text: /*
   * Copyright (C) 2007 Marco Gerards <marco@gnu.org>
   * Copyright (C) 2009 David Conrad
   * Copyright (C) 2011 Jordi Ortiz
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg 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.
   *
   * FFmpeg 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 FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * Dirac Decoder
   * @author Marco Gerards <marco@gnu.org>, David Conrad, Jordi Ortiz <nenjordi@gmail.com>
   */
  
  #include "libavutil/thread.h"
  #include "avcodec.h"
  #include "get_bits.h"
  #include "bytestream.h"
  #include "internal.h"
  #include "golomb.h"
  #include "dirac_arith.h"
  #include "dirac_vlc.h"
  #include "mpeg12data.h"
  #include "libavcodec/mpegvideo.h"
  #include "mpegvideoencdsp.h"
  #include "dirac_dwt.h"
  #include "dirac.h"
  #include "diractab.h"
  #include "diracdsp.h"
  #include "videodsp.h"
  
  /**
   * The spec limits this to 3 for frame coding, but in practice can be as high as 6
   */
  #define MAX_REFERENCE_FRAMES 8
  #define MAX_DELAY 5         /* limit for main profile for frame coding (TODO: field coding) */
  #define MAX_FRAMES (MAX_REFERENCE_FRAMES + MAX_DELAY + 1)
  #define MAX_QUANT 255        /* max quant for VC-2 */
  #define MAX_BLOCKSIZE 32    /* maximum xblen/yblen we support */
  
  /**
   * DiracBlock->ref flags, if set then the block does MC from the given ref
   */
  #define DIRAC_REF_MASK_REF1   1
  #define DIRAC_REF_MASK_REF2   2
  #define DIRAC_REF_MASK_GLOBAL 4
  
  /**
   * Value of Picture.reference when Picture is not a reference picture, but
   * is held for delayed output.
   */
  #define DELAYED_PIC_REF 4
  
  #define CALC_PADDING(size, depth)                       \
      (((size + (1 << depth) - 1) >> depth) << depth)
  
  #define DIVRNDUP(a, b) (((a) + (b) - 1) / (b))
  
  typedef struct {
      AVFrame *avframe;
      int interpolated[3];    /* 1 if hpel[] is valid */
      uint8_t *hpel[3][4];
      uint8_t *hpel_base[3][4];
      int reference;
  } DiracFrame;
  
  typedef struct {
      union {
          int16_t mv[2][2];
          int16_t dc[3];
      } u; /* anonymous unions aren't in C99 :( */
      uint8_t ref;
  } DiracBlock;
  
  typedef struct SubBand {
      int level;
      int orientation;
      int stride; /* in bytes */
      int width;
      int height;
      int pshift;
      int quant;
      uint8_t *ibuf;
      struct SubBand *parent;
  
      /* for low delay */
      unsigned length;
      const uint8_t *coeff_data;
  } SubBand;
  
  typedef struct Plane {
      DWTPlane idwt;
  
      int width;
      int height;
      ptrdiff_t stride;
  
      /* block length */
      uint8_t xblen;
      uint8_t yblen;
      /* block separation (block n+1 starts after this many pixels in block n) */
      uint8_t xbsep;
      uint8_t ybsep;
      /* amount of overspill on each edge (half of the overlap between blocks) */
      uint8_t xoffset;
      uint8_t yoffset;
  
      SubBand band[MAX_DWT_LEVELS][4];
  } Plane;
  
  /* Used by Low Delay and High Quality profiles */
  typedef struct DiracSlice {
      GetBitContext gb;
      int slice_x;
      int slice_y;
      int bytes;
  } DiracSlice;
  
  typedef struct DiracContext {
      AVCodecContext *avctx;
      MpegvideoEncDSPContext mpvencdsp;
      VideoDSPContext vdsp;
      DiracDSPContext diracdsp;
      DiracGolombLUT *reader_ctx;
      DiracVersionInfo version;
      GetBitContext gb;
      AVDiracSeqHeader seq;
      int seen_sequence_header;
      int frame_number;           /* number of the next frame to display       */
      Plane plane[3];
      int chroma_x_shift;
      int chroma_y_shift;
  
      int bit_depth;              /* bit depth                                 */
      int pshift;                 /* pixel shift = bit_depth > 8               */
  
      int zero_res;               /* zero residue flag                         */
      int is_arith;               /* whether coeffs use arith or golomb coding */
      int core_syntax;            /* use core syntax only                      */
      int low_delay;              /* use the low delay syntax                  */
      int hq_picture;             /* high quality picture, enables low_delay   */
      int ld_picture;             /* use low delay picture, turns on low_delay */
      int dc_prediction;          /* has dc prediction                         */
      int globalmc_flag;          /* use global motion compensation            */
      int num_refs;               /* number of reference pictures              */
  
      /* wavelet decoding */
      unsigned wavelet_depth;     /* depth of the IDWT                         */
      unsigned wavelet_idx;
  
      /**
       * schroedinger older than 1.0.8 doesn't store
       * quant delta if only one codebook exists in a band
       */
      unsigned old_delta_quant;
      unsigned codeblock_mode;
  
      unsigned num_x;              /* number of horizontal slices               */
      unsigned num_y;              /* number of vertical slices                 */
  
      uint8_t *thread_buf;         /* Per-thread buffer for coefficient storage */
      int threads_num_buf;         /* Current # of buffers allocated            */
      int thread_buf_size;         /* Each thread has a buffer this size        */
  
      DiracSlice *slice_params_buf;
      int slice_params_num_buf;
  
      struct {
          unsigned width;
          unsigned height;
      } codeblock[MAX_DWT_LEVELS+1];
  
      struct {
          AVRational bytes;       /* average bytes per slice                   */
          uint8_t quant[MAX_DWT_LEVELS][4]; /* [DIRAC_STD] E.1 */
      } lowdelay;
  
      struct {
          unsigned prefix_bytes;
          uint64_t size_scaler;
      } highquality;
  
      struct {
          int pan_tilt[2];        /* pan/tilt vector                           */
          int zrs[2][2];          /* zoom/rotate/shear matrix                  */
          int perspective[2];     /* perspective vector                        */
          unsigned zrs_exp;
          unsigned perspective_exp;
      } globalmc[2];
  
      /* motion compensation */
      uint8_t mv_precision;       /* [DIRAC_STD] REFS_WT_PRECISION             */
      int16_t weight[2];          /* [DIRAC_STD] REF1_WT and REF2_WT           */
      unsigned weight_log2denom;  /* [DIRAC_STD] REFS_WT_PRECISION             */
  
      int blwidth;                /* number of blocks (horizontally)           */
      int blheight;               /* number of blocks (vertically)             */
      int sbwidth;                /* number of superblocks (horizontally)      */
      int sbheight;               /* number of superblocks (vertically)        */
  
      uint8_t *sbsplit;
      DiracBlock *blmotion;
  
      uint8_t *edge_emu_buffer[4];
      uint8_t *edge_emu_buffer_base;
  
      uint16_t *mctmp;            /* buffer holding the MC data multiplied by OBMC weights */
      uint8_t *mcscratch;
      int buffer_stride;
  
      DECLARE_ALIGNED(16, uint8_t, obmc_weight)[3][MAX_BLOCKSIZE*MAX_BLOCKSIZE];
  
      void (*put_pixels_tab[4])(uint8_t *dst, const uint8_t *src[5], int stride, int h);
      void (*avg_pixels_tab[4])(uint8_t *dst, const uint8_t *src[5], int stride, int h);
      void (*add_obmc)(uint16_t *dst, const uint8_t *src, int stride, const uint8_t *obmc_weight, int yblen);
      dirac_weight_func weight_func;
      dirac_biweight_func biweight_func;
  
      DiracFrame *current_picture;
      DiracFrame *ref_pics[2];
  
      DiracFrame *ref_frames[MAX_REFERENCE_FRAMES+1];
      DiracFrame *delay_frames[MAX_DELAY+1];
      DiracFrame all_frames[MAX_FRAMES];
  } DiracContext;
  
  enum dirac_subband {
      subband_ll = 0,
      subband_hl = 1,
      subband_lh = 2,
      subband_hh = 3,
      subband_nb,
  };
  
  /* magic number division by 3 from schroedinger */
  static inline int divide3(int x)
  {
      return ((x+1)*21845 + 10922) >> 16;
  }
  
  static DiracFrame *remove_frame(DiracFrame *framelist[], int picnum)
  {
      DiracFrame *remove_pic = NULL;
      int i, remove_idx = -1;
  
      for (i = 0; framelist[i]; i++)
          if (framelist[i]->avframe->display_picture_number == picnum) {
              remove_pic = framelist[i];
              remove_idx = i;
          }
  
      if (remove_pic)
          for (i = remove_idx; framelist[i]; i++)
              framelist[i] = framelist[i+1];
  
      return remove_pic;
  }
  
  static int add_frame(DiracFrame *framelist[], int maxframes, DiracFrame *frame)
  {
      int i;
      for (i = 0; i < maxframes; i++)
          if (!framelist[i]) {
              framelist[i] = frame;
              return 0;
          }
      return -1;
  }
  
  static int alloc_sequence_buffers(DiracContext *s)
  {
      int sbwidth  = DIVRNDUP(s->seq.width,  4);
      int sbheight = DIVRNDUP(s->seq.height, 4);
      int i, w, h, top_padding;
  
      /* todo: think more about this / use or set Plane here */
      for (i = 0; i < 3; i++) {
          int max_xblen = MAX_BLOCKSIZE >> (i ? s->chroma_x_shift : 0);
          int max_yblen = MAX_BLOCKSIZE >> (i ? s->chroma_y_shift : 0);
          w = s->seq.width  >> (i ? s->chroma_x_shift : 0);
          h = s->seq.height >> (i ? s->chroma_y_shift : 0);
  
          /* we allocate the max we support here since num decompositions can
           * change from frame to frame. Stride is aligned to 16 for SIMD, and
           * 1<<MAX_DWT_LEVELS top padding to avoid if(y>0) in arith decoding
           * MAX_BLOCKSIZE padding for MC: blocks can spill up to half of that
           * on each side */
          top_padding = FFMAX(1<<MAX_DWT_LEVELS, max_yblen/2);
          w = FFALIGN(CALC_PADDING(w, MAX_DWT_LEVELS), 8); /* FIXME: Should this be 16 for SSE??? */
          h = top_padding + CALC_PADDING(h, MAX_DWT_LEVELS) + max_yblen/2;
  
          s->plane[i].idwt.buf_base = av_mallocz_array((w+max_xblen), h * (2 << s->pshift));
          s->plane[i].idwt.tmp      = av_malloc_array((w+16), 2 << s->pshift);
          s->plane[i].idwt.buf      = s->plane[i].idwt.buf_base + (top_padding*w)*(2 << s->pshift);
          if (!s->plane[i].idwt.buf_base || !s->plane[i].idwt.tmp)
              return AVERROR(ENOMEM);
      }
  
