/*

  * Indeo Video v3 compatible decoder
  * Copyright (c) 2009 - 2011 Maxim Poliakovski

  *

  * 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

  * This is a decoder for Intel Indeo Video v3.
  * It is based on vector quantization, run-length coding and motion compensation.
  * Known container formats: .avi and .mov
  * Known FOURCCs: 'IV31', 'IV32'

  *

  * @see http://wiki.multimedia.cx/index.php?title=Indeo_3

  */
 

 #include "libavutil/imgutils.h"

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"

 #include "copy_block.h"

 #include "bytestream.h"

 #include "get_bits.h"

 #include "hpeldsp.h"

 #include "internal.h"

 
 #include "indeo3data.h"
 

 /* RLE opcodes. */
 enum {
     RLE_ESC_F9    = 249, ///< same as RLE_ESC_FA + do the same with next block
     RLE_ESC_FA    = 250, ///< INTRA: skip block, INTER: copy data from reference
     RLE_ESC_FB    = 251, ///< apply null delta to N blocks / skip N blocks
     RLE_ESC_FC    = 252, ///< same as RLE_ESC_FD + do the same with next block
     RLE_ESC_FD    = 253, ///< apply null delta to all remaining lines of this block
     RLE_ESC_FE    = 254, ///< apply null delta to all lines up to the 3rd line
     RLE_ESC_FF    = 255  ///< apply null delta to all lines up to the 2nd line
 };

 /* Some constants for parsing frame bitstream flags. */

 #define BS_8BIT_PEL     (1 << 1) ///< 8-bit pixel bitdepth indicator

 #define BS_KEYFRAME     (1 << 2) ///< intra frame indicator
 #define BS_MV_Y_HALF    (1 << 4) ///< vertical mv halfpel resolution indicator
 #define BS_MV_X_HALF    (1 << 5) ///< horizontal mv halfpel resolution indicator
 #define BS_NONREF       (1 << 8) ///< nonref (discardable) frame indicator
 #define BS_BUFFER        9       ///< indicates which of two frame buffers should be used

 typedef struct Plane {
     uint8_t         *buffers[2];
     uint8_t         *pixels[2]; ///< pointer to the actual pixel data of the buffers above
     uint32_t        width;
     uint32_t        height;

     ptrdiff_t       pitch;

 } Plane;

 #define CELL_STACK_MAX  20
 
 typedef struct Cell {
     int16_t         xpos;       ///< cell coordinates in 4x4 blocks
     int16_t         ypos;
     int16_t         width;      ///< cell width  in 4x4 blocks
     int16_t         height;     ///< cell height in 4x4 blocks
     uint8_t         tree;       ///< tree id: 0- MC tree, 1 - VQ tree
     const int8_t    *mv_ptr;    ///< ptr to the motion vector if any
 } Cell;
 
 typedef struct Indeo3DecodeContext {
     AVCodecContext *avctx;

     HpelDSPContext  hdsp;

 
     GetBitContext   gb;
     int             need_resync;
     int             skip_bits;
     const uint8_t   *next_cell_data;
     const uint8_t   *last_byte;
     const int8_t    *mc_vectors;

     unsigned        num_vectors;    ///< number of motion vectors in mc_vectors

 
     int16_t         width, height;
     uint32_t        frame_num;      ///< current frame number (zero-based)

     int             data_size;      ///< size of the frame data in bytes

     uint16_t        frame_flags;    ///< frame properties
     uint8_t         cb_offset;      ///< needed for selecting VQ tables
     uint8_t         buf_sel;        ///< active frame buffer: 0 - primary, 1 -secondary
     const uint8_t   *y_data_ptr;
     const uint8_t   *v_data_ptr;
     const uint8_t   *u_data_ptr;
     int32_t         y_data_size;
     int32_t         v_data_size;
     int32_t         u_data_size;
     const uint8_t   *alt_quant;     ///< secondary VQ table set for the modes 1 and 4
     Plane           planes[3];

 } Indeo3DecodeContext;
 
 

 static uint8_t requant_tab[8][128];

 /*
  *  Build the static requantization table.
  *  This table is used to remap pixel values according to a specific
  *  quant index and thus avoid overflows while adding deltas.
  */
 static av_cold void build_requant_tab(void)

