BUILD.gn - third_party/ffmpeg - Git at Google

 # Copyright 2017 The Fuchsia Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

 import("ffmpeg_generated.gni")
 import("ffmpeg_options.gni")

 # Path to configuration files.
 #
 # Placing this file in //build/secondary/third_party/ffmpeg causes it to be mirrored in
 # //third_party/ffmpeg, where the build system expects it to be. The mirroring that achieves
 # that doesn't work for config files, however. As a result, we have to be specific about where
 # the config file can be found by the compiler.
 #
 # If at some point we are able to integrate this repo at //third_party/ffmpeg, this assignment
 # must be restored to its previous value, namely:
 #
 #     ffmpeg_config_root = "config/$ffmpeg_profile/$current_cpu"
 #
 ffmpeg_config_root =
     "//build/secondary/third_party/ffmpeg/config/$ffmpeg_profile/$current_cpu"

 has_yasm_deps = ffmpeg_yasm_sources != [] && current_cpu == "x64"
 if (has_yasm_deps) {
   import("//third_party/yasm/yasm_assemble.gni")
   yasm_assemble("ffmpeg_yasm") {
     sources = []
     foreach(source, ffmpeg_yasm_sources) {
       sources += [ "src/" + source ]
     }

     # Ensure the architecture defines go in the command line before the -P
     # file below, so don't use defines.
     yasm_flags = []
     if (current_cpu == "x86") {
       yasm_flags += [ "-DARCH_X86_32" ]
     } else if (current_cpu == "x64") {
       yasm_flags += [ "-DARCH_X86_64" ]
     }

     inputs = [
       # Sets visibility hidden for cglobal functions. Explicitly included
       # to avoid overlooking changes to this file in incremental builds.
       "src/libavutil/x86/x86inc.asm",
     ]

     defines = [ "PIC" ]
     include_dirs = [
       ffmpeg_config_root,
       "src/libavcodec/x86",
       "src/libavutil/x86",
       "src",
     ]

     # Disable warnings, prevents log spam for things we won't fix.
     yasm_flags += [
       "-w",
       "-P",
       rebase_path("$ffmpeg_config_root/config.asm", root_build_dir),
     ]

     if (is_mac) {
       # Necessary to ensure symbols end up with a _ prefix; added by
       # yasm_assemble.gni for Windows, but not Mac.
       defines += [ "PREFIX" ]
     }
   }
 }

 config("ffmpeg_dependent_config") {
   include_dirs = [
     ffmpeg_config_root,
     "src",
   ]
 }

 # gn orders flags on a target before flags from configs. The default config
 # adds -Wall, and these flags have to be after -Wall -- so they need to come
 # from a config and can't be on the target directly.
 config("ffmpegsumo_warnings") {
   cflags = [
     "-Wno-absolute-value",

     # ffmpeg uses its own deprecated functions.
     "-Wno-deprecated-declarations",

     # ffmpeg doesn't care about pointer constness.
     "-Wno-incompatible-pointer-types",

     # ffmpeg doesn't follow usual parentheses conventions.
     "-Wno-logical-op-parentheses",

     # ffmpeg doesn't care about pointer signedness.
     "-Wno-parentheses",

     # ffmpeg doesn't care about pointer signedness.
     "-Wno-pointer-sign",

     # ffmpeg doesn't believe in exhaustive switch statements.
     "-Wno-switch",

     # matroskadec.c has a "failed:" label that's only used if some
     # CONFIG_ flags we don't set are set.
     "-Wno-unused-label",

     # ffmpeg has a lot of unused variables.
     "-Wno-unused-variable",

     # This fires on `av_assert0(!"valid element size")` in utils.c
     "-Wno-string-conversion",

     # This fires on `pos_min` and `pos_max` in
     # autorename_libavformat_utils.c
     "-Wno-sometimes-uninitialized",

     # ffmpeg contains static functions in header files, which lead
     # to unused function warnings. There are a few legit unused
     # functions too.
     "-Wno-unused-function",

     # vp3data.h's vp31_inter_dequant stores '128' in an int8_t array.
     "-Wno-constant-conversion",

     "-Wno-string-plus-int",

     # ffmpeg compares ints and floats.
     "-Wno-implicit-int-float-conversion",
     "-Wno-implicit-int-conversion",
     "-Wno-implicit-float-conversion",
     "-Wno-float-conversion",
     "-Wno-shorten-64-to-32",
     "-Wno-unused-but-set-variable",

