Initial revision

CVS patchset: 1
CVS date: 2001/04/18 22:33:39

1 files changed, 1799 insertions, 0 deletions

diff --git a/src/libmpeg2/slice.c b/src/libmpeg2/slice.c
new file mode 100644
index 000000000..727adb3d9
--- /dev/null
+++ b/src/libmpeg2/slice.c
@@ -0,0 +1,1799 @@
+/*
+ * slice.c
+ * Copyright (C) 1999-2001 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
+ *
+ * mpeg2dec 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.
+ *
+ * mpeg2dec 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.h"
+
+#include <string.h>
+#include <inttypes.h>
+
+#include "video_out.h"
+#include "mpeg2_internal.h"
+#include "attributes.h"
+
+extern mc_functions_t mc_functions;
+extern void (* idct_block_copy) (int16_t * block, uint8_t * dest, int stride);
+extern void (* idct_block_add) (int16_t * block, uint8_t * dest, int stride);
+
+#include "vlc.h"
+
+static int non_linear_quantizer_scale [] = {
+     0,  1,  2,  3,  4,  5,   6,   7,
+     8, 10, 12, 14, 16, 18,  20,  22,
+    24, 28, 32, 36, 40, 44,  48,  52,
+    56, 64, 72, 80, 88, 96, 104, 112
+};
+
+static inline int get_macroblock_modes (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int macroblock_modes;
+    MBtab * tab;
+
+    switch (picture->picture_coding_type) {
+    case I_TYPE:
+
+	tab = MB_I + UBITS (bit_buf, 1);
+	DUMPBITS (bit_buf, bits, tab->len);
+	macroblock_modes = tab->modes;
+
+	if ((! (picture->frame_pred_frame_dct)) &&
+	    (picture->picture_structure == FRAME_PICTURE)) {
+	    macroblock_modes |= UBITS (bit_buf, 1) * DCT_TYPE_INTERLACED;
+	    DUMPBITS (bit_buf, bits, 1);
+	}
+
+	return macroblock_modes;
+
+    case P_TYPE:
+
+	tab = MB_P + UBITS (bit_buf, 5);
+	DUMPBITS (bit_buf, bits, tab->len);
+	macroblock_modes = tab->modes;
+
+	if (picture->picture_structure != FRAME_PICTURE) {
+	    if (macroblock_modes & MACROBLOCK_MOTION_FORWARD) {
+		macroblock_modes |= UBITS (bit_buf, 2) * MOTION_TYPE_BASE;
+		DUMPBITS (bit_buf, bits, 2);
+	    }
+	    return macroblock_modes;
+	} else if (picture->frame_pred_frame_dct) {
+	    if (macroblock_modes & MACROBLOCK_MOTION_FORWARD)
+		macroblock_modes |= MC_FRAME;
+	    return macroblock_modes;
+	} else {
+	    if (macroblock_modes & MACROBLOCK_MOTION_FORWARD) {
+		macroblock_modes |= UBITS (bit_buf, 2) * MOTION_TYPE_BASE;
+		DUMPBITS (bit_buf, bits, 2);
+	    }
+	    if (macroblock_modes & (MACROBLOCK_INTRA | MACROBLOCK_PATTERN)) {
+		macroblock_modes |= UBITS (bit_buf, 1) * DCT_TYPE_INTERLACED;
+		DUMPBITS (bit_buf, bits, 1);
+	    }
+	    return macroblock_modes;
+	}
+
+    case B_TYPE:
+
+	tab = MB_B + UBITS (bit_buf, 6);
+	DUMPBITS (bit_buf, bits, tab->len);
+	macroblock_modes = tab->modes;
+
+	if (picture->picture_structure != FRAME_PICTURE) {
+	    if (! (macroblock_modes & MACROBLOCK_INTRA)) {
+		macroblock_modes |= UBITS (bit_buf, 2) * MOTION_TYPE_BASE;
+		DUMPBITS (bit_buf, bits, 2);
+	    }
+	    return macroblock_modes;
+	} else if (picture->frame_pred_frame_dct) {
+	    /* if (! (macroblock_modes & MACROBLOCK_INTRA)) */
+	    macroblock_modes |= MC_FRAME;
+	    return macroblock_modes;
+	} else {
+	    if (macroblock_modes & MACROBLOCK_INTRA)
+		goto intra;
+	    macroblock_modes |= UBITS (bit_buf, 2) * MOTION_TYPE_BASE;
+	    DUMPBITS (bit_buf, bits, 2);
+	    if (macroblock_modes & (MACROBLOCK_INTRA | MACROBLOCK_PATTERN)) {
+	    intra:
+		macroblock_modes |= UBITS (bit_buf, 1) * DCT_TYPE_INTERLACED;
+		DUMPBITS (bit_buf, bits, 1);
+	    }
+	    return macroblock_modes;
+	}
+
+    case D_TYPE:
+
+	DUMPBITS (bit_buf, bits, 1);
+	return MACROBLOCK_INTRA;
+
+    default:
+	return 0;
+    }
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int get_quantizer_scale (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+
+    int quantizer_scale_code;
+
+    quantizer_scale_code = UBITS (bit_buf, 5);
+    DUMPBITS (bit_buf, bits, 5);
+
+    if (picture->q_scale_type)
+	return non_linear_quantizer_scale [quantizer_scale_code];
+    else
+	return quantizer_scale_code << 1;
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int get_motion_delta (picture_t * picture, int f_code)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+
+    int delta;
+    int sign;
+    MVtab * tab;
+
+    if (bit_buf & 0x80000000) {
+	DUMPBITS (bit_buf, bits, 1);
+	return 0;
+    } else if (bit_buf >= 0x0c000000) {
+
+	tab = MV_4 + UBITS (bit_buf, 4);
+	delta = (tab->delta << f_code) + 1;
+	bits += tab->len + f_code + 1;
+	bit_buf <<= tab->len;
+
+	sign = SBITS (bit_buf, 1);
+	bit_buf <<= 1;
+
+	if (f_code)
+	    delta += UBITS (bit_buf, f_code);
+	bit_buf <<= f_code;
+
+	return (delta ^ sign) - sign;
+
+    } else {
+
+	tab = MV_10 + UBITS (bit_buf, 10);
+	delta = (tab->delta << f_code) + 1;
+	bits += tab->len + 1;
+	bit_buf <<= tab->len;
+
+	sign = SBITS (bit_buf, 1);
+	bit_buf <<= 1;
+
+	if (f_code) {
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    delta += UBITS (bit_buf, f_code);
+	    DUMPBITS (bit_buf, bits, f_code);
+	}
+
+	return (delta ^ sign) - sign;
+
+    }
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int bound_motion_vector (int vector, int f_code)
+{
+#if 1
+    int limit;
+
+    limit = 16 << f_code;
+
+    if (vector >= limit)
+	return vector - 2*limit;
+    else if (vector < -limit)
+	return vector + 2*limit;
+    else return vector;
+#else
+    return (vector << (27 - f_code)) >> (27 - f_code);
+#endif
+}
+
+static inline int get_dmv (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+
+    DMVtab * tab;
+
+    tab = DMV_2 + UBITS (bit_buf, 2);
+    DUMPBITS (bit_buf, bits, tab->len);
+    return tab->dmv;
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int get_coded_block_pattern (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+
+    CBPtab * tab;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+
+    if (bit_buf >= 0x20000000) {
+
