path: root/libavcodec/vc1dec.c

/*
 * VC-1 and WMV3 decoder
 * Copyright (c) 2011 Mashiat Sarker Shakkhar
 * Copyright (c) 2006-2007 Konstantin Shishkov
 * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * VC-1 and WMV3 decoder
 */

#include "avcodec.h"
#include "blockdsp.h"
#include "get_bits.h"
#include "internal.h"
#include "mpeg_er.h"
#include "mpegvideo.h"
#include "msmpeg4.h"
#include "msmpeg4data.h"
#include "profiles.h"
#include "vc1.h"
#include "vc1data.h"

#if CONFIG_WMV3IMAGE_DECODER || CONFIG_VC1IMAGE_DECODER

typedef struct SpriteData {
    /**
     * Transform coefficients for both sprites in 16.16 fixed point format,
     * in the order they appear in the bitstream:
     *  x scale
     *  rotation 1 (unused)
     *  x offset
     *  rotation 2 (unused)
     *  y scale
     *  y offset
     *  alpha
     */
    int coefs[2][7];

    int effect_type, effect_flag;
    int effect_pcount1, effect_pcount2;   ///< amount of effect parameters stored in effect_params
    int effect_params1[15], effect_params2[10]; ///< effect parameters in 16.16 fixed point format
} SpriteData;

static inline int get_fp_val(GetBitContext* gb)
{
    return (get_bits_long(gb, 30) - (1 << 29)) << 1;
}

static void vc1_sprite_parse_transform(GetBitContext* gb, int c[7])
{
    c[1] = c[3] = 0;

    switch (get_bits(gb, 2)) {
    case 0:
        c[0] = 1 << 16;
        c[2] = get_fp_val(gb);
        c[4] = 1 << 16;
        break;
    case 1:
        c[0] = c[4] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        break;
    case 2:
        c[0] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        c[4] = get_fp_val(gb);
        break;
    case 3:
        c[0] = get_fp_val(gb);
        c[1] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        c[3] = get_fp_val(gb);
        c[4] = get_fp_val(gb);
        break;
    }
    c[5] = get_fp_val(gb);
    if (get_bits1(gb))
        c[6] = get_fp_val(gb);
    else
        c[6] = 1 << 16;
}

static void vc1_parse_sprites(VC1Context *v, GetBitContext* gb, SpriteData* sd)
{
    AVCodecContext *avctx = v->s.avctx;
    int sprite, i;

    for (sprite = 0; sprite <= v->two_sprites; sprite++) {
        vc1_sprite_parse_transform(gb, sd->coefs[sprite]);
        if (sd->coefs[sprite][1] || sd->coefs[sprite][3])
            avpriv_request_sample(avctx, "Non-zero rotation coefficients");
        av_log(avctx, AV_LOG_DEBUG, sprite ? "S2:" : "S1:");
        for (i = 0; i < 7; i++)
            av_log(avctx, AV_LOG_DEBUG, " %d.%.3d",
                   sd->coefs[sprite][i] / (1<<16),
                   (abs(sd->coefs[sprite][i]) & 0xFFFF) * 1000 / (1 << 16));
        av_log(avctx, AV_LOG_DEBUG, "\n");
    }

    skip_bits(gb, 2);
    if (sd->effect_type = get_bits_long(gb, 30)) {
        switch (sd->effect_pcount1 = get_bits(gb, 4)) {
        case 7:
            vc1_sprite_parse_transform(gb, sd->effect_params1);
            break;
        case 14:
            vc1_sprite_parse_transform(gb, sd->effect_params1);
            vc1_sprite_parse_transform(gb, sd->effect_params1 + 7);
            break;
        default:
            for (i = 0; i < sd->effect_pcount1; i++)
                sd->effect_params1[i] = get_fp_val(gb);
        }
        if (sd->effect_type != 13 || sd->effect_params1[0] != sd->coefs[0][6]) {
            // effect 13 is simple alpha blending and matches the opacity above
            av_log(avctx, AV_LOG_DEBUG, "Effect: %d; params: ", sd->effect_type);
            for (i = 0; i < sd->effect_pcount1; i++)
                av_log(avctx, AV_LOG_DEBUG, " %d.%.2d",
                       sd->effect_params1[i] / (1 << 16),
                       (abs(sd->effect_params1[i]) & 0xFFFF) * 1000 / (1 << 16));
            av_log(avctx, AV_LOG_DEBUG, "\n");
        }

