audio

#!/bin/sh -e
# Copyright (c) 2016 The crouton Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
REQUIRES='core'
DESCRIPTION="Support audio playback via Chromium OS's audio system."
CHROOTBIN='volume'
CHROOTETC='pulseaudio-default.pa'
. "${TARGETSDIR:="$PWD"}/common"

### Append to prepare.sh:

# Fetch CRAS source

CRASBUILDTMP="`mktemp -d crouton-cras.XXXXXX --tmpdir=/tmp`"

addtrap "rm -rf --one-file-system '$CRASBUILDTMP'"

# ADHD_HEAD is normally autodetected, but it can be set manually using a custom
# target sourced before this one (used for automated testing)
# The custom target also needs to set CROS_VER_1
if [ -z "$ADHD_HEAD" ]; then
    # Chrome OS version (e.g. 4100.86.0)
    CROS_VER="`sed -n 's/^CHROMEOS_RELEASE_VERSION=//p' /var/host/lsb-release`"

    # Set CROS_VER_1 to the major version number (e.g. 4100), used later on to
    # selectively apply patches.
    CROS_VER_1="${CROS_VER%%.*}"

    cras_version="`cat /var/host/cras-version 2>/dev/null || true`"
    ADHD_HEAD="${cras_version##*-}"
    # Make sure ADHD_HEAD looks like a commit id
    if [ "${#ADHD_HEAD}" -ne 40 -o "${head%[^0-9a-f]*}" != "$head" ]; then
        echo "Empty or invalid cras-version (${cras_version})." 1>&2
        ADHD_HEAD=""
    fi
fi

echo "Fetching CRAS (branch $ADHD_HEAD)..." 1>&2

# Try to download the CRAS commit id first, and fall back on master if that is
# not found (see crbug.com/417820).

archive="$CRASBUILDTMP/adhd.tar.gz"
log="$CRASBUILDTMP/wget.log"
urlbase="https://chromium.googlesource.com/chromiumos/third_party/adhd/+archive"
( wget -O "$archive" "$urlbase/$ADHD_HEAD.tar.gz" 2>&1 \
                                    || echo "Error fetching CRAS" ) | tee "$log"
if tail -n 1 "$log" | grep -q "^Error"; then
    if grep -q "404 Not Found" "$log" 2>/dev/null; then
        echo "Branch not found, falling back on master (audio might not work)..." 1>&2
        ADHD_HEAD="master"
        wget -O "$archive" "$urlbase/$ADHD_HEAD.tar.gz"
    else
        # wget already printed an explicit error
        exit 1
    fi
fi

# Build CRAS ALSA plugin for the given architecture ($1)
# A blank parameter means we are building for the native architecture.
build_cras() {
    local cras_arch="$1"
    local pkgsuffix=''
    local pkgdepextra=''
    local archextrapath=''
    local pkgconfigpath=''
    local archgccflags=''
    if [ -n "$cras_arch" ]; then
        pkgsuffix=":$cras_arch"
        pkgdepextra='gcc-multilib'
        archextrapath="/$cras_arch-linux-gnu"
        pkgconfigpath="/usr/lib$archextrapath/pkgconfig"
        archgccflags='-m32'

        # Add foreign architecture, if necessary
        if ! dpkg --print-foreign-architectures | grep -q "^$cras_arch$"; then
            echo "Adding foreign architecture $cras_arch to dpkg..." 1>&2
            dpkg --add-architecture "$cras_arch"
            apt-get update || true
        fi
    fi

    # Install CRAS dependencies
    install --minimal alsa-utils \
        libasound2$pkgsuffix \
        libasound2-plugins$pkgsuffix \
        libspeexdsp1$pkgsuffix

    install --minimal --asdeps gcc $pkgdepextra libc6-dev$pkgsuffix \
        pkg-config libspeexdsp-dev$pkgsuffix

    # precise does not allow libasound2-dev and libasound2-dev:i386 to be
    # installed simultaneously
    if release -le precise && [ -n "$cras_arch" ]; then
        install --minimal --asdeps libasound2-dev
        # Manually link .so file
        libasoundso="/usr/lib$archextrapath/libasound.so"
        if [ ! -f "$libasoundso" ]; then
            addtrap "rm -f '$libasoundso' 2>/dev/null"
            ln -sfT libasound.so.2 "$libasoundso"
        fi
        ALSALIBDIR="/usr/lib$archextrapath/alsa-lib"
    else
        install --minimal --asdeps libasound2-dev$pkgsuffix
        ALSALIBDIR="`PKG_CONFIG_PATH="$pkgconfigpath" \
                                pkg-config --variable=libdir alsa`/alsa-lib"
    fi

    # Start subshell for compilation
    (
        cd "$CRASBUILDTMP"

        # Make sure we start fresh
        rm -rf --one-file-system cras

        # -m prevents "time stamp is in the future" spam
        tar -xmf adhd.tar.gz cras/src

        cd cras/src

        # Create version file
        echo '#define VCSID "crouton-'"$ADHD_HEAD"'"' > common/cras_version.h

        install --minimal --asdeps patch

        # Remove SBC dependency
        sed -e 's/#include <sbc.*//' -i common/cras_sbc_codec.h
        cat > common/cras_sbc_codec.c <<END
#include <stdint.h>
#include <stdlib.h>
#include "cras_audio_codec.h"

struct cras_audio_codec *cras_sbc_codec_create(uint8_t freq,
		   uint8_t mode, uint8_t subbands, uint8_t alloc,
		   uint8_t blocks, uint8_t bitpool) {
    abort();
}
void cras_sbc_codec_destroy(struct cras_audio_codec *codec) {
    abort();
}
END