+	tab = CBP_7 - 16 + UBITS (bit_buf, 7);
+	DUMPBITS (bit_buf, bits, tab->len);
+	return tab->cbp;
+
+    } else {
+
+	tab = CBP_9 + UBITS (bit_buf, 9);
+	DUMPBITS (bit_buf, bits, tab->len);
+	return tab->cbp;
+    }
+
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int get_luma_dc_dct_diff (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    DCtab * tab;
+    int size;
+    int dc_diff;
+
+    if (bit_buf < 0xf8000000) {
+	tab = DC_lum_5 + UBITS (bit_buf, 5);
+	size = tab->size;
+	if (size) {
+	    bits += tab->len + size;
+	    bit_buf <<= tab->len;
+	    dc_diff =
+		UBITS (bit_buf, size) - UBITS (SBITS (~bit_buf, 1), size);
+	    bit_buf <<= size;
+	    return dc_diff;
+	} else {
+	    DUMPBITS (bit_buf, bits, 3);
+	    return 0;
+	}
+    } else {
+	tab = DC_long - 0x1e0 + UBITS (bit_buf, 9);
+	size = tab->size;
+	DUMPBITS (bit_buf, bits, tab->len);
+	NEEDBITS (bit_buf, bits, bit_ptr);
+	dc_diff = UBITS (bit_buf, size) - UBITS (SBITS (~bit_buf, 1), size);
+	DUMPBITS (bit_buf, bits, size);
+	return dc_diff;
+    }
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline int get_chroma_dc_dct_diff (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    DCtab * tab;
+    int size;
+    int dc_diff;
+
+    if (bit_buf < 0xf8000000) {
+	tab = DC_chrom_5 + UBITS (bit_buf, 5);
+	size = tab->size;
+	if (size) {
+	    bits += tab->len + size;
+	    bit_buf <<= tab->len;
+	    dc_diff =
+		UBITS (bit_buf, size) - UBITS (SBITS (~bit_buf, 1), size);
+	    bit_buf <<= size;
+	    return dc_diff;
+	} else {
+	    DUMPBITS (bit_buf, bits, 2);
+	    return 0;
+	}
+    } else {
+	tab = DC_long - 0x3e0 + UBITS (bit_buf, 10);
+	size = tab->size;
+	DUMPBITS (bit_buf, bits, tab->len + 1);
+	NEEDBITS (bit_buf, bits, bit_ptr);
+	dc_diff = UBITS (bit_buf, size) - UBITS (SBITS (~bit_buf, 1), size);
+	DUMPBITS (bit_buf, bits, size);
+	return dc_diff;
+    }
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+#define SATURATE(val)			\
+do {					\
+    if ((uint32_t)(val + 2048) > 4095)	\
+	val = (val > 0) ? 2047 : -2048;	\
+} while (0)
+
+static void get_intra_block_B14 (picture_t * picture)
+{
+    int i;
+    int j;
+    int val;
+    uint8_t * scan = picture->scan;
+    uint8_t * quant_matrix = picture->intra_quantizer_matrix;
+    int quantizer_scale = picture->quantizer_scale;
+    int mismatch;
+    DCTtab * tab;
+    uint32_t bit_buf;
+    int bits;
+    uint8_t * bit_ptr;
+    int16_t * dest;
+
+    dest = picture->DCTblock;
+    i = 0;
+    mismatch = ~dest[0];
+
+    bit_buf = picture->bitstream_buf;
+    bits = picture->bitstream_bits;
+    bit_ptr = picture->bitstream_ptr;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+
+    while (1) {
+	if (bit_buf >= 0x28000000) {
+
+	    tab = DCT_B14AC_5 - 5 + UBITS (bit_buf, 5);
+
+	    i += tab->run;
+	    if (i >= 64)
+		break;	/* end of block */
+
+	normal_code:
+	    j = scan[i];
+	    bit_buf <<= tab->len;
+	    bits += tab->len + 1;
+	    val = (tab->level * quantizer_scale * quant_matrix[j]) >> 4;
+
+	    /* if (bitstream_get (1)) val = -val; */
+	    val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);
+
+	    SATURATE (val);
+	    dest[j] = val;
+	    mismatch ^= val;
+
+	    bit_buf <<= 1;
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x04000000) {
+
+	    tab = DCT_B14_8 - 4 + UBITS (bit_buf, 8);
+
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+
+	    /* escape code */
+
+	    i += UBITS (bit_buf << 6, 6) - 64;
+	    if (i >= 64)
+		break;	/* illegal, check needed to avoid buffer overflow */
+
+	    j = scan[i];
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    val = (SBITS (bit_buf, 12) *
+		   quantizer_scale * quant_matrix[j]) / 16;
+
+	    SATURATE (val);
+	    dest[j] = val;
+	    mismatch ^= val;
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x02000000) {
+	    tab = DCT_B14_10 - 8 + UBITS (bit_buf, 10);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00800000) {
+	    tab = DCT_13 - 16 + UBITS (bit_buf, 13);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00200000) {
+	    tab = DCT_15 - 16 + UBITS (bit_buf, 15);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else {
+	    tab = DCT_16 + UBITS (bit_buf, 16);
+	    bit_buf <<= 16;
+	    GETWORD (bit_buf, bits + 16, bit_ptr);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	}
+	break;	/* illegal, check needed to avoid buffer overflow */
+    }
+    dest[63] ^= mismatch & 1;
+    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
+    picture->bitstream_buf = bit_buf;
+    picture->bitstream_bits = bits;
+    picture->bitstream_ptr = bit_ptr;
+}
+
+static void get_intra_block_B15 (picture_t * picture)
+{
+    int i;
+    int j;
+    int val;
+    uint8_t * scan = picture->scan;
+    uint8_t * quant_matrix = picture->intra_quantizer_matrix;
+    int quantizer_scale = picture->quantizer_scale;
+    int mismatch;
+    DCTtab * tab;
+    uint32_t bit_buf;
+    int bits;
+    uint8_t * bit_ptr;
+    int16_t * dest;
+
+    dest = picture->DCTblock;
+    i = 0;
+    mismatch = ~dest[0];
+
+    bit_buf = picture->bitstream_buf;
+    bits = picture->bitstream_bits;
+    bit_ptr = picture->bitstream_ptr;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+
+    while (1) {
+	if (bit_buf >= 0x04000000) {
+
+	    tab = DCT_B15_8 - 4 + UBITS (bit_buf, 8);
+
+	    i += tab->run;
+	    if (i < 64) {
+
+	    normal_code:
+		j = scan[i];
+		bit_buf <<= tab->len;
+		bits += tab->len + 1;
+		val = (tab->level * quantizer_scale * quant_matrix[j]) >> 4;
+
+		/* if (bitstream_get (1)) val = -val; */
+		val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);
+
+		SATURATE (val);
+		dest[j] = val;
+		mismatch ^= val;
+
+		bit_buf <<= 1;
+		NEEDBITS (bit_buf, bits, bit_ptr);
+
+		continue;
+
+	    } else {
+
+		/* end of block. I commented out this code because if we */