        sd->effect_pcount2 = get_bits(gb, 16);
        if (sd->effect_pcount2 > 10) {
            av_log(avctx, AV_LOG_ERROR, "Too many effect parameters\n");
            return;
        } else if (sd->effect_pcount2) {
            i = -1;
            av_log(avctx, AV_LOG_DEBUG, "Effect params 2: ");
            while (++i < sd->effect_pcount2) {
                sd->effect_params2[i] = get_fp_val(gb);
                av_log(avctx, AV_LOG_DEBUG, " %d.%.2d",
                       sd->effect_params2[i] / (1 << 16),
                       (abs(sd->effect_params2[i]) & 0xFFFF) * 1000 / (1 << 16));
            }
            av_log(avctx, AV_LOG_DEBUG, "\n");
        }
    }
    if (sd->effect_flag = get_bits1(gb))
        av_log(avctx, AV_LOG_DEBUG, "Effect flag set\n");

    if (get_bits_count(gb) >= gb->size_in_bits +
       (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE ? 64 : 0))
        av_log(avctx, AV_LOG_ERROR, "Buffer overrun\n");
    if (get_bits_count(gb) < gb->size_in_bits - 8)
        av_log(avctx, AV_LOG_WARNING, "Buffer not fully read\n");
}

static void vc1_draw_sprites(VC1Context *v, SpriteData* sd)
{
    int i, plane, row, sprite;
    int sr_cache[2][2] = { { -1, -1 }, { -1, -1 } };
    uint8_t* src_h[2][2];
    int xoff[2], xadv[2], yoff[2], yadv[2], alpha;
    int ysub[2];
    MpegEncContext *s = &v->s;

    for (i = 0; i < 2; i++) {
        xoff[i] = av_clip(sd->coefs[i][2], 0, v->sprite_width-1 << 16);
        xadv[i] = sd->coefs[i][0];
        if (xadv[i] != 1<<16 || (v->sprite_width << 16) - (v->output_width << 16) - xoff[i])
            xadv[i] = av_clip(xadv[i], 0, ((v->sprite_width<<16) - xoff[i] - 1) / v->output_width);

        yoff[i] = av_clip(sd->coefs[i][5], 0, v->sprite_height-1 << 16);
        yadv[i] = av_clip(sd->coefs[i][4], 0, ((v->sprite_height << 16) - yoff[i]) / v->output_height);
    }
    alpha = av_clip_uint16(sd->coefs[1][6]);

    for (plane = 0; plane < (s->avctx->flags & AV_CODEC_FLAG_GRAY ? 1 : 3); plane++) {
        int width = v->output_width>>!!plane;

        for (row = 0; row < v->output_height>>!!plane; row++) {
            uint8_t *dst = v->sprite_output_frame->data[plane] +
                           v->sprite_output_frame->linesize[plane] * row;

            for (sprite = 0; sprite <= v->two_sprites; sprite++) {
                uint8_t *iplane = s->current_picture.f->data[plane];
                int      iline  = s->current_picture.f->linesize[plane];
                int      ycoord = yoff[sprite] + yadv[sprite] * row;
                int      yline  = ycoord >> 16;
                int      next_line;
                ysub[sprite] = ycoord & 0xFFFF;
                if (sprite) {
                    iplane = s->last_picture.f->data[plane];
                    iline  = s->last_picture.f->linesize[plane];
                }
                next_line = FFMIN(yline + 1, (v->sprite_height >> !!plane) - 1) * iline;
                if (!(xoff[sprite] & 0xFFFF) && xadv[sprite] == 1 << 16) {
                        src_h[sprite][0] = iplane + (xoff[sprite] >> 16) +  yline      * iline;
                    if (ysub[sprite])
                        src_h[sprite][1] = iplane + (xoff[sprite] >> 16) + next_line;
                } else {
                    if (sr_cache[sprite][0] != yline) {
                        if (sr_cache[sprite][1] == yline) {
                            FFSWAP(uint8_t*, v->sr_rows[sprite][0], v->sr_rows[sprite][1]);
                            FFSWAP(int,        sr_cache[sprite][0],   sr_cache[sprite][1]);
                        } else {
                            v->vc1dsp.sprite_h(v->sr_rows[sprite][0], iplane + yline * iline, xoff[sprite], xadv[sprite], width);
                            sr_cache[sprite][0] = yline;
                        }
                    }
                    if (ysub[sprite] && sr_cache[sprite][1] != yline + 1) {
                        v->vc1dsp.sprite_h(v->sr_rows[sprite][1],
                                           iplane + next_line, xoff[sprite],
                                           xadv[sprite], width);
                        sr_cache[sprite][1] = yline + 1;
                    }
                    src_h[sprite][0] = v->sr_rows[sprite][0];
                    src_h[sprite][1] = v->sr_rows[sprite][1];
                }
            }

