Some ffmpeg encoding options working, with bugs

[Vidrep]

Some of the "BeEncoder" (ffmpeg) options are working somewhat (only on x86_gcc2h). I have encoded from wav to flac, raw, and AC-3. In each instance the output file is named *.wav.mp3, and when clicked, Haiku opens it with SoundRecorder instead of MediaPlayer. FileInfo in each case correctly identifies the container correctly (flac, raw, MP3). Opening with MediaPlayer produces mixed results. Raw plays fine. Flac and MP3 output noise. This app is "almost" working :)
I have several CD/DVD drives and lots of audio CD's, in case any dev wants to test further, or collaborate on getting this app working.

[Vidrep]

hrev51846 x86_64

Attempting to encode an audio CD wav to raw using BeEncoder->wav/Raw audio causes crash.

KERN: vm_soft_fault: va 0x0 not covered by area in address space
KERN: vm_page_fault: vm_soft_fault returned error 'Bad address' on fault at 0x5, ip 0x1d38aeebb8d, write 0, user 1, thread 0xc66
KERN: vm_page_fault: thread "Encoder" (3174) in team "Hare" (3146) tried to read address 0x5, ip 0x1d38aeebb8d ("libroot.so_seg0ro" +0xe1b8d)
KERN: debug_server: Thread 3174 entered the debugger: Segment violation
KERN: stack trace, current PC 0x1d38aeebb8d _ZN8BPrivate11processHeap4freeEPv + 0x63:
KERN: (0x7fcff7b676c0) 0x1d38aeed615 free + 0xfc
KERN: (0x7fcff7b676e0) 0x1be5d603fae av_buffer_unref + 0x1e

[Vidrep]

Hare-3146-debug-10-03-2018-21-01-09.report.txt

[Vidrep]

Building x86 and encoding also crashes in the same manner as x86_64.

[scottmc]

Issues with the encoders may be due to hardcoding of the paths. These should all be cleaned up.

[scottmc]

@Vidrep Can you try building the current code and provide feedback on the currently pending open issues?

[Vidrep]

Just did a quick test to see if it would do a wav (CD) to mp3 conversion using LAME. It worked.
All of the other encoder choices return an error message "The addon could not find the required executable."