+		/* dont exit here we will still exit at the later test :) */
+
+		/* if (i >= 128) break;	*/	/* end of block */
+
+		/* escape code */
+
+		i += UBITS (bit_buf << 6, 6) - 64;
+		if (i >= 64)
+		    break;	/* illegal, check against buffer overflow */
+
+		j = scan[i];
+
+		DUMPBITS (bit_buf, bits, 12);
+		NEEDBITS (bit_buf, bits, bit_ptr);
+		val = (SBITS (bit_buf, 12) *
+		       quantizer_scale * quant_matrix[j]) / 16;
+
+		SATURATE (val);
+		dest[j] = val;
+		mismatch ^= val;
+
+		DUMPBITS (bit_buf, bits, 12);
+		NEEDBITS (bit_buf, bits, bit_ptr);
+
+		continue;
+
+	    }
+	} else if (bit_buf >= 0x02000000) {
+	    tab = DCT_B15_10 - 8 + UBITS (bit_buf, 10);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00800000) {
+	    tab = DCT_13 - 16 + UBITS (bit_buf, 13);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00200000) {
+	    tab = DCT_15 - 16 + UBITS (bit_buf, 15);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else {
+	    tab = DCT_16 + UBITS (bit_buf, 16);
+	    bit_buf <<= 16;
+	    GETWORD (bit_buf, bits + 16, bit_ptr);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	}
+	break;	/* illegal, check needed to avoid buffer overflow */
+    }
+    dest[63] ^= mismatch & 1;
+    DUMPBITS (bit_buf, bits, 4);	/* dump end of block code */
+    picture->bitstream_buf = bit_buf;
+    picture->bitstream_bits = bits;
+    picture->bitstream_ptr = bit_ptr;
+}
+
+static void get_non_intra_block (picture_t * picture)
+{
+    int i;
+    int j;
+    int val;
+    uint8_t * scan = picture->scan;
+    uint8_t * quant_matrix = picture->non_intra_quantizer_matrix;
+    int quantizer_scale = picture->quantizer_scale;
+    int mismatch;
+    DCTtab * tab;
+    uint32_t bit_buf;
+    int bits;
+    uint8_t * bit_ptr;
+    int16_t * dest;
+
+    i = -1;
+    mismatch = 1;
+    dest = picture->DCTblock;
+
+    bit_buf = picture->bitstream_buf;
+    bits = picture->bitstream_bits;
+    bit_ptr = picture->bitstream_ptr;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    if (bit_buf >= 0x28000000) {
+	tab = DCT_B14DC_5 - 5 + UBITS (bit_buf, 5);
+	goto entry_1;
+    } else
+	goto entry_2;
+
+    while (1) {
+	if (bit_buf >= 0x28000000) {
+
+	    tab = DCT_B14AC_5 - 5 + UBITS (bit_buf, 5);
+
+	entry_1:
+	    i += tab->run;
+	    if (i >= 64)
+		break;	/* end of block */
+
+	normal_code:
+	    j = scan[i];
+	    bit_buf <<= tab->len;
+	    bits += tab->len + 1;
+	    val = ((2*tab->level+1) * quantizer_scale * quant_matrix[j]) >> 5;
+
+	    /* if (bitstream_get (1)) val = -val; */
+	    val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);
+
+	    SATURATE (val);
+	    dest[j] = val;
+	    mismatch ^= val;
+
+	    bit_buf <<= 1;
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	}
+
+    entry_2:
+	if (bit_buf >= 0x04000000) {
+
+	    tab = DCT_B14_8 - 4 + UBITS (bit_buf, 8);
+
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+
+	    /* escape code */
+
+	    i += UBITS (bit_buf << 6, 6) - 64;
+	    if (i >= 64)
+		break;	/* illegal, check needed to avoid buffer overflow */
+
+	    j = scan[i];
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    val = 2 * (SBITS (bit_buf, 12) + SBITS (bit_buf, 1)) + 1;
+	    val = (val * quantizer_scale * quant_matrix[j]) / 32;
+
+	    SATURATE (val);
+	    dest[j] = val;
+	    mismatch ^= val;
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x02000000) {
+	    tab = DCT_B14_10 - 8 + UBITS (bit_buf, 10);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00800000) {
+	    tab = DCT_13 - 16 + UBITS (bit_buf, 13);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00200000) {
+	    tab = DCT_15 - 16 + UBITS (bit_buf, 15);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else {
+	    tab = DCT_16 + UBITS (bit_buf, 16);
+	    bit_buf <<= 16;
+	    GETWORD (bit_buf, bits + 16, bit_ptr);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	}
+	break;	/* illegal, check needed to avoid buffer overflow */
+    }
+    dest[63] ^= mismatch & 1;
+    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
+    picture->bitstream_buf = bit_buf;
+    picture->bitstream_bits = bits;
+    picture->bitstream_ptr = bit_ptr;
+}
+
+static void get_mpeg1_intra_block (picture_t * picture)
+{
+    int i;
+    int j;
+    int val;
+    uint8_t * scan = picture->scan;
+    uint8_t * quant_matrix = picture->intra_quantizer_matrix;
+    int quantizer_scale = picture->quantizer_scale;
+    DCTtab * tab;
+    uint32_t bit_buf;
+    int bits;
+    uint8_t * bit_ptr;
+    int16_t * dest;
+
+    i = 0;
+    dest = picture->DCTblock;
+
+    bit_buf = picture->bitstream_buf;
+    bits = picture->bitstream_bits;
+    bit_ptr = picture->bitstream_ptr;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+
+    while (1) {
+	if (bit_buf >= 0x28000000) {
+
+	    tab = DCT_B14AC_5 - 5 + UBITS (bit_buf, 5);
+
+	    i += tab->run;
+	    if (i >= 64)
+		break;	/* end of block */
+
+	normal_code:
+	    j = scan[i];
+	    bit_buf <<= tab->len;
+	    bits += tab->len + 1;
+	    val = (tab->level * quantizer_scale * quant_matrix[j]) >> 4;
+
+	    /* oddification */
+	    val = (val - 1) | 1;
+
+	    /* if (bitstream_get (1)) val = -val; */
+	    val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);
+
+	    SATURATE (val);
+	    dest[j] = val;
+
+	    bit_buf <<= 1;
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x04000000) {
+
+	    tab = DCT_B14_8 - 4 + UBITS (bit_buf, 8);
+
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+
+	    /* escape code */
+
+	    i += UBITS (bit_buf << 6, 6) - 64;
+	    if (i >= 64)
+		break;	/* illegal, check needed to avoid buffer overflow */
+
+	    j = scan[i];
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    val = SBITS (bit_buf, 8);
+	    if (! (val & 0x7f)) {
+		DUMPBITS (bit_buf, bits, 8);
+		val = UBITS (bit_buf, 8) + 2 * val;
+	    }
+	    val = (val * quantizer_scale * quant_matrix[j]) / 16;