            if (!v->two_sprites) {
                if (ysub[0]) {
                    v->vc1dsp.sprite_v_single(dst, src_h[0][0], src_h[0][1], ysub[0], width);
                } else {
                    memcpy(dst, src_h[0][0], width);
                }
            } else {
                if (ysub[0] && ysub[1]) {
                    v->vc1dsp.sprite_v_double_twoscale(dst, src_h[0][0], src_h[0][1], ysub[0],
                                                       src_h[1][0], src_h[1][1], ysub[1], alpha, width);
                } else if (ysub[0]) {
                    v->vc1dsp.sprite_v_double_onescale(dst, src_h[0][0], src_h[0][1], ysub[0],
                                                       src_h[1][0], alpha, width);
                } else if (ysub[1]) {
                    v->vc1dsp.sprite_v_double_onescale(dst, src_h[1][0], src_h[1][1], ysub[1],
                                                       src_h[0][0], (1<<16)-1-alpha, width);
                } else {
                    v->vc1dsp.sprite_v_double_noscale(dst, src_h[0][0], src_h[1][0], alpha, width);
                }
            }
        }

        if (!plane) {
            for (i = 0; i < 2; i++) {
                xoff[i] >>= 1;
                yoff[i] >>= 1;
            }
        }

    }
}


static int vc1_decode_sprites(VC1Context *v, GetBitContext* gb)
{
    MpegEncContext *s     = &v->s;
    AVCodecContext *avctx = s->avctx;
    SpriteData sd;

    vc1_parse_sprites(v, gb, &sd);

    if (!s->current_picture.f->data[0]) {
        av_log(avctx, AV_LOG_ERROR, "Got no sprites\n");
        return -1;
    }

    if (v->two_sprites && (!s->last_picture_ptr || !s->last_picture.f->data[0])) {
        av_log(avctx, AV_LOG_WARNING, "Need two sprites, only got one\n");
        v->two_sprites = 0;
    }

    av_frame_unref(v->sprite_output_frame);
    if (ff_get_buffer(avctx, v->sprite_output_frame, 0) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    vc1_draw_sprites(v, &sd);

    return 0;
}

static void vc1_sprite_flush(AVCodecContext *avctx)
{
    VC1Context *v     = avctx->priv_data;
    MpegEncContext *s = &v->s;
    AVFrame *f = s->current_picture.f;
    int plane, i;

    /* Windows Media Image codecs have a convergence interval of two keyframes.
       Since we can't enforce it, clear to black the missing sprite. This is
       wrong but it looks better than doing nothing. */

    if (f && f->data[0])
        for (plane = 0; plane < (s->avctx->flags & AV_CODEC_FLAG_GRAY ? 1 : 3); plane++)
            for (i = 0; i < v->sprite_height>>!!plane; i++)
                memset(f->data[plane] + i * f->linesize[plane],
                       plane ? 128 : 0, f->linesize[plane]);
}

#endif

av_cold int ff_vc1_decode_init_alloc_tables(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int i;
    int mb_height = FFALIGN(s->mb_height, 2);

    /* Allocate mb bitplanes */
    v->mv_type_mb_plane = av_malloc (s->mb_stride * mb_height);
    v->direct_mb_plane  = av_malloc (s->mb_stride * mb_height);
    v->forward_mb_plane = av_malloc (s->mb_stride * mb_height);
    v->fieldtx_plane    = av_mallocz(s->mb_stride * mb_height);
    v->acpred_plane     = av_malloc (s->mb_stride * mb_height);
    v->over_flags_plane = av_malloc (s->mb_stride * mb_height);

    v->n_allocated_blks = s->mb_width + 2;
    v->block            = av_malloc(sizeof(*v->block) * v->n_allocated_blks);
    v->cbp_base         = av_malloc(sizeof(v->cbp_base[0]) * 2 * s->mb_stride);
    v->cbp              = v->cbp_base + s->mb_stride;
    v->ttblk_base       = av_malloc(sizeof(v->ttblk_base[0]) * 2 * s->mb_stride);
    v->ttblk            = v->ttblk_base + s->mb_stride;
    v->is_intra_base    = av_mallocz(sizeof(v->is_intra_base[0]) * 2 * s->mb_stride);
    v->is_intra         = v->is_intra_base + s->mb_stride;
    v->luma_mv_base     = av_malloc(sizeof(v->luma_mv_base[0]) * 2 * s->mb_stride);
    v->luma_mv          = v->luma_mv_base + s->mb_stride;

    /* allocate block type info in that way so it could be used with s->block_index[] */
    v->mb_type_base = av_malloc(s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2);
    v->mb_type[0]   = v->mb_type_base + s->b8_stride + 1;
    v->mb_type[1]   = v->mb_type_base + s->b8_stride * (mb_height * 2 + 1) + s->mb_stride + 1;
    v->mb_type[2]   = v->mb_type[1] + s->mb_stride * (mb_height + 1);

