Initial revision

Originally committed as revision 5 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 533 insertions, 0 deletions

diff --git a/libavcodec/libac3/downmix.c b/libavcodec/libac3/downmix.c
new file mode 100644
index 0000000000..9e7fbfb8b6
--- /dev/null
+++ b/libavcodec/libac3/downmix.c
@@ -0,0 +1,533 @@
+/*
+ *
+ *  downmix.c
+ *    
+ *	Copyright (C) Aaron Holtzman - Sept 1999
+ *
+ *	Originally based on code by Yuqing Deng.
+ *
+ *  This file is part of ac3dec, a free Dolby AC-3 stream decoder.
+ *	
+ *  ac3dec 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, or (at your option)
+ *  any later version.
+ *   
+ *  ac3dec 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 GNU Make; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
+ *
+ *
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+#include "ac3.h"
+#include "ac3_internal.h"
+
+
+#define CONVERT(acmod,output) (((output) << 3) + (acmod))
+
+int downmix_init (int input, int flags, float * level, float clev, float slev)
+{
+    static uint8_t table[11][8] = {
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_STEREO,
+	 AC3_STEREO,   AC3_STEREO, AC3_STEREO, AC3_STEREO},
+	{AC3_MONO,     AC3_MONO,   AC3_MONO,   AC3_MONO,
+	 AC3_MONO,     AC3_MONO,   AC3_MONO,   AC3_MONO},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_STEREO,
+	 AC3_STEREO,   AC3_STEREO, AC3_STEREO, AC3_STEREO},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_3F,
+	 AC3_STEREO,   AC3_3F,     AC3_STEREO, AC3_3F},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_STEREO,
+	 AC3_2F1R,     AC3_2F1R,   AC3_2F1R,   AC3_2F1R},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_STEREO,
+	 AC3_2F1R,     AC3_3F1R,   AC3_2F1R,   AC3_3F1R},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_3F,
+	 AC3_2F2R,     AC3_2F2R,   AC3_2F2R,   AC3_2F2R},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_3F,
+	 AC3_2F2R,     AC3_3F2R,   AC3_2F2R,   AC3_3F2R},
+	{AC3_CHANNEL1, AC3_MONO,   AC3_MONO,   AC3_MONO,
+	 AC3_MONO,     AC3_MONO,   AC3_MONO,   AC3_MONO},
+	{AC3_CHANNEL2, AC3_MONO,   AC3_MONO,   AC3_MONO,
+	 AC3_MONO,     AC3_MONO,   AC3_MONO,   AC3_MONO},
+	{AC3_CHANNEL,  AC3_DOLBY,  AC3_STEREO, AC3_DOLBY,
+	 AC3_DOLBY,    AC3_DOLBY,  AC3_DOLBY,  AC3_DOLBY}
+    };
+    int output;
+
+    output = flags & AC3_CHANNEL_MASK;
+    if (output > AC3_DOLBY)
+	return -1;
+
+    output = table[output][input & 7];
+
+    if ((output == AC3_STEREO) &&
+	((input == AC3_DOLBY) || ((input == AC3_3F) && (clev == LEVEL_3DB))))
+	output = AC3_DOLBY;
+
+    if (flags & AC3_ADJUST_LEVEL)
+	switch (CONVERT (input & 7, output)) {
+
+	case CONVERT (AC3_3F, AC3_MONO):
+	    *level *= LEVEL_3DB / (1 + clev);
+	    break;
+
+	case CONVERT (AC3_STEREO, AC3_MONO):
+	case CONVERT (AC3_2F2R, AC3_2F1R):
+	case CONVERT (AC3_3F2R, AC3_3F1R):
+	level_3db:
+	    *level *= LEVEL_3DB;
+	    break;
+
+	case CONVERT (AC3_3F2R, AC3_2F1R):
+	    if (clev < LEVEL_PLUS3DB - 1)
+		goto level_3db;
+	    // break thru
+	case CONVERT (AC3_3F, AC3_STEREO):
+	case CONVERT (AC3_3F1R, AC3_2F1R):
+	case CONVERT (AC3_3F1R, AC3_2F2R):
+	case CONVERT (AC3_3F2R, AC3_2F2R):
+	    *level /= 1 + clev;
+	    break;
+
+	case CONVERT (AC3_2F1R, AC3_MONO):
+	    *level *= LEVEL_PLUS3DB / (2 + slev);
+	    break;
+
+	case CONVERT (AC3_2F1R, AC3_STEREO):
+	case CONVERT (AC3_3F1R, AC3_3F):
+	    *level /= 1 + slev * LEVEL_3DB;
+	    break;
+
+	case CONVERT (AC3_3F1R, AC3_MONO):
+	    *level *= LEVEL_3DB / (1 + clev + 0.5 * slev);
+	    break;
+
+	case CONVERT (AC3_3F1R, AC3_STEREO):
+	    *level /= 1 + clev + slev * LEVEL_3DB;
+	    break;
+