+
+	    /* oddification */
+	    val = (val + ~SBITS (val, 1)) | 1;
+
+	    SATURATE (val);
+	    dest[j] = val;
+
+	    DUMPBITS (bit_buf, bits, 8);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x02000000) {
+	    tab = DCT_B14_10 - 8 + UBITS (bit_buf, 10);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00800000) {
+	    tab = DCT_13 - 16 + UBITS (bit_buf, 13);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00200000) {
+	    tab = DCT_15 - 16 + UBITS (bit_buf, 15);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else {
+	    tab = DCT_16 + UBITS (bit_buf, 16);
+	    bit_buf <<= 16;
+	    GETWORD (bit_buf, bits + 16, bit_ptr);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	}
+	break;	/* illegal, check needed to avoid buffer overflow */
+    }
+    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
+    picture->bitstream_buf = bit_buf;
+    picture->bitstream_bits = bits;
+    picture->bitstream_ptr = bit_ptr;
+}
+
+static void get_mpeg1_non_intra_block (picture_t * picture)
+{
+    int i;
+    int j;
+    int val;
+    uint8_t * scan = picture->scan;
+    uint8_t * quant_matrix = picture->non_intra_quantizer_matrix;
+    int quantizer_scale = picture->quantizer_scale;
+    DCTtab * tab;
+    uint32_t bit_buf;
+    int bits;
+    uint8_t * bit_ptr;
+    int16_t * dest;
+
+    i = -1;
+    dest = picture->DCTblock;
+
+    bit_buf = picture->bitstream_buf;
+    bits = picture->bitstream_bits;
+    bit_ptr = picture->bitstream_ptr;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    if (bit_buf >= 0x28000000) {
+	tab = DCT_B14DC_5 - 5 + UBITS (bit_buf, 5);
+	goto entry_1;
+    } else
+	goto entry_2;
+
+    while (1) {
+	if (bit_buf >= 0x28000000) {
+
+	    tab = DCT_B14AC_5 - 5 + UBITS (bit_buf, 5);
+
+	entry_1:
+	    i += tab->run;
+	    if (i >= 64)
+		break;	/* end of block */
+
+	normal_code:
+	    j = scan[i];
+	    bit_buf <<= tab->len;
+	    bits += tab->len + 1;
+	    val = ((2*tab->level+1) * quantizer_scale * quant_matrix[j]) >> 5;
+
+	    /* oddification */
+	    val = (val - 1) | 1;
+
+	    /* if (bitstream_get (1)) val = -val; */
+	    val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);
+
+	    SATURATE (val);
+	    dest[j] = val;
+
+	    bit_buf <<= 1;
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	}
+
+    entry_2:
+	if (bit_buf >= 0x04000000) {
+
+	    tab = DCT_B14_8 - 4 + UBITS (bit_buf, 8);
+
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+
+	    /* escape code */
+
+	    i += UBITS (bit_buf << 6, 6) - 64;
+	    if (i >= 64)
+		break;	/* illegal, check needed to avoid buffer overflow */
+
+	    j = scan[i];
+
+	    DUMPBITS (bit_buf, bits, 12);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    val = SBITS (bit_buf, 8);
+	    if (! (val & 0x7f)) {
+		DUMPBITS (bit_buf, bits, 8);
+		val = UBITS (bit_buf, 8) + 2 * val;
+	    }
+	    val = 2 * (val + SBITS (val, 1)) + 1;
+	    val = (val * quantizer_scale * quant_matrix[j]) / 32;
+
+	    /* oddification */
+	    val = (val + ~SBITS (val, 1)) | 1;
+
+	    SATURATE (val);
+	    dest[j] = val;
+
+	    DUMPBITS (bit_buf, bits, 8);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+
+	    continue;
+
+	} else if (bit_buf >= 0x02000000) {
+	    tab = DCT_B14_10 - 8 + UBITS (bit_buf, 10);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00800000) {
+	    tab = DCT_13 - 16 + UBITS (bit_buf, 13);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else if (bit_buf >= 0x00200000) {
+	    tab = DCT_15 - 16 + UBITS (bit_buf, 15);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	} else {
+	    tab = DCT_16 + UBITS (bit_buf, 16);
+	    bit_buf <<= 16;
+	    GETWORD (bit_buf, bits + 16, bit_ptr);
+	    i += tab->run;
+	    if (i < 64)
+		goto normal_code;
+	}
+	break;	/* illegal, check needed to avoid buffer overflow */
+    }
+    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
+    picture->bitstream_buf = bit_buf;
+    picture->bitstream_bits = bits;
+    picture->bitstream_ptr = bit_ptr;
+}
+
+static inline int get_macroblock_address_increment (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+
+    MBAtab * tab;
+    int mba;
+
+    mba = 0;
+
+    while (1) {
+	if (bit_buf >= 0x10000000) {
+	    tab = MBA_5 - 2 + UBITS (bit_buf, 5);
+	    DUMPBITS (bit_buf, bits, tab->len);
+	    return mba + tab->mba;
+	} else if (bit_buf >= 0x03000000) {
+	    tab = MBA_11 - 24 + UBITS (bit_buf, 11);
+	    DUMPBITS (bit_buf, bits, tab->len);
+	    return mba + tab->mba;
+	} else switch (UBITS (bit_buf, 11)) {
+	case 8:		/* macroblock_escape */
+	    mba += 33;
+	    /* no break here on purpose */
+	case 15:	/* macroblock_stuffing (MPEG1 only) */
+	    DUMPBITS (bit_buf, bits, 11);
+	    NEEDBITS (bit_buf, bits, bit_ptr);
+	    break;
+	default:	/* end of slice, or error */
+	    return 0;
+	}
+    }
+
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline void slice_intra_DCT (picture_t * picture, int cc,
+				    uint8_t * dest, int stride)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)  
+#define bit_ptr (picture->bitstream_ptr)
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    /* Get the intra DC coefficient and inverse quantize it */
+    if (cc == 0)
+	picture->dc_dct_pred[0] += get_luma_dc_dct_diff (picture);
+    else
+	picture->dc_dct_pred[cc] += get_chroma_dc_dct_diff (picture);
+    picture->DCTblock[0] =
+	picture->dc_dct_pred[cc] << (3 - picture->intra_dc_precision);
+    memset (picture->DCTblock + 1, 0, 63 * sizeof (int16_t));
+
+    if (picture->mpeg1) {
+	if (picture->picture_coding_type != D_TYPE)
+	    get_mpeg1_intra_block (picture);
+    } else if (picture->intra_vlc_format)
+	get_intra_block_B15 (picture);
+    else
+	get_intra_block_B14 (picture);
+    idct_block_copy (picture->DCTblock, dest, stride);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static inline void slice_non_intra_DCT (picture_t * picture, uint8_t * dest,