      /* fixme: allocate using real stride here */
      s->sbsplit  = av_malloc_array(sbwidth, sbheight);
      s->blmotion = av_malloc_array(sbwidth, sbheight * 16 * sizeof(*s->blmotion));
  
      if (!s->sbsplit || !s->blmotion)
          return AVERROR(ENOMEM);
      return 0;
  }
  
  static int alloc_buffers(DiracContext *s, int stride)
  {
      int w = s->seq.width;
      int h = s->seq.height;
  
      av_assert0(stride >= w);
      stride += 64;
  
      if (s->buffer_stride >= stride)
          return 0;
      s->buffer_stride = 0;
  
      av_freep(&s->edge_emu_buffer_base);
      memset(s->edge_emu_buffer, 0, sizeof(s->edge_emu_buffer));
      av_freep(&s->mctmp);
      av_freep(&s->mcscratch);
  
      s->edge_emu_buffer_base = av_malloc_array(stride, MAX_BLOCKSIZE);
  
      s->mctmp     = av_malloc_array((stride+MAX_BLOCKSIZE), (h+MAX_BLOCKSIZE) * sizeof(*s->mctmp));
      s->mcscratch = av_malloc_array(stride, MAX_BLOCKSIZE);
  
      if (!s->edge_emu_buffer_base || !s->mctmp || !s->mcscratch)
          return AVERROR(ENOMEM);
  
      s->buffer_stride = stride;
      return 0;
  }
  
  static void free_sequence_buffers(DiracContext *s)
  {
      int i, j, k;
  
      for (i = 0; i < MAX_FRAMES; i++) {
          if (s->all_frames[i].avframe->data[0]) {
              av_frame_unref(s->all_frames[i].avframe);
              memset(s->all_frames[i].interpolated, 0, sizeof(s->all_frames[i].interpolated));
          }
  
          for (j = 0; j < 3; j++)
              for (k = 1; k < 4; k++)
                  av_freep(&s->all_frames[i].hpel_base[j][k]);
      }
  
      memset(s->ref_frames, 0, sizeof(s->ref_frames));
      memset(s->delay_frames, 0, sizeof(s->delay_frames));
  
      for (i = 0; i < 3; i++) {
          av_freep(&s->plane[i].idwt.buf_base);
          av_freep(&s->plane[i].idwt.tmp);
      }
  
      s->buffer_stride = 0;
      av_freep(&s->sbsplit);
      av_freep(&s->blmotion);
      av_freep(&s->edge_emu_buffer_base);
  
      av_freep(&s->mctmp);
      av_freep(&s->mcscratch);
  }
  
  static AVOnce dirac_arith_init = AV_ONCE_INIT;
  
  static av_cold int dirac_decode_init(AVCodecContext *avctx)
  {
      DiracContext *s = avctx->priv_data;
      int i, ret;
  
      s->avctx = avctx;
      s->frame_number = -1;
  
      s->thread_buf = NULL;
      s->threads_num_buf = -1;
      s->thread_buf_size = -1;
  
      ff_dirac_golomb_reader_init(&s->reader_ctx);
      ff_diracdsp_init(&s->diracdsp);
      ff_mpegvideoencdsp_init(&s->mpvencdsp, avctx);
      ff_videodsp_init(&s->vdsp, 8);
  
      for (i = 0; i < MAX_FRAMES; i++) {
          s->all_frames[i].avframe = av_frame_alloc();
          if (!s->all_frames[i].avframe) {
              while (i > 0)
                  av_frame_free(&s->all_frames[--i].avframe);
              return AVERROR(ENOMEM);
          }
      }
      ret = ff_thread_once(&dirac_arith_init, ff_dirac_init_arith_tables);
      if (ret != 0)
          return AVERROR_UNKNOWN;
  
      return 0;
  }
  
  static void dirac_decode_flush(AVCodecContext *avctx)
  {
      DiracContext *s = avctx->priv_data;
      free_sequence_buffers(s);
      s->seen_sequence_header = 0;
      s->frame_number = -1;
  }
  
  static av_cold int dirac_decode_end(AVCodecContext *avctx)
  {
      DiracContext *s = avctx->priv_data;
      int i;
  
      ff_dirac_golomb_reader_end(&s->reader_ctx);
  
      dirac_decode_flush(avctx);
      for (i = 0; i < MAX_FRAMES; i++)
          av_frame_free(&s->all_frames[i].avframe);
  
      av_freep(&s->thread_buf);
      av_freep(&s->slice_params_buf);
  
      return 0;
  }
  
  static inline int coeff_unpack_golomb(GetBitContext *gb, int qfactor, int qoffset)
  {
      int coeff = dirac_get_se_golomb(gb);
      const int sign = FFSIGN(coeff);
      if (coeff)
          coeff = sign*((sign * coeff * qfactor + qoffset) >> 2);
      return coeff;
  }
  
  #define SIGN_CTX(x) (CTX_SIGN_ZERO + ((x) > 0) - ((x) < 0))
  
  #define UNPACK_ARITH(n, type) \
      static inline void coeff_unpack_arith_##n(DiracArith *c, int qfactor, int qoffset, \
                                                SubBand *b, type *buf, int x, int y) \
      { \
          int coeff, sign, sign_pred = 0, pred_ctx = CTX_ZPZN_F1; \
          const int mstride = -(b->stride >> (1+b->pshift)); \
          if (b->parent) { \
              const type *pbuf = (type *)b->parent->ibuf; \
              const int stride = b->parent->stride >> (1+b->parent->pshift); \
              pred_ctx += !!pbuf[stride * (y>>1) + (x>>1)] << 1; \
          } \
          if (b->orientation == subband_hl) \
              sign_pred = buf[mstride]; \
          if (x) { \
              pred_ctx += !(buf[-1] | buf[mstride] | buf[-1 + mstride]); \
              if (b->orientation == subband_lh) \
                  sign_pred = buf[-1]; \
          } else { \
              pred_ctx += !buf[mstride]; \
          } \
          coeff = dirac_get_arith_uint(c, pred_ctx, CTX_COEFF_DATA); \
          if (coeff) { \
              coeff = (coeff * qfactor + qoffset) >> 2; \
              sign  = dirac_get_arith_bit(c, SIGN_CTX(sign_pred)); \
              coeff = (coeff ^ -sign) + sign; \
          } \
          *buf = coeff; \
      } \
  
  UNPACK_ARITH(8, int16_t)
  UNPACK_ARITH(10, int32_t)
  
  /**
   * Decode the coeffs in the rectangle defined by left, right, top, bottom
   * [DIRAC_STD] 13.4.3.2 Codeblock unpacking loop. codeblock()
   */
  static inline void codeblock(DiracContext *s, SubBand *b,
                               GetBitContext *gb, DiracArith *c,
                               int left, int right, int top, int bottom,
                               int blockcnt_one, int is_arith)
  {
      int x, y, zero_block;
      int qoffset, qfactor;
      uint8_t *buf;
  
      /* check for any coded coefficients in this codeblock */
      if (!blockcnt_one) {
          if (is_arith)
              zero_block = dirac_get_arith_bit(c, CTX_ZERO_BLOCK);
          else
              zero_block = get_bits1(gb);
  
          if (zero_block)
              return;
      }
  
      if (s->codeblock_mode && !(s->old_delta_quant && blockcnt_one)) {
          int quant = b->quant;
          if (is_arith)
              quant += dirac_get_arith_int(c, CTX_DELTA_Q_F, CTX_DELTA_Q_DATA);
          else
              quant += dirac_get_se_golomb(gb);
          if (quant < 0) {
              av_log(s->avctx, AV_LOG_ERROR, "Invalid quant\n");
              return;
          }
          b->quant = quant;
      }
  
      if (b->quant > (DIRAC_MAX_QUANT_INDEX - 1)) {
          av_log(s->avctx, AV_LOG_ERROR, "Unsupported quant %d\n", b->quant);
          b->quant = 0;
          return;
      }
  
      qfactor = ff_dirac_qscale_tab[b->quant];
      /* TODO: context pointer? */
      if (!s->num_refs)
          qoffset = ff_dirac_qoffset_intra_tab[b->quant] + 2;
      else
          qoffset = ff_dirac_qoffset_inter_tab[b->quant] + 2;
  
      buf = b->ibuf + top * b->stride;
      if (is_arith) {
          for (y = top; y < bottom; y++) {
              for (x = left; x < right; x++) {
                  if (b->pshift) {
                      coeff_unpack_arith_10(c, qfactor, qoffset, b, (int32_t*)(buf)+x, x, y);
                  } else {
                      coeff_unpack_arith_8(c, qfactor, qoffset, b, (int16_t*)(buf)+x, x, y);
                  }
              }
              buf += b->stride;
          }
      } else {
          for (y = top; y < bottom; y++) {
              for (x = left; x < right; x++) {
                  int val = coeff_unpack_golomb(gb, qfactor, qoffset);
                  if (b->pshift) {
                      AV_WN32(&buf[4*x], val);
                  } else {
                      AV_WN16(&buf[2*x], val);
                  }
              }
              buf += b->stride;
           }
       }
  }
  
  /**
   * Dirac Specification ->
   * 13.3 intra_dc_prediction(band)
   */
  #define INTRA_DC_PRED(n, type) \
      static inline void intra_dc_prediction_##n(SubBand *b) \
      { \
          type *buf = (type*)b->ibuf; \
          int x, y; \
          \
          for (x = 1; x < b->width; x++) \
              buf[x] += buf[x-1]; \
          buf += (b->stride >> (1+b->pshift)); \
          \
          for (y = 1; y < b->height; y++) { \
              buf[0] += buf[-(b->stride >> (1+b->pshift))]; \
              \
              for (x = 1; x < b->width; x++) { \
                  int pred = buf[x - 1] + buf[x - (b->stride >> (1+b->pshift))] + buf[x - (b->stride >> (1+b->pshift))-1]; \
                  buf[x]  += divide3(pred); \
              } \
              buf += (b->stride >> (1+b->pshift)); \
          } \
      } \
  
  INTRA_DC_PRED(8, int16_t)
  INTRA_DC_PRED(10, int32_t)
  
  /**
   * Dirac Specification ->
   * 13.4.2 Non-skipped subbands.  subband_coeffs()
   */
  static av_always_inline void decode_subband_internal(DiracContext *s, SubBand *b, int is_arith)
  {
      int cb_x, cb_y, left, right, top, bottom;
      DiracArith c;
      GetBitContext gb;
      int cb_width  = s->codeblock[b->level + (b->orientation != subband_ll)].width;
      int cb_height = s->codeblock[b->level + (b->orientation != subband_ll)].height;
      int blockcnt_one = (cb_width + cb_height) == 2;
  
      if (!b->length)
          return;
  
      init_get_bits8(&gb, b->coeff_data, b->length);
  
      if (is_arith)
          ff_dirac_init_arith_decoder(&c, &gb, b->length);
  
      top = 0;
      for (cb_y = 0; cb_y < cb_height; cb_y++) {
          bottom = (b->height * (cb_y+1LL)) / cb_height;
          left = 0;
          for (cb_x = 0; cb_x < cb_width; cb_x++) {
              right = (b->width * (cb_x+1LL)) / cb_width;
              codeblock(s, b, &gb, &c, left, right, top, bottom, blockcnt_one, is_arith);
              left = right;
          }
          top = bottom;
      }
  
      if (b->orientation == subband_ll && s->num_refs == 0) {
          if (s->pshift) {
              intra_dc_prediction_10(b);
          } else {
              intra_dc_prediction_8(b);
          }
      }
  }
  
  static int decode_subband_arith(AVCodecContext *avctx, void *b)
  {
      DiracContext *s = avctx->priv_data;
      decode_subband_internal(s, b, 1);
      return 0;
  }
  
  static int decode_subband_golomb(AVCodecContext *avctx, void *arg)
  {
      DiracContext *s = avctx->priv_data;
      SubBand **b     = arg;
      decode_subband_internal(s, *b, 0);
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * [DIRAC_STD] 13.4.1 core_transform_data()
   */
  static void decode_component(DiracContext *s, int comp)
  {
      AVCodecContext *avctx = s->avctx;
      SubBand *bands[3*MAX_DWT_LEVELS+1];
      enum dirac_subband orientation;
      int level, num_bands = 0;
  
