ad252daf65
This patch enables ivfdec to decode WebM files. WebM demuxing is provided by the Matthew Gregan's Nestegg library. This patch also makes minor changes to the timebase->framerate handling when doing Y4M output. For WebM files, the framerate is guessed by looking at the first second of video. For IVF files, the timebase=1/(2*fps) hack is still in place, but is only used if the timebase denominator is less than 1000. This is in anticipation of change I8d25b5b, which introduces the distinction between framerate and timebase to ivfenc. In the case of high resolution timebases, like 100ns, we would have to guess the framerate like we do for WebM, but since WebM support in ivfenc will deprecate IVF output, we just assume 30fps rather than writing the lookahead code. Change-Id: I1dd8600f13bf6071533d2816f005da9ede4f60a2
vpx Multi-Format Codec SDK
README - 19 May 2010
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.
[1]: http://www.tortall.net/projects/yasm
[2]: http://www.cygwin.com
[3]: http://php.net
[4]: http://www.doxygen.org
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-linux-rvct
armv5te-linux-gcc
armv5te-symbian-gcc
armv5te-wince-vs8
armv6-darwin-gcc
armv6-linux-rvct
armv6-linux-gcc
armv6-symbian-gcc
armv6-wince-vs8
iwmmxt-linux-rvct
iwmmxt-linux-gcc
iwmmxt-wince-vs8
iwmmxt2-linux-rvct
iwmmxt2-linux-gcc
iwmmxt2-wince-vs8
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-users@webmproject.org for help.