mpegaudiodec: move imdct and windowing function to mpegaudiodsp

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

1 files changed, 190 insertions, 0 deletions

diff --git a/libavcodec/mpegaudiodsp_template.c b/libavcodec/mpegaudiodsp_template.c
index 5561c46135..5a6adb8cca 100644
--- a/libavcodec/mpegaudiodsp_template.c
+++ b/libavcodec/mpegaudiodsp_template.c
@@ -39,7 +39,12 @@ static inline float round_sample(float *sum)
 
 #define MACS(rt, ra, rb) rt+=(ra)*(rb)
 #define MULS(ra, rb) ((ra)*(rb))
+#define MULH3(x, y, s) ((s)*(y)*(x))
 #define MLSS(rt, ra, rb) rt-=(ra)*(rb)
+#define MULLx(x, y, s) ((y)*(x))
+#define FIXHR(x)        ((float)(x))
+#define FIXR(x)        ((float)(x))
+#define SHR(a,b)       ((a)*(1.0f/(1<<(b))))
 
 #else
 
@@ -57,8 +62,16 @@ static inline int round_sample(int64_t *sum)
 #   define MULS(ra, rb) MUL64(ra, rb)
 #   define MACS(rt, ra, rb) MAC64(rt, ra, rb)
 #   define MLSS(rt, ra, rb) MLS64(rt, ra, rb)
+#   define MULH3(x, y, s) MULH((s)*(x), y)
+#   define MULLx(x, y, s) MULL(x,y,s)
+#   define SHR(a,b)       ((a)>>(b))
+#   define FIXR(a)        ((int)((a) * FRAC_ONE + 0.5))
+#   define FIXHR(a)       ((int)((a) * (1LL<<32) + 0.5))
 #endif
 
+/** Window for MDCT. */
+DECLARE_ALIGNED(16, INTFLOAT, RENAME(ff_mdct_win))[8][36];
+
 DECLARE_ALIGNED(16, MPA_INT, RENAME(ff_mpa_synth_window))[512+256];
 
 #define SUM8(op, sum, w, p)               \
@@ -194,6 +207,7 @@ void av_cold RENAME(ff_mpa_synth_init)(MPA_INT *window)
             window[512 - i] = v;
     }
 
