linux libvpx编译安装,libvpx: VP8/VP9 视频编码器.需要ffmpeg编译的时候添加 –enable-libvpx....

README - 20 July 2020

Welcome to the WebM VP8/VP9 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[2].

* All Windows builds require that Cygwin[3] be installed.

* Building the documentation requires Doxygen[4]. If you do not

have this package, the install-docs option will be disabled.

* 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]: For Visual Studio the base yasm binary (not vsyasm) should be in the

PATH for Visual Studio. For VS2017 it is sufficient to rename

yasm--.exe to yasm.exe and place it in:

Program Files (x86)/Microsoft Visual Studio/2017//Common7/Tools/

[3]: http://www.cygwin.com

[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

$ 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. Compiler analyzers

Compilers have added sanitizers which instrument binaries with information

about address calculation, memory usage, threading, undefined behavior, and

other common errors. To simplify building libvpx with some of these features

use tools/set_analyzer_env.sh before running configure. It will set the

compiler and necessary flags for building as well as environment variables

read by the analyzer when testing the binaries.

$ source ../libvpx/tools/set_analyzer_env.sh address

5. 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:

arm64-android-gcc

arm64-darwin-gcc

arm64-darwin20-gcc

arm64-linux-gcc

arm64-win64-gcc

arm64-win64-vs15

armv7-android-gcc

armv7-darwin-gcc

armv7-linux-rvct

armv7-linux-gcc

armv7-none-rvct

armv7-win32-gcc

armv7-win32-vs14

armv7-win32-vs15

armv7s-darwin-gcc

armv8-linux-gcc

mips32-linux-gcc

mips64-linux-gcc

ppc64le-linux-gcc

sparc-solaris-gcc

x86-android-gcc

x86-darwin8-gcc

x86-darwin8-icc

x86-darwin9-gcc

x86-darwin9-icc

x86-darwin10-gcc

x86-darwin11-gcc

x86-darwin12-gcc

x86-darwin13-gcc

x86-darwin14-gcc

x86-darwin15-gcc

x86-darwin16-gcc

x86-darwin17-gcc

x86-iphonesimulator-gcc

x86-linux-gcc

x86-linux-icc

x86-os2-gcc

x86-solaris-gcc

x86-win32-gcc

x86-win32-vs14

x86-win32-vs15

x86-win32-vs16

x86_64-android-gcc

x86_64-darwin9-gcc

x86_64-darwin10-gcc

x86_64-darwin11-gcc

x86_64-darwin12-gcc

x86_64-darwin13-gcc

x86_64-darwin14-gcc

x86_64-darwin15-gcc

x86_64-darwin16-gcc

x86_64-darwin17-gcc

x86_64-darwin18-gcc

x86_64-darwin19-gcc

x86_64-darwin20-gcc

x86_64-iphonesimulator-gcc

x86_64-linux-gcc

x86_64-linux-icc

x86_64-solaris-gcc

x86_64-win64-gcc

x86_64-win64-vs14

x86_64-win64-vs15

x86_64-win64-vs16

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.

6. Configuration errors

If the configuration step fails, the first step is to look in the error log.

This defaults to config.log. This should give a good indication of what went

wrong. If not, contact us for support.

VP8/VP9 TEST VECTORS:

The test vectors can be downloaded and verified using the build system after

running configure. To specify an alternate directory the

LIBVPX_TEST_DATA_PATH environment variable can be used.

$ ./configure --enable-unit-tests

$ LIBVPX_TEST_DATA_PATH=../libvpx-test-data make testdata

CODE STYLE:

The coding style used by this project is enforced with clang-format using the

configuration contained in the .clang-format file in the root of the

repository.

Before pushing changes for review you can format your code with:

# Apply clang-format to modified .c, .h and .cc files

$ clang-format -i --style=file \

$(git diff --name-only --diff-filter=ACMR '*.[hc]' '*.cc')

Check the .clang-format file for the version used to generate it if there is

any difference between your local formatting and the review system.

See also: http://clang.llvm.org/docs/ClangFormat.html

SUPPORT

This library is an open source project supported by its community. Please

email [e-mail] for help.