+	case CONVERT (AC3_2F2R, AC3_MONO):
+	    *level *= LEVEL_3DB / (1 + slev);
+	    break;
+
+	case CONVERT (AC3_2F2R, AC3_STEREO):
+	case CONVERT (AC3_3F2R, AC3_3F):
+	    *level /= (1 + slev);
+	    break;
+
+	case CONVERT (AC3_3F2R, AC3_MONO):
+	    *level *= LEVEL_3DB / (1 + clev + slev);
+	    break;
+
+	case CONVERT (AC3_3F2R, AC3_STEREO):
+	    *level /= 1 + clev + slev;
+	    break;
+
+	case CONVERT (AC3_MONO, AC3_DOLBY):
+	    *level *= LEVEL_PLUS3DB;
+	    break;
+
+	case CONVERT (AC3_3F, AC3_DOLBY):
+	case CONVERT (AC3_2F1R, AC3_DOLBY):
+	    *level *= 1 / (1 + LEVEL_3DB);
+	    break;
+
+	case CONVERT (AC3_3F1R, AC3_DOLBY):
+	case CONVERT (AC3_2F2R, AC3_DOLBY):
+	    *level *= 1 / (1 + 2 * LEVEL_3DB);
+	    break;
+
+	case CONVERT (AC3_3F2R, AC3_DOLBY):
+	    *level *= 1 / (1 + 3 * LEVEL_3DB);
+	    break;
+    }
+
+    return output;
+}
+
+static void mix1to1 (float * samples, float level, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = samples[i] * level + bias;
+}
+
+static void move1to1 (float * src, float * dest, float level, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	dest[i] = src[i] * level + bias;
+}
+
+static void mix2to1 (float * samples, float level, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = (samples[i] + samples[i + 256]) * level + bias;
+}
+
+static void move2to1 (float * src, float * dest, float level, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	dest[i] = (src[i] + src[i + 256]) * level + bias;
+}
+
+static void mix3to1 (float * samples, float level, float clev, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = ((samples[i] + samples[i + 512]) * level +
+		      samples[i + 256] * clev + bias);
+}
+
+static void mix21to1 (float * samples, float level, float slev, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = ((samples[i] + samples[i + 256]) * level +
+		      samples[i + 512] * slev + bias);
+}
+
+static void mix31to1 (float * samples, float level, float clev, float slev,
+		      float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = ((samples[i] + samples[i + 512]) * level +
+		      samples[i + 256] * clev + samples[i + 768] * slev +
+		      bias);
+}
+
+static void mix22to1 (float * samples, float level, float slev, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = ((samples[i] + samples[i + 256]) * level +
+		      (samples[i + 512] + samples[i + 768]) * slev + bias);
+}
+
+static void mix32to1 (float * samples, float level, float clev, float slev,
+		      float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	samples[i] = ((samples[i] + samples[i + 512]) * level +
+		      samples[i + 256] * clev +
+		      (samples[i + 768] + samples[i + 1024]) * slev + bias);
+}
+
+static void mix1to2 (float * src, float * dest, float level, float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	dest[i] = src[i] = src[i] * level + bias;
+}
+
+static void mix3to2 (float * samples, float level, float clev, float bias)
+{
+    int i;
+    float common;
+
+    for (i = 0; i < 256; i++) {
+	common = samples[i + 256] * clev + bias;
+	samples[i] = samples[i] * level + common;
+	samples[i + 256] = samples[i + 512] * level + common;
+    }
+}
+
+static void mix21to2 (float * left, float * right, float level, float slev,
+		      float bias)
+{
+    int i;
+    float common;
+
+    for (i = 0; i < 256; i++) {
+	common = right[i + 256] * slev + bias;
+	left[i] = left[i] * level + common;
+	right[i] = right[i] * level + common;
+    }
+}
+
+static void mix11to1 (float * front, float * rear, float level, float slev,
+		      float bias)
+{
+    int i;
+
+    for (i = 0; i < 256; i++)
