16-bit int fixes.

This fixes a number of issues for platforms with a 16-bit int, but
 by no means all of them.
The type change for ec_window (for platforms where sizeof(size_t)==2)
 will break ABI (but not API) compatibility with libsilk and libopus,
 and reduce speed on x86-64, but allows the code to work in real-mode
 DOS without using the huge memory model, which is useful for testing
 16-bit int compliance.

libcelt/celt.c

@@ -872,7 +872,7 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
 {
 #endif
    int i, c, N;
-   int bits;
+   celt_int32 bits;
    ec_enc _enc;
    VARDECL(celt_sig, in);
    VARDECL(celt_sig, freq);
@@ -1439,8 +1439,8 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, i
    ALLOC(pulses, st->mode->nbEBands, int);
    ALLOC(fine_priority, st->mode->nbEBands, int);
 
-   /* bits =   packet size        -       where we are         - safety*/
-   bits = (nbCompressedBytes*8<<BITRES) - ec_tell_frac(enc) - 1;
+   /* bits =           packet size                    - where we are - safety*/
+   bits = ((celt_int32)nbCompressedBytes*8<<BITRES) - ec_tell_frac(enc) - 1;
    anti_collapse_rsv = isTransient&&LM>=2&&bits>=(LM+2<<BITRES) ? (1<<BITRES) : 0;
    bits -= anti_collapse_rsv;
    codedBands = compute_allocation(st->mode, st->start, st->end, offsets, cap,
@@ -2151,7 +2151,7 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
 #endif
    int c, i, N;
    int spread_decision;
-   int bits;
+   celt_int32 bits;
    ec_dec _dec;
    VARDECL(celt_sig, freq);
    VARDECL(celt_norm, X);
@@ -2367,7 +2367,7 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
    alloc_trim = tell+(6<<BITRES) <= total_bits ?
          ec_dec_icdf(dec, trim_icdf, 7) : 5;
 
-   bits = (len*8<<BITRES) - ec_tell_frac(dec) - 1;
+   bits = ((celt_int32)len*8<<BITRES) - ec_tell_frac(dec) - 1;
    anti_collapse_rsv = isTransient&&LM>=2&&bits>=(LM+2<<BITRES) ? (1<<BITRES) : 0;
    bits -= anti_collapse_rsv;
    codedBands = compute_allocation(st->mode, st->start, st->end, offsets, cap,

libcelt/entcode.h

@@ -41,14 +41,15 @@
 
 typedef celt_int32            ec_int32;
 typedef celt_uint32           ec_uint32;
-typedef size_t                ec_window;
+typedef celt_uint32           ec_window;
 typedef struct ec_ctx         ec_ctx;
 typedef struct ec_ctx         ec_enc;
 typedef struct ec_ctx         ec_dec;
 
 
 
-/*This must be at least 32 bits.*/
+/*OPT: This must be at least 32 bits, but if you have fast arithmetic on a
+   larger type, you can speed up the decoder by using it for ec_window.*/
 # define EC_WINDOW_SIZE ((int)sizeof(ec_window)*CHAR_BIT)
 
 /*The number of bits to use for the range-coded part of unsigned integers.*/

libcelt/entdec.c

@@ -222,7 +222,7 @@ ec_uint32 ec_dec_uint(ec_dec *_this,ec_uint32 _ft){
     ft=(unsigned)(_ft>>ftb)+1;
     s=ec_decode(_this,ft);
     ec_dec_update(_this,s,s+1,ft);
-    t=s<<ftb|ec_dec_bits(_this,ftb);
+    t=(ec_uint32)s<<ftb|ec_dec_bits(_this,ftb);
     if(t<=_ft)return t;
     _this->error=1;
     return _ft;

libcelt/rate.c

@@ -252,11 +252,11 @@ void compute_pulse_cache(CELTMode *m, int LM)
 #define ALLOC_STEPS 6
 
 static inline int interp_bits2pulses(const CELTMode *m, int start, int end, int skip_start,
-      const int *bits1, const int *bits2, const int *thresh, const int *cap, int total, celt_int32 *_balance,
+      const int *bits1, const int *bits2, const int *thresh, const int *cap, celt_int32 total, celt_int32 *_balance,
       int skip_rsv, int *intensity, int intensity_rsv, int *dual_stereo, int dual_stereo_rsv, int *bits,
       int *ebits, int *fine_priority, int _C, int LM, ec_ctx *ec, int encode, int prev)
 {
-   int psum;
+   celt_int32 psum;
    int lo, hi;
    int i, j;
    int logM;
@@ -264,7 +264,7 @@ static inline int interp_bits2pulses(const CELTMode *m, int start, int end, int
    int stereo;
    int codedBands=-1;
    int alloc_floor;
-   int left, percoeff;
+   celt_int32 left, percoeff;
    int done;
    int balance;
    SAVE_STACK;
@@ -282,7 +282,7 @@ static inline int interp_bits2pulses(const CELTMode *m, int start, int end, int
       done = 0;
       for (j=end;j-->start;)
       {
-         int tmp = bits1[j] + (mid*bits2[j]>>ALLOC_STEPS);
+         int tmp = bits1[j] + (mid*(celt_int32)bits2[j]>>ALLOC_STEPS);
          if (tmp >= thresh[j] || done)
          {
             done = 1;
@@ -344,7 +344,7 @@ static inline int interp_bits2pulses(const CELTMode *m, int start, int end, int
       left -= (m->eBands[codedBands]-m->eBands[start])*percoeff;
       rem = IMAX(left-(m->eBands[j]-m->eBands[start]),0);
       band_width = m->eBands[codedBands]-m->eBands[j];
-      band_bits = bits[j] + percoeff*band_width + rem;
+      band_bits = (int)(bits[j] + percoeff*band_width + rem);
       /*Only code a skip decision if we're above the threshold for this band.
         Otherwise it is force-skipped.
         This ensures that we have enough bits to code the skip flag.*/
@@ -420,10 +420,10 @@ static inline int interp_bits2pulses(const CELTMode *m, int start, int end, int
    percoeff = left/(m->eBands[codedBands]-m->eBands[start]);
    left -= (m->eBands[codedBands]-m->eBands[start])*percoeff;
    for (j=start;j<codedBands;j++)
-      bits[j] += percoeff*(m->eBands[j+1]-m->eBands[j]);
+      bits[j] += (int)(percoeff*(m->eBands[j+1]-m->eBands[j]));
    for (j=start;j<codedBands;j++)
    {
-      int tmp = IMIN(left, m->eBands[j+1]-m->eBands[j]);
+      int tmp = (int)IMIN(left, m->eBands[j+1]-m->eBands[j]);
       bits[j] += tmp;
       left -= tmp;
    }

libcelt/rate.h

@@ -105,7 +105,7 @@ celt_int16 **compute_alloc_cache(CELTMode *m, int M);
  @return Total number of bits allocated
 */
 int compute_allocation(const CELTMode *m, int start, int end, const int *offsets, const int *cap, int alloc_trim, int *intensity, int *dual_stero,
-      int total, celt_int32 *balance, int *pulses, int *ebits, int *fine_priority, int _C, int LM, ec_ctx *ec, int encode, int prev);
+      celt_int32 total, celt_int32 *balance, int *pulses, int *ebits, int *fine_priority, int _C, int LM, ec_ctx *ec, int encode, int prev);
 
 
 #endif