path: root/src/gallium/auxiliary/vl/vp8/decodeframe.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */


#include "recon.h"
#include "idct_dispatch.h"
#include "detokenize.h"
#include "invtrans.h"
#include "alloccommon.h"
#include "entropymode.h"
#include "dequantize_common.h"
#include "dequantize_dispatch.h"
#include "decodemv.h"
#include "treereader.h"
#include "yv12utils.h"

#include "vp8_decoder.h"
#include "vp8_mem.h"

#include <assert.h>
#include <stdio.h>

#define RTCD_VTABLE(x) NULL

void mb_init_dequantizer(VP8_COMMON *common, MACROBLOCKD *mb)
{
    int i;
    int QIndex;
    MB_MODE_INFO *mbmi = &mb->mode_info_context->mbmi;

    /* Decide whether to use the default or alternate baseline Q value. */
    if (mb->segmentation_enabled)
    {
        if (mb->mb_segement_abs_delta == SEGMENT_ABSDATA)
        {
            /* Abs Value */
            QIndex = mb->segment_feature_data[MB_LVL_ALT_Q][mbmi->segment_id];
        }
        else
        {
            /* Delta Value */
            QIndex = common->base_qindex + mb->segment_feature_data[MB_LVL_ALT_Q][mbmi->segment_id];
            QIndex = (QIndex >= 0) ? ((QIndex <= MAXQ) ? QIndex : MAXQ) : 0; /* Clamp to valid range */
        }
    }
    else
    {
        QIndex = common->base_qindex;
    }

    /* Set up the block level dequant pointers */
    for (i = 0; i < 16; i++)
    {
        mb->block[i].dequant = common->Y1dequant[QIndex];
    }

    for (i = 16; i < 24; i++)
    {
        mb->block[i].dequant = common->UVdequant[QIndex];
    }

    mb->block[24].dequant = common->Y2dequant[QIndex];
}

/**
 * skip_recon_mb() is Modified: Instead of writing the result to predictor
 * buffer and then copying it to dst buffer, we can write the result directly
 * to dst buffer. This eliminates unnecessary copy.
 */
static void skip_recon_mb(VP8_COMMON *common, MACROBLOCKD *mb)
{
    if (mb->mode_info_context->mbmi.ref_frame == INTRA_FRAME)
    {
        RECON_INVOKE(&common->rtcd.recon, build_intra_predictors_mbuv_s)(mb);
        RECON_INVOKE(&common->rtcd.recon, build_intra_predictors_mby_s)(mb);
    }
    else
    {
        vp8_build_inter16x16_predictors_mb(mb, mb->dst.y_buffer,
                                           mb->dst.u_buffer, mb->dst.v_buffer,
                                           mb->dst.y_stride, mb->dst.uv_stride);
    }
}

/**
 * If the MV points so far into the UMV border that no visible pixels
 * are used for reconstruction, the subpel part of the MV can be
 * discarded and the MV limited to 16 pixels with equivalent results.
 *
 * This limit kicks in at 19 pixels for the top and left edges, for
 * the 16 pixels plus 3 taps right of the central pixel when subpel
 * filtering. The bottom and right edges use 16 pixels plus 2 pixels
 * left of the central pixel when filtering.
 */
static void clamp_mv_to_umv_border(MV *mv, const MACROBLOCKD *mb)
{
    if (mv->col < (mb->mb_to_left_edge - (19 << 3)))
        mv->col = mb->mb_to_left_edge - (16 << 3);
    else if (mv->col > mb->mb_to_right_edge + (18 << 3))
        mv->col = mb->mb_to_right_edge + (16 << 3);

    if (mv->row < (mb->mb_to_top_edge - (19 << 3)))
        mv->row = mb->mb_to_top_edge - (16 << 3);
    else if (mv->row > mb->mb_to_bottom_edge + (18 << 3))
        mv->row = mb->mb_to_bottom_edge + (16 << 3);
}

