Can't compile Speex Library Samplenc

Question

I'm actually trying to recode a skype like application. I successfully managed to install and use portaudio and opencv libraries but I'm having some trouble with Speex on visual studio 2013 (for the compression codec).

At the moment, I'm just trying to compile the sample given by Speex to test the library.

#include <speex/speex.h>
#include <stdio.h>

/*The frame size in hardcoded for this sample code but it doesn't have to be*/
#define FRAME_SIZE 160
int main(int argc, char **argv)
{
   char *inFile;
   FILE *fin;
   short in[FRAME_SIZE];
   float input[FRAME_SIZE];
   char cbits[200];
   int nbBytes;
   /*Holds the state of the encoder*/
   void *state;
   /*Holds bits so they can be read and written to by the Speex routines*/
   SpeexBits bits;
   int i, tmp;

   /*Create a new encoder state in narrowband mode*/
   state = speex_encoder_init(&speex_nb_mode);

   /*Set the quality to 8 (15 kbps)*/
   tmp=8;
   speex_encoder_ctl(state, SPEEX_SET_QUALITY, &tmp);

   inFile = argv[1];
   fin = fopen(inFile, "r");

   /*Initialization of the structure that holds the bits*/
   speex_bits_init(&bits);
   while (1)
   {
      /*Read a 16 bits/sample audio frame*/
      fread(in, sizeof(short), FRAME_SIZE, fin);
      if (feof(fin))
         break;
      /*Copy the 16 bits values to float so Speex can work on them*/
      for (i=0;i<FRAME_SIZE;i++)
         input[i]=in[i];

      /*Flush all the bits in the struct so we can encode a new frame*/
      speex_bits_reset(&bits);

      /*Encode the frame*/
      speex_encode(state, input, &bits);
      /*Copy the bits to an array of char that can be written*/
      nbBytes = speex_bits_write(&bits, cbits, 200);

      /*Write the size of the frame first. This is what sampledec expects but
       it's likely to be different in your own application*/
      fwrite(&nbBytes, sizeof(int), 1, stdout);
      /*Write the compressed data*/
      fwrite(cbits, 1, nbBytes, stdout);

   }

   /*Destroy the encoder state*/
   speex_encoder_destroy(state);
   /*Destroy the bit-packing struct*/
   speex_bits_destroy(&bits);
   fclose(fin);
   return 0;
}

The thing is, I added the lib and include repertories in the properties, and I also added libspeex.lib and libspeexdsp.lib to the additionnal dependencies in the Linker properties (input).

That's exactly what I did for the two previous libraries but it doesn't seem to work for this one. I always got this error : "error LNK2001 : unresolved external symbol _speex_nb_mode".

I could really appreciate some help on that ! Thanks guys !