1 files changed, 688 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/liba52/downmix.c b/lib/rbcodec/codecs/liba52/downmix.c
new file mode 100644
index 0000000000..dd2867cb92
--- /dev/null
+++ b/lib/rbcodec/codecs/liba52/downmix.c
@@ -0,0 +1,688 @@
+/*
+ * downmix.c
+ * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
+ * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of a52dec, a free ATSC A-52 stream decoder.
+ * See http://liba52.sourceforge.net/ for updates.
+ *
+ * a52dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * a52dec is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "config-a52.h"
+
+#include <string.h>
+#include <inttypes.h>
+
+#include "a52.h"
+#include "a52_internal.h"
+
+#define CONVERT(acmod,output) (((output) << 3) + (acmod))
+
+int a52_downmix_init (int input, int flags, level_t * level,
+                      level_t clev, level_t slev)
+{
+    static uint8_t table[11][8] = {
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_STEREO,
+         A52_STEREO,    A52_STEREO,     A52_STEREO,     A52_STEREO},
+        {A52_MONO,      A52_MONO,       A52_MONO,       A52_MONO,
+         A52_MONO,      A52_MONO,       A52_MONO,       A52_MONO},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_STEREO,
+         A52_STEREO,    A52_STEREO,     A52_STEREO,     A52_STEREO},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_3F,
+         A52_STEREO,    A52_3F,         A52_STEREO,     A52_3F},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_STEREO,
+         A52_2F1R,      A52_2F1R,       A52_2F1R,       A52_2F1R},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_STEREO,
+         A52_2F1R,      A52_3F1R,       A52_2F1R,       A52_3F1R},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_3F,
+         A52_2F2R,      A52_2F2R,       A52_2F2R,       A52_2F2R},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_3F,
+         A52_2F2R,      A52_3F2R,       A52_2F2R,       A52_3F2R},
+        {A52_CHANNEL1,  A52_MONO,       A52_MONO,       A52_MONO,
+         A52_MONO,      A52_MONO,       A52_MONO,       A52_MONO},
+        {A52_CHANNEL2,  A52_MONO,       A52_MONO,       A52_MONO,
+         A52_MONO,      A52_MONO,       A52_MONO,       A52_MONO},
+        {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_DOLBY,
+         A52_DOLBY,     A52_DOLBY,      A52_DOLBY,      A52_DOLBY}
+    };
+    int output;
+
+    output = flags & A52_CHANNEL_MASK;
+    if (output > A52_DOLBY)
+        return -1;
+
+    output = table[output][input & 7];
+
+    if (output == A52_STEREO &&
+        (input == A52_DOLBY || (input == A52_3F && clev == LEVEL (LEVEL_3DB))))
+        output = A52_DOLBY;
+
+    if (flags & A52_ADJUST_LEVEL) {
+        level_t adjust;
+
+        switch (CONVERT (input & 7, output)) {
+
+        case CONVERT (A52_3F, A52_MONO):
+            adjust = DIV (LEVEL_3DB, LEVEL (1) + clev);
+            break;
+
+        case CONVERT (A52_STEREO, A52_MONO):
+        case CONVERT (A52_2F2R, A52_2F1R):
+        case CONVERT (A52_3F2R, A52_3F1R):
+        level_3db:
+            adjust = LEVEL (LEVEL_3DB);
+            break;
+
+        case CONVERT (A52_3F2R, A52_2F1R):
+            if (clev < LEVEL (LEVEL_PLUS3DB - 1))
+                goto level_3db;
+            /* break thru */
+        case CONVERT (A52_3F, A52_STEREO):
+        case CONVERT (A52_3F1R, A52_2F1R):
+        case CONVERT (A52_3F1R, A52_2F2R):
+        case CONVERT (A52_3F2R, A52_2F2R):
+            adjust = DIV (1, LEVEL (1) + clev);
+            break;
+
+        case CONVERT (A52_2F1R, A52_MONO):
+            adjust = DIV (LEVEL_PLUS3DB, LEVEL (2) + slev);
+            break;
+
+        case CONVERT (A52_2F1R, A52_STEREO):
+        case CONVERT (A52_3F1R, A52_3F):
+            adjust = DIV (1, LEVEL (1) + MUL_C (slev, LEVEL_3DB));
+            break;
+
+        case CONVERT (A52_3F1R, A52_MONO):