+
     // Needed for avoiding shuffles in ASM implementations
     for(i=0; i < 8; i++)
         for(j=0; j < 16; j++)
@@ -203,3 +217,179 @@ void av_cold RENAME(ff_mpa_synth_init)(MPA_INT *window)
         for(j=0; j < 16; j++)
             window[512+128+16*i+j] = window[64*i+48-j];
 }
+
+void RENAME(ff_init_mpadsp_tabs)(void)
+{
+    int i, j;
+    /* compute mdct windows */
+    for (i = 0; i < 36; i++) {
+        for (j = 0; j < 4; j++) {
+            double d;
+
+            if (j == 2 && i % 3 != 1)
+                continue;
+
+            d = sin(M_PI * (i + 0.5) / 36.0);
+            if (j == 1) {
+                if      (i >= 30) d = 0;
+                else if (i >= 24) d = sin(M_PI * (i - 18 + 0.5) / 12.0);
+                else if (i >= 18) d = 1;
+            } else if (j == 3) {
+                if      (i <   6) d = 0;
+                else if (i <  12) d = sin(M_PI * (i -  6 + 0.5) / 12.0);
+                else if (i <  18) d = 1;
+            }
+            //merge last stage of imdct into the window coefficients
+            d *= 0.5 / cos(M_PI * (2 * i + 19) / 72);
+
+            if (j == 2)
+                RENAME(ff_mdct_win)[j][i/3] = FIXHR((d / (1<<5)));
+            else
+                RENAME(ff_mdct_win)[j][i  ] = FIXHR((d / (1<<5)));
+        }
+    }
+
+    /* NOTE: we do frequency inversion adter the MDCT by changing
+        the sign of the right window coefs */
+    for (j = 0; j < 4; j++) {
+        for (i = 0; i < 36; i += 2) {
+            RENAME(ff_mdct_win)[j + 4][i    ] =  RENAME(ff_mdct_win)[j][i    ];
+            RENAME(ff_mdct_win)[j + 4][i + 1] = -RENAME(ff_mdct_win)[j][i + 1];
+        }
+    }
+}
+/* cos(pi*i/18) */
+#define C1 FIXHR(0.98480775301220805936/2)
+#define C2 FIXHR(0.93969262078590838405/2)
+#define C3 FIXHR(0.86602540378443864676/2)
+#define C4 FIXHR(0.76604444311897803520/2)
+#define C5 FIXHR(0.64278760968653932632/2)
+#define C6 FIXHR(0.5/2)
+#define C7 FIXHR(0.34202014332566873304/2)
+#define C8 FIXHR(0.17364817766693034885/2)
+
+/* 0.5 / cos(pi*(2*i+1)/36) */
+static const INTFLOAT icos36[9] = {
+    FIXR(0.50190991877167369479),
+    FIXR(0.51763809020504152469), //0
+    FIXR(0.55168895948124587824),
+    FIXR(0.61038729438072803416),
+    FIXR(0.70710678118654752439), //1
+    FIXR(0.87172339781054900991),
+    FIXR(1.18310079157624925896),
+    FIXR(1.93185165257813657349), //2
+    FIXR(5.73685662283492756461),
+};
+
+/* 0.5 / cos(pi*(2*i+1)/36) */
+static const INTFLOAT icos36h[9] = {
+    FIXHR(0.50190991877167369479/2),
+    FIXHR(0.51763809020504152469/2), //0
+    FIXHR(0.55168895948124587824/2),
+    FIXHR(0.61038729438072803416/2),
+    FIXHR(0.70710678118654752439/2), //1
+    FIXHR(0.87172339781054900991/2),
+    FIXHR(1.18310079157624925896/4),
+    FIXHR(1.93185165257813657349/4), //2
+//    FIXHR(5.73685662283492756461),
+};
+
+/* using Lee like decomposition followed by hand coded 9 points DCT */
+static void imdct36(INTFLOAT *out, INTFLOAT *buf, INTFLOAT *in, INTFLOAT *win)
+{
+    int i, j;
+    INTFLOAT t0, t1, t2, t3, s0, s1, s2, s3;
+    INTFLOAT tmp[18], *tmp1, *in1;
+
+    for (i = 17; i >= 1; i--)
+        in[i] += in[i-1];
+    for (i = 17; i >= 3; i -= 2)
+        in[i] += in[i-2];
+
+    for (j = 0; j < 2; j++) {
+        tmp1 = tmp + j;
+        in1 = in + j;
+
+        t2 = in1[2*4] + in1[2*8] - in1[2*2];
+
+        t3 = in1[2*0] + SHR(in1[2*6],1);
+        t1 = in1[2*0] - in1[2*6];
+        tmp1[ 6] = t1 - SHR(t2,1);
+        tmp1[16] = t1 + t2;
+
+        t0 = MULH3(in1[2*2] + in1[2*4] ,    C2, 2);
+        t1 = MULH3(in1[2*4] - in1[2*8] , -2*C8, 1);
+        t2 = MULH3(in1[2*2] + in1[2*8] ,   -C4, 2);
+
+        tmp1[10] = t3 - t0 - t2;
+        tmp1[ 2] = t3 + t0 + t1;
+        tmp1[14] = t3 + t2 - t1;
+
+        tmp1[ 4] = MULH3(in1[2*5] + in1[2*7] - in1[2*1], -C3, 2);
+        t2 = MULH3(in1[2*1] + in1[2*5],    C1, 2);
+        t3 = MULH3(in1[2*5] - in1[2*7], -2*C7, 1);
+        t0 = MULH3(in1[2*3], C3, 2);
+
+        t1 = MULH3(in1[2*1] + in1[2*7],   -C5, 2);
+
+        tmp1[ 0] = t2 + t3 + t0;
+        tmp1[12] = t2 + t1 - t0;
+        tmp1[ 8] = t3 - t1 - t0;
+    }
+
+    i = 0;
+    for (j = 0; j < 4; j++) {
+        t0 = tmp[i];
+        t1 = tmp[i + 2];
+        s0 = t1 + t0;
+        s2 = t1 - t0;
+
+        t2 = tmp[i + 1];
+        t3 = tmp[i + 3];
+        s1 = MULH3(t3 + t2, icos36h[    j], 2);
+        s3 = MULLx(t3 - t2, icos36 [8 - j], FRAC_BITS);
+
+        t0 = s0 + s1;
+        t1 = s0 - s1;
+        out[(9 + j) * SBLIMIT] = MULH3(t1, win[     9 + j], 1) + buf[4*(9 + j)];
+        out[(8 - j) * SBLIMIT] = MULH3(t1, win[     8 - j], 1) + buf[4*(8 - j)];
+        buf[4 * ( 9 + j     )] = MULH3(t0, win[18 + 9 + j], 1);
+        buf[4 * ( 8 - j     )] = MULH3(t0, win[18 + 8 - j], 1);
+
+        t0 = s2 + s3;
+        t1 = s2 - s3;
+        out[(9 + 8 - j) * SBLIMIT] = MULH3(t1, win[     9 + 8 - j], 1) + buf[4*(9 + 8 - j)];
+        out[         j  * SBLIMIT] = MULH3(t1, win[             j], 1) + buf[4*(        j)];
+        buf[4 * ( 9 + 8 - j     )] = MULH3(t0, win[18 + 9 + 8 - j], 1);
+        buf[4 * (         j     )] = MULH3(t0, win[18         + j], 1);
+        i += 4;
+    }
+
+    s0 = tmp[16];
+    s1 = MULH3(tmp[17], icos36h[4], 2);
+    t0 = s0 + s1;
+    t1 = s0 - s1;
+    out[(9 + 4) * SBLIMIT] = MULH3(t1, win[     9 + 4], 1) + buf[4*(9 + 4)];
+    out[(8 - 4) * SBLIMIT] = MULH3(t1, win[     8 - 4], 1) + buf[4*(8 - 4)];
+    buf[4 * ( 9 + 4     )] = MULH3(t0, win[18 + 9 + 4], 1);
+    buf[4 * ( 8 - 4     )] = MULH3(t0, win[18 + 8 - 4], 1);
+}
+
+void RENAME(ff_imdct36_blocks)(INTFLOAT *out, INTFLOAT *buf, INTFLOAT *in,
+                               int count, int switch_point, int block_type)
+{
+    int j;
+    for (j=0 ; j < count; j++) {
+        /* apply window & overlap with previous buffer */
+
+        /* select window */
+        int win_idx = (switch_point && j < 2) ? 0 : block_type;
+        INTFLOAT *win = RENAME(ff_mdct_win)[win_idx + (4 & -(j & 1))];
+
+        imdct36(out, buf, in, win);
+
+        in  += 18;
+        buf += ((j&3) != 3 ? 1 : (72-3));
+        out++;
+    }
+}