c456b35fdf
This adds Debargha's DCT/DWT hybrid and a regular 32x32 DCT, and adds code all over the place to wrap that in the bitstream/encoder/decoder/RD. Some implementation notes (these probably need careful review): - token range is extended by 1 bit, since the value range out of this transform is [-16384,16383]. - the coefficients coming out of the FDCT are manually scaled back by 1 bit, or else they won't fit in int16_t (they are 17 bits). Because of this, the RD error scoring does not right-shift the MSE score by two (unlike for 4x4/8x8/16x16). - to compensate for this loss in precision, the quantizer is halved also. This is currently a little hacky. - FDCT and IDCT is double-only right now. Needs a fixed-point impl. - There are no default probabilities for the 32x32 transform yet; I'm simply using the 16x16 luma ones. A future commit will add newly generated probabilities for all transforms. - No ADST version. I don't think we'll add one for this level; if an ADST is desired, transform-size selection can scale back to 16x16 or lower, and use an ADST at that level. Additional notes specific to Debargha's DWT/DCT hybrid: - coefficient scale is different for the top/left 16x16 (DCT-over-DWT) block than for the rest (DWT pixel differences) of the block. Therefore, RD error scoring isn't easily scalable between coefficient and pixel domain. Thus, unfortunately, we need to compute the RD distortion in the pixel domain until we figure out how to scale these appropriately. Change-Id: I00386f20f35d7fabb19aba94c8162f8aee64ef2b
vpx Multi-Format Codec SDK
README - 21 June 2012
Welcome to the WebM VP8 Codec SDK!
COMPILING THE APPLICATIONS/LIBRARIES:
The build system used is similar to autotools. Building generally consists of
"configuring" with your desired build options, then using GNU make to build
the application.
1. Prerequisites
* All x86 targets require the Yasm[1] assembler be installed.
* All Windows builds require that Cygwin[2] be installed.
* Building the documentation requires PHP[3] and Doxygen[4]. If you do not
have these packages, you must pass --disable-install-docs to the
configure script.
* Downloading the data for the unit tests requires curl[5] and sha1sum.
sha1sum is provided via the GNU coreutils, installed by default on
many *nix platforms, as well as MinGW and Cygwin. If coreutils is not
available, a compatible version of sha1sum can be built from
source[6]. These requirements are optional if not running the unit
tests.
[1]: http://www.tortall.net/projects/yasm
[2]: http://www.cygwin.com
[3]: http://php.net
[4]: http://www.doxygen.org
[5]: http://curl.haxx.se
[6]: http://www.microbrew.org/tools/md5sha1sum/
2. Out-of-tree builds
Out of tree builds are a supported method of building the application. For
an out of tree build, the source tree is kept separate from the object
files produced during compilation. For instance:
$ mkdir build
$ cd build
$ ../libvpx/configure <options>
$ make
3. Configuration options
The 'configure' script supports a number of options. The --help option can be
used to get a list of supported options:
$ ../libvpx/configure --help
4. Cross development
For cross development, the most notable option is the --target option. The
most up-to-date list of supported targets can be found at the bottom of the
--help output of the configure script. As of this writing, the list of
available targets is:
armv5te-android-gcc
armv5te-linux-rvct
armv5te-linux-gcc
armv6-darwin-gcc
armv6-linux-rvct
armv6-linux-gcc
armv7-android-gcc
armv7-linux-rvct
armv7-linux-gcc
mips32-linux-gcc
ppc32-darwin8-gcc
ppc32-darwin9-gcc
ppc64-darwin8-gcc
ppc64-darwin9-gcc
ppc64-linux-gcc
x86-darwin8-gcc
x86-darwin8-icc
x86-darwin9-gcc
x86-darwin9-icc
x86-linux-gcc
x86-linux-icc
x86-solaris-gcc
x86-win32-vs7
x86-win32-vs8
x86_64-darwin9-gcc
x86_64-linux-gcc
x86_64-solaris-gcc
x86_64-win64-vs8
universal-darwin8-gcc
universal-darwin9-gcc
generic-gnu
The generic-gnu target, in conjunction with the CROSS environment variable,
can be used to cross compile architectures that aren't explicitly listed, if
the toolchain is a cross GNU (gcc/binutils) toolchain. Other POSIX toolchains
will likely work as well. For instance, to build using the mipsel-linux-uclibc
toolchain, the following command could be used (note, POSIX SH syntax, adapt
to your shell as necessary):
$ CROSS=mipsel-linux-uclibc- ../libvpx/configure
In addition, the executables to be invoked can be overridden by specifying the
environment variables: CC, AR, LD, AS, STRIP, NM. Additional flags can be
passed to these executables with CFLAGS, LDFLAGS, and ASFLAGS.
5. Configuration errors
If the configuration step fails, the first step is to look in the error log.
This defaults to config.err. This should give a good indication of what went
wrong. If not, contact us for support.
SUPPORT
This library is an open source project supported by its community. Please
please email webm-discuss@webmproject.org for help.