+	front[i] = front[i] * level + rear[i] * slev + bias;
+}
+
+static void mix31to2 (float * samples, float level, float clev, float slev,
+		      float bias)
+{
+    int i;
+    float common;
+
+    for (i = 0; i < 256; i++) {
+	common = samples[i + 256] * clev + samples[i + 768] * slev + bias;
+	samples[i] = samples[i] * level + common;
+	samples[i + 256] = samples[i + 512] * level + common;
+    }
+}
+
+static void mix32to2 (float * samples, float level, float clev, float slev,
+		      float bias)
+{
+    int i;
+    float common;
+
+    for (i = 0; i < 256; i++) {
+	common = samples[i + 256] * clev + bias;
+	samples[i] = samples[i] * level + common + samples[i + 768] * slev;
+	samples[i + 256] = (samples[i + 512] * level + common +
+			    samples[i + 1024] * slev);
+    }
+}
+
+static void mix21toS (float * samples, float level, float level3db, float bias)
+{
+    int i;
+    float surround;
+
+    for (i = 0; i < 256; i++) {
+	surround = samples[i + 512] * level3db;
+	samples[i] = samples[i] * level - surround + bias;
+	samples[i + 256] = samples[i + 256] * level + surround + bias;
+    }
+}
+
+static void mix22toS (float * samples, float level, float level3db, float bias)
+{
+    int i;
+    float surround;
+
+    for (i = 0; i < 256; i++) {
+	surround = (samples[i + 512] + samples[i + 768]) * level3db;
+	samples[i] = samples[i] * level - surround + bias;
+	samples[i + 256] = samples[i + 256] * level + surround + bias;
+    }
+}
+
+static void mix31toS (float * samples, float level, float level3db, float bias)
+{
+    int i;
+    float common, surround;
+
+    for (i = 0; i < 256; i++) {
+	common = samples[i + 256] * level3db + bias;
+	surround = samples[i + 768] * level3db;
+	samples[i] = samples[i] * level + common - surround;
+	samples[i + 256] = samples[i + 512] * level + common + surround;
+    }
+}
+
+static void mix32toS (float * samples, float level, float level3db, float bias)
+{
+    int i;
+    float common, surround;
+
+    for (i = 0; i < 256; i++) {
+	common = samples[i + 256] * level3db + bias;
+	surround = (samples[i + 768] + samples[i + 1024]) * level3db;
+	samples[i] = samples[i] * level + common - surround;
+	samples[i + 256] = samples[i + 512] * level + common + surround;
+    }
+}
+
+void downmix (float * samples, int acmod, int output, float level, float bias,
+	      float clev, float slev)
+{
+    switch (CONVERT (acmod, output & AC3_CHANNEL_MASK)) {
+
+    case CONVERT (AC3_3F2R, AC3_3F2R):
+	mix1to1 (samples + 1024, level, bias);
+    case CONVERT (AC3_3F1R, AC3_3F1R):
+    case CONVERT (AC3_2F2R, AC3_2F2R):
+	mix1to1 (samples + 768, level, bias);
+    case CONVERT (AC3_3F, AC3_3F):
+    case CONVERT (AC3_2F1R, AC3_2F1R):
+    mix_3to3:
+	mix1to1 (samples + 512, level, bias);
+    case CONVERT (AC3_CHANNEL, AC3_CHANNEL):
+    case CONVERT (AC3_STEREO, AC3_STEREO):
+    case CONVERT (AC3_STEREO, AC3_DOLBY):
+    mix_2to2:
+	mix1to1 (samples + 256, level, bias);
+    case CONVERT (AC3_CHANNEL, AC3_CHANNEL1):
+    case CONVERT (AC3_MONO, AC3_MONO):
+	mix1to1 (samples, level, bias);
+	break;
+
+    case CONVERT (AC3_CHANNEL, AC3_CHANNEL2):
+    mix_1to1_b:
+	mix1to1 (samples + 256, level, bias);
+	break;
+
+    case CONVERT (AC3_STEREO, AC3_MONO):
+    mix_2to1:
+	mix2to1 (samples, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_2F1R, AC3_MONO):
+	if (slev == 0)
+	    goto mix_2to1;
+	mix21to1 (samples, level * LEVEL_3DB, level * slev * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_2F2R, AC3_MONO):
+	if (slev == 0)
+	    goto mix_2to1;
+	mix22to1 (samples, level * LEVEL_3DB, level * slev * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F, AC3_MONO):
