simonwunderlich / fft_eval Goto Github PK

[ruben@bragi FFT_eval]$ ./fft_eval ../fft_14-09-12T22-37
WARNING: Experimental Software! Don't trust anything you see. :)

read 113 scan results
Initializing SDL failed
Failed to initialize graphics.

Compiled under arch-linux with kernel 3.15.8, gcc 4.9.1 and sdl 1.2.15-6

Hi Guys,

I'm working on a Spectrum Analyzer module for LuCI, compatible with OpenWRT/LEDE.
For this I need to separate the SDL functionality and the data conversion functionality, and make some sort of JSON output.

I've been trying to do it myself based on @altergui work here: libremesh@5787074 but it is taking a lot of energy from me.

I wondered if you could be able to do this. That would make my part easier and I can focus on creating the LuCI modules and the ubus daemons for this.

Basically, the proposal is to add a mode on the code that allows to export the data information as JSON, and a conditional build switch to split the SDL dependencies.

Thanks!

If the library is before the -o, then it will fail as below:

gcc -lSDL -lSDL_ttf -o fft_eval fft_eval.o
fft_eval.o: In function graphics_init_sdl': fft_eval.c:(.text+0xc): undefined reference toSDL_Init'
fft_eval.c:(.text+0x19): undefined reference to SDL_GetVideoInfo' fft_eval.c:(.text+0x53): undefined reference toSDL_WM_SetCaption'
fft_eval.c:(.text+0x73): undefined reference to SDL_SetVideoMode' fft_eval.c:(.text+0x7d): undefined reference toTTF_Init'
fft_eval.c:(.text+0x95): undefined reference to TTF_OpenFont' fft_eval.o: In functionrender_text':
fft_eval.c:(.text+0x34d): undefined reference to TTF_RenderText_Solid' fft_eval.c:(.text+0x373): undefined reference toSDL_UpperBlit'
fft_eval.c:(.text+0x37b): undefined reference to SDL_FreeSurface' fft_eval.o: In functiondraw_picture':
fft_eval.c:(.text+0x3f7): undefined reference to SDL_CreateRGBSurface' fft_eval.c:(.text+0x695): undefined reference tolog10f'
fft_eval.c:(.text+0x6a5): undefined reference to log10f' fft_eval.c:(.text+0x75c): undefined reference toSDL_UpperBlit'
fft_eval.c:(.text+0x768): undefined reference to SDL_FreeSurface' fft_eval.c:(.text+0x775): undefined reference toSDL_Flip'
fft_eval.o: In function graphics_main': fft_eval.c:(.text+0xac2): undefined reference toSDL_EnableKeyRepeat'
fft_eval.c:(.text+0xb1c): undefined reference to SDL_PollEvent' fft_eval.c:(.text+0xb91): undefined reference toSDL_WaitEvent'
fft_eval.c:(.text+0xbca): undefined reference to SDL_Quit' fft_eval.o: In functiongraphics_quit_sdl':
fft_eval.c:(.text+0x171): undefined reference to `SDL_Quit'
collect2: ld returned 1 exit status
make: *** [fft_eval] Error 1

have to change the library order to
$(LD) -o $@ $(OBJ) $(LIBS)
in the Makefile, and it works

Sometimes signal values can be positive for all scan. Not sure why this happens.