     # fmmpeg may have questionable indentation. We should come back later
     # to confirm if this indentation is expected.
     "-Wno-misleading-indentation",

     "-Wno-extra-semi",
   ]
 }

 config("ffmpeg_warnings") {
   cflags = [
     "-Wno-sign-compare",
     "-Wno-missing-field-initializers",
     "-Wno-pointer-bool-conversion",
     "-Wno-implicit-fallthrough",
     "-Wno-implicit-int-float-conversion",
     "-Wno-implicit-int-conversion",
     "-Wno-implicit-float-conversion",
     "-Wno-float-conversion",
     "-Wno-shorten-64-to-32",
     "-Wno-string-plus-int",
     "-Wno-unused-but-set-variable",
     "-Wno-misleading-indentation",
   ]
 }

 shared_library("ffmpeg") {
   sources = []
   foreach(source, ffmpeg_c_sources + ffmpeg_gas_sources) {
     sources += [ "src/" + source ]
   }
   sources += [
     "$ffmpeg_config_root/config.h",
     "$ffmpeg_config_root/libavutil/avconfig.h",
   ]
   public_configs = [ ":ffmpeg_dependent_config" ]
   defines = [
     "HAVE_AV_CONFIG_H",
     "_POSIX_C_SOURCE=200112",
     "_XOPEN_SOURCE=600",
     "PIC",

     # Disable deprecated features that generate spammy warnings.
     "FF_API_CONVERGENCE_DURATION=0",

     # Upstream libavcodec/utils.c still uses the deprecated
     # av_dup_packet(), avcodec_encode_{audio,video}2(), and
     # libavformat/utils.c still accesses the deprecated AVStream.codec,
     # causing deprecation warnings.
     # The normal fix for such things is to disable the features like setting
     # "FF_API_AVPACKET_OLD_API=0", but the upstream code does not yet compile
     # with it disabled (in the case of av_dup_packet()), and has no FF_API*
     # gate for avcodec_encode_{audio,video}2() or AVStream.codec.  In the
     # meantime, we directly disable those warnings locally in the C files.
   ]

   # So we can append below and assume they're defined.
   cflags = []
   ldflags = []
   libs = []
   deps = [
     # TODO(https://fxbug.dev/98632): workaround for toolchain issues.
     "//build/config/fuchsia:uses-outline-atomics-fxbug98632",
     "//third_party/opus",
   ]

   configs += [
     ":ffmpeg_warnings",
     ":ffmpegsumo_warnings",
   ]

   # Since we are not often debugging FFmpeg, and performance is unacceptable
   # without optimization, we always optimize for speed.
   #
   # In addition to the above reasons, /Od optimization won't remove symbols
   # that are under "if (0)" style sections.  Which lead to link time errors
   # when for example it tries to link an ARM symbol on X86.
   configs -= [ "//build/config:default_optimize" ]
   configs += [ "//build/config:optimize_speed" ]

   # Make all symbols visible.
   configs -= [ "//build/config:symbol_visibility_hidden" ]

   cflags += [
     # ffmpeg uses its own deprecated functions.
     "-Wno-deprecated-declarations",
     "-Wno-deprecated-non-prototype",
     "-Wno-strict-prototypes",
   ]

   defines += [
     "_ISOC99_SOURCE",
     "_LARGEFILE_SOURCE",
   ]

   cflags += [
     "-std=c99",
     "-pthread",
     "-fno-math-errno",
     "-fno-signed-zeros",
     "-fno-tree-vectorize",
     "-fomit-frame-pointer",
   ]
   ldflags = [
     # Avoid PIC relocation errors from assembly code.
     "-Wl,-Bsymbolic",
     "-L",
     rebase_path(target_gen_dir, root_build_dir),
   ]

   if (has_yasm_deps) {
     deps += [ ":ffmpeg_yasm" ]
   }
 }

 group("ffmpeg_variants") {
   deps = []
   _variants = select_variant
   if (select_variant != []) {
     _variants += [ "novariant" ]
   }
   foreach(variant, _variants) {
     deps += [ ":ffmpeg(${toolchain_variant.base}-${variant}-shared)" ]
   }
 }
	# Copyright 2017 The Fuchsia Authors. All rights reserved.
	# Use of this source code is governed by a BSD-style license that can be
	# found in the LICENSE file.