 {

     static const int8_t offsets[8] = { 1, 1, 2, -3, -3, 3, 4, 4 };
     static const int8_t deltas [8] = { 0, 1, 0,  4,  4, 1, 0, 1 };

     int i, j, step;

     for (i = 0; i < 8; i++) {
         step = i + 2;
         for (j = 0; j < 128; j++)
                 requant_tab[i][j] = (j + offsets[i]) / step * step + deltas[i];

     }

     /* some last elements calculated above will have values >= 128 */
     /* pixel values shall never exceed 127 so set them to non-overflowing values */
     /* according with the quantization step of the respective section */
     requant_tab[0][127] = 126;
     requant_tab[1][119] = 118;
     requant_tab[1][120] = 118;
     requant_tab[2][126] = 124;
     requant_tab[2][127] = 124;
     requant_tab[6][124] = 120;
     requant_tab[6][125] = 120;
     requant_tab[6][126] = 120;
     requant_tab[6][127] = 120;
 
     /* Patch for compatibility with the Intel's binary decoders */
     requant_tab[1][7] = 10;
     requant_tab[4][8] = 10;

 }
 

 static av_cold void free_frame_buffers(Indeo3DecodeContext *ctx)
 {
     int p;
 
     ctx->width = ctx->height = 0;
 
     for (p = 0; p < 3; p++) {
         av_freep(&ctx->planes[p].buffers[0]);
         av_freep(&ctx->planes[p].buffers[1]);
         ctx->planes[p].pixels[0] = ctx->planes[p].pixels[1] = 0;
     }
 }
 
 

 static av_cold int allocate_frame_buffers(Indeo3DecodeContext *ctx,

                                           AVCodecContext *avctx, int luma_width, int luma_height)

 {

     int p, chroma_width, chroma_height;

     int luma_size, chroma_size;
     ptrdiff_t luma_pitch, chroma_pitch;

 
     if (luma_width  < 16 || luma_width  > 640 ||
         luma_height < 16 || luma_height > 480 ||
         luma_width  &  3 || luma_height &   3) {
         av_log(avctx, AV_LOG_ERROR, "Invalid picture dimensions: %d x %d!\n",
                luma_width, luma_height);
         return AVERROR_INVALIDDATA;
     }
 

     ctx->width  = luma_width ;
     ctx->height = luma_height;
 

     chroma_width  = FFALIGN(luma_width  >> 2, 4);
     chroma_height = FFALIGN(luma_height >> 2, 4);
 
     luma_pitch   = FFALIGN(luma_width,   16);
     chroma_pitch = FFALIGN(chroma_width, 16);
 
     /* Calculate size of the luminance plane.  */
     /* Add one line more for INTRA prediction. */
     luma_size = luma_pitch * (luma_height + 1);
 
     /* Calculate size of a chrominance planes. */
     /* Add one line more for INTRA prediction. */
     chroma_size = chroma_pitch * (chroma_height + 1);
 
     /* allocate frame buffers */
     for (p = 0; p < 3; p++) {
         ctx->planes[p].pitch  = !p ? luma_pitch  : chroma_pitch;
         ctx->planes[p].width  = !p ? luma_width  : chroma_width;
         ctx->planes[p].height = !p ? luma_height : chroma_height;
 
         ctx->planes[p].buffers[0] = av_malloc(!p ? luma_size : chroma_size);
         ctx->planes[p].buffers[1] = av_malloc(!p ? luma_size : chroma_size);
 

         if (!ctx->planes[p].buffers[0] || !ctx->planes[p].buffers[1]) {
             free_frame_buffers(ctx);
             return AVERROR(ENOMEM);
         }
 

         /* fill the INTRA prediction lines with the middle pixel value = 64 */
         memset(ctx->planes[p].buffers[0], 0x40, ctx->planes[p].pitch);
         memset(ctx->planes[p].buffers[1], 0x40, ctx->planes[p].pitch);
 
         /* set buffer pointers = buf_ptr + pitch and thus skip the INTRA prediction line */
         ctx->planes[p].pixels[0] = ctx->planes[p].buffers[0] + ctx->planes[p].pitch;
         ctx->planes[p].pixels[1] = ctx->planes[p].buffers[1] + ctx->planes[p].pitch;

         memset(ctx->planes[p].pixels[0], 0, ctx->planes[p].pitch * ctx->planes[p].height);
         memset(ctx->planes[p].pixels[1], 0, ctx->planes[p].pitch * ctx->planes[p].height);