      /* Unpack all subbands at all levels. */
      for (level = 0; level < s->wavelet_depth; level++) {
          for (orientation = !!level; orientation < 4; orientation++) {
              SubBand *b = &s->plane[comp].band[level][orientation];
              bands[num_bands++] = b;
  
              align_get_bits(&s->gb);
              /* [DIRAC_STD] 13.4.2 subband() */
              b->length = get_interleaved_ue_golomb(&s->gb);
              if (b->length) {
                  b->quant = get_interleaved_ue_golomb(&s->gb);
                  align_get_bits(&s->gb);
                  b->coeff_data = s->gb.buffer + get_bits_count(&s->gb)/8;
                  b->length = FFMIN(b->length, FFMAX(get_bits_left(&s->gb)/8, 0));
                  skip_bits_long(&s->gb, b->length*8);
              }
          }
          /* arithmetic coding has inter-level dependencies, so we can only execute one level at a time */
          if (s->is_arith)
              avctx->execute(avctx, decode_subband_arith, &s->plane[comp].band[level][!!level],
                             NULL, 4-!!level, sizeof(SubBand));
      }
      /* golomb coding has no inter-level dependencies, so we can execute all subbands in parallel */
      if (!s->is_arith)
          avctx->execute(avctx, decode_subband_golomb, bands, NULL, num_bands, sizeof(SubBand*));
  }
  
  #define PARSE_VALUES(type, x, gb, ebits, buf1, buf2) \
      type *buf = (type *)buf1; \
      buf[x] = coeff_unpack_golomb(gb, qfactor, qoffset); \
      if (get_bits_count(gb) >= ebits) \
          return; \
      if (buf2) { \
          buf = (type *)buf2; \
          buf[x] = coeff_unpack_golomb(gb, qfactor, qoffset); \
          if (get_bits_count(gb) >= ebits) \
              return; \
      } \
  
  static void decode_subband(DiracContext *s, GetBitContext *gb, int quant,
                             int slice_x, int slice_y, int bits_end,
                             SubBand *b1, SubBand *b2)
  {
      int left   = b1->width  * slice_x    / s->num_x;
      int right  = b1->width  *(slice_x+1) / s->num_x;
      int top    = b1->height * slice_y    / s->num_y;
      int bottom = b1->height *(slice_y+1) / s->num_y;
  
      int qfactor, qoffset;
  
      uint8_t *buf1 =      b1->ibuf + top * b1->stride;
      uint8_t *buf2 = b2 ? b2->ibuf + top * b2->stride: NULL;
      int x, y;
  
      if (quant > (DIRAC_MAX_QUANT_INDEX - 1)) {
          av_log(s->avctx, AV_LOG_ERROR, "Unsupported quant %d\n", quant);
          return;
      }
      qfactor = ff_dirac_qscale_tab[quant];
      qoffset = ff_dirac_qoffset_intra_tab[quant] + 2;
      /* we have to constantly check for overread since the spec explicitly
         requires this, with the meaning that all remaining coeffs are set to 0 */
      if (get_bits_count(gb) >= bits_end)
          return;
  
      if (s->pshift) {
          for (y = top; y < bottom; y++) {
              for (x = left; x < right; x++) {
                  PARSE_VALUES(int32_t, x, gb, bits_end, buf1, buf2);
              }
              buf1 += b1->stride;
              if (buf2)
                  buf2 += b2->stride;
          }
      }
      else {
          for (y = top; y < bottom; y++) {
              for (x = left; x < right; x++) {
                  PARSE_VALUES(int16_t, x, gb, bits_end, buf1, buf2);
              }
              buf1 += b1->stride;
              if (buf2)
                  buf2 += b2->stride;
          }
      }
  }
  
  /**
   * Dirac Specification ->
   * 13.5.2 Slices. slice(sx,sy)
   */
  static int decode_lowdelay_slice(AVCodecContext *avctx, void *arg)
  {
      DiracContext *s = avctx->priv_data;
      DiracSlice *slice = arg;
      GetBitContext *gb = &slice->gb;
      enum dirac_subband orientation;
      int level, quant, chroma_bits, chroma_end;
  
      int quant_base  = get_bits(gb, 7); /*[DIRAC_STD] qindex */
      int length_bits = av_log2(8 * slice->bytes)+1;
      int luma_bits   = get_bits_long(gb, length_bits);
      int luma_end    = get_bits_count(gb) + FFMIN(luma_bits, get_bits_left(gb));
  
      /* [DIRAC_STD] 13.5.5.2 luma_slice_band */
      for (level = 0; level < s->wavelet_depth; level++)
          for (orientation = !!level; orientation < 4; orientation++) {
              quant = FFMAX(quant_base - s->lowdelay.quant[level][orientation], 0);
              decode_subband(s, gb, quant, slice->slice_x, slice->slice_y, luma_end,
                             &s->plane[0].band[level][orientation], NULL);
          }
  
      /* consume any unused bits from luma */
      skip_bits_long(gb, get_bits_count(gb) - luma_end);
  
      chroma_bits = 8*slice->bytes - 7 - length_bits - luma_bits;
      chroma_end  = get_bits_count(gb) + FFMIN(chroma_bits, get_bits_left(gb));
      /* [DIRAC_STD] 13.5.5.3 chroma_slice_band */
      for (level = 0; level < s->wavelet_depth; level++)
          for (orientation = !!level; orientation < 4; orientation++) {
              quant = FFMAX(quant_base - s->lowdelay.quant[level][orientation], 0);
              decode_subband(s, gb, quant, slice->slice_x, slice->slice_y, chroma_end,
                             &s->plane[1].band[level][orientation],
                             &s->plane[2].band[level][orientation]);
          }
  
      return 0;
  }
  
  typedef struct SliceCoeffs {
      int left;
      int top;
      int tot_h;
      int tot_v;
      int tot;
  } SliceCoeffs;
  
  static int subband_coeffs(DiracContext *s, int x, int y, int p,
                            SliceCoeffs c[MAX_DWT_LEVELS])
  {
      int level, coef = 0;
      for (level = 0; level < s->wavelet_depth; level++) {
          SliceCoeffs *o = &c[level];
          SubBand *b = &s->plane[p].band[level][3]; /* orientation doens't matter */
          o->top   = b->height * y / s->num_y;
          o->left  = b->width  * x / s->num_x;
          o->tot_h = ((b->width  * (x + 1)) / s->num_x) - o->left;
          o->tot_v = ((b->height * (y + 1)) / s->num_y) - o->top;
          o->tot   = o->tot_h*o->tot_v;
          coef    += o->tot * (4 - !!level);
      }
      return coef;
  }
  
  /**
   * VC-2 Specification ->
   * 13.5.3 hq_slice(sx,sy)
   */
  static int decode_hq_slice(DiracContext *s, DiracSlice *slice, uint8_t *tmp_buf)
  {
      int i, level, orientation, quant_idx;
      int qfactor[MAX_DWT_LEVELS][4], qoffset[MAX_DWT_LEVELS][4];
      GetBitContext *gb = &slice->gb;
      SliceCoeffs coeffs_num[MAX_DWT_LEVELS];
  
      skip_bits_long(gb, 8*s->highquality.prefix_bytes);
      quant_idx = get_bits(gb, 8);
  
      if (quant_idx > DIRAC_MAX_QUANT_INDEX) {
          av_log(s->avctx, AV_LOG_ERROR, "Invalid quantization index - %i\n", quant_idx);
          return AVERROR_INVALIDDATA;
      }
  
      /* Slice quantization (slice_quantizers() in the specs) */
      for (level = 0; level < s->wavelet_depth; level++) {
          for (orientation = !!level; orientation < 4; orientation++) {
              const int quant = FFMAX(quant_idx - s->lowdelay.quant[level][orientation], 0);
              qfactor[level][orientation] = ff_dirac_qscale_tab[quant];
              qoffset[level][orientation] = ff_dirac_qoffset_intra_tab[quant] + 2;
          }
      }
  
      /* Luma + 2 Chroma planes */
      for (i = 0; i < 3; i++) {
          int coef_num, coef_par, off = 0;
          int64_t length = s->highquality.size_scaler*get_bits(gb, 8);
          int64_t bits_end = get_bits_count(gb) + 8*length;
          const uint8_t *addr = align_get_bits(gb);
  
          if (length*8 > get_bits_left(gb)) {
              av_log(s->avctx, AV_LOG_ERROR, "end too far away\n");
              return AVERROR_INVALIDDATA;
          }
  
          coef_num = subband_coeffs(s, slice->slice_x, slice->slice_y, i, coeffs_num);
  
          if (s->pshift)
              coef_par = ff_dirac_golomb_read_32bit(s->reader_ctx, addr,
                                                    length, tmp_buf, coef_num);
          else
              coef_par = ff_dirac_golomb_read_16bit(s->reader_ctx, addr,
                                                    length, tmp_buf, coef_num);
  
          if (coef_num > coef_par) {
              const int start_b = coef_par * (1 << (s->pshift + 1));
              const int end_b   = coef_num * (1 << (s->pshift + 1));
              memset(&tmp_buf[start_b], 0, end_b - start_b);
          }
  
          for (level = 0; level < s->wavelet_depth; level++) {
              const SliceCoeffs *c = &coeffs_num[level];
              for (orientation = !!level; orientation < 4; orientation++) {
                  const SubBand *b1 = &s->plane[i].band[level][orientation];
                  uint8_t *buf = b1->ibuf + c->top * b1->stride + (c->left << (s->pshift + 1));
  
                  /* Change to c->tot_h <= 4 for AVX2 dequantization */
                  const int qfunc = s->pshift + 2*(c->tot_h <= 2);
                  s->diracdsp.dequant_subband[qfunc](&tmp_buf[off], buf, b1->stride,
                                                     qfactor[level][orientation],
                                                     qoffset[level][orientation],
                                                     c->tot_v, c->tot_h);
  
                  off += c->tot << (s->pshift + 1);
              }
          }
  
          skip_bits_long(gb, bits_end - get_bits_count(gb));
      }
  
      return 0;
  }
  
  static int decode_hq_slice_row(AVCodecContext *avctx, void *arg, int jobnr, int threadnr)
  {
      int i;
      DiracContext *s = avctx->priv_data;
      DiracSlice *slices = ((DiracSlice *)arg) + s->num_x*jobnr;
      uint8_t *thread_buf = &s->thread_buf[s->thread_buf_size*threadnr];
      for (i = 0; i < s->num_x; i++)
          decode_hq_slice(s, &slices[i], thread_buf);
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * 13.5.1 low_delay_transform_data()
   */
  static int decode_lowdelay(DiracContext *s)
  {
      AVCodecContext *avctx = s->avctx;
      int slice_x, slice_y, bufsize;
      int64_t coef_buf_size, bytes = 0;
      const uint8_t *buf;
      DiracSlice *slices;
      SliceCoeffs tmp[MAX_DWT_LEVELS];
      int slice_num = 0;
  
      if (s->slice_params_num_buf != (s->num_x * s->num_y)) {
          s->slice_params_buf = av_realloc_f(s->slice_params_buf, s->num_x * s->num_y, sizeof(DiracSlice));
          if (!s->slice_params_buf) {
              av_log(s->avctx, AV_LOG_ERROR, "slice params buffer allocation failure\n");
              s->slice_params_num_buf = 0;
              return AVERROR(ENOMEM);
          }
          s->slice_params_num_buf = s->num_x * s->num_y;
      }
      slices = s->slice_params_buf;
  