    /* allocate memory to store block level MV info */
    v->blk_mv_type_base = av_mallocz(     s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2);
    v->blk_mv_type      = v->blk_mv_type_base + s->b8_stride + 1;
    v->mv_f_base        = av_mallocz(2 * (s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2));
    v->mv_f[0]          = v->mv_f_base + s->b8_stride + 1;
    v->mv_f[1]          = v->mv_f[0] + (s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2);
    v->mv_f_next_base   = av_mallocz(2 * (s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2));
    v->mv_f_next[0]     = v->mv_f_next_base + s->b8_stride + 1;
    v->mv_f_next[1]     = v->mv_f_next[0] + (s->b8_stride * (mb_height * 2 + 1) + s->mb_stride * (mb_height + 1) * 2);

    ff_intrax8_common_init(&v->x8,s);

    if (s->avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || s->avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        for (i = 0; i < 4; i++)
            if (!(v->sr_rows[i >> 1][i & 1] = av_malloc(v->output_width))) return -1;
    }

    if (!v->mv_type_mb_plane || !v->direct_mb_plane || !v->acpred_plane || !v->over_flags_plane ||
        !v->block || !v->cbp_base || !v->ttblk_base || !v->is_intra_base || !v->luma_mv_base ||
        !v->mb_type_base) {
        av_freep(&v->mv_type_mb_plane);
        av_freep(&v->direct_mb_plane);
        av_freep(&v->acpred_plane);
        av_freep(&v->over_flags_plane);
        av_freep(&v->block);
        av_freep(&v->cbp_base);
        av_freep(&v->ttblk_base);
        av_freep(&v->is_intra_base);
        av_freep(&v->luma_mv_base);
        av_freep(&v->mb_type_base);
        return AVERROR(ENOMEM);
    }

    return 0;
}

av_cold void ff_vc1_init_transposed_scantables(VC1Context *v)
{
    int i;
    for (i = 0; i < 64; i++) {
#define transpose(x) ((x >> 3) | ((x & 7) << 3))
        v->zz_8x8[0][i] = transpose(ff_wmv1_scantable[0][i]);
        v->zz_8x8[1][i] = transpose(ff_wmv1_scantable[1][i]);
        v->zz_8x8[2][i] = transpose(ff_wmv1_scantable[2][i]);
        v->zz_8x8[3][i] = transpose(ff_wmv1_scantable[3][i]);
        v->zzi_8x8[i]   = transpose(ff_vc1_adv_interlaced_8x8_zz[i]);
    }
    v->left_blk_sh = 0;
    v->top_blk_sh  = 3;
}

/** Initialize a VC1/WMV3 decoder
 * @todo TODO: Handle VC-1 IDUs (Transport level?)
 * @todo TODO: Decypher remaining bits in extra_data
 */
static av_cold int vc1_decode_init(AVCodecContext *avctx)
{
    VC1Context *v = avctx->priv_data;
    MpegEncContext *s = &v->s;
    GetBitContext gb;

    /* save the container output size for WMImage */
    v->output_width  = avctx->width;
    v->output_height = avctx->height;

    if (!avctx->extradata_size || !avctx->extradata)
        return -1;
    if (!(avctx->flags & AV_CODEC_FLAG_GRAY))
        avctx->pix_fmt = ff_get_format(avctx, avctx->codec->pix_fmts);
    else
        avctx->pix_fmt = AV_PIX_FMT_GRAY8;
    v->s.avctx = avctx;

    if (ff_vc1_init_common(v) < 0)
        return -1;
    ff_blockdsp_init(&s->bdsp, avctx);
    ff_h264chroma_init(&v->h264chroma, 8);
    ff_qpeldsp_init(&s->qdsp);

    if (avctx->codec_id == AV_CODEC_ID_WMV3 || avctx->codec_id == AV_CODEC_ID_WMV3IMAGE) {
        int count = 0;

        // looks like WMV3 has a sequence header stored in the extradata
        // advanced sequence header may be before the first frame
        // the last byte of the extradata is a version number, 1 for the
        // samples we can decode

        init_get_bits(&gb, avctx->extradata, avctx->extradata_size*8);

        if (ff_vc1_decode_sequence_header(avctx, v, &gb) < 0)
          return -1;