+            adjust = DIV (LEVEL_3DB, LEVEL (1) + clev + MUL_C (slev, 0.5));
+            break;
+
+        case CONVERT (A52_3F1R, A52_STEREO):
+            adjust = DIV (1, LEVEL (1) + clev + MUL_C (slev, LEVEL_3DB));
+            break;
+
+        case CONVERT (A52_2F2R, A52_MONO):
+            adjust = DIV (LEVEL_3DB, LEVEL (1) + slev);
+            break;
+
+        case CONVERT (A52_2F2R, A52_STEREO):
+        case CONVERT (A52_3F2R, A52_3F):
+            adjust = DIV (1, LEVEL (1) + slev);
+            break;
+
+        case CONVERT (A52_3F2R, A52_MONO):
+            adjust = DIV (LEVEL_3DB, LEVEL (1) + clev + slev);
+            break;
+
+        case CONVERT (A52_3F2R, A52_STEREO):
+            adjust = DIV (1, LEVEL (1) + clev + slev);
+            break;
+
+        case CONVERT (A52_MONO, A52_DOLBY):
+            adjust = LEVEL (LEVEL_PLUS3DB);
+            break;
+
+        case CONVERT (A52_3F, A52_DOLBY):
+        case CONVERT (A52_2F1R, A52_DOLBY):
+            adjust = LEVEL (1 / (1 + LEVEL_3DB));
+            break;
+
+        case CONVERT (A52_3F1R, A52_DOLBY):
+        case CONVERT (A52_2F2R, A52_DOLBY):
+            adjust = LEVEL (1 / (1 + 2 * LEVEL_3DB));
+            break;
+
+        case CONVERT (A52_3F2R, A52_DOLBY):
+            adjust = LEVEL (1 / (1 + 3 * LEVEL_3DB));
+            break;
+
+        default:
+            return output;
+        }
+
+        *level = MUL_L (*level, adjust);
+    }
+
+    return output;
+}
+
+int a52_downmix_coeff (level_t * coeff, int acmod, int output, level_t level,
+                       level_t clev, level_t slev)
+{
+    level_t level_3db;
+
+    level_3db = MUL_C (level, LEVEL_3DB);
+
+    switch (CONVERT (acmod, output & A52_CHANNEL_MASK)) {
+
+    case CONVERT (A52_CHANNEL, A52_CHANNEL):
+    case CONVERT (A52_MONO, A52_MONO):
+    case CONVERT (A52_STEREO, A52_STEREO):
+    case CONVERT (A52_3F, A52_3F):
+    case CONVERT (A52_2F1R, A52_2F1R):
+    case CONVERT (A52_3F1R, A52_3F1R):
+    case CONVERT (A52_2F2R, A52_2F2R):
+    case CONVERT (A52_3F2R, A52_3F2R):
+    case CONVERT (A52_STEREO, A52_DOLBY):
+        coeff[0] = coeff[1] = coeff[2] = coeff[3] = coeff[4] = level;
+        return 0;
+
+    case CONVERT (A52_CHANNEL, A52_MONO):
+        coeff[0] = coeff[1] = MUL_C (level, LEVEL_6DB);
+        return 3;
+
+    case CONVERT (A52_STEREO, A52_MONO):
+        coeff[0] = coeff[1] = level_3db;
+        return 3;
+
+    case CONVERT (A52_3F, A52_MONO):
+        coeff[0] = coeff[2] = level_3db;
+        coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
+        return 7;
+
+    case CONVERT (A52_2F1R, A52_MONO):
+        coeff[0] = coeff[1] = level_3db;
+        coeff[2] = MUL_L (level_3db, slev);
+        return 7;
+
+    case CONVERT (A52_2F2R, A52_MONO):
+        coeff[0] = coeff[1] = level_3db;
+        coeff[2] = coeff[3] = MUL_L (level_3db, slev);
+        return 15;
+
+    case CONVERT (A52_3F1R, A52_MONO):
+        coeff[0] = coeff[2] = level_3db;
+        coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
+        coeff[3] = MUL_L (level_3db, slev);
+        return 15;
+
+    case CONVERT (A52_3F2R, A52_MONO):
+        coeff[0] = coeff[2] = level_3db;
+        coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
+        coeff[3] = coeff[4] = MUL_L (level_3db, slev);
+        return 31;
+
+    case CONVERT (A52_MONO, A52_DOLBY):
+        coeff[0] = level_3db;
+        return 0;
+
+    case CONVERT (A52_3F, A52_DOLBY):
+        coeff[0] = coeff[2] = coeff[3] = coeff[4] = level;
+        coeff[1] = level_3db;
+        return 7;
+
+    case CONVERT (A52_3F, A52_STEREO):
+    case CONVERT (A52_3F1R, A52_2F1R):
+    case CONVERT (A52_3F2R, A52_2F2R):
+        coeff[0] = coeff[2] = coeff[3] = coeff[4] = level;
+        coeff[1] = MUL_L (level, clev);
+        return 7;
+
+    case CONVERT (A52_2F1R, A52_DOLBY):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = level_3db;