      /* 8 becacuse that's how much the golomb reader could overread junk data
       * from another plane/slice at most, and 512 because SIMD */
      coef_buf_size = subband_coeffs(s, s->num_x - 1, s->num_y - 1, 0, tmp) + 8;
      coef_buf_size = (coef_buf_size << (1 + s->pshift)) + 512;
  
      if (s->threads_num_buf != avctx->thread_count ||
          s->thread_buf_size != coef_buf_size) {
          s->threads_num_buf  = avctx->thread_count;
          s->thread_buf_size  = coef_buf_size;
          s->thread_buf       = av_realloc_f(s->thread_buf, avctx->thread_count, s->thread_buf_size);
          if (!s->thread_buf) {
              av_log(s->avctx, AV_LOG_ERROR, "thread buffer allocation failure\n");
              return AVERROR(ENOMEM);
          }
      }
  
      align_get_bits(&s->gb);
      /*[DIRAC_STD] 13.5.2 Slices. slice(sx,sy) */
      buf = s->gb.buffer + get_bits_count(&s->gb)/8;
      bufsize = get_bits_left(&s->gb);
  
      if (s->hq_picture) {
          int i;
  
          for (slice_y = 0; bufsize > 0 && slice_y < s->num_y; slice_y++) {
              for (slice_x = 0; bufsize > 0 && slice_x < s->num_x; slice_x++) {
                  bytes = s->highquality.prefix_bytes + 1;
                  for (i = 0; i < 3; i++) {
                      if (bytes <= bufsize/8)
                          bytes += buf[bytes] * s->highquality.size_scaler + 1;
                  }
                  if (bytes >= INT_MAX || bytes*8 > bufsize) {
                      av_log(s->avctx, AV_LOG_ERROR, "too many bytes\n");
                      return AVERROR_INVALIDDATA;
                  }
  
                  slices[slice_num].bytes   = bytes;
                  slices[slice_num].slice_x = slice_x;
                  slices[slice_num].slice_y = slice_y;
                  init_get_bits(&slices[slice_num].gb, buf, bufsize);
                  slice_num++;
  
                  buf     += bytes;
                  if (bufsize/8 >= bytes)
                      bufsize -= bytes*8;
                  else
                      bufsize = 0;
              }
          }
  
          if (s->num_x*s->num_y != slice_num) {
              av_log(s->avctx, AV_LOG_ERROR, "too few slices\n");
              return AVERROR_INVALIDDATA;
          }
  
          avctx->execute2(avctx, decode_hq_slice_row, slices, NULL, s->num_y);
      } else {
          for (slice_y = 0; bufsize > 0 && slice_y < s->num_y; slice_y++) {
              for (slice_x = 0; bufsize > 0 && slice_x < s->num_x; slice_x++) {
                  bytes = (slice_num+1) * (int64_t)s->lowdelay.bytes.num / s->lowdelay.bytes.den
                         - slice_num    * (int64_t)s->lowdelay.bytes.num / s->lowdelay.bytes.den;
                  slices[slice_num].bytes   = bytes;
                  slices[slice_num].slice_x = slice_x;
                  slices[slice_num].slice_y = slice_y;
                  init_get_bits(&slices[slice_num].gb, buf, bufsize);
                  slice_num++;
  
                  buf     += bytes;
                  if (bufsize/8 >= bytes)
                      bufsize -= bytes*8;
                  else
                      bufsize = 0;
              }
          }
          avctx->execute(avctx, decode_lowdelay_slice, slices, NULL, slice_num,
                         sizeof(DiracSlice)); /* [DIRAC_STD] 13.5.2 Slices */
      }
  
      if (s->dc_prediction) {
          if (s->pshift) {
              intra_dc_prediction_10(&s->plane[0].band[0][0]); /* [DIRAC_STD] 13.3 intra_dc_prediction() */
              intra_dc_prediction_10(&s->plane[1].band[0][0]); /* [DIRAC_STD] 13.3 intra_dc_prediction() */
              intra_dc_prediction_10(&s->plane[2].band[0][0]); /* [DIRAC_STD] 13.3 intra_dc_prediction() */
          } else {
              intra_dc_prediction_8(&s->plane[0].band[0][0]);
              intra_dc_prediction_8(&s->plane[1].band[0][0]);
              intra_dc_prediction_8(&s->plane[2].band[0][0]);
          }
      }
  
      return 0;
  }
  
  static void init_planes(DiracContext *s)
  {
      int i, w, h, level, orientation;
  
      for (i = 0; i < 3; i++) {
          Plane *p = &s->plane[i];
  
          p->width       = s->seq.width  >> (i ? s->chroma_x_shift : 0);
          p->height      = s->seq.height >> (i ? s->chroma_y_shift : 0);
          p->idwt.width  = w = CALC_PADDING(p->width , s->wavelet_depth);
          p->idwt.height = h = CALC_PADDING(p->height, s->wavelet_depth);
          p->idwt.stride = FFALIGN(p->idwt.width, 8) << (1 + s->pshift);
  
          for (level = s->wavelet_depth-1; level >= 0; level--) {
              w = w>>1;
              h = h>>1;
              for (orientation = !!level; orientation < 4; orientation++) {
                  SubBand *b = &p->band[level][orientation];
  
                  b->pshift = s->pshift;
                  b->ibuf   = p->idwt.buf;
                  b->level  = level;
                  b->stride = p->idwt.stride << (s->wavelet_depth - level);
                  b->width  = w;
                  b->height = h;
                  b->orientation = orientation;
  
                  if (orientation & 1)
                      b->ibuf += w << (1+b->pshift);
                  if (orientation > 1)
                      b->ibuf += (b->stride>>1);
  
                  if (level)
                      b->parent = &p->band[level-1][orientation];
              }
          }
  
          if (i > 0) {
              p->xblen = s->plane[0].xblen >> s->chroma_x_shift;
              p->yblen = s->plane[0].yblen >> s->chroma_y_shift;
              p->xbsep = s->plane[0].xbsep >> s->chroma_x_shift;
              p->ybsep = s->plane[0].ybsep >> s->chroma_y_shift;
          }
  
          p->xoffset = (p->xblen - p->xbsep)/2;
          p->yoffset = (p->yblen - p->ybsep)/2;
      }
  }
  
  /**
   * Unpack the motion compensation parameters
   * Dirac Specification ->
   * 11.2 Picture prediction data. picture_prediction()
   */
  static int dirac_unpack_prediction_parameters(DiracContext *s)
  {
      static const uint8_t default_blen[] = { 4, 12, 16, 24 };
  
      GetBitContext *gb = &s->gb;
      unsigned idx, ref;
  
      align_get_bits(gb);
      /* [DIRAC_STD] 11.2.2 Block parameters. block_parameters() */
      /* Luma and Chroma are equal. 11.2.3 */
      idx = get_interleaved_ue_golomb(gb); /* [DIRAC_STD] index */
  
      if (idx > 4) {
          av_log(s->avctx, AV_LOG_ERROR, "Block prediction index too high\n");
          return AVERROR_INVALIDDATA;
      }
  
      if (idx == 0) {
          s->plane[0].xblen = get_interleaved_ue_golomb(gb);
          s->plane[0].yblen = get_interleaved_ue_golomb(gb);
          s->plane[0].xbsep = get_interleaved_ue_golomb(gb);
          s->plane[0].ybsep = get_interleaved_ue_golomb(gb);
      } else {
          /*[DIRAC_STD] preset_block_params(index). Table 11.1 */
          s->plane[0].xblen = default_blen[idx-1];
          s->plane[0].yblen = default_blen[idx-1];
          s->plane[0].xbsep = 4 * idx;
          s->plane[0].ybsep = 4 * idx;
      }
      /*[DIRAC_STD] 11.2.4 motion_data_dimensions()
        Calculated in function dirac_unpack_block_motion_data */
  
      if (s->plane[0].xblen % (1 << s->chroma_x_shift) != 0 ||
          s->plane[0].yblen % (1 << s->chroma_y_shift) != 0 ||
          !s->plane[0].xblen || !s->plane[0].yblen) {
          av_log(s->avctx, AV_LOG_ERROR,
                 "invalid x/y block length (%d/%d) for x/y chroma shift (%d/%d)\n",
                 s->plane[0].xblen, s->plane[0].yblen, s->chroma_x_shift, s->chroma_y_shift);
          return AVERROR_INVALIDDATA;
      }
      if (!s->plane[0].xbsep || !s->plane[0].ybsep || s->plane[0].xbsep < s->plane[0].xblen/2 || s->plane[0].ybsep < s->plane[0].yblen/2) {
          av_log(s->avctx, AV_LOG_ERROR, "Block separation too small\n");
          return AVERROR_INVALIDDATA;
      }
      if (s->plane[0].xbsep > s->plane[0].xblen || s->plane[0].ybsep > s->plane[0].yblen) {
          av_log(s->avctx, AV_LOG_ERROR, "Block separation greater than size\n");
          return AVERROR_INVALIDDATA;
      }
      if (FFMAX(s->plane[0].xblen, s->plane[0].yblen) > MAX_BLOCKSIZE) {
          av_log(s->avctx, AV_LOG_ERROR, "Unsupported large block size\n");
          return AVERROR_PATCHWELCOME;
      }
  
      /*[DIRAC_STD] 11.2.5 Motion vector precision. motion_vector_precision()
        Read motion vector precision */
      s->mv_precision = get_interleaved_ue_golomb(gb);
      if (s->mv_precision > 3) {
          av_log(s->avctx, AV_LOG_ERROR, "MV precision finer than eighth-pel\n");
          return AVERROR_INVALIDDATA;
      }
  
      /*[DIRAC_STD] 11.2.6 Global motion. global_motion()
        Read the global motion compensation parameters */
      s->globalmc_flag = get_bits1(gb);
      if (s->globalmc_flag) {
          memset(s->globalmc, 0, sizeof(s->globalmc));
          /* [DIRAC_STD] pan_tilt(gparams) */
          for (ref = 0; ref < s->num_refs; ref++) {
              if (get_bits1(gb)) {
                  s->globalmc[ref].pan_tilt[0] = dirac_get_se_golomb(gb);
                  s->globalmc[ref].pan_tilt[1] = dirac_get_se_golomb(gb);
              }
              /* [DIRAC_STD] zoom_rotate_shear(gparams)
                 zoom/rotation/shear parameters */
              if (get_bits1(gb)) {
                  s->globalmc[ref].zrs_exp   = get_interleaved_ue_golomb(gb);
                  s->globalmc[ref].zrs[0][0] = dirac_get_se_golomb(gb);
                  s->globalmc[ref].zrs[0][1] = dirac_get_se_golomb(gb);
                  s->globalmc[ref].zrs[1][0] = dirac_get_se_golomb(gb);
                  s->globalmc[ref].zrs[1][1] = dirac_get_se_golomb(gb);
              } else {
                  s->globalmc[ref].zrs[0][0] = 1;
                  s->globalmc[ref].zrs[1][1] = 1;
              }
              /* [DIRAC_STD] perspective(gparams) */
              if (get_bits1(gb)) {
                  s->globalmc[ref].perspective_exp = get_interleaved_ue_golomb(gb);
                  s->globalmc[ref].perspective[0]  = dirac_get_se_golomb(gb);
                  s->globalmc[ref].perspective[1]  = dirac_get_se_golomb(gb);
              }
          }
      }
  
      /*[DIRAC_STD] 11.2.7 Picture prediction mode. prediction_mode()
        Picture prediction mode, not currently used. */
      if (get_interleaved_ue_golomb(gb)) {
          av_log(s->avctx, AV_LOG_ERROR, "Unknown picture prediction mode\n");
          return AVERROR_INVALIDDATA;
      }
  
      /* [DIRAC_STD] 11.2.8 Reference picture weight. reference_picture_weights()
         just data read, weight calculation will be done later on. */
      s->weight_log2denom = 1;
      s->weight[0]        = 1;
      s->weight[1]        = 1;
  
      if (get_bits1(gb)) {
          s->weight_log2denom = get_interleaved_ue_golomb(gb);
          s->weight[0] = dirac_get_se_golomb(gb);
          if (s->num_refs == 2)
              s->weight[1] = dirac_get_se_golomb(gb);
      }
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * 11.3 Wavelet transform data. wavelet_transform()
   */
  static int dirac_unpack_idwt_params(DiracContext *s)
  {
      GetBitContext *gb = &s->gb;
      int i, level;
      unsigned tmp;
  