        count = avctx->extradata_size*8 - get_bits_count(&gb);
        if (count > 0) {
            av_log(avctx, AV_LOG_INFO, "Extra data: %i bits left, value: %X\n",
                   count, get_bits_long(&gb, FFMIN(count, 32)));
        } else if (count < 0) {
            av_log(avctx, AV_LOG_INFO, "Read %i bits in overflow\n", -count);
        }
    } else { // VC1/WVC1/WVP2
        const uint8_t *start = avctx->extradata;
        uint8_t *end = avctx->extradata + avctx->extradata_size;
        const uint8_t *next;
        int size, buf2_size;
        uint8_t *buf2 = NULL;
        int seq_initialized = 0, ep_initialized = 0;

        if (avctx->extradata_size < 16) {
            av_log(avctx, AV_LOG_ERROR, "Extradata size too small: %i\n", avctx->extradata_size);
            return -1;
        }

        buf2  = av_mallocz(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
        start = find_next_marker(start, end); // in WVC1 extradata first byte is its size, but can be 0 in mkv
        next  = start;
        for (; next < end; start = next) {
            next = find_next_marker(start + 4, end);
            size = next - start - 4;
            if (size <= 0)
                continue;
            buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
            init_get_bits(&gb, buf2, buf2_size * 8);
            switch (AV_RB32(start)) {
            case VC1_CODE_SEQHDR:
                if (ff_vc1_decode_sequence_header(avctx, v, &gb) < 0) {
                    av_free(buf2);
                    return -1;
                }
                seq_initialized = 1;
                break;
            case VC1_CODE_ENTRYPOINT:
                if (ff_vc1_decode_entry_point(avctx, v, &gb) < 0) {
                    av_free(buf2);
                    return -1;
                }
                ep_initialized = 1;
                break;
            }
        }
        av_free(buf2);
        if (!seq_initialized || !ep_initialized) {
            av_log(avctx, AV_LOG_ERROR, "Incomplete extradata\n");
            return -1;
        }
        v->res_sprite = (avctx->codec_id == AV_CODEC_ID_VC1IMAGE);
    }

    v->sprite_output_frame = av_frame_alloc();
    if (!v->sprite_output_frame)
        return AVERROR(ENOMEM);

    avctx->profile = v->profile;
    if (v->profile == PROFILE_ADVANCED)
        avctx->level = v->level;

    avctx->has_b_frames = !!avctx->max_b_frames;

    if (v->color_prim == 1 || v->color_prim == 5 || v->color_prim == 6)
        avctx->color_primaries = v->color_prim;
    if (v->transfer_char == 1 || v->transfer_char == 7)
        avctx->color_trc = v->transfer_char;
    if (v->matrix_coef == 1 || v->matrix_coef == 6 || v->matrix_coef == 7)
        avctx->colorspace = v->matrix_coef;

    s->mb_width  = (avctx->coded_width  + 15) >> 4;
    s->mb_height = (avctx->coded_height + 15) >> 4;

    if (v->profile == PROFILE_ADVANCED || v->res_fasttx) {
        ff_vc1_init_transposed_scantables(v);
    } else {
        memcpy(v->zz_8x8, ff_wmv1_scantable, 4*64);
        v->left_blk_sh = 3;
        v->top_blk_sh  = 0;
    }

    if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        v->sprite_width  = avctx->coded_width;
        v->sprite_height = avctx->coded_height;

        avctx->coded_width  = avctx->width  = v->output_width;
        avctx->coded_height = avctx->height = v->output_height;

        // prevent 16.16 overflows
        if (v->sprite_width  > 1 << 14 ||
            v->sprite_height > 1 << 14 ||
            v->output_width  > 1 << 14 ||
            v->output_height > 1 << 14) return -1;
    }
    return 0;
}

/** Close a VC1/WMV3 decoder
 * @warning Initial try at using MpegEncContext stuff
 */
av_cold int ff_vc1_decode_end(AVCodecContext *avctx)
{
    VC1Context *v = avctx->priv_data;
    int i;

    av_frame_free(&v->sprite_output_frame);

    for (i = 0; i < 4; i++)
        av_freep(&v->sr_rows[i >> 1][i & 1]);
    av_freep(&v->hrd_rate);
    av_freep(&v->hrd_buffer);
    ff_mpv_common_end(&v->s);
    av_freep(&v->mv_type_mb_plane);
    av_freep(&v->direct_mb_plane);
    av_freep(&v->forward_mb_plane);
    av_freep(&v->fieldtx_plane);
    av_freep(&v->acpred_plane);
    av_freep(&v->over_flags_plane);
    av_freep(&v->mb_type_base);
    av_freep(&v->blk_mv_type_base);
    av_freep(&v->mv_f_base);
    av_freep(&v->mv_f_next_base);
    av_freep(&v->block);
    av_freep(&v->cbp_base);
    av_freep(&v->ttblk_base);
    av_freep(&v->is_intra_base); // FIXME use v->mb_type[]
    av_freep(&v->luma_mv_base);
    ff_intrax8_common_end(&v->x8);
    return 0;
}


