This simply works for me in Emscripten 1.32.0. Disable shared libraries
when configuring, because those are not supported by Emscripten. I used
"emconfigure ./configure --disable-shared". The library is generated
at .libs/libjpeg.a. Then I added main() to example.c:
int main(void) {
printf("got %i\n", read_JPEG_file("testimg.jpg"));
return 0;
}
I also commented out "put_scanline_someplace(buffer[0], row_stride);"
because it doesn't exist and added "#include <stdlib.h>". Finally, I built
it with:
emcc --preload-file testimg.jpg example.c .libs/libjpeg.a -o example.html
On Thursday, 30 April 2015 11:21:42 UTC-4, Björn K. wrote:
>
> Hi there!
>
> I'm trying to compile libjpeg to JavaScript for using it in a webapp. So
> far I've had no luck with getting it to work. What I've done:
>
> 1. I've set up emscripten with my Ubuntu 14.04 LTS, the simple "Hello
> world"-c-code compiled successfully to JavaScript.
> 2. I've downloaded/extracted http://www.ijg.org/files/jpegsrc.v9a.tar.gz.
> I've made sure that I can build the included programs like djpeg or cjpeg.
> 3. I've made some modifications to example.c (mainly adding a
> main-function) and created a makefile for compiling it with gcc.
> 4. I've made sure I can successfully run the natively compiled "example".
> 5. I called emcc for example.c with HTML-output, getting the following:
> warning: unresolved symbol: jpeg_read_header
> warning: unresolved symbol: jpeg_CreateDecompress
> warning: unresolved symbol: jpeg_start_decompress
> warning: unresolved symbol: jpeg_stdio_src
> warning: unresolved symbol: jpeg_std_error
> warning: unresolved symbol: jpeg_destroy_decompress
> warning: unresolved symbol: jpeg_finish_decompress
> warning: unresolved symbol: jpeg_read_scanlines
> 6. I've opened the generated HTML-output in a Firefox instance, but get
> file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.data
> uncaught exception: abort(-1) at
> jsStackTrace@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:1316:13
>
> stackTrace@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:1333:22
>
> abort@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10939:44
>
> _jpeg_std_error@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:6541:59
>
> _jpeg_std_error__wrapper@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10637:59
>
> dynCall_ii@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10605:10
>
> invoke_ii@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:6663:12
>
> _read_JPEG_file@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:6902:11
>
> _main@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:7091:8
>
> asm._main@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10676:8
>
> callMain@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10805:15
>
> doRun@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10863:42
>
> run/<@file:///home/kopiske/emscripten/jpeg-components/jpeg-9a/example.js:10874:7
>
> "pre-main prep time: 241 ms" example.html:1245
> Module.printErr() example.html:1245
> doRun() example.js:10858
> run/<() example.js:10874
>
> "missing function: jpeg_std_error" example.html:1245
> Module.printErr() example.html:1245
> _jpeg_std_error() example.js:6541
> _jpeg_std_error__wrapper() example.js:10637
> dynCall_ii() example.js:10605
> invoke_ii() example.js:6663
> _read_JPEG_file() example.js:6902
> _main() example.js:7091
> asm._main() example.js:10676
> callMain() example.js:10805
> doRun() example.js:10863
> run/<()
>
>
> I haven't provided the modified example.c, since I get the same warnings
> mentioned in step 5 when I try to compile the unmodified "djpeg" with emcc.
>
> When I provide -s INCLUDE_FULL_LIBRARY=1 to emcc, the warnings disappear,
> but the error in 6 still remains. I have no idea why the used functions are
> not included.
>
> Any help with this is highly appreciated! (As you might have noticed, my
> knowledge of C is rudimentary to non-existent ;-))
>
> Best regards,
> Björn
>
>
--
You received this message because you are subscribed to the Google Groups
"emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