+					int stride)
+{
+    memset (picture->DCTblock, 0, 64 * sizeof (int16_t));
+    if (picture->mpeg1)
+	get_mpeg1_non_intra_block (picture);
+    else
+	get_non_intra_block (picture);
+    idct_block_add (picture->DCTblock, dest, stride);
+}
+
+#define MOTION_Y(table,offset_x,offset_y,motion_x,motion_y,		\
+		 dest,src,offset_dest,offset_src,stride,height)		\
+do {									\
+    int xy_half;							\
+    int total_offset;							\
+									\
+    xy_half = ((motion_y & 1) << 1) | (motion_x & 1);			\
+    total_offset = ((offset_y + (motion_y >> 1)) * stride +		\
+		    offset_x + (motion_x >> 1) + (offset_src));		\
+    table[xy_half] (dest[0] + offset_x + (offset_dest),			\
+		    src[0] + total_offset, stride, height);		\
+} while (0)
+
+#define MOTION_UV(table,offset_x,offset_y,motion_x,motion_y,		\
+		  dest,src,offset_dest,offset_src,stride,height)	\
+do {									\
+    int xy_half;							\
+    int total_offset;							\
+									\
+    xy_half = ((motion_y & 1) << 1) | (motion_x & 1);			\
+    total_offset = (((offset_y + motion_y) >> 1) * (stride) +		\
+		    ((offset_x + motion_x) >> 1) + (offset_src));	\
+    table[4+xy_half] (dest[1] + (offset_x >> 1) + (offset_dest),	\
+		      src[1] + total_offset, stride, height);		\
+    table[4+xy_half] (dest[2] + (offset_x >> 1) + (offset_dest),	\
+		      src[2] + total_offset, stride, height);		\
+} while (0)
+
+static inline void motion_block (void (** table) (uint8_t *, uint8_t *,
+						  int32_t, int32_t),
+				 int x_offset, int y_offset, int mb_y_8_offset,
+				 int src_field, int dest_field,
+				 int x_pred, int y_pred,
+				 uint8_t * dest[3], uint8_t * src[3],
+				 int stride, int height)
+{
+    MOTION_Y (table, x_offset, y_offset, x_pred, y_pred, dest, src,
+	      dest_field + mb_y_8_offset*8*stride, src_field, stride, height);
+
+    x_pred /= 2;
+    y_pred /= 2;
+    stride >>= 1;
+    height >>= 1;
+
+    MOTION_UV (table, x_offset, y_offset, x_pred, y_pred, dest, src,
+	       (dest_field >> 1) + mb_y_8_offset*4*stride, src_field >> 1,
+	       stride, height);
+}
+
+static void motion_mp1 (picture_t * picture, motion_t * motion,
+			uint8_t * dest[3], int offset, int stride,
+			void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[0][1] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[0]);
+    motion->pmv[0][1] = motion_y;
+
+    if (motion->f_code[1]) {
+	motion_x <<= 1;
+	motion_y <<= 1;
+    }
+
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y, dest, motion->ref[0], stride, 16);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_mp1_reuse (picture_t * picture, motion_t * motion,
+			      uint8_t * dest[3], int offset, int stride,
+			      void (** table) (uint8_t *, uint8_t *, int, int))
+{
+    int motion_x, motion_y;
+
+    motion_x = motion->pmv[0][0];
+    motion_y = motion->pmv[0][1];
+
+    if (motion->f_code[1]) {
+	motion_x <<= 1;
+	motion_y <<= 1;
+    }
+
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y, dest, motion->ref[0], stride, 16);
+}
+
+static void motion_fr_frame (picture_t * picture, motion_t * motion,
+			     uint8_t * dest[3], int offset, int stride,
+			     void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[0][1] + get_motion_delta (picture,
+						     motion->f_code[1]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[1]);
+    motion->pmv[1][1] = motion->pmv[0][1] = motion_y;
+
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y, dest, motion->ref[0], stride, 16);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fr_field (picture_t * picture, motion_t * motion,
+			     uint8_t * dest[3], int offset, int stride,
+			     void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+    int field_select;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    field_select = SBITS (bit_buf, 1);
+    DUMPBITS (bit_buf, bits, 1);
+
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = (motion->pmv[0][1] >> 1) + get_motion_delta (picture,
+							    motion->f_code[1]);
+    /* motion_y = bound_motion_vector (motion_y, motion->f_code[1]); */
+    motion->pmv[0][1] = motion_y << 1;
+
+    motion_block (table, offset, picture->v_offset >> 1,
+		  0, (field_select & stride), 0,
+		  motion_x, motion_y, dest, motion->ref[0], stride * 2, 8);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    field_select = SBITS (bit_buf, 1);
+    DUMPBITS (bit_buf, bits, 1);
+
+    motion_x = motion->pmv[1][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = (motion->pmv[1][1] >> 1) + get_motion_delta (picture,
+							    motion->f_code[1]);
+    /* motion_y = bound_motion_vector (motion_y, motion->f_code[1]); */
+    motion->pmv[1][1] = motion_y << 1;
+
+    motion_block (table, offset, picture->v_offset >> 1,
+		  0, (field_select & stride), stride,
+		  motion_x, motion_y, dest, motion->ref[0], stride * 2, 8);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fr_dmv (picture_t * picture, motion_t * motion,
+			   uint8_t * dest[3], int offset, int stride,
+			   void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+    int dmv_x, dmv_y;
+    int m;
+    int other_x, other_y;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    dmv_x = get_dmv (picture);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = (motion->pmv[0][1] >> 1) + get_motion_delta (picture,
+							    motion->f_code[1]);
+    /* motion_y = bound_motion_vector (motion_y, motion->f_code[1]); */
+    motion->pmv[1][1] = motion->pmv[0][1] = motion_y << 1;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    dmv_y = get_dmv (picture);
+
+    motion_block (mc_functions.put, offset, picture->v_offset >> 1, 0, 0, 0,
+		  motion_x, motion_y, dest, motion->ref[0], stride * 2, 8);
+
+    m = picture->top_field_first ? 1 : 3;