/** Decode a VC1/WMV3 frame
 * @todo TODO: Handle VC-1 IDUs (Transport level?)
 */
static int vc1_decode_frame(AVCodecContext *avctx, void *data,
                            int *got_frame, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size, n_slices = 0, i, ret;
    VC1Context *v = avctx->priv_data;
    MpegEncContext *s = &v->s;
    AVFrame *pict = data;
    uint8_t *buf2 = NULL;
    const uint8_t *buf_start = buf;
    int mb_height, n_slices1;
    struct {
        uint8_t *buf;
        GetBitContext gb;
        int mby_start;
    } *slices = NULL, *tmp;

    /* no supplementary picture */
    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == VC1_CODE_ENDOFSEQ)) {
        /* special case for last picture */
        if (s->low_delay == 0 && s->next_picture_ptr) {
            if ((ret = av_frame_ref(pict, s->next_picture_ptr->f)) < 0)
                return ret;
            s->next_picture_ptr = NULL;

            *got_frame = 1;
        }

        return 0;
    }

    //for advanced profile we may need to parse and unescape data
    if (avctx->codec_id == AV_CODEC_ID_VC1 || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        int buf_size2 = 0;
        buf2 = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE);

        if (IS_MARKER(AV_RB32(buf))) { /* frame starts with marker and needs to be parsed */
            const uint8_t *start, *end, *next;
            int size;

            next = buf;
            for (start = buf, end = buf + buf_size; next < end; start = next) {
                next = find_next_marker(start + 4, end);
                size = next - start - 4;
                if (size <= 0) continue;
                switch (AV_RB32(start)) {
                case VC1_CODE_FRAME:
                    if (avctx->hwaccel)
                        buf_start = start;
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    break;
                case VC1_CODE_FIELD: {
                    int buf_size3;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                        goto err;
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                        goto err;
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    /* assuming that the field marker is at the exact middle,
                       hope it's correct */
                    slices[n_slices].mby_start = s->mb_height >> 1;
                    n_slices1 = n_slices - 1; // index of the last slice of the first field
                    n_slices++;
                    break;
                }
                case VC1_CODE_ENTRYPOINT: /* it should be before frame data */
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    init_get_bits(&s->gb, buf2, buf_size2 * 8);
                    ff_vc1_decode_entry_point(avctx, v, &s->gb);
                    break;
                case VC1_CODE_SLICE: {
                    int buf_size3;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                        goto err;
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                        goto err;
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    slices[n_slices].mby_start = get_bits(&slices[n_slices].gb, 9);
                    n_slices++;
                    break;
                }
                }
            }
        } else if (v->interlace && ((buf[0] & 0xC0) == 0xC0)) { /* WVC1 interlaced stores both fields divided by marker */
            const uint8_t *divider;
            int buf_size3;

            divider = find_next_marker(buf, buf + buf_size);
            if ((divider == (buf + buf_size)) || AV_RB32(divider) != VC1_CODE_FIELD) {
                av_log(avctx, AV_LOG_ERROR, "Error in WVC1 interlaced frame\n");
                goto err;
            } else { // found field marker, unescape second field
                tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                if (!tmp)
                    goto err;
                slices = tmp;
                slices[n_slices].buf = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
                if (!slices[n_slices].buf)
                    goto err;
                buf_size3 = vc1_unescape_buffer(divider + 4, buf + buf_size - divider - 4, slices[n_slices].buf);
                init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                              buf_size3 << 3);
                slices[n_slices].mby_start = s->mb_height >> 1;
                n_slices1 = n_slices - 1;
                n_slices++;
            }
            buf_size2 = vc1_unescape_buffer(buf, divider - buf, buf2);
        } else {
            buf_size2 = vc1_unescape_buffer(buf, buf_size, buf2);
        }
        init_get_bits(&s->gb, buf2, buf_size2*8);
    } else
        init_get_bits(&s->gb, buf, buf_size*8);

    if (v->res_sprite) {
        v->new_sprite  = !get_bits1(&s->gb);
        v->two_sprites =  get_bits1(&s->gb);
        /* res_sprite means a Windows Media Image stream, AV_CODEC_ID_*IMAGE means
           we're using the sprite compositor. These are intentionally kept separate
           so you can get the raw sprites by using the wmv3 decoder for WMVP or
           the vc1 one for WVP2 */
        if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
            if (v->new_sprite) {
                // switch AVCodecContext parameters to those of the sprites
                avctx->width  = avctx->coded_width  = v->sprite_width;
                avctx->height = avctx->coded_height = v->sprite_height;
            } else {
                goto image;
            }
        }
    }

    if (s->context_initialized &&
        (s->width  != avctx->coded_width ||
         s->height != avctx->coded_height)) {
        ff_vc1_decode_end(avctx);
    }

    if (!s->context_initialized) {
        if (ff_msmpeg4_decode_init(avctx) < 0)
            goto err;
        if (ff_vc1_decode_init_alloc_tables(v) < 0) {
            ff_mpv_common_end(s);
            goto err;
        }

        s->low_delay = !avctx->has_b_frames || v->res_sprite;

        if (v->profile == PROFILE_ADVANCED) {
            s->h_edge_pos = avctx->coded_width;
            s->v_edge_pos = avctx->coded_height;
        }
    }