  #define CHECKEDREAD(dst, cond, errmsg) \
      tmp = get_interleaved_ue_golomb(gb); \
      if (cond) { \
          av_log(s->avctx, AV_LOG_ERROR, errmsg); \
          return AVERROR_INVALIDDATA; \
      }\
      dst = tmp;
  
      align_get_bits(gb);
  
      s->zero_res = s->num_refs ? get_bits1(gb) : 0;
      if (s->zero_res)
          return 0;
  
      /*[DIRAC_STD] 11.3.1 Transform parameters. transform_parameters() */
      CHECKEDREAD(s->wavelet_idx, tmp > 6, "wavelet_idx is too big\n")
  
      CHECKEDREAD(s->wavelet_depth, tmp > MAX_DWT_LEVELS || tmp < 1, "invalid number of DWT decompositions\n")
  
      if (!s->low_delay) {
          /* Codeblock parameters (core syntax only) */
          if (get_bits1(gb)) {
              for (i = 0; i <= s->wavelet_depth; i++) {
                  CHECKEDREAD(s->codeblock[i].width , tmp < 1 || tmp > (s->avctx->width >>s->wavelet_depth-i), "codeblock width invalid\n")
                  CHECKEDREAD(s->codeblock[i].height, tmp < 1 || tmp > (s->avctx->height>>s->wavelet_depth-i), "codeblock height invalid\n")
              }
  
              CHECKEDREAD(s->codeblock_mode, tmp > 1, "unknown codeblock mode\n")
          }
          else {
              for (i = 0; i <= s->wavelet_depth; i++)
                  s->codeblock[i].width = s->codeblock[i].height = 1;
          }
      }
      else {
          s->num_x        = get_interleaved_ue_golomb(gb);
          s->num_y        = get_interleaved_ue_golomb(gb);
          if (s->num_x * s->num_y == 0 || s->num_x * (uint64_t)s->num_y > INT_MAX) {
              av_log(s->avctx,AV_LOG_ERROR,"Invalid numx/y\n");
              s->num_x = s->num_y = 0;
              return AVERROR_INVALIDDATA;
          }
          if (s->ld_picture) {
              s->lowdelay.bytes.num = get_interleaved_ue_golomb(gb);
              s->lowdelay.bytes.den = get_interleaved_ue_golomb(gb);
              if (s->lowdelay.bytes.den <= 0) {
                  av_log(s->avctx,AV_LOG_ERROR,"Invalid lowdelay.bytes.den\n");
                  return AVERROR_INVALIDDATA;
              }
          } else if (s->hq_picture) {
              s->highquality.prefix_bytes = get_interleaved_ue_golomb(gb);
              s->highquality.size_scaler  = get_interleaved_ue_golomb(gb);
              if (s->highquality.prefix_bytes >= INT_MAX / 8) {
                  av_log(s->avctx,AV_LOG_ERROR,"too many prefix bytes\n");
                  return AVERROR_INVALIDDATA;
              }
          }
  
          /* [DIRAC_STD] 11.3.5 Quantisation matrices (low-delay syntax). quant_matrix() */
          if (get_bits1(gb)) {
              av_log(s->avctx,AV_LOG_DEBUG,"Low Delay: Has Custom Quantization Matrix!\n");
              /* custom quantization matrix */
              s->lowdelay.quant[0][0] = get_interleaved_ue_golomb(gb);
              for (level = 0; level < s->wavelet_depth; level++) {
                  s->lowdelay.quant[level][1] = get_interleaved_ue_golomb(gb);
                  s->lowdelay.quant[level][2] = get_interleaved_ue_golomb(gb);
                  s->lowdelay.quant[level][3] = get_interleaved_ue_golomb(gb);
              }
          } else {
              if (s->wavelet_depth > 4) {
                  av_log(s->avctx,AV_LOG_ERROR,"Mandatory custom low delay matrix missing for depth %d\n", s->wavelet_depth);
                  return AVERROR_INVALIDDATA;
              }
              /* default quantization matrix */
              for (level = 0; level < s->wavelet_depth; level++)
                  for (i = 0; i < 4; i++) {
                      s->lowdelay.quant[level][i] = ff_dirac_default_qmat[s->wavelet_idx][level][i];
                      /* haar with no shift differs for different depths */
                      if (s->wavelet_idx == 3)
                          s->lowdelay.quant[level][i] += 4*(s->wavelet_depth-1 - level);
                  }
          }
      }
      return 0;
  }
  
  static inline int pred_sbsplit(uint8_t *sbsplit, int stride, int x, int y)
  {
      static const uint8_t avgsplit[7] = { 0, 0, 1, 1, 1, 2, 2 };
  
      if (!(x|y))
          return 0;
      else if (!y)
          return sbsplit[-1];
      else if (!x)
          return sbsplit[-stride];
  
      return avgsplit[sbsplit[-1] + sbsplit[-stride] + sbsplit[-stride-1]];
  }
  
  static inline int pred_block_mode(DiracBlock *block, int stride, int x, int y, int refmask)
  {
      int pred;
  
      if (!(x|y))
          return 0;
      else if (!y)
          return block[-1].ref & refmask;
      else if (!x)
          return block[-stride].ref & refmask;
  
      /* return the majority */
      pred = (block[-1].ref & refmask) + (block[-stride].ref & refmask) + (block[-stride-1].ref & refmask);
      return (pred >> 1) & refmask;
  }
  
  static inline void pred_block_dc(DiracBlock *block, int stride, int x, int y)
  {
      int i, n = 0;
  
      memset(block->u.dc, 0, sizeof(block->u.dc));
  
      if (x && !(block[-1].ref & 3)) {
          for (i = 0; i < 3; i++)
              block->u.dc[i] += block[-1].u.dc[i];
          n++;
      }
  
      if (y && !(block[-stride].ref & 3)) {
          for (i = 0; i < 3; i++)
              block->u.dc[i] += block[-stride].u.dc[i];
          n++;
      }
  
      if (x && y && !(block[-1-stride].ref & 3)) {
          for (i = 0; i < 3; i++)
              block->u.dc[i] += block[-1-stride].u.dc[i];
          n++;
      }
  
      if (n == 2) {
          for (i = 0; i < 3; i++)
              block->u.dc[i] = (block->u.dc[i]+1)>>1;
      } else if (n == 3) {
          for (i = 0; i < 3; i++)
              block->u.dc[i] = divide3(block->u.dc[i]);
      }
  }
  
  static inline void pred_mv(DiracBlock *block, int stride, int x, int y, int ref)
  {
      int16_t *pred[3];
      int refmask = ref+1;
      int mask = refmask | DIRAC_REF_MASK_GLOBAL; /*  exclude gmc blocks */
      int n = 0;
  
      if (x && (block[-1].ref & mask) == refmask)
          pred[n++] = block[-1].u.mv[ref];
  
      if (y && (block[-stride].ref & mask) == refmask)
          pred[n++] = block[-stride].u.mv[ref];
  
      if (x && y && (block[-stride-1].ref & mask) == refmask)
          pred[n++] = block[-stride-1].u.mv[ref];
  
      switch (n) {
      case 0:
          block->u.mv[ref][0] = 0;
          block->u.mv[ref][1] = 0;
          break;
      case 1:
          block->u.mv[ref][0] = pred[0][0];
          block->u.mv[ref][1] = pred[0][1];
          break;
      case 2:
          block->u.mv[ref][0] = (pred[0][0] + pred[1][0] + 1) >> 1;
          block->u.mv[ref][1] = (pred[0][1] + pred[1][1] + 1) >> 1;
          break;
      case 3:
          block->u.mv[ref][0] = mid_pred(pred[0][0], pred[1][0], pred[2][0]);
          block->u.mv[ref][1] = mid_pred(pred[0][1], pred[1][1], pred[2][1]);
          break;
      }
  }
  
  static void global_mv(DiracContext *s, DiracBlock *block, int x, int y, int ref)
  {
      int ez      = s->globalmc[ref].zrs_exp;
      int ep      = s->globalmc[ref].perspective_exp;
      int (*A)[2] = s->globalmc[ref].zrs;
      int *b      = s->globalmc[ref].pan_tilt;
      int *c      = s->globalmc[ref].perspective;
  
      int m       = (1<<ep) - (c[0]*x + c[1]*y);
      int mx      = m * ((A[0][0] * x + A[0][1]*y) + (1<<ez) * b[0]);
      int my      = m * ((A[1][0] * x + A[1][1]*y) + (1<<ez) * b[1]);
  
      block->u.mv[ref][0] = (mx + (1<<(ez+ep))) >> (ez+ep);
      block->u.mv[ref][1] = (my + (1<<(ez+ep))) >> (ez+ep);
  }
  
  static void decode_block_params(DiracContext *s, DiracArith arith[8], DiracBlock *block,
                                  int stride, int x, int y)
  {
      int i;
  
      block->ref  = pred_block_mode(block, stride, x, y, DIRAC_REF_MASK_REF1);
      block->ref ^= dirac_get_arith_bit(arith, CTX_PMODE_REF1);
  
      if (s->num_refs == 2) {
          block->ref |= pred_block_mode(block, stride, x, y, DIRAC_REF_MASK_REF2);
          block->ref ^= dirac_get_arith_bit(arith, CTX_PMODE_REF2) << 1;
      }
  
      if (!block->ref) {
          pred_block_dc(block, stride, x, y);
          for (i = 0; i < 3; i++)
              block->u.dc[i] += dirac_get_arith_int(arith+1+i, CTX_DC_F1, CTX_DC_DATA);
          return;
      }
  
      if (s->globalmc_flag) {
          block->ref |= pred_block_mode(block, stride, x, y, DIRAC_REF_MASK_GLOBAL);
          block->ref ^= dirac_get_arith_bit(arith, CTX_GLOBAL_BLOCK) << 2;
      }
  
      for (i = 0; i < s->num_refs; i++)
          if (block->ref & (i+1)) {
              if (block->ref & DIRAC_REF_MASK_GLOBAL) {
                  global_mv(s, block, x, y, i);
              } else {
                  pred_mv(block, stride, x, y, i);
                  block->u.mv[i][0] += dirac_get_arith_int(arith + 4 + 2 * i, CTX_MV_F1, CTX_MV_DATA);
                  block->u.mv[i][1] += dirac_get_arith_int(arith + 5 + 2 * i, CTX_MV_F1, CTX_MV_DATA);
              }
          }
  }
  
  /**
   * Copies the current block to the other blocks covered by the current superblock split mode
   */
  static void propagate_block_data(DiracBlock *block, int stride, int size)
  {
      int x, y;
      DiracBlock *dst = block;
  
      for (x = 1; x < size; x++)
          dst[x] = *block;
  
      for (y = 1; y < size; y++) {
          dst += stride;
          for (x = 0; x < size; x++)
              dst[x] = *block;
      }
  }
  
  /**
   * Dirac Specification ->
   * 12. Block motion data syntax
   */
  static int dirac_unpack_block_motion_data(DiracContext *s)
  {
      GetBitContext *gb = &s->gb;
      uint8_t *sbsplit = s->sbsplit;
      int i, x, y, q, p;
      DiracArith arith[8];
  
      align_get_bits(gb);
  
      /* [DIRAC_STD] 11.2.4 and 12.2.1 Number of blocks and superblocks */
      s->sbwidth  = DIVRNDUP(s->seq.width,  4*s->plane[0].xbsep);
      s->sbheight = DIVRNDUP(s->seq.height, 4*s->plane[0].ybsep);
      s->blwidth  = 4 * s->sbwidth;
      s->blheight = 4 * s->sbheight;
  