+    mix_3to1:
+	mix3to1 (samples, level * LEVEL_3DB, level * clev * LEVEL_PLUS3DB,
+		 bias);
+	break;
+
+    case CONVERT (AC3_3F1R, AC3_MONO):
+	if (slev == 0)
+	    goto mix_3to1;
+	mix31to1 (samples, level * LEVEL_3DB, level * clev * LEVEL_PLUS3DB,
+		  level * slev * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F2R, AC3_MONO):
+	if (slev == 0)
+	    goto mix_3to1;
+	mix32to1 (samples, level * LEVEL_3DB, level * clev * LEVEL_PLUS3DB,
+		  level * slev * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_CHANNEL, AC3_MONO):
+	mix2to1 (samples, level * LEVEL_6DB, bias);
+	break;
+
+    case CONVERT (AC3_MONO, AC3_DOLBY):
+	mix1to2 (samples, samples + 256, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F, AC3_DOLBY):
+	clev = LEVEL_3DB;
+    case CONVERT (AC3_3F, AC3_STEREO):
+    mix_3to2:
+	mix3to2 (samples, level, level * clev, bias);
+	break;
+
+    case CONVERT (AC3_2F1R, AC3_DOLBY):
+	mix21toS (samples, level, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F1R, AC3_DOLBY):
+	mix31toS (samples, level, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_2F2R, AC3_DOLBY):
+	mix22toS (samples, level, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F2R, AC3_DOLBY):
+	mix32toS (samples, level, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_2F1R, AC3_STEREO):
+	if (slev == 0)
+	    goto mix_2to2;
+	mix21to2 (samples, samples + 256, level, level * slev * LEVEL_3DB,
+		  bias);
+	break;
+
+    case CONVERT (AC3_3F1R, AC3_STEREO):
+	if (slev == 0)
+	    goto mix_3to2;
+	mix31to2 (samples, level, level * clev, level * slev * LEVEL_3DB,
+		  bias);
+	break;
+
+    case CONVERT (AC3_2F2R, AC3_STEREO):
+	if (slev == 0)
+	    goto mix_2to2;
+	mix11to1 (samples, samples + 512, level, level * slev, bias);
+	mix11to1 (samples + 256, samples + 768, level, level * slev, bias);
+	break;
+
+    case CONVERT (AC3_3F2R, AC3_STEREO):
+	if (slev == 0)
+	    goto mix_3to2;
+	mix32to2 (samples, level, level * clev, level * slev, bias);
+	break;
+
+    case CONVERT (AC3_3F1R, AC3_3F):
+	if (slev == 0)
+	    goto mix_3to3;
+	mix21to2 (samples, samples + 512, level, level * slev * LEVEL_3DB,
+		  bias);
+
+    case CONVERT (AC3_3F2R, AC3_3F):
+	if (slev == 0)
+	    goto mix_3to3;
+	mix11to1 (samples, samples + 768, level, level * slev, bias);
+	mix11to1 (samples + 512, samples + 1024, level, level * slev, bias);
+	goto mix_1to1_b;
+
+    case CONVERT (AC3_2F1R, AC3_2F2R):
+	mix1to2 (samples + 512, samples + 768, level * LEVEL_3DB, bias);
+	goto mix_2to2;
+
+    case CONVERT (AC3_3F1R, AC3_3F2R):
+	mix1to2 (samples + 768, samples + 1024, level * LEVEL_3DB, bias);
+	goto mix_3to3;
+
+    case CONVERT (AC3_2F2R, AC3_2F1R):
+	mix2to1 (samples + 512, level * LEVEL_3DB, bias);
+	goto mix_2to2;
+
+    case CONVERT (AC3_3F2R, AC3_3F1R):
+	mix2to1 (samples + 768, level * LEVEL_3DB, bias);
+	goto mix_3to3;
+
+    case CONVERT (AC3_3F1R, AC3_2F2R):
+	mix3to2 (samples, level, level * clev, bias);
+	mix1to2 (samples + 768, samples + 512, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F1R, AC3_2F1R):
+	mix3to2 (samples, level, level * clev, bias);
+	move1to1 (samples + 768, samples + 512, level, bias);
+	break;
+
+    case CONVERT (AC3_3F2R, AC3_2F1R):
+	mix3to2 (samples, level, level * clev, bias);
+	move2to1 (samples + 768, samples + 512, level * LEVEL_3DB, bias);
+	break;
+
+    case CONVERT (AC3_3F2R, AC3_2F2R):
+	mix3to2 (samples, level, level * clev, bias);
+	move1to1 (samples + 768, samples + 512, level, bias);
+	move1to1 (samples + 1024, samples + 768, level, bias);
+	break;
+
+    }
+}