/**
 * \note clamp_uvmv_to_umv_border() is a chroma block MVs version of the
 *       function clamp_mv_to_umv_border().
 */
static void clamp_uvmv_to_umv_border(MV *mv, const MACROBLOCKD *mb)
{
    mv->col = (2*mv->col < (mb->mb_to_left_edge - (19 << 3))) ? (mb->mb_to_left_edge - (16 << 3)) >> 1 : mv->col;
    mv->col = (2*mv->col > mb->mb_to_right_edge + (18 << 3)) ? (mb->mb_to_right_edge + (16 << 3)) >> 1 : mv->col;

    mv->row = (2*mv->row < (mb->mb_to_top_edge - (19 << 3))) ? (mb->mb_to_top_edge - (16 << 3)) >> 1 : mv->row;
    mv->row = (2*mv->row > mb->mb_to_bottom_edge + (18 << 3)) ? (mb->mb_to_bottom_edge + (16 << 3)) >> 1 : mv->row;
}

static void clamp_mvs(MACROBLOCKD *mb)
{
    if (mb->mode_info_context->mbmi.mode == SPLITMV)
    {
        int i;

        for (i = 0; i < 16; i++)
            clamp_mv_to_umv_border(&mb->block[i].bmi.mv.as_mv, mb);
        for (i = 16; i < 24; i++)
            clamp_uvmv_to_umv_border(&mb->block[i].bmi.mv.as_mv, mb);
    }
    else
    {
        clamp_mv_to_umv_border(&mb->mode_info_context->mbmi.mv.as_mv, mb);
        clamp_uvmv_to_umv_border(&mb->block[16].bmi.mv.as_mv, mb);
    }
}

static int get_delta_q(BOOL_DECODER *bd, int prev, int *q_update)
{
    int ret_val = 0;

    if (vp8_read_bit(bd))
    {
        ret_val = vp8_read_literal(bd, 4);

        if (vp8_read_bit(bd))
            ret_val = -ret_val;
    }

    /* Trigger a quantizer update if the delta-q value has changed */
    if (ret_val != prev)
        *q_update = 1;

    return ret_val;
}

/**
 * \note The extension is only for the last row, for intra prediction purpose.
 */
static void vp8_extend_mb_row(YV12_BUFFER_CONFIG *ybf,
                              unsigned char *YPtr,
                              unsigned char *UPtr,
                              unsigned char *VPtr)
{
    int i;

    YPtr += ybf->y_stride * 14;
    UPtr += ybf->uv_stride * 6;
    VPtr += ybf->uv_stride * 6;

    for (i = 0; i < 4; i++)
    {
        YPtr[i] = YPtr[-1];
        UPtr[i] = UPtr[-1];
        VPtr[i] = VPtr[-1];
    }

    YPtr += ybf->y_stride;
    UPtr += ybf->uv_stride;
    VPtr += ybf->uv_stride;

    for (i = 0; i < 4; i++)
    {
        YPtr[i] = YPtr[-1];
        UPtr[i] = UPtr[-1];
        VPtr[i] = VPtr[-1];
    }
}

static void decode_macroblock(VP8_COMMON *common, MACROBLOCKD *mb, unsigned int mb_idx)
{
    int i;
    int eobtotal = 0;
    MB_PREDICTION_MODE mode;

    if (mb->mode_info_context->mbmi.mb_skip_coeff)
    {
        vp8_reset_mb_tokens_context(mb);
    }
    else
    {
        eobtotal = vp8_decode_mb_tokens(common, mb);
    }

    /* Perform temporary clamping of the MV to be used for prediction */
    if (mb->mode_info_context->mbmi.need_to_clamp_mvs)
    {
        clamp_mvs(mb);
    }

    mode = mb->mode_info_context->mbmi.mode;

    if (eobtotal == 0 && mode != B_PRED && mode != SPLITMV)
    {
        /* Special case: Force the loopfilter to skip when eobtotal and
         * mb_skip_coeff are zero. */
        mb->mode_info_context->mbmi.mb_skip_coeff = 1;

        skip_recon_mb(common, mb);
        return;
    }

    if (mb->segmentation_enabled)
        mb_init_dequantizer(common, mb);