      /* [DIRAC_STD] 12.3.1 Superblock splitting modes. superblock_split_modes()
         decode superblock split modes */
      ff_dirac_init_arith_decoder(arith, gb, get_interleaved_ue_golomb(gb));     /* get_interleaved_ue_golomb(gb) is the length */
      for (y = 0; y < s->sbheight; y++) {
          for (x = 0; x < s->sbwidth; x++) {
              unsigned int split  = dirac_get_arith_uint(arith, CTX_SB_F1, CTX_SB_DATA);
              if (split > 2)
                  return AVERROR_INVALIDDATA;
              sbsplit[x] = (split + pred_sbsplit(sbsplit+x, s->sbwidth, x, y)) % 3;
          }
          sbsplit += s->sbwidth;
      }
  
      /* setup arith decoding */
      ff_dirac_init_arith_decoder(arith, gb, get_interleaved_ue_golomb(gb));
      for (i = 0; i < s->num_refs; i++) {
          ff_dirac_init_arith_decoder(arith + 4 + 2 * i, gb, get_interleaved_ue_golomb(gb));
          ff_dirac_init_arith_decoder(arith + 5 + 2 * i, gb, get_interleaved_ue_golomb(gb));
      }
      for (i = 0; i < 3; i++)
          ff_dirac_init_arith_decoder(arith+1+i, gb, get_interleaved_ue_golomb(gb));
  
      for (y = 0; y < s->sbheight; y++)
          for (x = 0; x < s->sbwidth; x++) {
              int blkcnt = 1 << s->sbsplit[y * s->sbwidth + x];
              int step   = 4 >> s->sbsplit[y * s->sbwidth + x];
  
              for (q = 0; q < blkcnt; q++)
                  for (p = 0; p < blkcnt; p++) {
                      int bx = 4 * x + p*step;
                      int by = 4 * y + q*step;
                      DiracBlock *block = &s->blmotion[by*s->blwidth + bx];
                      decode_block_params(s, arith, block, s->blwidth, bx, by);
                      propagate_block_data(block, s->blwidth, step);
                  }
          }
  
      return 0;
  }
  
  static int weight(int i, int blen, int offset)
  {
  #define ROLLOFF(i) offset == 1 ? ((i) ? 5 : 3) :        \
      (1 + (6*(i) + offset - 1) / (2*offset - 1))
  
      if (i < 2*offset)
          return ROLLOFF(i);
      else if (i > blen-1 - 2*offset)
          return ROLLOFF(blen-1 - i);
      return 8;
  }
  
  static void init_obmc_weight_row(Plane *p, uint8_t *obmc_weight, int stride,
                                   int left, int right, int wy)
  {
      int x;
      for (x = 0; left && x < p->xblen >> 1; x++)
          obmc_weight[x] = wy*8;
      for (; x < p->xblen >> right; x++)
          obmc_weight[x] = wy*weight(x, p->xblen, p->xoffset);
      for (; x < p->xblen; x++)
          obmc_weight[x] = wy*8;
      for (; x < stride; x++)
          obmc_weight[x] = 0;
  }
  
  static void init_obmc_weight(Plane *p, uint8_t *obmc_weight, int stride,
                               int left, int right, int top, int bottom)
  {
      int y;
      for (y = 0; top && y < p->yblen >> 1; y++) {
          init_obmc_weight_row(p, obmc_weight, stride, left, right, 8);
          obmc_weight += stride;
      }
      for (; y < p->yblen >> bottom; y++) {
          int wy = weight(y, p->yblen, p->yoffset);
          init_obmc_weight_row(p, obmc_weight, stride, left, right, wy);
          obmc_weight += stride;
      }
      for (; y < p->yblen; y++) {
          init_obmc_weight_row(p, obmc_weight, stride, left, right, 8);
          obmc_weight += stride;
      }
  }
  
  static void init_obmc_weights(DiracContext *s, Plane *p, int by)
  {
      int top = !by;
      int bottom = by == s->blheight-1;
  
      /* don't bother re-initing for rows 2 to blheight-2, the weights don't change */
      if (top || bottom || by == 1) {
          init_obmc_weight(p, s->obmc_weight[0], MAX_BLOCKSIZE, 1, 0, top, bottom);
          init_obmc_weight(p, s->obmc_weight[1], MAX_BLOCKSIZE, 0, 0, top, bottom);
          init_obmc_weight(p, s->obmc_weight[2], MAX_BLOCKSIZE, 0, 1, top, bottom);
      }
  }
  
  static const uint8_t epel_weights[4][4][4] = {
      {{ 16,  0,  0,  0 },
       { 12,  4,  0,  0 },
       {  8,  8,  0,  0 },
       {  4, 12,  0,  0 }},
      {{ 12,  0,  4,  0 },
       {  9,  3,  3,  1 },
       {  6,  6,  2,  2 },
       {  3,  9,  1,  3 }},
      {{  8,  0,  8,  0 },
       {  6,  2,  6,  2 },
       {  4,  4,  4,  4 },
       {  2,  6,  2,  6 }},
      {{  4,  0, 12,  0 },
       {  3,  1,  9,  3 },
       {  2,  2,  6,  6 },
       {  1,  3,  3,  9 }}
  };
  
  /**
   * For block x,y, determine which of the hpel planes to do bilinear
   * interpolation from and set src[] to the location in each hpel plane
   * to MC from.
   *
   * @return the index of the put_dirac_pixels_tab function to use
   *  0 for 1 plane (fpel,hpel), 1 for 2 planes (qpel), 2 for 4 planes (qpel), and 3 for epel
   */
  static int mc_subpel(DiracContext *s, DiracBlock *block, const uint8_t *src[5],
                       int x, int y, int ref, int plane)
  {
      Plane *p = &s->plane[plane];
      uint8_t **ref_hpel = s->ref_pics[ref]->hpel[plane];
      int motion_x = block->u.mv[ref][0];
      int motion_y = block->u.mv[ref][1];
      int mx, my, i, epel, nplanes = 0;
  
      if (plane) {
          motion_x >>= s->chroma_x_shift;
          motion_y >>= s->chroma_y_shift;
      }
  
      mx         = motion_x & ~(-1U << s->mv_precision);
      my         = motion_y & ~(-1U << s->mv_precision);
      motion_x >>= s->mv_precision;
      motion_y >>= s->mv_precision;
      /* normalize subpel coordinates to epel */
      /* TODO: template this function? */
      mx      <<= 3 - s->mv_precision;
      my      <<= 3 - s->mv_precision;
  
      x += motion_x;
      y += motion_y;
      epel = (mx|my)&1;
  
      /* hpel position */
      if (!((mx|my)&3)) {
          nplanes = 1;
          src[0] = ref_hpel[(my>>1)+(mx>>2)] + y*p->stride + x;
      } else {
          /* qpel or epel */
          nplanes = 4;
          for (i = 0; i < 4; i++)
              src[i] = ref_hpel[i] + y*p->stride + x;
  
          /* if we're interpolating in the right/bottom halves, adjust the planes as needed
             we increment x/y because the edge changes for half of the pixels */
          if (mx > 4) {
              src[0] += 1;
              src[2] += 1;
              x++;
          }
          if (my > 4) {
              src[0] += p->stride;
              src[1] += p->stride;
              y++;
          }
  
          /* hpel planes are:
             [0]: F  [1]: H
             [2]: V  [3]: C */
          if (!epel) {
              /* check if we really only need 2 planes since either mx or my is
                 a hpel position. (epel weights of 0 handle this there) */
              if (!(mx&3)) {
                  /* mx == 0: average [0] and [2]
                     mx == 4: average [1] and [3] */
                  src[!mx] = src[2 + !!mx];
                  nplanes = 2;
              } else if (!(my&3)) {
                  src[0] = src[(my>>1)  ];
                  src[1] = src[(my>>1)+1];
                  nplanes = 2;
              }
          } else {
              /* adjust the ordering if needed so the weights work */
              if (mx > 4) {
                  FFSWAP(const uint8_t *, src[0], src[1]);
                  FFSWAP(const uint8_t *, src[2], src[3]);
              }
              if (my > 4) {
                  FFSWAP(const uint8_t *, src[0], src[2]);
                  FFSWAP(const uint8_t *, src[1], src[3]);
              }
              src[4] = epel_weights[my&3][mx&3];
          }
      }
  
      /* fixme: v/h _edge_pos */
      if (x + p->xblen > p->width +EDGE_WIDTH/2 ||
          y + p->yblen > p->height+EDGE_WIDTH/2 ||
          x < 0 || y < 0) {
          for (i = 0; i < nplanes; i++) {
              s->vdsp.emulated_edge_mc(s->edge_emu_buffer[i], src[i],
                                       p->stride, p->stride,
                                       p->xblen, p->yblen, x, y,
                                       p->width+EDGE_WIDTH/2, p->height+EDGE_WIDTH/2);
              src[i] = s->edge_emu_buffer[i];
          }
      }
      return (nplanes>>1) + epel;
  }
  
  static void add_dc(uint16_t *dst, int dc, int stride,
                     uint8_t *obmc_weight, int xblen, int yblen)
  {
      int x, y;
      dc += 128;
  
      for (y = 0; y < yblen; y++) {
          for (x = 0; x < xblen; x += 2) {
              dst[x  ] += dc * obmc_weight[x  ];
              dst[x+1] += dc * obmc_weight[x+1];
          }
          dst          += stride;
          obmc_weight  += MAX_BLOCKSIZE;
      }
  }
  
  static void block_mc(DiracContext *s, DiracBlock *block,
                       uint16_t *mctmp, uint8_t *obmc_weight,
                       int plane, int dstx, int dsty)
  {
      Plane *p = &s->plane[plane];
      const uint8_t *src[5];
      int idx;
  
      switch (block->ref&3) {
      case 0: /* DC */
          add_dc(mctmp, block->u.dc[plane], p->stride, obmc_weight, p->xblen, p->yblen);
          return;
      case 1:
      case 2:
          idx = mc_subpel(s, block, src, dstx, dsty, (block->ref&3)-1, plane);
          s->put_pixels_tab[idx](s->mcscratch, src, p->stride, p->yblen);
          if (s->weight_func)
              s->weight_func(s->mcscratch, p->stride, s->weight_log2denom,
                             s->weight[0] + s->weight[1], p->yblen);
          break;
      case 3:
          idx = mc_subpel(s, block, src, dstx, dsty, 0, plane);
          s->put_pixels_tab[idx](s->mcscratch, src, p->stride, p->yblen);
          idx = mc_subpel(s, block, src, dstx, dsty, 1, plane);
          if (s->biweight_func) {
              /* fixme: +32 is a quick hack */
              s->put_pixels_tab[idx](s->mcscratch + 32, src, p->stride, p->yblen);
              s->biweight_func(s->mcscratch, s->mcscratch+32, p->stride, s->weight_log2denom,
                               s->weight[0], s->weight[1], p->yblen);
          } else
              s->avg_pixels_tab[idx](s->mcscratch, src, p->stride, p->yblen);
          break;
      }
      s->add_obmc(mctmp, s->mcscratch, p->stride, obmc_weight, p->yblen);
  }
  
  static void mc_row(DiracContext *s, DiracBlock *block, uint16_t *mctmp, int plane, int dsty)
  {
      Plane *p = &s->plane[plane];
      int x, dstx = p->xbsep - p->xoffset;
  
      block_mc(s, block, mctmp, s->obmc_weight[0], plane, -p->xoffset, dsty);
      mctmp += p->xbsep;
  
      for (x = 1; x < s->blwidth-1; x++) {
          block_mc(s, block+x, mctmp, s->obmc_weight[1], plane, dstx, dsty);
          dstx  += p->xbsep;
          mctmp += p->xbsep;
      }
      block_mc(s, block+x, mctmp, s->obmc_weight[2], plane, dstx, dsty);
  }
  
  static void select_dsp_funcs(DiracContext *s, int width, int height, int xblen, int yblen)
  {
      int idx = 0;
      if (xblen > 8)
          idx = 1;
      if (xblen > 16)
          idx = 2;
  
      memcpy(s->put_pixels_tab, s->diracdsp.put_dirac_pixels_tab[idx], sizeof(s->put_pixels_tab));
      memcpy(s->avg_pixels_tab, s->diracdsp.avg_dirac_pixels_tab[idx], sizeof(s->avg_pixels_tab));
      s->add_obmc = s->diracdsp.add_dirac_obmc[idx];
      if (s->weight_log2denom > 1 || s->weight[0] != 1 || s->weight[1] != 1) {
          s->weight_func   = s->diracdsp.weight_dirac_pixels_tab[idx];
          s->biweight_func = s->diracdsp.biweight_dirac_pixels_tab[idx];
      } else {
          s->weight_func   = NULL;
          s->biweight_func = NULL;
      }
  }
  
  static int interpolate_refplane(DiracContext *s, DiracFrame *ref, int plane, int width, int height)
  {
      /* chroma allocates an edge of 8 when subsampled
         which for 4:2:2 means an h edge of 16 and v edge of 8
         just use 8 for everything for the moment */
      int i, edge = EDGE_WIDTH/2;
  
      ref->hpel[plane][0] = ref->avframe->data[plane];
      s->mpvencdsp.draw_edges(ref->hpel[plane][0], ref->avframe->linesize[plane], width, height, edge, edge, EDGE_TOP | EDGE_BOTTOM); /* EDGE_TOP | EDGE_BOTTOM values just copied to make it build, this needs to be ensured */
  
