Compiling FFmpeg with Alpine Linux: Overcoming LD Errors

When attempting to compile FFmpeg on Alpine Linux, you may encounter LD errors due to the lack of support for position-independent code (PIC). In this article, we will explore how to overcome these issues and successfully compile FFmpeg on your Alpine Linux system.

The error message typically appears as follows:

```

/usr/bin/ld: /tmp/libpostproc.so.54.: relocation R_X86_64_PC32 against undefined symbol `w05' cannot be used when making a shared object; recompile with -fPIC

/usr/bin/ld: /tmp/libavcodec.so.57.: relocation R_X86_64_PC32 against undefined symbol `ff_h264_cabac_tables' cannot be used when making a shared object; recompile with -fPIC

```

The problem arises because the latest versions of x265 and x264 do not support PIC by default, which is required for creating shared objects. To overcome this limitation, you need to recompile these libraries with the `-fPIC` flag.

To achieve this, you can modify your `configure` command when compiling FFmpeg. For example:

```

./configure --prefix=/usr --enable-shared --with-ffplay --disable-static

```

By adding the `-fPIC` flag to your compiler options, you can ensure that the necessary libraries are compiled with PIC support.

Here is an updated example of how to modify your `make` command:

```

CC='gcc -fPIC' ./configure --prefix=/usr --enable-shared --with-ffplay --disable-static

```

By making this modification, you should be able to successfully compile FFmpeg on your Alpine Linux system without encountering LD errors.

In addition to compiling the necessary libraries with PIC support, you may also need to update your `ld` configuration to ensure that it is correctly handling shared objects. You can do this by adding the following line to your `/etc/ld.so.conf` file:

```

/usr/lib

```

This will allow the linker to properly resolve symbols when creating shared objects.

By following these steps and modifying your compile command accordingly, you should be able to successfully compile FFmpeg on your Alpine Linux system. If you encounter any further issues or have questions about this process, please don't hesitate to reach out to our community for assistance.

Alpine linux ffmpeg