    /* do prediction */
    if (mb->mode_info_context->mbmi.ref_frame == INTRA_FRAME)
    {
        RECON_INVOKE(&common->rtcd.recon, build_intra_predictors_mbuv)(mb);

        if (mode != B_PRED)
        {
            RECON_INVOKE(&common->rtcd.rtcd.recon, build_intra_predictors_mby)(mb);
        }
        else
        {
            vp8_intra_prediction_down_copy(mb);
        }
    }
    else
    {
        vp8_build_inter_predictors_mb(mb);
    }

    /* dequantization and idct */
    if (mode == B_PRED)
    {
        for (i = 0; i < 16; i++)
        {
            BLOCKD *b = &mb->block[i];
            RECON_INVOKE(RTCD_VTABLE(recon), intra4x4_predict)
                        (b, b->bmi.as_mode, b->predictor);

            if (mb->eobs[i] > 1)
            {
                DEQUANT_INVOKE(&common->dequant, idct_add)
                              (b->qcoeff, b->dequant, b->predictor,
                             *(b->base_dst) + b->dst, 16, b->dst_stride);
            }
            else
            {
                IDCT_INVOKE(RTCD_VTABLE(idct), idct1_scalar_add)
                           (b->qcoeff[0] * b->dequant[0], b->predictor,
                          *(b->base_dst) + b->dst, 16, b->dst_stride);

                ((int *)b->qcoeff)[0] = 0;
            }
        }

    }
    else if (mode == SPLITMV)
    {
        DEQUANT_INVOKE(&common->dequant, idct_add_y_block)
                      (mb->qcoeff, mb->block[0].dequant,
                       mb->predictor, mb->dst.y_buffer,
                       mb->dst.y_stride, mb->eobs);
    }
    else
    {
        BLOCKD *b = &mb->block[24];

        DEQUANT_INVOKE(&common->dequant, block)(b);

        /* do 2nd order transform on the dc block */
        if (mb->eobs[24] > 1)
        {
            IDCT_INVOKE(RTCD_VTABLE(idct), iwalsh16)(&b->dqcoeff[0], b->diff);
            ((int *)b->qcoeff)[0] = 0;
            ((int *)b->qcoeff)[1] = 0;
            ((int *)b->qcoeff)[2] = 0;
            ((int *)b->qcoeff)[3] = 0;
            ((int *)b->qcoeff)[4] = 0;
            ((int *)b->qcoeff)[5] = 0;
            ((int *)b->qcoeff)[6] = 0;
            ((int *)b->qcoeff)[7] = 0;
        }
        else
        {
            IDCT_INVOKE(RTCD_VTABLE(idct), iwalsh1)(&b->dqcoeff[0], b->diff);
            ((int *)b->qcoeff)[0] = 0;
        }

        DEQUANT_INVOKE (&common->dequant, dc_idct_add_y_block)
                       (mb->qcoeff, mb->block[0].dequant,
                        mb->predictor, mb->dst.y_buffer,
                        mb->dst.y_stride, mb->eobs, mb->block[24].diff);
    }

    DEQUANT_INVOKE (&common->dequant, idct_add_uv_block)
                   (mb->qcoeff+16*16, mb->block[16].dequant,
                    mb->predictor+16*16, mb->dst.u_buffer, mb->dst.v_buffer,
                    mb->dst.uv_stride, mb->eobs+16);
}

static void
decode_macroblock_row(VP8_COMMON *common, int mb_row, MACROBLOCKD *mb)
{
    int recon_yoffset, recon_uvoffset;
    int mb_col;
    int ref_fb_idx = common->lst_fb_idx;
    int dst_fb_idx = common->new_fb_idx;
    int recon_y_stride = common->yv12_fb[ref_fb_idx].y_stride;
    int recon_uv_stride = common->yv12_fb[ref_fb_idx].uv_stride;

    memset(&common->left_context, 0, sizeof(common->left_context));
    recon_yoffset = mb_row * recon_y_stride * 16;
    recon_uvoffset = mb_row * recon_uv_stride * 8;