	import("ffmpeg_generated.gni")
	import("ffmpeg_options.gni")

	# Path to configuration files.
	#
	# Placing this file in //build/secondary/third_party/ffmpeg causes it to be mirrored in
	# //third_party/ffmpeg, where the build system expects it to be. The mirroring that achieves
	# that doesn't work for config files, however. As a result, we have to be specific about where
	# the config file can be found by the compiler.
	#
	# If at some point we are able to integrate this repo at //third_party/ffmpeg, this assignment
	# must be restored to its previous value, namely:
	#
	# ffmpeg_config_root = "config/$ffmpeg_profile/$current_cpu"
	#
	ffmpeg_config_root =
	"//build/secondary/third_party/ffmpeg/config/$ffmpeg_profile/$current_cpu"

	has_yasm_deps = ffmpeg_yasm_sources != [] && current_cpu == "x64"
	if (has_yasm_deps) {
	import("//third_party/yasm/yasm_assemble.gni")
	yasm_assemble("ffmpeg_yasm") {
	sources = []
	foreach(source, ffmpeg_yasm_sources) {
	sources += [ "src/" + source ]
	}

	# Ensure the architecture defines go in the command line before the -P
	# file below, so don't use defines.
	yasm_flags = []
	if (current_cpu == "x86") {
	yasm_flags += [ "-DARCH_X86_32" ]
	} else if (current_cpu == "x64") {
	yasm_flags += [ "-DARCH_X86_64" ]
	}

	inputs = [
	# Sets visibility hidden for cglobal functions. Explicitly included
	# to avoid overlooking changes to this file in incremental builds.
	"src/libavutil/x86/x86inc.asm",
	]

	defines = [ "PIC" ]
	include_dirs = [
	ffmpeg_config_root,
	"src/libavcodec/x86",
	"src/libavutil/x86",
	"src",
	]

	# Disable warnings, prevents log spam for things we won't fix.
	yasm_flags += [
	"-w",
	"-P",
	rebase_path("$ffmpeg_config_root/config.asm", root_build_dir),
	]

	if (is_mac) {
	# Necessary to ensure symbols end up with a _ prefix; added by
	# yasm_assemble.gni for Windows, but not Mac.
	defines += [ "PREFIX" ]
	}
	}
	}

	config("ffmpeg_dependent_config") {
	include_dirs = [
	ffmpeg_config_root,
	"src",
	]
	}

	# gn orders flags on a target before flags from configs. The default config
	# adds -Wall, and these flags have to be after -Wall -- so they need to come
	# from a config and can't be on the target directly.
	config("ffmpegsumo_warnings") {
	cflags = [
	"-Wno-absolute-value",

	# ffmpeg uses its own deprecated functions.
	"-Wno-deprecated-declarations",

	# ffmpeg doesn't care about pointer constness.
	"-Wno-incompatible-pointer-types",

	# ffmpeg doesn't follow usual parentheses conventions.
	"-Wno-logical-op-parentheses",

	# ffmpeg doesn't care about pointer signedness.
	"-Wno-parentheses",

	# ffmpeg doesn't care about pointer signedness.
	"-Wno-pointer-sign",

	# ffmpeg doesn't believe in exhaustive switch statements.
	"-Wno-switch",

	# matroskadec.c has a "failed:" label that's only used if some
	# CONFIG_ flags we don't set are set.
	"-Wno-unused-label",

	# ffmpeg has a lot of unused variables.
	"-Wno-unused-variable",

	# This fires on `av_assert0(!"valid element size")` in utils.c
	"-Wno-string-conversion",

	# This fires on `pos_min` and `pos_max` in
	# autorename_libavformat_utils.c
	"-Wno-sometimes-uninitialized",

	# ffmpeg contains static functions in header files, which lead
	# to unused function warnings. There are a few legit unused
	# functions too.
	"-Wno-unused-function",

	# vp3data.h's vp31_inter_dequant stores '128' in an int8_t array.
	"-Wno-constant-conversion",

	"-Wno-string-plus-int",

	# ffmpeg compares ints and floats.
	"-Wno-implicit-int-float-conversion",
	"-Wno-implicit-int-conversion",
	"-Wno-implicit-float-conversion",
	"-Wno-float-conversion",
	"-Wno-shorten-64-to-32",
	"-Wno-unused-but-set-variable",