        # Find the cras test client
        cras_test_client='tools/cras_test_client/cras_test_client.c'
        # FIXME: remove when 12334.0.0 (R77) becomes minimum target
        if [ ! -f "$cras_test_client" ]; then
            cras_test_client='tests/cras_test_client.c'
        fi

        # Drop SBC constants
        sed -e 's/SBC_[A-Z0-9_]*/0/g' -i "$cras_test_client"

	# FIXME(crbug.com/864815) Remove when fixed upstream
	if [ "$cras_arch" = "i386" ]; then
	    sed -i -e 's/Dumping AEC info to %s, stream %lu/Dumping AEC info to %s, stream %llu/' \
		"$cras_test_client"
	fi
	sed -i -e 's/cras_stream_id_t stream_id;/cras_stream_id_t stream_id = 0;/' \
	    "$cras_test_client"

	# FIXME(http://crrev.com/c/1759370): Remove when R78 becomes minimum target
	sed -i -e 's/\(strncpy.*sizeof(info.name)\));/\1 - 1); info.name[sizeof(info.name) - 1] = '"'"'\\0'"'"';/' \
		common/cras_shm.c
	sed -i -e 's/^struct \([^_]\)/struct __attribute__((__packed__)) \1/' \
		common/cras_messages.h

        # Directory to install CRAS library/binaries
        CRASLIBDIR="/usr/local$archextrapath/lib"
        CRASBINDIR="/usr/local$archextrapath/bin"

        echo "Compiling CRAS (${cras_arch:-native})..." 1>&2
        # Convert Makefile.am to a shell script, and run it.
        {
            convert_automake

            echo '
                CFLAGS="$CFLAGS -DCRAS_SOCKET_FILE_DIR=\"/var/run/cras\" -Wno-error"

                buildlib libcras

                # Pass -rpath=$CRASLIBDIR to linker, so we do not need to add
                # the directory to ldconfig search path (some distributions do
                # not include /usr/local/lib in /etc/ld.so.conf).
                # We also need to add "-L." as we are not using .la files.
                extraflags="-Wl,-rpath='"$CRASLIBDIR"' -L."

                buildlib libasound_module_pcm_cras "$extraflags"
                buildlib libasound_module_ctl_cras "$extraflags"
                buildexe cras_test_client "$extraflags"
            '
        } | sh -s -e $SETOPTIONS

        echo "Installing CRAS..." 1>&2

        mkdir -p "$CRASBINDIR/" "$CRASLIBDIR/" "$ALSALIBDIR/"
        # Only install libcras.so.X.Y.Z
        /usr/bin/install -s libcras.so.*.* "$CRASLIBDIR/"
        # Generate symbolic link to libcras.so.X
        ldconfig -l "$CRASLIBDIR"/libcras.so.*.*
        /usr/bin/install -s libasound_module_pcm_cras.so "$ALSALIBDIR/"
        /usr/bin/install -s libasound_module_ctl_cras.so "$ALSALIBDIR/"
        /usr/bin/install -s cras_test_client "$CRASBINDIR/"
    ) # End compilation subshell
}

# On x86_64, the ALSA plugin needs to be compiled for both 32-bit and 64-bit
# to allow audio playback using 32-bit applications.
if [ "$ARCH" = 'amd64' ]; then
    build_cras 'i386'
fi

# Build CRAS for native architecture
build_cras

alsaconf='/etc/alsa/conf.d'
if [ ! -d "$alsaconf" ]; then
    alsaconf='/usr/share/alsa/alsa.conf.d'
    if [ ! -d "$alsaconf" ]; then
        echo "Unable to find correct ALSA configuration directory." 1>&2
        alsaconf='/tmp'
    fi
fi
echo "Writing ALSA config into $alsaconf/10-cras.conf" 1>&2
cat > "$alsaconf/10-cras.conf" <<EOF
pcm.cras {
    type cras
    hint {
        show on
        description "Chromium OS Audio Server"
    }
}
ctl.cras {
    type cras
}

# Default: route all audio through the CRAS plugin.
pcm.!default {
    type cras
    hint {
        show on
        description "Default ALSA Output (currently Chromium OS Audio Server)"
    }
}
ctl.!default {
    type cras
}
EOF

# Configure pulseaudio even if it is not installed (yet).
# We use ~/.config/pulse/default.pa for this purpose, but the main user may
# not have been created yet, so we add a script in /etc/profile.d to link
# ~/.config/pulse/default.pa to /etc/crouton/pulseaudio-default.pa.

paconfigdir='$HOME/.config/pulse'
# Old versions of pulseaudio use ~/.pulse/default.pa
if release -le quantal -le wheezy; then
    paconfigdir='$HOME/.pulse'
fi

profiledsh='/etc/profile.d/crouton-pulseaudio-cras.sh'
# Make sure symbolic link is setup on login
echo '#!/bin/sh

defaultpa="'"$paconfigdir"'/default.pa"
# Do not install if user is root, or $HOME does not exist
if [ "`id -u`" -ne 0 -a -d "$HOME" -a ! -e "$defaultpa" ]; then
    mkdir -p "'"$paconfigdir"'"
    ln -sfT /etc/crouton/pulseaudio-default.pa "$defaultpa"
fi' > "$profiledsh"

chmod 755 "$profiledsh"

TIPS="$TIPS
Audio from the chroot will now be forwarded to CRAS (Chromium OS audio server),
through an ALSA plugin.

Future Chromium OS upgrades may break compatibility with the installed version
of CRAS. Should this happen, simply update your chroot.
"