ffmpeg won't ./configure in iOS5.1

Question

I am trying to build ffmpeg on iOS5.1 (armv7), when I try to run ./configure like this:

./configure --disable-doc --disable-ffmpeg --disable-ffplay --disable         


        

Answer 1

the instructions have changed since there is no longer a gcc in the xcode SDK.

What you need to do is specify that cc is the iphoneos compiler using xcrun, so where we previously just put the path to gcc, we're now going to put a reference to xcrun for clang.

I downloaded the latest ffmpeg from git, made sure I had a copy of gas-preprocess.pl on the path, and then changed the --cc= line to read:

--cc='xcrun -sdk iphoneos clang -mios-version-min=5.1'

(this assumes you're building and still targetting ios 5.1 - if you're targetting newer, then you change the value to the newer release. I specified 7.0 for mine, but I'm also using the iOS 8.4 SDK, so the configure line looks like:

./configure --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffserver \
 --enable-cross-compile --arch=arm --target-os=darwin \
 --cc='xcrun -sdk iphoneos clang -mios-version-min=7.0' \
 --sysroot=/applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.4.sdk \
 --cpu=cortex-a8 --extra-cflags='-arch armv7' \
 --extra-ldflags='-arch armv7 -isysroot /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.4.sdk' \
 --enable-pic

which builds ffmpeg from the ios8.4 SDK. These instructions should keep working; you just need to replace the appropriate 7.0/8.4 values for the newer SDKs.

OLD ANSWER

That's what happens when you try to compile iOS code using the MacOS version of the compiler.

You need to specify the iPhoneOS version of gcc using:

./configure --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffserver
   --enable-cross-compile --arch=arm --target-os=darwin
   --cc=/applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc
   --as='gas-preprocessor/gas-preprocessor.pl /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc'
   --sysroot=/applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk
   --cpu=cortex-a8 --extra-cflags='-arch armv7'
   --extra-ldflags='-arch armv7
   -isysroot /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk'
   --enable-pic

The first step when trying to debug problems with configure is to look at the config.log file which is generated as part of the run.