      /* no need for hpel if we only have fpel vectors */
      if (!s->mv_precision)
          return 0;
  
      for (i = 1; i < 4; i++) {
          if (!ref->hpel_base[plane][i])
              ref->hpel_base[plane][i] = av_malloc((height+2*edge) * ref->avframe->linesize[plane] + 32);
          if (!ref->hpel_base[plane][i]) {
              return AVERROR(ENOMEM);
          }
          /* we need to be 16-byte aligned even for chroma */
          ref->hpel[plane][i] = ref->hpel_base[plane][i] + edge*ref->avframe->linesize[plane] + 16;
      }
  
      if (!ref->interpolated[plane]) {
          s->diracdsp.dirac_hpel_filter(ref->hpel[plane][1], ref->hpel[plane][2],
                                        ref->hpel[plane][3], ref->hpel[plane][0],
                                        ref->avframe->linesize[plane], width, height);
          s->mpvencdsp.draw_edges(ref->hpel[plane][1], ref->avframe->linesize[plane], width, height, edge, edge, EDGE_TOP | EDGE_BOTTOM);
          s->mpvencdsp.draw_edges(ref->hpel[plane][2], ref->avframe->linesize[plane], width, height, edge, edge, EDGE_TOP | EDGE_BOTTOM);
          s->mpvencdsp.draw_edges(ref->hpel[plane][3], ref->avframe->linesize[plane], width, height, edge, edge, EDGE_TOP | EDGE_BOTTOM);
      }
      ref->interpolated[plane] = 1;
  
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * 13.0 Transform data syntax. transform_data()
   */
  static int dirac_decode_frame_internal(DiracContext *s)
  {
      DWTContext d;
      int y, i, comp, dsty;
      int ret;
  
      if (s->low_delay) {
          /* [DIRAC_STD] 13.5.1 low_delay_transform_data() */
          if (!s->hq_picture) {
              for (comp = 0; comp < 3; comp++) {
                  Plane *p = &s->plane[comp];
                  memset(p->idwt.buf, 0, p->idwt.stride * p->idwt.height);
              }
          }
          if (!s->zero_res) {
              if ((ret = decode_lowdelay(s)) < 0)
                  return ret;
          }
      }
  
      for (comp = 0; comp < 3; comp++) {
          Plane *p       = &s->plane[comp];
          uint8_t *frame = s->current_picture->avframe->data[comp];
  
          /* FIXME: small resolutions */
          for (i = 0; i < 4; i++)
              s->edge_emu_buffer[i] = s->edge_emu_buffer_base + i*FFALIGN(p->width, 16);
  
          if (!s->zero_res && !s->low_delay)
          {
              memset(p->idwt.buf, 0, p->idwt.stride * p->idwt.height);
              decode_component(s, comp); /* [DIRAC_STD] 13.4.1 core_transform_data() */
          }
          ret = ff_spatial_idwt_init(&d, &p->idwt, s->wavelet_idx+2,
                                     s->wavelet_depth, s->bit_depth);
          if (ret < 0)
              return ret;
  
          if (!s->num_refs) { /* intra */
              for (y = 0; y < p->height; y += 16) {
                  int idx = (s->bit_depth - 8) >> 1;
                  ff_spatial_idwt_slice2(&d, y+16); /* decode */
                  s->diracdsp.put_signed_rect_clamped[idx](frame + y*p->stride,
                                                           p->stride,
                                                           p->idwt.buf + y*p->idwt.stride,
                                                           p->idwt.stride, p->width, 16);
              }
          } else { /* inter */
              int rowheight = p->ybsep*p->stride;
  
              select_dsp_funcs(s, p->width, p->height, p->xblen, p->yblen);
  
              for (i = 0; i < s->num_refs; i++) {
                  int ret = interpolate_refplane(s, s->ref_pics[i], comp, p->width, p->height);
                  if (ret < 0)
                      return ret;
              }
  
              memset(s->mctmp, 0, 4*p->yoffset*p->stride);
  
              dsty = -p->yoffset;
              for (y = 0; y < s->blheight; y++) {
                  int h     = 0,
                      start = FFMAX(dsty, 0);
                  uint16_t *mctmp    = s->mctmp + y*rowheight;
                  DiracBlock *blocks = s->blmotion + y*s->blwidth;
  
                  init_obmc_weights(s, p, y);
  
                  if (y == s->blheight-1 || start+p->ybsep > p->height)
                      h = p->height - start;
                  else
                      h = p->ybsep - (start - dsty);
                  if (h < 0)
                      break;
  
                  memset(mctmp+2*p->yoffset*p->stride, 0, 2*rowheight);
                  mc_row(s, blocks, mctmp, comp, dsty);
  
                  mctmp += (start - dsty)*p->stride + p->xoffset;
                  ff_spatial_idwt_slice2(&d, start + h); /* decode */
                  /* NOTE: add_rect_clamped hasn't been templated hence the shifts.
                   * idwt.stride is passed as pixels, not in bytes as in the rest of the decoder */
                  s->diracdsp.add_rect_clamped(frame + start*p->stride, mctmp, p->stride,
                                               (int16_t*)(p->idwt.buf) + start*(p->idwt.stride >> 1), (p->idwt.stride >> 1), p->width, h);
  
                  dsty += p->ybsep;
              }
          }
      }
  
  
      return 0;
  }
  
  static int get_buffer_with_edge(AVCodecContext *avctx, AVFrame *f, int flags)
  {
      int ret, i;
      int chroma_x_shift, chroma_y_shift;
      avcodec_get_chroma_sub_sample(avctx->pix_fmt, &chroma_x_shift, &chroma_y_shift);
  
      f->width  = avctx->width  + 2 * EDGE_WIDTH;
      f->height = avctx->height + 2 * EDGE_WIDTH + 2;
      ret = ff_get_buffer(avctx, f, flags);
      if (ret < 0)
          return ret;
  
      for (i = 0; f->data[i]; i++) {
          int offset = (EDGE_WIDTH >> (i && i<3 ? chroma_y_shift : 0)) *
                       f->linesize[i] + 32;
          f->data[i] += offset;
      }
      f->width  = avctx->width;
      f->height = avctx->height;
  
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * 11.1.1 Picture Header. picture_header()
   */
  static int dirac_decode_picture_header(DiracContext *s)
  {
      unsigned retire, picnum;
      int i, j, ret;
      int64_t refdist, refnum;
      GetBitContext *gb = &s->gb;
  
      /* [DIRAC_STD] 11.1.1 Picture Header. picture_header() PICTURE_NUM */
      picnum = s->current_picture->avframe->display_picture_number = get_bits_long(gb, 32);
  
  
      av_log(s->avctx,AV_LOG_DEBUG,"PICTURE_NUM: %d\n",picnum);
  
      /* if this is the first keyframe after a sequence header, start our
         reordering from here */
      if (s->frame_number < 0)
          s->frame_number = picnum;
  
      s->ref_pics[0] = s->ref_pics[1] = NULL;
      for (i = 0; i < s->num_refs; i++) {
          refnum = (picnum + dirac_get_se_golomb(gb)) & 0xFFFFFFFF;
          refdist = INT64_MAX;
  
          /* find the closest reference to the one we want */
          /* Jordi: this is needed if the referenced picture hasn't yet arrived */
          for (j = 0; j < MAX_REFERENCE_FRAMES && refdist; j++)
              if (s->ref_frames[j]
                  && FFABS(s->ref_frames[j]->avframe->display_picture_number - refnum) < refdist) {
                  s->ref_pics[i] = s->ref_frames[j];
                  refdist = FFABS(s->ref_frames[j]->avframe->display_picture_number - refnum);
              }
  
          if (!s->ref_pics[i] || refdist)
              av_log(s->avctx, AV_LOG_DEBUG, "Reference not found\n");
  
          /* if there were no references at all, allocate one */
          if (!s->ref_pics[i])
              for (j = 0; j < MAX_FRAMES; j++)
                  if (!s->all_frames[j].avframe->data[0]) {
                      s->ref_pics[i] = &s->all_frames[j];
                      ret = get_buffer_with_edge(s->avctx, s->ref_pics[i]->avframe, AV_GET_BUFFER_FLAG_REF);
                      if (ret < 0)
                          return ret;
                      break;
                  }
  
          if (!s->ref_pics[i]) {
              av_log(s->avctx, AV_LOG_ERROR, "Reference could not be allocated\n");
              return AVERROR_INVALIDDATA;
          }
  
      }
  
      /* retire the reference frames that are not used anymore */
      if (s->current_picture->reference) {
          retire = (picnum + dirac_get_se_golomb(gb)) & 0xFFFFFFFF;
          if (retire != picnum) {
              DiracFrame *retire_pic = remove_frame(s->ref_frames, retire);
  
              if (retire_pic)
                  retire_pic->reference &= DELAYED_PIC_REF;
              else
                  av_log(s->avctx, AV_LOG_DEBUG, "Frame to retire not found\n");
          }
  
          /* if reference array is full, remove the oldest as per the spec */
          while (add_frame(s->ref_frames, MAX_REFERENCE_FRAMES, s->current_picture)) {
              av_log(s->avctx, AV_LOG_ERROR, "Reference frame overflow\n");
              remove_frame(s->ref_frames, s->ref_frames[0]->avframe->display_picture_number)->reference &= DELAYED_PIC_REF;
          }
      }
  
      if (s->num_refs) {
          ret = dirac_unpack_prediction_parameters(s);  /* [DIRAC_STD] 11.2 Picture Prediction Data. picture_prediction() */
          if (ret < 0)
              return ret;
          ret = dirac_unpack_block_motion_data(s);      /* [DIRAC_STD] 12. Block motion data syntax                       */
          if (ret < 0)
              return ret;
      }
      ret = dirac_unpack_idwt_params(s);                /* [DIRAC_STD] 11.3 Wavelet transform data                        */
      if (ret < 0)
          return ret;
  
      init_planes(s);
      return 0;
  }
  
  static int get_delayed_pic(DiracContext *s, AVFrame *picture, int *got_frame)
  {
      DiracFrame *out = s->delay_frames[0];
      int i, out_idx  = 0;
      int ret;
  