+        return 7;
+
+    case CONVERT (A52_2F1R, A52_STEREO):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = MUL_L (level_3db, slev);
+        return 7;
+
+    case CONVERT (A52_3F1R, A52_DOLBY):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = coeff[3] = level_3db;
+        return 15;
+
+    case CONVERT (A52_3F1R, A52_STEREO):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = MUL_L (level, clev);
+        coeff[3] = MUL_L (level_3db, slev);
+        return 15;
+
+    case CONVERT (A52_2F2R, A52_DOLBY):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = coeff[3] = level_3db;
+        return 15;
+
+    case CONVERT (A52_2F2R, A52_STEREO):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = coeff[3] = MUL_L (level, slev);
+        return 15;
+
+    case CONVERT (A52_3F2R, A52_DOLBY):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = coeff[3] = coeff[4] = level_3db;
+        return 31;
+
+    case CONVERT (A52_3F2R, A52_2F1R):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = MUL_L (level, clev);
+        coeff[3] = coeff[4] = level_3db;
+        return 31;
+
+    case CONVERT (A52_3F2R, A52_STEREO):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = MUL_L (level, clev);
+        coeff[3] = coeff[4] = MUL_L (level, slev);
+        return 31;
+
+    case CONVERT (A52_3F1R, A52_3F):
+        coeff[0] = coeff[1] = coeff[2] = level;
+        coeff[3] = MUL_L (level_3db, slev);
+        return 13;
+
+    case CONVERT (A52_3F2R, A52_3F):
+        coeff[0] = coeff[1] = coeff[2] = level;
+        coeff[3] = coeff[4] = MUL_L (level, slev);
+        return 29;
+
+    case CONVERT (A52_2F2R, A52_2F1R):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = coeff[3] = level_3db;
+        return 12;
+
+    case CONVERT (A52_3F2R, A52_3F1R):
+        coeff[0] = coeff[1] = coeff[2] = level;
+        coeff[3] = coeff[4] = level_3db;
+        return 24;
+
+    case CONVERT (A52_2F1R, A52_2F2R):
+        coeff[0] = coeff[1] = level;
+        coeff[2] = level_3db;
+        return 0;
+
+    case CONVERT (A52_3F1R, A52_2F2R):
+        coeff[0] = coeff[2] = level;
+        coeff[1] = MUL_L (level, clev);
+        coeff[3] = level_3db;
+        return 7;
+
+    case CONVERT (A52_3F1R, A52_3F2R):
+        coeff[0] = coeff[1] = coeff[2] = level;
+        coeff[3] = level_3db;
+        return 0;
+
+    case CONVERT (A52_CHANNEL, A52_CHANNEL1):
+        coeff[0] = level;
+        coeff[1] = 0;
+        return 0;
+
+    case CONVERT (A52_CHANNEL, A52_CHANNEL2):
+        coeff[0] = 0;
+        coeff[1] = level;
+        return 0;
+    }
+
+    return -1;  /* NOTREACHED */
+}
+
+static void mix2to1 (sample_t * dest, sample_t * src)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        dest[i] += BIAS (src[i]);
+}
+
+static void mix3to1 (sample_t * samples)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        samples[i] += BIAS (samples[i + 256] + samples[i + 512]);
+}
+
+static void mix4to1 (sample_t * samples)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        samples[i] += BIAS (samples[i + 256] + samples[i + 512] +
+                            samples[i + 768]);
+}
+
+static void mix5to1 (sample_t * samples)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        samples[i] += BIAS (samples[i + 256] + samples[i + 512] +
+                            samples[i + 768] + samples[i + 1024]);
+}
+
+static void mix3to2 (sample_t * samples)
+{
+    int i;
+    sample_t common;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (samples[i + 256]);
+        samples[i] += common;
+        samples[i + 256] = samples[i + 512] + common;
+    }
+}
+
+static void mix21to2 (sample_t * left, sample_t * right)
+{
+    int i;
+    sample_t common;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (right[i + 256]);
+        left[i] += common;
+        right[i] += common;
+    }
+}
+