    /* Reset above block coeffs */
    mb->above_context = common->above_context;
    mb->up_available = (mb_row != 0);

    mb->mb_to_top_edge = -((mb_row * 16)) << 3;
    mb->mb_to_bottom_edge = ((common->mb_rows - 1 - mb_row) * 16) << 3;

    for (mb_col = 0; mb_col < common->mb_cols; mb_col++)
    {
        /* Distance of Mb to the various image edges.
         * These are specified to 8th pel as they are always compared to values
         * that are in 1/8th pel units. */
        mb->mb_to_left_edge = -((mb_col * 16) << 3);
        mb->mb_to_right_edge = ((common->mb_cols - 1 - mb_col) * 16) << 3;

        update_blockd_bmi(mb);

        mb->dst.y_buffer = common->yv12_fb[dst_fb_idx].y_buffer + recon_yoffset;
        mb->dst.u_buffer = common->yv12_fb[dst_fb_idx].u_buffer + recon_uvoffset;
        mb->dst.v_buffer = common->yv12_fb[dst_fb_idx].v_buffer + recon_uvoffset;

        mb->left_available = (mb_col != 0);

        /* Select the appropriate reference frame for this MB */
        if (mb->mode_info_context->mbmi.ref_frame == LAST_FRAME)
            ref_fb_idx = common->lst_fb_idx;
        else if (mb->mode_info_context->mbmi.ref_frame == GOLDEN_FRAME)
            ref_fb_idx = common->gld_fb_idx;
        else
            ref_fb_idx = common->alt_fb_idx;

        mb->pre.y_buffer = common->yv12_fb[ref_fb_idx].y_buffer + recon_yoffset;
        mb->pre.u_buffer = common->yv12_fb[ref_fb_idx].u_buffer + recon_uvoffset;
        mb->pre.v_buffer = common->yv12_fb[ref_fb_idx].v_buffer + recon_uvoffset;

        if (mb->mode_info_context->mbmi.ref_frame != INTRA_FRAME)
        {
            /* Propagate errors from reference frames */
            mb->corrupted |= common->yv12_fb[ref_fb_idx].corrupted;
        }

        vp8_build_uvmvs(mb, common->full_pixel);

        decode_macroblock(common, mb, mb_row * common->mb_cols + mb_col);

        /* Check if the boolean decoder has suffered an error */
        mb->corrupted |= vp8dx_bool_error(mb->current_bd);

        recon_yoffset += 16;
        recon_uvoffset += 8;

        ++mb->mode_info_context; /* next mb */

        mb->above_context++;
    }

    /* Adjust to the next row of mbs */
    vp8_extend_mb_row(&common->yv12_fb[dst_fb_idx],
                      mb->dst.y_buffer + 16,
                      mb->dst.u_buffer + 8,
                      mb->dst.v_buffer + 8);

    /* Skip prediction column */
    ++mb->mode_info_context;
}

static unsigned int token_decoder_readpartitionsize(const unsigned char *cx_size)
{
    const unsigned int size = cx_size[0] + (cx_size[1] << 8) + (cx_size[2] << 16);
    return size;
}

static void token_decoder_setup(VP8_COMMON *common,
                                const unsigned char *cx_data)
{
    int num_part;
    int i;
    const unsigned char *user_data_end = common->data + common->data_size;

    /* Set up pointers to the first partition */
    BOOL_DECODER        *bool_decoder = &common->bd2;
    const unsigned char *partition = cx_data;

