VP5 and VP6 video decoder

Originally committed as revision 6213 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 248 insertions, 0 deletions

diff --git a/libavcodec/vp56.h b/libavcodec/vp56.h
new file mode 100644
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--- /dev/null
+++ b/libavcodec/vp56.h
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+/**
+ * @file vp56.h
+ * VP5 and VP6 compatible video decoder (common features)
+ *
+ * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef VP56_H
+#define VP56_H
+
+#include <stdint.h>
+
+#include "vp56data.h"
+#include "dsputil.h"
+#include "mpegvideo.h"
+
+
+typedef struct vp56_context vp56_context_t;
+typedef struct vp56_mv vp56_mv_t;
+
+typedef void (*vp56_parse_vector_adjustment_t)(vp56_context_t *s,
+                                               vp56_mv_t *vector);
+typedef int (*vp56_adjust_t)(int v, int t);
+typedef void (*vp56_filter_t)(vp56_context_t *s, uint8_t *dst, uint8_t *src,
+                              int offset1, int offset2, int stride,
+                              vp56_mv_t mv, int mask, int select, int luma);
+typedef void (*vp56_parse_coeff_t)(vp56_context_t *s);
+typedef void (*vp56_default_models_init_t)(vp56_context_t *s);
+typedef void (*vp56_parse_vector_models_t)(vp56_context_t *s);
+typedef void (*vp56_parse_coeff_models_t)(vp56_context_t *s);
+typedef int (*vp56_parse_header_t)(vp56_context_t *s, uint8_t *buf,
+                                   int buf_size, int *golden_frame);
+
+typedef struct {
+    int high;
+    int bits;
+    const uint8_t *buffer;
+    unsigned long code_word;
+} vp56_range_coder_t;
+
+typedef struct {
+    uint8_t not_null_dc;
+    vp56_frame_t ref_frame;
+    DCTELEM dc_coeff;
+} vp56_ref_dc_t;
+
+struct vp56_mv {
+    int x;
+    int y;
+};
+
+typedef struct {
+    uint8_t type;
+    vp56_mv_t mv;
+} vp56_macroblock_t;
+
+struct vp56_context {
+    AVCodecContext *avctx;
+    DSPContext dsp;
+    ScanTable scantable;
+    AVFrame frames[3];
+    uint8_t *edge_emu_buffer_alloc;
+    uint8_t *edge_emu_buffer;
+    vp56_range_coder_t c;
+
+    /* frame info */
+    int plane_width[3];
+    int plane_height[3];
+    int mb_width;   /* number of horizontal MB */
+    int mb_height;  /* number of vertical MB */
+    int block_offset[6];
+
+    int quantizer;
+    uint16_t dequant_dc;
+    uint16_t dequant_ac;
+
+    /* DC predictors management */
+    vp56_ref_dc_t *above_blocks;
+    vp56_ref_dc_t left_block[4];
+    int above_block_idx[6];
+    DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
+
+    /* blocks / macroblock */
+    vp56_mb_t mb_type;
+    vp56_macroblock_t *macroblocks;
+    DECLARE_ALIGNED_16(DCTELEM, block_coeff[6][64]);
+    uint8_t coeff_reorder[64];       /* used in vp6 only */
+    uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
+
+    /* motion vectors */
+    vp56_mv_t mv[6];  /* vectors for each block in MB */
+    vp56_mv_t vector_candidate[2];
+    int vector_candidate_pos;
+
+    /* filtering hints */
+    int deblock_filtering;
+    int filter_selection;
+    int filter_mode;
+    int max_vector_length;
+    int sample_variance_threshold;
+
+    /* AC models */
+    uint8_t vector_model_sig[2];           /* delta sign */
+    uint8_t vector_model_dct[2];           /* delta coding types */
+    uint8_t vector_model_pdi[2][2];        /* predefined delta init */
+    uint8_t vector_model_pdv[2][7];        /* predefined delta values */
+    uint8_t vector_model_fdv[2][8];        /* 8 bit delta value definition */
+    uint8_t mb_type_model[3][10][10];      /* model for decoding MB type */