+    other_x = ((motion_x * m + (motion_x > 0)) >> 1) + dmv_x;
+    other_y = ((motion_y * m + (motion_y > 0)) >> 1) + dmv_y - 1;
+    motion_block (mc_functions.avg, offset, picture->v_offset >> 1, 0, stride, 0,
+		  other_x, other_y, dest, motion->ref[0], stride * 2, 8);
+
+    motion_block (mc_functions.put, offset, picture->v_offset >> 1,
+		  0, stride, stride,
+		  motion_x, motion_y, dest, motion->ref[0], stride * 2, 8);
+
+    m = picture->top_field_first ? 3 : 1;
+    other_x = ((motion_x * m + (motion_x > 0)) >> 1) + dmv_x;
+    other_y = ((motion_y * m + (motion_y > 0)) >> 1) + dmv_y + 1;
+    motion_block (mc_functions.avg, offset, picture->v_offset >> 1, 0, 0, stride,
+		  other_x, other_y, dest, motion->ref[0], stride * 2, 8);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+/* like motion_frame, but reuse previous motion vectors */
+static void motion_fr_reuse (picture_t * picture, motion_t * motion,
+			     uint8_t * dest[3], int offset, int stride,
+			     void (** table) (uint8_t *, uint8_t *, int, int))
+{
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion->pmv[0][0], motion->pmv[0][1],
+		  dest, motion->ref[0], stride, 16);
+}
+
+/* like motion_frame, but use null motion vectors */
+static void motion_fr_zero (picture_t * picture, motion_t * motion,
+			    uint8_t * dest[3], int offset, int stride,
+			    void (** table) (uint8_t *, uint8_t *, int, int))
+{
+    motion_block (table, offset, picture->v_offset, 0, 0, 0, 0, 0,
+		  dest, motion->ref[0], stride, 16);
+}
+
+/* like motion_frame, but parsing without actual motion compensation */
+static void motion_fr_conceal (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int tmp;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    tmp = (picture->f_motion.pmv[0][0] +
+	   get_motion_delta (picture, picture->f_motion.f_code[0]));
+    tmp = bound_motion_vector (tmp, picture->f_motion.f_code[0]);
+    picture->f_motion.pmv[1][0] = picture->f_motion.pmv[0][0] = tmp;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    tmp = (picture->f_motion.pmv[0][1] +
+	   get_motion_delta (picture, picture->f_motion.f_code[1]));
+    tmp = bound_motion_vector (tmp, picture->f_motion.f_code[1]);
+    picture->f_motion.pmv[1][1] = picture->f_motion.pmv[0][1] = tmp;
+
+    DUMPBITS (bit_buf, bits, 1); /* remove marker_bit */
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fi_field (picture_t * picture, motion_t * motion,
+			     uint8_t * dest[3], int offset, int stride,
+			     void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+    int field_select;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    field_select = UBITS (bit_buf, 1);
+    DUMPBITS (bit_buf, bits, 1);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[0][1] + get_motion_delta (picture,
+						     motion->f_code[1]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[1]);
+    motion->pmv[1][1] = motion->pmv[0][1] = motion_y;
+
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y,
+		  dest, motion->ref[field_select], stride, 16);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fi_16x8 (picture_t * picture, motion_t * motion,
+			    uint8_t * dest[3], int offset, int stride,
+			    void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+    int field_select;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    field_select = UBITS (bit_buf, 1);
+    DUMPBITS (bit_buf, bits, 1);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[0][1] + get_motion_delta (picture,
+						     motion->f_code[1]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[1]);
+    motion->pmv[0][1] = motion_y;
+
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y,
+		  dest, motion->ref[field_select], stride, 8);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    field_select = UBITS (bit_buf, 1);
+    DUMPBITS (bit_buf, bits, 1);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[1][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[1][1] + get_motion_delta (picture,
+						     motion->f_code[1]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[1]);
+    motion->pmv[1][1] = motion_y;
+
+    motion_block (table, offset, picture->v_offset+8, 1, 0, 0,
+		  motion_x, motion_y,
+		  dest, motion->ref[field_select], stride, 8);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fi_dmv (picture_t * picture, motion_t * motion,
+			   uint8_t * dest[3], int offset, int stride,
+			   void (** table) (uint8_t *, uint8_t *, int, int))
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int motion_x, motion_y;
+    int dmv_x, dmv_y;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_x = motion->pmv[0][0] + get_motion_delta (picture,
+						     motion->f_code[0]);
+    motion_x = bound_motion_vector (motion_x, motion->f_code[0]);
+    motion->pmv[1][0] = motion->pmv[0][0] = motion_x;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    dmv_x = get_dmv (picture);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    motion_y = motion->pmv[0][1] + get_motion_delta (picture,
+						     motion->f_code[1]);
+    motion_y = bound_motion_vector (motion_y, motion->f_code[1]);
+    motion->pmv[1][1] = motion->pmv[0][1] = motion_y;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    dmv_y = get_dmv (picture);
+
+    motion_block (mc_functions.put, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y,
+		  dest, motion->ref[picture->current_field], stride, 16);
+
+    motion_x = ((motion_x + (motion_x > 0)) >> 1) + dmv_x;
+    motion_y = ((motion_y + (motion_y > 0)) >> 1) + dmv_y +
+	2 * picture->current_field - 1;
+    motion_block (mc_functions.avg, offset, picture->v_offset, 0, 0, 0,
+		  motion_x, motion_y,
+		  dest, motion->ref[!picture->current_field], stride, 16);
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+static void motion_fi_reuse (picture_t * picture, motion_t * motion,