    /* Parse number of token partitions to use */
    const TOKEN_PARTITION multi_token_partition = (TOKEN_PARTITION)vp8_read_literal(&common->bd, 2);

    /* Only update the multi_token_partition field if we are sure the value is correct. */
    if (!vp8dx_bool_error(&common->bd))
        common->multi_token_partition = multi_token_partition;

    num_part = 1 << common->multi_token_partition;

    if (num_part > 1)
    {
        common->mbd = vpx_memalign(32, num_part * sizeof(BOOL_DECODER));
        if (!common->mbd)
        {
            // Memory allocation failed
            assert(0);
        }

        bool_decoder = common->mbd;
        partition += 3 * (num_part - 1);
    }

    for (i = 0; i < num_part; i++)
    {
        const unsigned char *partition_size_ptr = cx_data + i * 3;
        ptrdiff_t            partition_size;

        /* Calculate the length of this partition. The last partition size is implicit. */
        if (i < num_part - 1)
        {
            partition_size = token_decoder_readpartitionsize(partition_size_ptr);
        }
        else
        {
            partition_size = user_data_end - partition;
        }

        if (partition + partition_size > user_data_end ||
            partition + partition_size < partition)
        {
            vpx_internal_error(&common->error, VPX_CODEC_CORRUPT_FRAME,
                               "Truncated packet or corrupt partition "
                               "%d length", i + 1);
        }

        if (vp8dx_start_decode(bool_decoder, partition, partition_size))
        {
            vpx_internal_error(&common->error, VPX_CODEC_MEM_ERROR,
                               "Failed to allocate bool decoder %d", i + 1);
        }

        /* Advance to the next partition */
        partition += partition_size;
        bool_decoder++;
    }
}

static void token_decoder_stop(VP8_COMMON *common)
{
    if (common->multi_token_partition != ONE_PARTITION)
    {
        vpx_free(common->mbd);
        common->mbd = NULL;
    }
}

static void vp8_frame_init(VP8_COMMON *common)
{
    MACROBLOCKD *const mb = &common->mb;

    if (common->frame_type == KEY_FRAME)
    {
        /* Various keyframe initializations. */
        memcpy(common->fc.mvc, vp8_default_mv_context, sizeof(vp8_default_mv_context));

        vp8_init_mbmode_probs(common);

        vp8_default_coef_probs(common);
        vp8_kf_default_bmode_probs(common->kf_bmode_prob);

        /* Reset the segment feature data to 0 with delta coding (Default state). */
        memset(mb->segment_feature_data, 0, sizeof(mb->segment_feature_data));
        mb->mb_segement_abs_delta = SEGMENT_DELTADATA;

        /* Reset the mode ref deltasa for loop filter. */
        memset(mb->ref_lf_deltas, 0, sizeof(mb->ref_lf_deltas));
        memset(mb->mode_lf_deltas, 0, sizeof(mb->mode_lf_deltas));

        /* All buffers are implicitly updated on key frames. */
        common->refresh_golden_frame = 1;
        common->refresh_alternate_frame = 1;
        common->copy_buffer_to_golden = 0;
        common->copy_buffer_to_alternate = 0;