    // do parse frame header
    v->pic_header_flag = 0;
    v->first_pic_header_flag = 1;
    if (v->profile < PROFILE_ADVANCED) {
        if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
            goto err;
        }
    } else {
        if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
            goto err;
        }
    }
    v->first_pic_header_flag = 0;

    if ((avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE)
        && s->pict_type != AV_PICTURE_TYPE_I) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Sprite decoder: expected I-frame\n");
        goto err;
    }

    // for skipping the frame
    s->current_picture.f->pict_type = s->pict_type;
    s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;

    /* skip B-frames if we don't have reference frames */
    if (!s->last_picture_ptr && (s->pict_type == AV_PICTURE_TYPE_B || s->droppable)) {
        goto end;
    }
    if ((avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type == AV_PICTURE_TYPE_B) ||
        (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) ||
         avctx->skip_frame >= AVDISCARD_ALL) {
        goto end;
    }

    if (s->next_p_frame_damaged) {
        if (s->pict_type == AV_PICTURE_TYPE_B)
            goto end;
        else
            s->next_p_frame_damaged = 0;
    }

    if (ff_mpv_frame_start(s, avctx) < 0) {
        goto err;
    }

    // process pulldown flags
    s->current_picture_ptr->f->repeat_pict = 0;
    // Pulldown flags are only valid when 'broadcast' has been set.
    // So ticks_per_frame will be 2
    if (v->rff) {
        // repeat field
        s->current_picture_ptr->f->repeat_pict = 1;
    } else if (v->rptfrm) {
        // repeat frames
        s->current_picture_ptr->f->repeat_pict = v->rptfrm * 2;
    }

    s->me.qpel_put = s->qdsp.put_qpel_pixels_tab;
    s->me.qpel_avg = s->qdsp.avg_qpel_pixels_tab;

    if (avctx->hwaccel) {
        if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
            goto err;
        if (avctx->hwaccel->decode_slice(avctx, buf_start, (buf + buf_size) - buf_start) < 0)
            goto err;
        if (avctx->hwaccel->end_frame(avctx) < 0)
            goto err;
    } else {
        int header_ret = 0;

        ff_mpeg_er_frame_start(s);

        v->bits = buf_size * 8;
        v->end_mb_x = s->mb_width;
        if (v->field_mode) {
            s->current_picture.f->linesize[0] <<= 1;
            s->current_picture.f->linesize[1] <<= 1;
            s->current_picture.f->linesize[2] <<= 1;
            s->linesize                      <<= 1;
            s->uvlinesize                    <<= 1;
        }
        mb_height = s->mb_height >> v->field_mode;

        if (!mb_height) {
            av_log(v->s.avctx, AV_LOG_ERROR, "Invalid mb_height.\n");
            goto err;
        }