+    uint8_t coeff_model_dccv[2][11];       /* DC coeff value */
+    uint8_t coeff_model_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
+    uint8_t coeff_model_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
+    uint8_t coeff_model_dcct[2][36][5];    /* DC coeff coding type */
+    uint8_t coeff_model_runv[2][14];       /* run value (vp6 only) */
+    uint8_t mb_types_stats[3][10][2];      /* contextual, next MB type stats */
+    uint8_t coeff_ctx[4][64];              /* used in vp5 only */
+    uint8_t coeff_ctx_last[4];             /* used in vp5 only */
+
+    /* upside-down flipping hints */
+    int flip;  /* are we flipping ? */
+    int frbi;  /* first row block index in MB */
+    int srbi;  /* second row block index in MB */
+    int stride[3];  /* stride for each plan */
+
+    const uint8_t *vp56_coord_div;
+    vp56_parse_vector_adjustment_t parse_vector_adjustment;
+    vp56_adjust_t adjust;
+    vp56_filter_t filter;
+    vp56_parse_coeff_t parse_coeff;
+    vp56_default_models_init_t default_models_init;
+    vp56_parse_vector_models_t parse_vector_models;
+    vp56_parse_coeff_models_t parse_coeff_models;
+    vp56_parse_header_t parse_header;
+};
+
+
+void vp56_init(vp56_context_t *s, AVCodecContext *avctx, int flip);
+int vp56_free(AVCodecContext *avctx);
+void vp56_init_dequant(vp56_context_t *s, int quantizer);
+int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
+                      uint8_t *buf, int buf_size);
+
+
+/**
+ * vp56 specific range coder implementation
+ */
+
+static inline void vp56_init_range_decoder(vp56_range_coder_t *c,
+                                           const uint8_t *buf, int buf_size)
+{
+    c->high = 255;
+    c->bits = 8;
+    c->buffer = buf;
+    c->code_word = *c->buffer++ << 8;
+    c->code_word |= *c->buffer++;
+}
+
+static inline int vp56_rac_get_prob(vp56_range_coder_t *c, uint8_t prob)
+{
+    unsigned int low = 1 + (((c->high - 1) * prob) / 256);
+    unsigned int low_shift = low << 8;
+    int bit = c->code_word >= low_shift;
+
+    if (bit) {
+        c->high -= low;
+        c->code_word -= low_shift;
+    } else {
+        c->high = low;
+    }
+
+    /* normalize */
+    while (c->high < 128) {
+        c->high <<= 1;
+        c->code_word <<= 1;
+        if (--c->bits == 0) {
+            c->bits = 8;
+            c->code_word |= *c->buffer++;
+        }
+    }
+    return bit;
+}
+
+static inline int vp56_rac_get(vp56_range_coder_t *c)
+{
+    /* equiprobable */
+    int low = (c->high + 1) >> 1;
+    unsigned int low_shift = low << 8;
+    int bit = c->code_word >= low_shift;
+    if (bit) {
+        c->high = (c->high - low) << 1;
+        c->code_word -= low_shift;
+    } else {
+        c->high = low << 1;
+    }
+
+    /* normalize */
+    c->code_word <<= 1;
+    if (--c->bits == 0) {
+        c->bits = 8;
+        c->code_word |= *c->buffer++;
+    }
+    return bit;
+}
+
+static inline int vp56_rac_gets(vp56_range_coder_t *c, int bits)
+{
+    int value = 0;
+
+    while (bits--) {
+        value = (value << 1) | vp56_rac_get(c);
+    }
+
+    return value;
+}
+
+static inline int vp56_rac_gets_nn(vp56_range_coder_t *c, int bits)
+{
+    int v = vp56_rac_gets(c, 7) << 1;
+    return v + !v;
+}
+
+static inline int vp56_rac_get_tree(vp56_range_coder_t *c,
+                                    const vp56_tree_t *tree,
+                                    const uint8_t *probs)
+{
+    while (tree->val > 0) {
+        if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
+            tree += tree->val;
+        else
+            tree++;
+    }
+    return -tree->val;
+}
+
+#endif /* VP56_H */