        /* Note that Golden and Altref modes cannot be used on a key frame so
         * ref_frame_sign_bias[] is undefined and meaningless. */
        common->ref_frame_sign_bias[GOLDEN_FRAME] = 0;
        common->ref_frame_sign_bias[ALTREF_FRAME] = 0;
    }
    else
    {
        if (common->use_bilinear_mc_filter)
        {
            common->mcomp_filter_type = BILINEAR;
            mb->filter_predict4x4     = FILTER_INVOKE(RTCD_VTABLE(filter), bilinear4x4);
            mb->filter_predict8x4     = FILTER_INVOKE(RTCD_VTABLE(filter), bilinear8x4);
            mb->filter_predict8x8     = FILTER_INVOKE(RTCD_VTABLE(filter), bilinear8x8);
            mb->filter_predict16x16   = FILTER_INVOKE(RTCD_VTABLE(filter), bilinear16x16);
        }
        else
        {
            common->mcomp_filter_type = SIXTAP;
            mb->filter_predict4x4     = FILTER_INVOKE(RTCD_VTABLE(filter), sixtap4x4);
            mb->filter_predict8x4     = FILTER_INVOKE(RTCD_VTABLE(filter), sixtap8x4);
            mb->filter_predict8x8     = FILTER_INVOKE(RTCD_VTABLE(filter), sixtap8x8);
            mb->filter_predict16x16   = FILTER_INVOKE(RTCD_VTABLE(filter), sixtap16x16);
        }
    }

    mb->left_context = &common->left_context;
    mb->mode_info_context = common->mi;
    mb->frame_type = common->frame_type;
    mb->mode_info_context->mbmi.mode = DC_PRED;
    mb->mode_info_stride = common->mode_info_stride;
    mb->corrupted = 0; /* init without corruption */
}

int vp8_frame_decode(VP8_COMMON *common, struct pipe_vp8_picture_desc *frame_header)
{
    BOOL_DECODER *const bd = &common->bd;
    MACROBLOCKD *const mb = &common->mb;
    const unsigned char *data = common->data;
    const unsigned char *data_end = data + common->data_size;
    ptrdiff_t first_partition_length_in_bytes = (ptrdiff_t)frame_header->first_part_size;

    int mb_row;
    int i, j, k, l;

    /* Start with no corruption of current frame */
    mb->corrupted = 0;
    common->yv12_fb[common->new_fb_idx].corrupted = 0;

    common->frame_type = (FRAME_TYPE)frame_header->key_frame;
    common->version = (int)frame_header->base.profile;
    common->show_frame = (int)frame_header->show_frame;

    vp8_setup_version(common);

    if (common->frame_type == KEY_FRAME)
    {
        if (common->width != frame_header->width ||
            common->height != frame_header->height)
        {
            if (vp8_alloc_frame_buffers(common, frame_header->width, frame_header->height))
            {
                vpx_internal_error(&common->error, VPX_CODEC_MEM_ERROR,
                                   "Failed to allocate frame buffers");
            }
        }

        common->width = frame_header->width;
        common->horizontal_scale = frame_header->horizontal_scale;
        common->height = frame_header->height;
        common->vertical_scale = frame_header->vertical_scale;
    }

    vp8_frame_init(common);

    if (vp8dx_start_decode(bd, data, data_end - data))
    {
        vpx_internal_error(&common->error, VPX_CODEC_MEM_ERROR,
                           "Failed to allocate bool decoder 0");
    }

    if (common->frame_type == KEY_FRAME)
    {
        common->color_space   = (YUV_TYPE)vp8_read_bit(bd);
        common->clamping_type = (CLAMP_TYPE)vp8_read_bit(bd);
    }

    /* Is segmentation enabled */
    mb->segmentation_enabled = (unsigned char)vp8_read_bit(bd);

    if (mb->segmentation_enabled)
    {
        /* Signal whether or not the segmentation map is being explicitly updated this frame. */
        mb->update_mb_segmentation_map = (unsigned char)vp8_read_bit(bd);
        mb->update_mb_segmentation_data = (unsigned char)vp8_read_bit(bd);

        if (mb->update_mb_segmentation_data)
        {
            mb->mb_segement_abs_delta = (unsigned char)vp8_read_bit(bd);

            memset(mb->segment_feature_data, 0, sizeof(mb->segment_feature_data));

            /* For each segmentation feature (Quant and loop filter level) */
            for (i = 0; i < MB_LVL_MAX; i++)
            {
                for (j = 0; j < MAX_MB_SEGMENTS; j++)
                {
                    /* Frame level data */
                    if (vp8_read_bit(bd))
                    {
                        mb->segment_feature_data[i][j] = (signed char)vp8_read_literal(bd, vp8_mb_feature_data_bits[i]);