+			     uint8_t * dest[3], int offset, int stride,
+			     void (** table) (uint8_t *, uint8_t *, int, int))
+{
+    motion_block (table, offset, picture->v_offset, 0, 0, 0,
+		  motion->pmv[0][0], motion->pmv[0][1],
+		  dest, motion->ref[picture->current_field], stride, 16);
+}
+
+static void motion_fi_zero (picture_t * picture, motion_t * motion,
+			    uint8_t * dest[3], int offset, int stride,
+			    void (** table) (uint8_t *, uint8_t *, int, int))
+{
+    motion_block (table, offset, picture->v_offset, 0, 0, 0, 0, 0,
+		  dest, motion->ref[picture->current_field], stride, 16);
+}
+
+static void motion_fi_conceal (picture_t * picture)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int tmp;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    DUMPBITS (bit_buf, bits, 1); /* remove field_select */
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    tmp = (picture->f_motion.pmv[0][0] +
+	   get_motion_delta (picture, picture->f_motion.f_code[0]));
+    tmp = bound_motion_vector (tmp, picture->f_motion.f_code[0]);
+    picture->f_motion.pmv[1][0] = picture->f_motion.pmv[0][0] = tmp;
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    tmp = (picture->f_motion.pmv[0][1] +
+	   get_motion_delta (picture, picture->f_motion.f_code[1]));
+    tmp = bound_motion_vector (tmp, picture->f_motion.f_code[1]);
+    picture->f_motion.pmv[1][1] = picture->f_motion.pmv[0][1] = tmp;
+
+    DUMPBITS (bit_buf, bits, 1); /* remove marker_bit */
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}
+
+#define MOTION(routine,direction)					\
+do {									\
+    if ((direction) & MACROBLOCK_MOTION_FORWARD)			\
+	routine (picture, &(picture->f_motion), dest, offset, stride,	\
+		 mc_functions.put);					\
+    if ((direction) & MACROBLOCK_MOTION_BACKWARD)			\
+	routine (picture, &(picture->b_motion), dest, offset, stride,	\
+		 ((direction) & MACROBLOCK_MOTION_FORWARD ?		\
+		  mc_functions.avg : mc_functions.put));		\
+} while (0)
+
+#define CHECK_DISPLAY							\
+do {									\
+    if (offset == picture->coded_picture_width) {			\
+	do { /* just so we can use the break statement */		\
+	    if (picture->current_frame->copy) {				\
+		picture->current_frame->copy (picture->current_frame,	\
+					      dest);			\
+		if (picture->picture_coding_type == B_TYPE)		\
+		    break;						\
+	    }								\
+	    dest[0] += 16 * stride;					\
+	    dest[1] += 4 * stride;					\
+	    dest[2] += 4 * stride;					\
+	} while (0);							\
+	if (! (picture->mpeg1))						\
+	    return 0;							\
+	picture->v_offset += 16;					\
+	if (picture->v_offset >= picture->coded_picture_height)		\
+	    return 0;							\
+	offset = 0;							\
+    }									\
+} while (0)
+
+int slice_process (picture_t * picture, uint8_t code, uint8_t * buffer)
+{
+#define bit_buf (picture->bitstream_buf)
+#define bits (picture->bitstream_bits)
+#define bit_ptr (picture->bitstream_ptr)
+    int macroblock_modes;
+    int stride;
+    uint8_t * dest[3];
+    int offset;
+    uint8_t ** forward_ref[2];
+
+    stride = picture->coded_picture_width;
+    offset = (code - 1) * stride * 4;
+    picture->v_offset = (code - 1) * 16;
+
+    forward_ref[0] = picture->forward_reference_frame->base;
+    if (picture->picture_structure != FRAME_PICTURE) {
+	forward_ref[1] = picture->forward_reference_frame->base;
+	offset <<= 1;
+	picture->current_field = (picture->picture_structure == BOTTOM_FIELD);
+	if ((picture->second_field) &&
+	    (picture->picture_coding_type != B_TYPE))
+	    forward_ref[picture->picture_structure == TOP_FIELD] =
+		picture->current_frame->base;
+
+	picture->f_motion.ref[1][0] = forward_ref[1][0] + stride;
+	picture->f_motion.ref[1][1] = forward_ref[1][1] + (stride >> 1);
+	picture->f_motion.ref[1][2] = forward_ref[1][2] + (stride >> 1);
+
+	picture->b_motion.ref[1][0] =
+	    picture->backward_reference_frame->base[0] + stride;
+	picture->b_motion.ref[1][1] =
+	    picture->backward_reference_frame->base[1] + (stride >> 1);
+	picture->b_motion.ref[1][2] =
+	    picture->backward_reference_frame->base[2] + (stride >> 1);
+    }
+
+    picture->f_motion.ref[0][0] = forward_ref[0][0];
+    picture->f_motion.ref[0][1] = forward_ref[0][1];
+    picture->f_motion.ref[0][2] = forward_ref[0][2];
+
+    picture->f_motion.pmv[0][0] = picture->f_motion.pmv[0][1] = 0;
+    picture->f_motion.pmv[1][0] = picture->f_motion.pmv[1][1] = 0;
+
+    picture->b_motion.ref[0][0] = picture->backward_reference_frame->base[0];
+    picture->b_motion.ref[0][1] = picture->backward_reference_frame->base[1];
+    picture->b_motion.ref[0][2] = picture->backward_reference_frame->base[2];
+
+    picture->b_motion.pmv[0][0] = picture->b_motion.pmv[0][1] = 0;
+    picture->b_motion.pmv[1][0] = picture->b_motion.pmv[1][1] = 0;
+
+    if ((picture->current_frame->copy) &&
+	(picture->picture_coding_type == B_TYPE))
+	offset = 0;
+
+    dest[0] = picture->current_frame->base[0] + offset * 4;
+    dest[1] = picture->current_frame->base[1] + offset;
+    dest[2] = picture->current_frame->base[2] + offset;
+
+    switch (picture->picture_structure) {
+    case BOTTOM_FIELD:
+	dest[0] += stride;
+	dest[1] += stride >> 1;
+	dest[2] += stride >> 1;
+	/* follow thru */
+    case TOP_FIELD:
+	stride <<= 1;
+    }
+
+    picture->dc_dct_pred[0] = picture->dc_dct_pred[1] =
+	picture->dc_dct_pred[2] = 1 << (picture->intra_dc_precision + 7);
+
+    bitstream_init (picture, buffer);
+
+    picture->quantizer_scale = get_quantizer_scale (picture);
+
+    /* ignore intra_slice and all the extra data */
+    while (bit_buf & 0x80000000) {
+	DUMPBITS (bit_buf, bits, 9);
+	NEEDBITS (bit_buf, bits, bit_ptr);
+    }
+    DUMPBITS (bit_buf, bits, 1);
+
+    NEEDBITS (bit_buf, bits, bit_ptr);
+    offset = get_macroblock_address_increment (picture) << 4;
+
+    while (1) {