+static void mix21toS (sample_t * samples)
+{
+    int i;
+    sample_t surround;
+
+    for (i = 0; i < 256; i++) {
+        surround = samples[i + 512];
+        samples[i] += BIAS (-surround);
+        samples[i + 256] += BIAS (surround);
+    }
+}
+
+static void mix31to2 (sample_t * samples)
+{
+    int i;
+    sample_t common;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (samples[i + 256] + samples[i + 768]);
+        samples[i] += common;
+        samples[i + 256] = samples[i + 512] + common;
+    }
+}
+
+static void mix31toS (sample_t * samples)
+{
+    int i;
+    sample_t common, surround;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (samples[i + 256]);
+        surround = samples[i + 768];
+        samples[i] += common - surround;
+        samples[i + 256] = samples[i + 512] + common + surround;
+    }
+}
+
+static void mix22toS (sample_t * samples)
+{
+    int i;
+    sample_t surround;
+
+    for (i = 0; i < 256; i++) {
+        surround = samples[i + 512] + samples[i + 768];
+        samples[i] += BIAS (-surround);
+        samples[i + 256] += BIAS (surround);
+    }
+}
+
+static void mix32to2 (sample_t * samples)
+{
+    int i;
+    sample_t common;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (samples[i + 256]);
+        samples[i] += common + samples[i + 768];
+        samples[i + 256] = common + samples[i + 512] + samples[i + 1024];
+    }
+}
+
+static void mix32toS (sample_t * samples)
+{
+    int i;
+    sample_t common, surround;
+
+    for (i = 0; i < 256; i++) {
+        common = BIAS (samples[i + 256]);
+        surround = samples[i + 768] + samples[i + 1024];
+        samples[i] += common - surround;
+        samples[i + 256] = samples[i + 512] + common + surround;
+    }
+}
+
+static void move2to1 (sample_t * src, sample_t * dest)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        dest[i] = BIAS (src[i] + src[i + 256]);
+}
+
+static void zero (sample_t * samples)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+        samples[i] = 0;
+}
+
+void a52_downmix (sample_t * samples, int acmod, int output,
+                  level_t clev, level_t slev)
+{
+    /* avoid compiler warning */
+    (void)clev;
+
+    switch (CONVERT (acmod, output & A52_CHANNEL_MASK)) {
+
+    case CONVERT (A52_CHANNEL, A52_CHANNEL2):
+        memcpy (samples, samples + 256, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_CHANNEL, A52_MONO):
+    case CONVERT (A52_STEREO, A52_MONO):
+    mix_2to1:
+        mix2to1 (samples, samples + 256);
+        break;
+
+    case CONVERT (A52_2F1R, A52_MONO):
+        if (slev == 0)
+            goto mix_2to1;
+    case CONVERT (A52_3F, A52_MONO):
+    mix_3to1:
+        mix3to1 (samples);
+        break;
+
+    case CONVERT (A52_3F1R, A52_MONO):
+        if (slev == 0)
+            goto mix_3to1;
+    case CONVERT (A52_2F2R, A52_MONO):
+        if (slev == 0)
+            goto mix_2to1;
+        mix4to1 (samples);
+        break;
+
+    case CONVERT (A52_3F2R, A52_MONO):
+        if (slev == 0)
+            goto mix_3to1;
+        mix5to1 (samples);
+        break;
+
+    case CONVERT (A52_MONO, A52_DOLBY):
+        memcpy (samples + 256, samples, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_3F, A52_STEREO):
+    case CONVERT (A52_3F, A52_DOLBY):
+    mix_3to2:
+        mix3to2 (samples);
+        break;
+
+    case CONVERT (A52_2F1R, A52_STEREO):
+        if (slev == 0)
+            break;
+        mix21to2 (samples, samples + 256);
+        break;
+
+    case CONVERT (A52_2F1R, A52_DOLBY):
+        mix21toS (samples);
+        break;
+
+    case CONVERT (A52_3F1R, A52_STEREO):
+        if (slev == 0)
+            goto mix_3to2;
+        mix31to2 (samples);
+        break;
+
+    case CONVERT (A52_3F1R, A52_DOLBY):
+        mix31toS (samples);
+        break;
+
+    case CONVERT (A52_2F2R, A52_STEREO):
+        if (slev == 0)
+            break;
