[SOLVED] SDL2_image jpeg not loading on slackware 14.2

timsoft · 10-11-2016, 05:11 PM

has anyone come across this issue with SDL2_image not loading jpegs on slackware 14.2 and got a fix?
I used dugan's sbobuild via sbopkg and it loads png and bmp images ok but fails to load jpgs.
I didn't see any errors in the build log, so I assume the jpeg library included with sdl2_image is different from the slackware 14.2 one, causing some sort of issue.

to confirm, slackware 14.2 switched to libjpeg-turbo 1.5.0 instead of libjpeg v8a used by slackware 14.1 (and by sdl2_image)

presumably the header file for the library and functions included is different in some critical way.
Any clues? without jpg reading, sdl2_image is "not a full shilling".

dugan · 10-11-2016, 05:45 PM

If you're the same person who emailed me, then my response is the same: report it to the libsdl mailing list.

I assume you didn't see anything obviously relevant in SDL2_image's ./configure output, such as "...disabling JPEG support" or "JPEG support: no"?

dugan · 10-11-2016, 09:56 PM

I just checked. There is nothing wrong with the SlackBuild.

Take it to the libsdl mailing list. Give them your sample code, the command you used to compile it, and how you know it's not working (something more technically detailed than "fails to load").

Post back here only, and I mean only, if they say it's an issue with how SDL2_image is built. And when you do, the first thing I want to see is a direct link to the issue tracker comment or mailing list post that sent you back here.

timsoft · 10-12-2016, 04:09 AM

Hi dugan, yes it is the same person. I have found a solution which works.

If you add

Code:

--enable-jpg-shared=no

to the configure line in your slackbuild, then loading jpgs works with slackware 14.2

On hindsight, it is obvious that enable-jpg-shared=yes (the default if not specified) will not work as the system (ie slackware 14.2) library is different from the one included in the sdl2_image source code. The only way to make that work would be either overwriting the default slackware jpeg library and headers(probably not a preferred option), or to replace the sdl2_image jpg source with the slackware turbo-jpg source and hope it works.

note: this is not an issue with earlier versions of slackware which don't use the turbo-jpg library.

If you still would like me to chase the libsdl mailing list I can do so, although from the reasoning above, I don't see how the source could easily be changed to accommodate both jpg libraries at the same time.
Regards, Tim

test case program is listed below,

Code:

#include <stdbool.h>
#include <SDL.h>
#include <SDL_image.h>
int main(int argc, char ** argv)
{
    bool quit = false;
    SDL_Event event;
    SDL_Init(SDL_INIT_VIDEO);
    IMG_Init(IMG_INIT_JPG);
    SDL_Window * window = SDL_CreateWindow("SDL2 Displaying Image",
        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);
    SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, 0);
/*    SDL_Surface * image = SDL_LoadBMP("image.bmp");  */
    SDL_Surface *image;
    image = IMG_Load("image.jpg");
    if (!image) {
      printf("IMG_Load: %s\n", IMG_GetError());
    }
    SDL_Texture * texture = SDL_CreateTextureFromSurface(renderer, image);
    while (!quit)
    {
       SDL_WaitEvent(&event);
       switch(event.type)
       {
       case SDL_QUIT:
           quit = true;
           break;
       }
       SDL_RenderCopy(renderer, texture, NULL, NULL);
       SDL_RenderPresent(renderer);
    }
    SDL_DestroyTexture(texture);
    SDL_FreeSurface(image);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    IMG_Quit();
    SDL_Quit();
    return 0;
}

makefile for above is below

Code:

LIBS = `pkg-config --libs sdl2 SDL2_image`
CFLAGS = `pkg-config --cflags sdl2 SDL2_image`
OBJS = testprog.o
VERSION = 1.0
DATADIR += ""
PROG = testprog
# top level rule to create the program
ALL = $(PROG)
all: $(ALL)
#compiling other source files
%.c: src/%.c src/*.h
        $(CC) $(CFLAGS) -c -DVERSION=\"$(VERSION)\" -DDATADIR=\"$(DATADIR)\"
$<
#linking the program
$(PROG): $(OBJS)
        $(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) -o $(PROG) $(LIBS)
clean:
        $(RM_ $(OBJS) $(ALL)

test program requires a image.jpg picture in the same directory as the program

dugan · 10-12-2016, 09:18 AM

Thanks for the solution, and my apologies for having been dismissive about this.

I've sent SBo an updated SlackBuild.

I have not yet had time to try out your test program.

timsoft · 10-12-2016, 01:29 PM

no probs. The simple test program can test loading all supporting image formats. just change the filename in the IMGLoad function call and recompile.
I tested it with a png a bmp and a jpg.
As soon as willy or rob or dave push the updates on sbo I'll be able to submit the slackbuild I am updating for slackware 14.2
Thanks for the quick response.

willysr · 10-13-2016, 04:36 AM

It's been pushed in my branch