        for (i = 0; i <= n_slices; i++) {
            if (i > 0 &&  slices[i - 1].mby_start >= mb_height) {
                if (v->field_mode <= 0) {
                    av_log(v->s.avctx, AV_LOG_ERROR, "Slice %d starts beyond "
                           "picture boundary (%d >= %d)\n", i,
                           slices[i - 1].mby_start, mb_height);
                    continue;
                }
                v->second_field = 1;
                v->blocks_off   = s->mb_width  * s->mb_height << 1;
                v->mb_off       = s->mb_stride * s->mb_height >> 1;
            } else {
                v->second_field = 0;
                v->blocks_off   = 0;
                v->mb_off       = 0;
            }
            if (i) {
                v->pic_header_flag = 0;
                if (v->field_mode && i == n_slices1 + 2) {
                    if ((header_ret = ff_vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Field header damaged\n");
                        if (avctx->err_recognition & AV_EF_EXPLODE)
                            goto err;
                        continue;
                    }
                } else if (get_bits1(&s->gb)) {
                    v->pic_header_flag = 1;
                    if ((header_ret = ff_vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Slice header damaged\n");
                        if (avctx->err_recognition & AV_EF_EXPLODE)
                            goto err;
                        continue;
                    }
                }
            }
            if (header_ret < 0)
                continue;
            s->start_mb_y = (i == 0) ? 0 : FFMAX(0, slices[i-1].mby_start % mb_height);
            if (!v->field_mode || v->second_field)
                s->end_mb_y = (i == n_slices     ) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            else
                s->end_mb_y = (i <= n_slices1 + 1) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            ff_vc1_decode_blocks(v);
            if (i != n_slices)
                s->gb = slices[i].gb;
        }
        if (v->field_mode) {
            v->second_field = 0;
            s->current_picture.f->linesize[0] >>= 1;
            s->current_picture.f->linesize[1] >>= 1;
            s->current_picture.f->linesize[2] >>= 1;
            s->linesize                      >>= 1;
            s->uvlinesize                    >>= 1;
            if (v->s.pict_type != AV_PICTURE_TYPE_BI && v->s.pict_type != AV_PICTURE_TYPE_B) {
                FFSWAP(uint8_t *, v->mv_f_next[0], v->mv_f[0]);
                FFSWAP(uint8_t *, v->mv_f_next[1], v->mv_f[1]);
            }
        }
        ff_dlog(s->avctx, "Consumed %i/%i bits\n",
                get_bits_count(&s->gb), s->gb.size_in_bits);
//  if (get_bits_count(&s->gb) > buf_size * 8)
//      return -1;
        if (!v->field_mode)
            ff_er_frame_end(&s->er);
    }

    ff_mpv_frame_end(s);

    if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
image:
        avctx->width  = avctx->coded_width  = v->output_width;
        avctx->height = avctx->coded_height = v->output_height;
        if (avctx->skip_frame >= AVDISCARD_NONREF)
            goto end;
#if CONFIG_WMV3IMAGE_DECODER || CONFIG_VC1IMAGE_DECODER
        if (vc1_decode_sprites(v, &s->gb))
            goto err;
#endif
        if ((ret = av_frame_ref(pict, v->sprite_output_frame)) < 0)
            goto err;
        *got_frame = 1;
    } else {
        if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
            if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
                goto err;
            ff_print_debug_info(s, s->current_picture_ptr);
            *got_frame = 1;
        } else if (s->last_picture_ptr) {
            if ((ret = av_frame_ref(pict, s->last_picture_ptr->f)) < 0)
                goto err;
            ff_print_debug_info(s, s->last_picture_ptr);
            *got_frame = 1;
        }
    }

end:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return buf_size;

err:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return -1;
}


static const enum AVPixelFormat vc1_hwaccel_pixfmt_list_420[] = {
#if CONFIG_VC1_DXVA2_HWACCEL
    AV_PIX_FMT_DXVA2_VLD,
#endif
#if CONFIG_VC1_D3D11VA_HWACCEL
    AV_PIX_FMT_D3D11VA_VLD,
#endif
#if CONFIG_VC1_VAAPI_HWACCEL
    AV_PIX_FMT_VAAPI_VLD,
#endif
#if CONFIG_VC1_VDPAU_HWACCEL
    AV_PIX_FMT_VDPAU,
#endif
    AV_PIX_FMT_YUV420P,
    AV_PIX_FMT_NONE
};

AVCodec ff_vc1_decoder = {
    .name           = "vc1",
    .long_name      = NULL_IF_CONFIG_SMALL("SMPTE VC-1"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_VC1,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .flush          = ff_mpeg_flush,
    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
    .pix_fmts       = vc1_hwaccel_pixfmt_list_420,
    .profiles       = NULL_IF_CONFIG_SMALL(ff_vc1_profiles)
};

#if CONFIG_WMV3_DECODER
AVCodec ff_wmv3_decoder = {
    .name           = "wmv3",
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_WMV3,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .flush          = ff_mpeg_flush,
    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
    .pix_fmts       = vc1_hwaccel_pixfmt_list_420,
    .profiles       = NULL_IF_CONFIG_SMALL(ff_vc1_profiles)
};
#endif

#if CONFIG_WMV3IMAGE_DECODER
AVCodec ff_wmv3image_decoder = {
    .name           = "wmv3image",
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 Image"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_WMV3IMAGE,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .flush          = vc1_sprite_flush,
    .pix_fmts       = (const enum AVPixelFormat[]) {
        AV_PIX_FMT_YUV420P,
        AV_PIX_FMT_NONE
    },
};
#endif

#if CONFIG_VC1IMAGE_DECODER
AVCodec ff_vc1image_decoder = {
    .name           = "vc1image",
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 Image v2"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_VC1IMAGE,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .flush          = vc1_sprite_flush,
    .pix_fmts       = (const enum AVPixelFormat[]) {
        AV_PIX_FMT_YUV420P,
        AV_PIX_FMT_NONE
    },
};
#endif