+        mix2to1 (samples, samples + 512);
+        mix2to1 (samples + 256, samples + 768);
+        break;
+
+    case CONVERT (A52_2F2R, A52_DOLBY):
+        mix22toS (samples);
+        break;
+
+    case CONVERT (A52_3F2R, A52_STEREO):
+        if (slev == 0)
+            goto mix_3to2;
+        mix32to2 (samples);
+        break;
+
+    case CONVERT (A52_3F2R, A52_DOLBY):
+        mix32toS (samples);
+        break;
+
+    case CONVERT (A52_3F1R, A52_3F):
+        if (slev == 0)
+            break;
+        mix21to2 (samples, samples + 512);
+        break;
+
+    case CONVERT (A52_3F2R, A52_3F):
+        if (slev == 0)
+            break;
+        mix2to1 (samples, samples + 768);
+        mix2to1 (samples + 512, samples + 1024);
+        break;
+
+    case CONVERT (A52_3F1R, A52_2F1R):
+        mix3to2 (samples);
+        memcpy (samples + 512, samples + 768, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_2F2R, A52_2F1R):
+        mix2to1 (samples + 512, samples + 768);
+        break;
+
+    case CONVERT (A52_3F2R, A52_2F1R):
+        mix3to2 (samples);
+        move2to1 (samples + 768, samples + 512);
+        break;
+
+    case CONVERT (A52_3F2R, A52_3F1R):
+        mix2to1 (samples + 768, samples + 1024);
+        break;
+
+    case CONVERT (A52_2F1R, A52_2F2R):
+        memcpy (samples + 768, samples + 512, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_3F1R, A52_2F2R):
+        mix3to2 (samples);
+        memcpy (samples + 512, samples + 768, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_3F2R, A52_2F2R):
+        mix3to2 (samples);
+        memcpy (samples + 512, samples + 768, 256 * sizeof (sample_t));
+        memcpy (samples + 768, samples + 1024, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_3F1R, A52_3F2R):
+        memcpy (samples + 1024, samples + 768, 256 * sizeof (sample_t));
+        break;
+    }
+}
+
+void a52_upmix (sample_t * samples, int acmod, int output)
+{
+    switch (CONVERT (acmod, output & A52_CHANNEL_MASK)) {
+
+    case CONVERT (A52_CHANNEL, A52_CHANNEL2):
+        memcpy (samples + 256, samples, 256 * sizeof (sample_t));
+        break;
+
+    case CONVERT (A52_3F2R, A52_MONO):
+        zero (samples + 1024);
+    case CONVERT (A52_3F1R, A52_MONO):
+    case CONVERT (A52_2F2R, A52_MONO):
+        zero (samples + 768);
+    case CONVERT (A52_3F, A52_MONO):
+    case CONVERT (A52_2F1R, A52_MONO):
+        zero (samples + 512);
+    case CONVERT (A52_CHANNEL, A52_MONO):
+    case CONVERT (A52_STEREO, A52_MONO):
+        zero (samples + 256);
+        break;
+
+    case CONVERT (A52_3F2R, A52_STEREO):
+    case CONVERT (A52_3F2R, A52_DOLBY):
+        zero (samples + 1024);
+    case CONVERT (A52_3F1R, A52_STEREO):
+    case CONVERT (A52_3F1R, A52_DOLBY):
+        zero (samples + 768);
+    case CONVERT (A52_3F, A52_STEREO):
+    case CONVERT (A52_3F, A52_DOLBY):
+    mix_3to2:
+        memcpy (samples + 512, samples + 256, 256 * sizeof (sample_t));
+        zero (samples + 256);
+        break;
+
+    case CONVERT (A52_2F2R, A52_STEREO):
+    case CONVERT (A52_2F2R, A52_DOLBY):
+        zero (samples + 768);
+    case CONVERT (A52_2F1R, A52_STEREO):
+    case CONVERT (A52_2F1R, A52_DOLBY):
+        zero (samples + 512);
+        break;
+
+    case CONVERT (A52_3F2R, A52_3F):
+        zero (samples + 1024);
+    case CONVERT (A52_3F1R, A52_3F):
+    case CONVERT (A52_2F2R, A52_2F1R):
+        zero (samples + 768);
+        break;
+
+    case CONVERT (A52_3F2R, A52_3F1R):
+        zero (samples + 1024);
+        break;
+
+    case CONVERT (A52_3F2R, A52_2F1R):
+        zero (samples + 1024);
+    case CONVERT (A52_3F1R, A52_2F1R):
+    mix_31to21:
+        memcpy (samples + 768, samples + 512, 256 * sizeof (sample_t));
+        goto mix_3to2;
+
+    case CONVERT (A52_3F2R, A52_2F2R):
+        memcpy (samples + 1024, samples + 768, 256 * sizeof (sample_t));
+        goto mix_31to21;
+    }
+}