     }

     return 0;

 }
 

 /**
  *  Copy pixels of the cell(x + mv_x, y + mv_y) from the previous frame into
  *  the cell(x, y) in the current frame.
  *
  *  @param ctx      pointer to the decoder context
  *  @param plane    pointer to the plane descriptor
  *  @param cell     pointer to the cell  descriptor
  */

 static int copy_cell(Indeo3DecodeContext *ctx, Plane *plane, Cell *cell)

 {
     int     h, w, mv_x, mv_y, offset, offset_dst;
     uint8_t *src, *dst;
 
     /* setup output and reference pointers */
     offset_dst  = (cell->ypos << 2) * plane->pitch + (cell->xpos << 2);
     dst         = plane->pixels[ctx->buf_sel] + offset_dst;

     if(cell->mv_ptr){

     mv_y        = cell->mv_ptr[0];
     mv_x        = cell->mv_ptr[1];

     }else
         mv_x= mv_y= 0;

 
     /* -1 because there is an extra line on top for prediction */
     if ((cell->ypos << 2) + mv_y < -1 || (cell->xpos << 2) + mv_x < 0 ||

         ((cell->ypos + cell->height) << 2) + mv_y > plane->height     ||
         ((cell->xpos + cell->width)  << 2) + mv_x > plane->width) {

         av_log(ctx->avctx, AV_LOG_ERROR,
                "Motion vectors point out of the frame.\n");
         return AVERROR_INVALIDDATA;
     }
 

     offset      = offset_dst + mv_y * plane->pitch + mv_x;
     src         = plane->pixels[ctx->buf_sel ^ 1] + offset;
 
     h = cell->height << 2;
 
     for (w = cell->width; w > 0;) {
         /* copy using 16xH blocks */
         if (!((cell->xpos << 2) & 15) && w >= 4) {
             for (; w >= 4; src += 16, dst += 16, w -= 4)

                 ctx->hdsp.put_pixels_tab[0][0](dst, src, plane->pitch, h);

         }

         /* copy using 8xH blocks */
         if (!((cell->xpos << 2) & 7) && w >= 2) {

             ctx->hdsp.put_pixels_tab[1][0](dst, src, plane->pitch, h);

             w -= 2;
             src += 8;
             dst += 8;

         } else if (w >= 1) {

             ctx->hdsp.put_pixels_tab[2][0](dst, src, plane->pitch, h);

             w--;
             src += 4;
             dst += 4;
         }

     }

 
     return 0;

 }

 /* Average 4/8 pixels at once without rounding using SWAR */
 #define AVG_32(dst, src, ref) \

     AV_WN32A(dst, ((AV_RN32(src) + AV_RN32(ref)) >> 1) & 0x7F7F7F7FUL)

 #define AVG_64(dst, src, ref) \

     AV_WN64A(dst, ((AV_RN64(src) + AV_RN64(ref)) >> 1) & 0x7F7F7F7F7F7F7F7FULL)

 /*
  *  Replicate each even pixel as follows:
  *  ABCDEFGH -> AACCEEGG
  */
 static inline uint64_t replicate64(uint64_t a) {
 #if HAVE_BIGENDIAN
     a &= 0xFF00FF00FF00FF00ULL;
     a |= a >> 8;
 #else
     a &= 0x00FF00FF00FF00FFULL;
     a |= a << 8;
 #endif
     return a;
 }

 static inline uint32_t replicate32(uint32_t a) {
 #if HAVE_BIGENDIAN
     a &= 0xFF00FF00UL;
     a |= a >> 8;
 #else
     a &= 0x00FF00FFUL;
     a |= a << 8;
 #endif
     return a;
 }

 /* Fill n lines with 64-bit pixel value pix */

 static inline void fill_64(uint8_t *dst, const uint64_t pix, int32_t n,
                            int32_t row_offset)
 {
     for (; n > 0; dst += row_offset, n--)
         AV_WN64A(dst, pix);
 }

