Remove the EC_SMALLMUL experimental flag.
This experiment has been fully adopted and is now an integral part
of the draft AV1 bitstream definition.
objdump -d libaom.a gives identical output before and after this
patch.
Change-Id: I6f936f4b10de23a9471e0ccadf9cf178fb62be69
diff --git a/aom_dsp/entdec.c b/aom_dsp/entdec.c
index 49b176c..71dad0d 100644
--- a/aom_dsp/entdec.c
+++ b/aom_dsp/entdec.c
@@ -114,12 +114,8 @@
OD_ASSERT(rng <= 65535U);
d = 16 - OD_ILOG_NZ(rng);
dec->cnt -= d;
-#if CONFIG_EC_SMALLMUL
/*This is equivalent to shifting in 1's instead of 0's.*/
dec->dif = ((dif + 1) << d) - 1;
-#else
- dec->dif = dif << d;
-#endif
dec->rng = rng << d;
if (dec->cnt < 0) od_ec_dec_refill(dec);
return ret;
@@ -137,11 +133,7 @@
dec->tell_offs = 10 - (OD_EC_WINDOW_SIZE - 8);
dec->end = buf + storage;
dec->bptr = buf;
-#if CONFIG_EC_SMALLMUL
dec->dif = ((od_ec_window)1 << (OD_EC_WINDOW_SIZE - 1)) - 1;
-#else
- dec->dif = 0;
-#endif
dec->rng = 0x8000;
dec->cnt = -15;
dec->error = 0;
@@ -149,8 +141,7 @@
}
/*Decode a single binary value.
- {EC_SMALLMUL} f: The probability that the bit is one, scaled by 32768.
- {else} f: The probability that the bit is zero, scaled by 32768.
+ f: The probability that the bit is one, scaled by 32768.
Return: The value decoded (0 or 1).*/
int od_ec_decode_bool_q15(od_ec_dec *dec, unsigned f) {
od_ec_window dif;
@@ -165,7 +156,6 @@
r = dec->rng;
OD_ASSERT(dif >> (OD_EC_WINDOW_SIZE - 16) < r);
OD_ASSERT(32768U <= r);
-#if CONFIG_EC_SMALLMUL
v = (r >> 8) * (uint32_t)f >> 7;
vw = (od_ec_window)v << (OD_EC_WINDOW_SIZE - 16);
ret = 1;
@@ -175,30 +165,19 @@
dif -= vw;
ret = 0;
}
-#else
- v = f * (uint32_t)r >> 15;
- vw = (od_ec_window)v << (OD_EC_WINDOW_SIZE - 16);
- ret = 0;
- r_new = v;
- if (dif >= vw) {
- r_new = r - v;
- dif -= vw;
- ret = 1;
- }
-#endif
return od_ec_dec_normalize(dec, dif, r_new, ret);
}
-/*Decodes a symbol given a cumulative distribution function (CDF) table in Q15.
- cdf: The CDF, such that symbol s falls in the range
- [s > 0 ? cdf[s - 1] : 0, cdf[s]).
- The values must be monotonically non-increasing, and cdf[nsyms - 1]
- must be 32768.
- {EC_SMALLMUL}: The CDF contains 32768 minus those values.
+/*Decodes a symbol given an inverse cumulative distribution function (CDF)
+ table in Q15.
+ icdf: 32768 minus the CDF, such that symbol s falls in the range
+ [s > 0 ? (32768 - icdf[s - 1]) : 0, 32768 - icdf[s]).
+ The values must be monotonically non-increasing, and icdf[nsyms - 1]
+ must be 0.
nsyms: The number of symbols in the alphabet.
This should be at most 16.
Return: The decoded symbol s.*/
-int od_ec_decode_cdf_q15(od_ec_dec *dec, const uint16_t *cdf, int nsyms) {
+int od_ec_decode_cdf_q15(od_ec_dec *dec, const uint16_t *icdf, int nsyms) {
od_ec_window dif;
unsigned r;
unsigned c;
@@ -209,33 +188,19 @@
dif = dec->dif;
r = dec->rng;
OD_ASSERT(dif >> (OD_EC_WINDOW_SIZE - 16) < r);
- OD_ASSERT(cdf[nsyms - 1] == OD_ICDF(32768U));
+ OD_ASSERT(icdf[nsyms - 1] == OD_ICDF(32768U));
OD_ASSERT(32768U <= r);
-#if CONFIG_EC_SMALLMUL
c = (unsigned)(dif >> (OD_EC_WINDOW_SIZE - 16));
v = r;
ret = -1;
do {
u = v;
- v = (r >> 8) * (uint32_t)cdf[++ret] >> 7;
+ v = (r >> 8) * (uint32_t)icdf[++ret] >> 7;
} while (c < v);
OD_ASSERT(v < u);
OD_ASSERT(u <= r);
r = u - v;
dif -= (od_ec_window)v << (OD_EC_WINDOW_SIZE - 16);
-#else
- c = (unsigned)(dif >> (OD_EC_WINDOW_SIZE - 16));
- v = 0;
- ret = -1;
- do {
- u = v;
- v = cdf[++ret] * (uint32_t)r >> 15;
- } while (v <= c);
- OD_ASSERT(u < v);
- OD_ASSERT(v <= r);
- r = v - u;
- dif -= (od_ec_window)u << (OD_EC_WINDOW_SIZE - 16);
-#endif
return od_ec_dec_normalize(dec, dif, r, ret);
}
