+adds code to kernel space.
+
+Also even if the CGMBUF ioctl and v4l1 style mmap are supported, then most
+cams still deliver pixelformats which v4l1 applications do not understand.
+
+This libv4l1 was born as an easy way to get v4l1 applications to work with
+v4l2 devices without requiring full v4l1 emulation (including format
+conversion) in the kernel, and without requiring major changes to the
+applications.
+
+
+Q: Why should I use libv4l2 in my app instead of direct device access
+combined with libv4lconvert?
+
+libv4l2 is mainly meant for quickly and easily adding support for more
+pixelformats to existing v4l2 applications. So if you feel better directly
+accessing the device in combination with libv4lconvert thats fine too.
+
+Notice that libv4l2 also does emulation of the read() call on devices which
+do not support it in the driver. In the background this uses mmap buffers
+(even on devices which do support the read call). This mmap gives libv4lconvert
+zero-copy access to the captured frame, and then it can write the converted
+data directly to the buffer the application provided to v4l2_read(). Thus
+another reason to use liv4l2 is to get the no memcpy advantage of the mmap
+capture method combined with the simplicity of making a simple read() call.
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/README.multi-threading
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/README.multi-threading Tue Jul 01 21:18:23
2008 +0200
@@ -0,0 +1,12 @@
+libv4lconvert is not safe for using one convert instance as returned by
+v4lconvert_create from multiple threads, if you want to use one v4lconvert
+instance from multiple threads you must provide your own locking and make
+sure no simultanious calls are made.
+
+libv4l1 and libv4l2 are safe for multithread use *under* *the* *following*
+*conditions* :
+
+* when using v4lx_fd_open, do not make any v4lx_ calls to the passed fd until
+ v4lx_fd_open has completed
+
+* all v4lx_ calls must be completed before calling v4lx_close
diff -r 055a5f35b132 -r ab8e95a2398f v4l2-apps/lib/libv4l/TODO
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-apps/lib/libv4l/TODO Tue Jul 01 21:18:23 2008 +0200
@@ -0,0 +1,26 @@
+-protect open() against being called from different threads simultaniously,
+ we are then thread safe except for the jpeg decompression under the following
+ assumption:
+ * We assume all device setup (for a single device) is done from a single
+ thread
+ * We assume that at the time an videodev fd gets closed all other threads
+ which may have been using it have stopped using it.
+
+-add support for setting / getting the number of read buffers
+
+-add code to v4l2_read to not return frames more then say 5 seconds old
+
+-add support for libv4l1 for non pure capture (combined capture and overlay)
+ devices so that atleast CGMBUF emulation (but no conversion, as thats
+ impossible for overlays) can be done, so that it will no longer be
+ necessary to implement CGMBUF in the kernel for each driver.
+
+-add (configurable) support for alsa faking enum_fmt to libv4l2 ?
+
+-check v4l2_field during conversion
+
+-add make install target
+
+-add conversion from bgr24 to yuv420
+
+-add v4l2_dup, make re-entrant safe (for gstreamer v4l2 support)
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/ab8e95a2398fa39c419177f6dd44b283536e5f5b
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