      /* find frame with lowest picture number */
      for (i = 1; s->delay_frames[i]; i++)
          if (s->delay_frames[i]->avframe->display_picture_number < out->avframe->display_picture_number) {
              out     = s->delay_frames[i];
              out_idx = i;
          }
  
      for (i = out_idx; s->delay_frames[i]; i++)
          s->delay_frames[i] = s->delay_frames[i+1];
  
      if (out) {
          out->reference ^= DELAYED_PIC_REF;
          if((ret = av_frame_ref(picture, out->avframe)) < 0)
              return ret;
          *got_frame = 1;
      }
  
      return 0;
  }
  
  /**
   * Dirac Specification ->
   * 9.6 Parse Info Header Syntax. parse_info()
   * 4 byte start code + byte parse code + 4 byte size + 4 byte previous size
   */
  #define DATA_UNIT_HEADER_SIZE 13
  
  /* [DIRAC_STD] dirac_decode_data_unit makes reference to the while defined in 9.3
     inside the function parse_sequence() */
  static int dirac_decode_data_unit(AVCodecContext *avctx, const uint8_t *buf, int size)
  {
      DiracContext *s   = avctx->priv_data;
      DiracFrame *pic   = NULL;
      AVDiracSeqHeader *dsh;
      int ret, i;
      uint8_t parse_code;
      unsigned tmp;
  
      if (size < DATA_UNIT_HEADER_SIZE)
          return AVERROR_INVALIDDATA;
  
      parse_code = buf[4];
  
      init_get_bits(&s->gb, &buf[13], 8*(size - DATA_UNIT_HEADER_SIZE));
  
      if (parse_code == DIRAC_PCODE_SEQ_HEADER) {
          if (s->seen_sequence_header)
              return 0;
  
          /* [DIRAC_STD] 10. Sequence header */
          ret = av_dirac_parse_sequence_header(&dsh, buf + DATA_UNIT_HEADER_SIZE, size - DATA_UNIT_HEADER_SIZE, avctx);
          if (ret < 0) {
              av_log(avctx, AV_LOG_ERROR, "error parsing sequence header");
              return ret;
          }
  
          ret = ff_set_dimensions(avctx, dsh->width, dsh->height);
          if (ret < 0) {
              av_freep(&dsh);
              return ret;
          }
  
          ff_set_sar(avctx, dsh->sample_aspect_ratio);
          avctx->pix_fmt         = dsh->pix_fmt;
          avctx->color_range     = dsh->color_range;
          avctx->color_trc       = dsh->color_trc;
          avctx->color_primaries = dsh->color_primaries;
          avctx->colorspace      = dsh->colorspace;
          avctx->profile         = dsh->profile;
          avctx->level           = dsh->level;
          avctx->framerate       = dsh->framerate;
          s->bit_depth           = dsh->bit_depth;
          s->version.major       = dsh->version.major;
          s->version.minor       = dsh->version.minor;
          s->seq                 = *dsh;
          av_freep(&dsh);
  
          s->pshift = s->bit_depth > 8;
  
          avcodec_get_chroma_sub_sample(avctx->pix_fmt, &s->chroma_x_shift, &s->chroma_y_shift);
  
          ret = alloc_sequence_buffers(s);
          if (ret < 0)
              return ret;
  
          s->seen_sequence_header = 1;
      } else if (parse_code == DIRAC_PCODE_END_SEQ) { /* [DIRAC_STD] End of Sequence */
          free_sequence_buffers(s);
          s->seen_sequence_header = 0;
      } else if (parse_code == DIRAC_PCODE_AUX) {
          if (buf[13] == 1) {     /* encoder implementation/version */
              int ver[3];
              /* versions older than 1.0.8 don't store quant delta for
                 subbands with only one codeblock */
              if (sscanf(buf+14, "Schroedinger %d.%d.%d", ver, ver+1, ver+2) == 3)
                  if (ver[0] == 1 && ver[1] == 0 && ver[2] <= 7)
                      s->old_delta_quant = 1;
          }
      } else if (parse_code & 0x8) {  /* picture data unit */
          if (!s->seen_sequence_header) {
              av_log(avctx, AV_LOG_DEBUG, "Dropping frame without sequence header\n");
              return AVERROR_INVALIDDATA;
          }
  
          /* find an unused frame */
          for (i = 0; i < MAX_FRAMES; i++)
              if (s->all_frames[i].avframe->data[0] == NULL)
                  pic = &s->all_frames[i];
          if (!pic) {
              av_log(avctx, AV_LOG_ERROR, "framelist full\n");
              return AVERROR_INVALIDDATA;
          }
  
          av_frame_unref(pic->avframe);
  
          /* [DIRAC_STD] Defined in 9.6.1 ... */
          tmp            =  parse_code & 0x03;                   /* [DIRAC_STD] num_refs()      */
          if (tmp > 2) {
              av_log(avctx, AV_LOG_ERROR, "num_refs of 3\n");
              return AVERROR_INVALIDDATA;
          }
          s->num_refs      = tmp;
          s->is_arith      = (parse_code & 0x48) == 0x08;          /* [DIRAC_STD] using_ac()            */
          s->low_delay     = (parse_code & 0x88) == 0x88;          /* [DIRAC_STD] is_low_delay()        */
          s->core_syntax   = (parse_code & 0x88) == 0x08;          /* [DIRAC_STD] is_core_syntax()      */
          s->ld_picture    = (parse_code & 0xF8) == 0xC8;          /* [DIRAC_STD] is_ld_picture()       */
          s->hq_picture    = (parse_code & 0xF8) == 0xE8;          /* [DIRAC_STD] is_hq_picture()       */
          s->dc_prediction = (parse_code & 0x28) == 0x08;          /* [DIRAC_STD] using_dc_prediction() */
          pic->reference   = (parse_code & 0x0C) == 0x0C;          /* [DIRAC_STD] is_reference()        */
          pic->avframe->key_frame = s->num_refs == 0;              /* [DIRAC_STD] is_intra()            */
          pic->avframe->pict_type = s->num_refs + 1;               /* Definition of AVPictureType in avutil.h */
  
          /* VC-2 Low Delay has a different parse code than the Dirac Low Delay */
          if (s->version.minor == 2 && parse_code == 0x88)
              s->ld_picture = 1;
  
          if (s->low_delay && !(s->ld_picture || s->hq_picture) ) {
              av_log(avctx, AV_LOG_ERROR, "Invalid low delay flag\n");
              return AVERROR_INVALIDDATA;
          }
  
          if ((ret = get_buffer_with_edge(avctx, pic->avframe, (parse_code & 0x0C) == 0x0C ? AV_GET_BUFFER_FLAG_REF : 0)) < 0)
              return ret;
          s->current_picture = pic;
          s->plane[0].stride = pic->avframe->linesize[0];
          s->plane[1].stride = pic->avframe->linesize[1];
          s->plane[2].stride = pic->avframe->linesize[2];
  
          if (alloc_buffers(s, FFMAX3(FFABS(s->plane[0].stride), FFABS(s->plane[1].stride), FFABS(s->plane[2].stride))) < 0)
              return AVERROR(ENOMEM);
  
          /* [DIRAC_STD] 11.1 Picture parse. picture_parse() */
          ret = dirac_decode_picture_header(s);
          if (ret < 0)
              return ret;
  
          /* [DIRAC_STD] 13.0 Transform data syntax. transform_data() */
          ret = dirac_decode_frame_internal(s);
          if (ret < 0)
              return ret;
      }
      return 0;
  }
  
  static int dirac_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *pkt)
  {
      DiracContext *s     = avctx->priv_data;
      AVFrame *picture    = data;
      uint8_t *buf        = pkt->data;
      int buf_size        = pkt->size;
      int i, buf_idx      = 0;
      int ret;
      unsigned data_unit_size;
  
      /* release unused frames */
      for (i = 0; i < MAX_FRAMES; i++)
          if (s->all_frames[i].avframe->data[0] && !s->all_frames[i].reference) {
              av_frame_unref(s->all_frames[i].avframe);
              memset(s->all_frames[i].interpolated, 0, sizeof(s->all_frames[i].interpolated));
          }
  
      s->current_picture = NULL;
      *got_frame = 0;
  
      /* end of stream, so flush delayed pics */
      if (buf_size == 0)
          return get_delayed_pic(s, (AVFrame *)data, got_frame);
  
      for (;;) {
          /*[DIRAC_STD] Here starts the code from parse_info() defined in 9.6
            [DIRAC_STD] PARSE_INFO_PREFIX = "BBCD" as defined in ISO/IEC 646
            BBCD start code search */
          for (; buf_idx + DATA_UNIT_HEADER_SIZE < buf_size; buf_idx++) {
              if (buf[buf_idx  ] == 'B' && buf[buf_idx+1] == 'B' &&
                  buf[buf_idx+2] == 'C' && buf[buf_idx+3] == 'D')
                  break;
          }
          /* BBCD found or end of data */
          if (buf_idx + DATA_UNIT_HEADER_SIZE >= buf_size)
              break;
  
          data_unit_size = AV_RB32(buf+buf_idx+5);
          if (data_unit_size > buf_size - buf_idx || !data_unit_size) {
              if(data_unit_size > buf_size - buf_idx)
              av_log(s->avctx, AV_LOG_ERROR,
                     "Data unit with size %d is larger than input buffer, discarding\n",
                     data_unit_size);
              buf_idx += 4;
              continue;
          }
          /* [DIRAC_STD] dirac_decode_data_unit makes reference to the while defined in 9.3 inside the function parse_sequence() */
          ret = dirac_decode_data_unit(avctx, buf+buf_idx, data_unit_size);
          if (ret < 0)
          {
              av_log(s->avctx, AV_LOG_ERROR,"Error in dirac_decode_data_unit\n");
              return ret;
          }
          buf_idx += data_unit_size;
      }
  
      if (!s->current_picture)
          return buf_size;
  
      if (s->current_picture->avframe->display_picture_number > s->frame_number) {
          DiracFrame *delayed_frame = remove_frame(s->delay_frames, s->frame_number);
  
          s->current_picture->reference |= DELAYED_PIC_REF;
  
          if (add_frame(s->delay_frames, MAX_DELAY, s->current_picture)) {
              int min_num = s->delay_frames[0]->avframe->display_picture_number;
              /* Too many delayed frames, so we display the frame with the lowest pts */
              av_log(avctx, AV_LOG_ERROR, "Delay frame overflow\n");
  
              for (i = 1; s->delay_frames[i]; i++)
                  if (s->delay_frames[i]->avframe->display_picture_number < min_num)
                      min_num = s->delay_frames[i]->avframe->display_picture_number;
  
              delayed_frame = remove_frame(s->delay_frames, min_num);
              add_frame(s->delay_frames, MAX_DELAY, s->current_picture);
          }
  
          if (delayed_frame) {
              delayed_frame->reference ^= DELAYED_PIC_REF;
              if((ret=av_frame_ref(data, delayed_frame->avframe)) < 0)
                  return ret;
              *got_frame = 1;
          }
      } else if (s->current_picture->avframe->display_picture_number == s->frame_number) {
          /* The right frame at the right time :-) */
          if((ret=av_frame_ref(data, s->current_picture->avframe)) < 0)
              return ret;
          *got_frame = 1;
      }
  
      if (*got_frame)
          s->frame_number = picture->display_picture_number + 1;
  
      return buf_idx;
  }
  
  AVCodec ff_dirac_decoder = {
      .name           = "dirac",
      .long_name      = NULL_IF_CONFIG_SMALL("BBC Dirac VC-2"),
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_DIRAC,
      .priv_data_size = sizeof(DiracContext),
      .init           = dirac_decode_init,
      .close          = dirac_decode_end,
      .decode         = dirac_decode_frame,
      .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS | AV_CODEC_CAP_DR1,
      .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
      .flush          = dirac_decode_flush,
  };
  