	# fmmpeg may have questionable indentation. We should come back later
	# to confirm if this indentation is expected.
	"-Wno-misleading-indentation",

	"-Wno-extra-semi",
	]
	}

	config("ffmpeg_warnings") {
	cflags = [
	"-Wno-sign-compare",
	"-Wno-missing-field-initializers",
	"-Wno-pointer-bool-conversion",
	"-Wno-implicit-fallthrough",
	"-Wno-implicit-int-float-conversion",
	"-Wno-implicit-int-conversion",
	"-Wno-implicit-float-conversion",
	"-Wno-float-conversion",
	"-Wno-shorten-64-to-32",
	"-Wno-string-plus-int",
	"-Wno-unused-but-set-variable",
	"-Wno-misleading-indentation",
	]
	}

	shared_library("ffmpeg") {
	sources = []
	foreach(source, ffmpeg_c_sources + ffmpeg_gas_sources) {
	sources += [ "src/" + source ]
	}
	sources += [
	"$ffmpeg_config_root/config.h",
	"$ffmpeg_config_root/libavutil/avconfig.h",
	]
	public_configs = [ ":ffmpeg_dependent_config" ]
	defines = [
	"HAVE_AV_CONFIG_H",
	"_POSIX_C_SOURCE=200112",
	"_XOPEN_SOURCE=600",
	"PIC",

	# Disable deprecated features that generate spammy warnings.
	"FF_API_CONVERGENCE_DURATION=0",

	# Upstream libavcodec/utils.c still uses the deprecated
	# av_dup_packet(), avcodec_encode_{audio,video}2(), and
	# libavformat/utils.c still accesses the deprecated AVStream.codec,
	# causing deprecation warnings.
	# The normal fix for such things is to disable the features like setting
	# "FF_API_AVPACKET_OLD_API=0", but the upstream code does not yet compile
	# with it disabled (in the case of av_dup_packet()), and has no FF_API*
	# gate for avcodec_encode_{audio,video}2() or AVStream.codec. In the
	# meantime, we directly disable those warnings locally in the C files.
	]

	# So we can append below and assume they're defined.
	cflags = []
	ldflags = []
	libs = []
	deps = [
	# TODO(https://fxbug.dev/98632): workaround for toolchain issues.
	"//build/config/fuchsia:uses-outline-atomics-fxbug98632",
	"//third_party/opus",
	]

	configs += [
	":ffmpeg_warnings",
	":ffmpegsumo_warnings",
	]

	# Since we are not often debugging FFmpeg, and performance is unacceptable
	# without optimization, we always optimize for speed.
	#
	# In addition to the above reasons, /Od optimization won't remove symbols
	# that are under "if (0)" style sections. Which lead to link time errors
	# when for example it tries to link an ARM symbol on X86.
	configs -= [ "//build/config:default_optimize" ]
	configs += [ "//build/config:optimize_speed" ]

	# Make all symbols visible.
	configs -= [ "//build/config:symbol_visibility_hidden" ]

	cflags += [
	# ffmpeg uses its own deprecated functions.
	"-Wno-deprecated-declarations",
	"-Wno-deprecated-non-prototype",
	"-Wno-strict-prototypes",
	]

	defines += [
	"_ISOC99_SOURCE",
	"_LARGEFILE_SOURCE",
	]

	cflags += [
	"-std=c99",
	"-pthread",
	"-fno-math-errno",
	"-fno-signed-zeros",
	"-fno-tree-vectorize",
	"-fomit-frame-pointer",
	]
	ldflags = [
	# Avoid PIC relocation errors from assembly code.
	"-Wl,-Bsymbolic",
	"-L",
	rebase_path(target_gen_dir, root_build_dir),
	]

	if (has_yasm_deps) {
	deps += [ ":ffmpeg_yasm" ]
	}
	}

	group("ffmpeg_variants") {
	deps = []
	_variants = select_variant
	if (select_variant != []) {
	_variants += [ "novariant" ]
	}
	foreach(variant, _variants) {
	deps += [ ":ffmpeg(${toolchain_variant.base}-${variant}-shared)" ]
	}
	}