                        if (vp8_read_bit(bd))
                            mb->segment_feature_data[i][j] = -mb->segment_feature_data[i][j];
                    }
                    else
                        mb->segment_feature_data[i][j] = 0;
                }
            }
        }

        if (mb->update_mb_segmentation_map)
        {
            /* Which macro block level features are enabled */
            memset(mb->mb_segment_tree_probs, 255, sizeof(mb->mb_segment_tree_probs));

            /* Read the probs used to decode the segment id for each macro block. */
            for (i = 0; i < MB_FEATURE_TREE_PROBS; i++)
            {
                /* If not explicitly set value is defaulted to 255 by memset above. */
                if (vp8_read_bit(bd))
                    mb->mb_segment_tree_probs[i] = (vp8_prob)vp8_read_literal(bd, 8);
            }
        }
    }

    /* Read the loop filter level and type */
    common->filter_type = (LOOPFILTER_TYPE)vp8_read_bit(bd);
    common->filter_level = vp8_read_literal(bd, 6);
    common->sharpness_level = vp8_read_literal(bd, 3);

    /* Read in loop filter deltas applied at the MB level based on mode or ref frame. */
    mb->mode_ref_lf_delta_update = 0;
    mb->mode_ref_lf_delta_enabled = (unsigned char)vp8_read_bit(bd);

    if (mb->mode_ref_lf_delta_enabled)
    {
        /* Do the deltas need to be updated */
        mb->mode_ref_lf_delta_update = (unsigned char)vp8_read_bit(bd);

        if (mb->mode_ref_lf_delta_update)
        {
            /* Send update */
            for (i = 0; i < MAX_REF_LF_DELTAS; i++)
            {
                if (vp8_read_bit(bd))
                {
                    mb->ref_lf_deltas[i] = (signed char)vp8_read_literal(bd, 6);

                    /* Apply sign */
                    if (vp8_read_bit(bd))
                        mb->ref_lf_deltas[i] = mb->ref_lf_deltas[i] * -1;
                }
            }

            /* Send update */
            for (i = 0; i < MAX_MODE_LF_DELTAS; i++)
            {
                if (vp8_read_bit(bd))
                {
                    mb->mode_lf_deltas[i] = (signed char)vp8_read_literal(bd, 6);

                    /* Apply sign */
                    if (vp8_read_bit(bd))
                        mb->mode_lf_deltas[i] = mb->mode_lf_deltas[i] * -1;
                }
            }
        }
    }

    token_decoder_setup(common, data + first_partition_length_in_bytes);
    mb->current_bd = &common->bd2;

    /* Read the default quantizers. */
    {
        int q_update = 0;

        common->base_qindex  = vp8_read_literal(bd, 7); /* AC 1st order Q = default */
        common->y1dc_delta_q = get_delta_q(bd, common->y1dc_delta_q, &q_update);
        common->y2dc_delta_q = get_delta_q(bd, common->y2dc_delta_q, &q_update);
        common->y2ac_delta_q = get_delta_q(bd, common->y2ac_delta_q, &q_update);
        common->uvdc_delta_q = get_delta_q(bd, common->uvdc_delta_q, &q_update);
        common->uvac_delta_q = get_delta_q(bd, common->uvac_delta_q, &q_update);

        if (q_update)
            vp8_initialize_dequantizer(common);

        /* MB level dequantizer setup */
        mb_init_dequantizer(common, &common->mb);
    }

    /* Determine if the golden frame or ARF buffer should be updated and how.
     * For all non key frames the GF and ARF refresh flags and sign bias
     * flags must be set explicitly. */
    if (common->frame_type != KEY_FRAME)
    {
        /* Should the GF or ARF be updated from the current frame. */
        common->refresh_golden_frame = vp8_read_bit(bd);
        common->refresh_alternate_frame = vp8_read_bit(bd);

