How can I get FFmpeg to locate installed libraries when --sysroot is pointing to another directory?

Question

I've been going at this, literally for days. I'm trying to build FFmpeg with libmp3lame for use in an Android application. The build script sets a --sysroot flag that points to the Android NDK directory necessary to build these libraries in a way that Android can use them.

The problem comes when I add the flag to --enable-libmp3lame; I get ERROR: libmp3lame >= 3.98.3 not found during the build start up. I know that LAME, and it's libraries are installed, because I can just run ./configure --enable-libmp3lame manually and the configuration launches without a hitch, and shows that libmp3lame is enabled for this build. However, building like this will simply not work for what I need it for, since I need the Android NDK to do some work.

I've tracked the problem down to the fact that this build script is declaring the sysroot, and through some research, I've tried adding -Luser/include, -L/user/includeto the extra cflags, and ldflags (which I've read is the default search location for gcc). I've tried several other things as well, but I'm confident that someone out here can help with this specific problem. This entire build script is as follows:

Extra info:

• Build OS: Ubuntu 11.10
• FFmpeg Ver: Latest from git
• LAME Ver: 3.9.x
• Android NDK: r7

build.sh

#!/bin/bash

if [ "$NDK" = "" ]; then
    echo NDK variable not set, assuming ${HOME}/android-ndk
    export NDK=${HOME}/android-ndk
fi

SYSROOT=$NDK/platforms/android-3/arch-arm
# Expand the prebuilt/* path into the correct one
TOOLCHAIN=`echo $NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/*-x86`
export PATH=$TOOLCHAIN/bin:$PATH

rm -rf build/ffmpeg
mkdir -p build/ffmpeg
cd ffmpeg

# Don't build any neon version for now
for version in armv5te armv7a; do

        DEST=../build/ffmpeg
        FLAGS="--target-os=linux --cross-prefix=arm-linux-androideabi- --arch=arm"
        FLAGS="$FLAGS --sysroot=$SYSROOT"
        FLAGS="$FLAGS --soname-prefix=/data/data/net.smartnotes/lib/"
        FLAGS="$FLAGS --enable-shared --disable-symver"
        FLAGS="$FLAGS --enable-small --optimization-flags=-O2"
        FLAGS="$FLAGS --disable-everything --enable-protocol=file"
        FLAGS="$FLAGS --enable-libmp3lame --enable-encoder=nellymoser"

        case "$version" in
                neon)
                    EXTRA_CFLAGS="-march=armv7-a -mfloat-abi=softfp -mfpu=neon"
                    EXTRA_LDFLAGS="-Wl,--fix-cortex-a8"
                    # Runtime choosing neon vs non-neon requires
                    # renamed files
                    ABI="armeabi-v7a"
                    ;;
                armv7a)
                    # I have tried many things here.
                    EXTRA_CFLAGS="-march=armv7-a -mfloat-abi=softfp"
                    EXTRA_LDFLAGS=""
                    ABI="armeabi-v7a"
                    ;;
                *)
                    # I have tried many things here.
                    EXTRA_CFLAGS="-Luser/include"
                    EXTRA_LDFLAGS=""
                    ABI="armeabi"
                    ;;
        esac
        DEST="$DEST/$ABI"
        FLAGS="$FLAGS --prefix=$DEST"

        mkdir -p $DEST
        echo $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" > $DEST/info.txt
        ./configure $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" | tee $DEST/configuration.txt
        [ $PIPESTATUS == 0 ] || exit 1
        make clean
        make -j4 || exit 1
        make install || exit 1

done

Answer 1

Instead of changing the include paths, why don't you try copying all the libmp3lame files that were created by 'make install' to the relevant directory where the script will look for them. Insert ECHO statements to find out what exactly the PATH/CFLAGS/LDFLAGS are at the point where you get the error, and copy the files there so it does find them.