+	NEEDBITS (bit_buf, bits, bit_ptr);
+
+	macroblock_modes = get_macroblock_modes (picture);
+
+	/* maybe integrate MACROBLOCK_QUANT test into get_macroblock_modes ? */
+	if (macroblock_modes & MACROBLOCK_QUANT)
+	    picture->quantizer_scale = get_quantizer_scale (picture);
+
+	if (macroblock_modes & MACROBLOCK_INTRA) {
+
+	    int DCT_offset, DCT_stride;
+
+	    if (picture->concealment_motion_vectors) {
+		if (picture->picture_structure == FRAME_PICTURE)
+		    motion_fr_conceal (picture);
+		else
+		    motion_fi_conceal (picture);
+	    } else {
+		picture->f_motion.pmv[0][0] = picture->f_motion.pmv[0][1] = 0;
+		picture->f_motion.pmv[1][0] = picture->f_motion.pmv[1][1] = 0;
+		picture->b_motion.pmv[0][0] = picture->b_motion.pmv[0][1] = 0;
+		picture->b_motion.pmv[1][0] = picture->b_motion.pmv[1][1] = 0;
+	    }
+
+	    if (macroblock_modes & DCT_TYPE_INTERLACED) {
+		DCT_offset = stride;
+		DCT_stride = stride * 2;
+	    } else {
+		DCT_offset = stride * 8;
+		DCT_stride = stride;
+	    }
+
+	    slice_intra_DCT (picture, 0, dest[0] + offset, DCT_stride);
+	    slice_intra_DCT (picture, 0, dest[0] + offset + 8, DCT_stride);
+	    slice_intra_DCT (picture, 0, dest[0] + offset + DCT_offset,
+			     DCT_stride);
+	    slice_intra_DCT (picture, 0, dest[0] + offset + DCT_offset + 8,
+			     DCT_stride);
+
+	    slice_intra_DCT (picture, 1, dest[1] + (offset >> 1), stride >> 1);
+	    slice_intra_DCT (picture, 2, dest[2] + (offset >> 1), stride >> 1);
+
+	    if (picture->picture_coding_type == D_TYPE) {
+		NEEDBITS (bit_buf, bits, bit_ptr);
+		DUMPBITS (bit_buf, bits, 1);
+	    }
+	} else {
+
+	    if (picture->mpeg1) {
+		if ((macroblock_modes & MOTION_TYPE_MASK) == MC_FRAME)
+		    MOTION (motion_mp1, macroblock_modes);
+		else {
+		    /* non-intra mb without forward mv in a P picture */
+		    picture->f_motion.pmv[0][0] = 0;
+		    picture->f_motion.pmv[0][1] = 0;
+		    picture->f_motion.pmv[1][0] = 0;
+		    picture->f_motion.pmv[1][1] = 0;
+		    MOTION (motion_fr_zero, MACROBLOCK_MOTION_FORWARD);
+		}
+	    } else if (picture->picture_structure == FRAME_PICTURE)
+		switch (macroblock_modes & MOTION_TYPE_MASK) {
+		case MC_FRAME:
+		    MOTION (motion_fr_frame, macroblock_modes);
+		    break;
+
+		case MC_FIELD:
+		    MOTION (motion_fr_field, macroblock_modes);
+		    break;
+
+		case MC_DMV:
+		    MOTION (motion_fr_dmv, MACROBLOCK_MOTION_FORWARD);
+		    break;
+
+		case 0:
+		    /* non-intra mb without forward mv in a P picture */
+		    picture->f_motion.pmv[0][0] = 0;
+		    picture->f_motion.pmv[0][1] = 0;
+		    picture->f_motion.pmv[1][0] = 0;
+		    picture->f_motion.pmv[1][1] = 0;
+		    MOTION (motion_fr_zero, MACROBLOCK_MOTION_FORWARD);
+		    break;
+		}
+	    else
+		switch (macroblock_modes & MOTION_TYPE_MASK) {
+		case MC_FIELD:
+		    MOTION (motion_fi_field, macroblock_modes);
+		    break;
+
+		case MC_16X8:
+		    MOTION (motion_fi_16x8, macroblock_modes);
+		    break;
+
+		case MC_DMV:
+		    MOTION (motion_fi_dmv, MACROBLOCK_MOTION_FORWARD);
+		    break;
+
+		case 0:
+		    /* non-intra mb without forward mv in a P picture */
+		    picture->f_motion.pmv[0][0] = 0;
+		    picture->f_motion.pmv[0][1] = 0;
+		    picture->f_motion.pmv[1][0] = 0;
+		    picture->f_motion.pmv[1][1] = 0;
+		    MOTION (motion_fi_zero, MACROBLOCK_MOTION_FORWARD);
+		    break;
+		}
+
+	    if (macroblock_modes & MACROBLOCK_PATTERN) {
+		int coded_block_pattern;
+		int DCT_offset, DCT_stride;
+
+		if (macroblock_modes & DCT_TYPE_INTERLACED) {
+		    DCT_offset = stride;
+		    DCT_stride = stride * 2;
+		} else {
+		    DCT_offset = stride * 8;
+		    DCT_stride = stride;
+		}
+
+		coded_block_pattern = get_coded_block_pattern (picture);
+
+		if (coded_block_pattern & 0x20)
+		    slice_non_intra_DCT (picture, dest[0] + offset,
+					 DCT_stride);
+		if (coded_block_pattern & 0x10)
+		    slice_non_intra_DCT (picture, dest[0] + offset + 8,
+					 DCT_stride);
+		if (coded_block_pattern & 0x08)
+		    slice_non_intra_DCT (picture,
+					 dest[0] + offset + DCT_offset,
+					 DCT_stride);
+		if (coded_block_pattern & 0x04)
+		    slice_non_intra_DCT (picture,
+					 dest[0] + offset + DCT_offset + 8,
+					 DCT_stride);
+
+		if (coded_block_pattern & 0x2)
+		    slice_non_intra_DCT (picture, dest[1] + (offset >> 1),
+					 stride >> 1);
+		if (coded_block_pattern & 0x1)
+		    slice_non_intra_DCT (picture, dest[2] + (offset >> 1),
+					 stride >> 1);
+	    }
+
+	    picture->dc_dct_pred[0] = picture->dc_dct_pred[1] =
+		picture->dc_dct_pred[2] = 1 << (picture->intra_dc_precision+7);
+	}
+
+	offset += 16;
+	CHECK_DISPLAY;
+
+	NEEDBITS (bit_buf, bits, bit_ptr);
+
+	if (bit_buf & 0x80000000) {
+	    DUMPBITS (bit_buf, bits, 1);
+	} else {
+	    int mba_inc;
+
+	    mba_inc = get_macroblock_address_increment (picture);
+	    if (!mba_inc)
+		break;
+
+	    picture->dc_dct_pred[0] = picture->dc_dct_pred[1] =
+		picture->dc_dct_pred[2] = 1 << (picture->intra_dc_precision+7);
+
+	    if (picture->picture_coding_type == P_TYPE) {
+		picture->f_motion.pmv[0][0] = picture->f_motion.pmv[0][1] = 0;
+		picture->f_motion.pmv[1][0] = picture->f_motion.pmv[1][1] = 0;
+
+		do {
+		    if (picture->picture_structure == FRAME_PICTURE)
+			MOTION (motion_fr_zero, MACROBLOCK_MOTION_FORWARD);
+		    else
+			MOTION (motion_fi_zero, MACROBLOCK_MOTION_FORWARD);
+
+		    offset += 16;
+		    CHECK_DISPLAY;
+		} while (--mba_inc);
+	    } else {
+		do {
+		    if (picture->mpeg1)
+			MOTION (motion_mp1_reuse, macroblock_modes);
+		    else if (picture->picture_structure == FRAME_PICTURE)
+			MOTION (motion_fr_reuse, macroblock_modes);
+		    else
+			MOTION (motion_fi_reuse, macroblock_modes);
+
+		    offset += 16;
+		    CHECK_DISPLAY;
+		} while (--mba_inc);
+	    }
+	}
+    }
+
+    return 0;
+#undef bit_buf
+#undef bits
+#undef bit_ptr
+}