        /* Buffer to buffer copy flags. */
        common->copy_buffer_to_golden = 0;
        common->copy_buffer_to_alternate = 0;

        if (!common->refresh_golden_frame)
            common->copy_buffer_to_golden = vp8_read_literal(bd, 2);

        if (!common->refresh_alternate_frame)
            common->copy_buffer_to_alternate = vp8_read_literal(bd, 2);

        common->ref_frame_sign_bias[GOLDEN_FRAME] = vp8_read_bit(bd);
        common->ref_frame_sign_bias[ALTREF_FRAME] = vp8_read_bit(bd);
    }

    common->refresh_entropy_probs = vp8_read_bit(bd);
    if (common->refresh_entropy_probs == 0)
    {
        memcpy(&common->lfc, &common->fc, sizeof(common->fc));
    }

    common->refresh_last_frame = (common->frame_type == KEY_FRAME || vp8_read_bit(bd));

    /* Read coef probability tree */
    for (i = 0; i < BLOCK_TYPES; i++)
        for (j = 0; j < COEF_BANDS; j++)
            for (k = 0; k < PREV_COEF_CONTEXTS; k++)
                for (l = 0; l < ENTROPY_NODES; l++)
                {
                    vp8_prob *const p = common->fc.coef_probs[i][j][k] + l;

                    if (vp8_read(bd, vp8_coef_update_probs[i][j][k][l]))
                    {
                        *p = (vp8_prob)vp8_read_literal(bd, 8);
                    }
                }

    memcpy(&mb->pre, &common->yv12_fb[common->lst_fb_idx], sizeof(YV12_BUFFER_CONFIG));
    memcpy(&mb->dst, &common->yv12_fb[common->new_fb_idx], sizeof(YV12_BUFFER_CONFIG));

    /* Set up frame new frame for intra coded blocks */
    vp8_setup_intra_recon(&common->yv12_fb[common->new_fb_idx]);

    vp8_setup_block_dptrs(mb);

    vp8_setup_block_doffsets(mb);

    /* Clear out the coeff buffer */
    memset(mb->qcoeff, 0, sizeof(mb->qcoeff));

    /* Read the mb_no_coeff_skip flag */
    common->mb_no_skip_coeff = vp8_read_bit(bd);

    vp8_decode_mode_mvs(common);

    memset(common->above_context, 0, sizeof(ENTROPY_CONTEXT_PLANES) * common->mb_cols);

    {
        int ibc = 0;
        int num_part = 1 << common->multi_token_partition;

        /* Decode the individual macro block */
        for (mb_row = 0; mb_row < common->mb_rows; mb_row++)
        {
            if (num_part > 1)
            {
                mb->current_bd = &common->mbd[ibc];
                ibc++;

                if (ibc == num_part)
                    ibc = 0;
            }

            decode_macroblock_row(common, mb_row, mb);
        }
    }

    token_decoder_stop(common);

    /* Collect information about decoder corruption. */
    /* 1. Check first boolean decoder for errors. */
    common->yv12_fb[common->new_fb_idx].corrupted = vp8dx_bool_error(bd);

    /* 2. Check the macroblock information */
    common->yv12_fb[common->new_fb_idx].corrupted |= mb->corrupted;

    /* printf("Decoder: Frame Decoded, Size Roughly:%d bytes \n", bc->pos+pbi->bc2.pos); */

    /* If this was a kf or Gf note the Q used */
    if (common->frame_type == KEY_FRAME ||
        common->refresh_golden_frame ||
        common->refresh_alternate_frame)
    {
        common->last_kf_gf_q = common->base_qindex;
    }

    if (common->refresh_entropy_probs == 0)
    {
        memcpy(&common->fc, &common->lfc, sizeof(common->fc));
    }

    return 0;
}