 /* Error codes for cell decoding. */
 enum {
     IV3_NOERR       = 0,
     IV3_BAD_RLE     = 1,
     IV3_BAD_DATA    = 2,
     IV3_BAD_COUNTER = 3,
     IV3_UNSUPPORTED = 4,
     IV3_OUT_OF_DATA = 5
 };

 #define BUFFER_PRECHECK \
 if (*data_ptr >= last_ptr) \
     return IV3_OUT_OF_DATA; \
 
 #define RLE_BLOCK_COPY \
     if (cell->mv_ptr || !skip_flag) \
         copy_block4(dst, ref, row_offset, row_offset, 4 << v_zoom)
 
 #define RLE_BLOCK_COPY_8 \

     pix64 = AV_RN64(ref);\

     if (is_first_row) {/* special prediction case: top line of a cell */\
         pix64 = replicate64(pix64);\
         fill_64(dst + row_offset, pix64, 7, row_offset);\
         AVG_64(dst, ref, dst + row_offset);\
     } else \
         fill_64(dst, pix64, 8, row_offset)
 
 #define RLE_LINES_COPY \
     copy_block4(dst, ref, row_offset, row_offset, num_lines << v_zoom)
 
 #define RLE_LINES_COPY_M10 \

     pix64 = AV_RN64(ref);\

     if (is_top_of_cell) {\
         pix64 = replicate64(pix64);\
         fill_64(dst + row_offset, pix64, (num_lines << 1) - 1, row_offset);\
         AVG_64(dst, ref, dst + row_offset);\
     } else \
         fill_64(dst, pix64, num_lines << 1, row_offset)
 
 #define APPLY_DELTA_4 \

     AV_WN16A(dst + line_offset    ,\

              (AV_RN16(ref    ) + delta_tab->deltas[dyad1]) & 0x7F7F);\

     AV_WN16A(dst + line_offset + 2,\

              (AV_RN16(ref + 2) + delta_tab->deltas[dyad2]) & 0x7F7F);\

     if (mode >= 3) {\
         if (is_top_of_cell && !cell->ypos) {\

             AV_COPY32U(dst, dst + row_offset);\

         } else {\
             AVG_32(dst, ref, dst + row_offset);\
         }\
     }

 #define APPLY_DELTA_8 \
     /* apply two 32-bit VQ deltas to next even line */\
     if (is_top_of_cell) { \
         AV_WN32A(dst + row_offset    , \

                  (replicate32(AV_RN32(ref    )) + delta_tab->deltas_m10[dyad1]) & 0x7F7F7F7F);\

         AV_WN32A(dst + row_offset + 4, \

                  (replicate32(AV_RN32(ref + 4)) + delta_tab->deltas_m10[dyad2]) & 0x7F7F7F7F);\

     } else { \
         AV_WN32A(dst + row_offset    , \

                  (AV_RN32(ref    ) + delta_tab->deltas_m10[dyad1]) & 0x7F7F7F7F);\

         AV_WN32A(dst + row_offset + 4, \

                  (AV_RN32(ref + 4) + delta_tab->deltas_m10[dyad2]) & 0x7F7F7F7F);\

     } \
     /* odd lines are not coded but rather interpolated/replicated */\
     /* first line of the cell on the top of image? - replicate */\
     /* otherwise - interpolate */\
     if (is_top_of_cell && !cell->ypos) {\

         AV_COPY64U(dst, dst + row_offset);\

     } else \
         AVG_64(dst, ref, dst + row_offset);
 
 
 #define APPLY_DELTA_1011_INTER \
     if (mode == 10) { \
         AV_WN32A(dst                 , \

                  (AV_RN32(dst                 ) + delta_tab->deltas_m10[dyad1]) & 0x7F7F7F7F);\

         AV_WN32A(dst + 4             , \

                  (AV_RN32(dst + 4             ) + delta_tab->deltas_m10[dyad2]) & 0x7F7F7F7F);\

         AV_WN32A(dst + row_offset    , \

                  (AV_RN32(dst + row_offset    ) + delta_tab->deltas_m10[dyad1]) & 0x7F7F7F7F);\

         AV_WN32A(dst + row_offset + 4, \

                  (AV_RN32(dst + row_offset + 4) + delta_tab->deltas_m10[dyad2]) & 0x7F7F7F7F);\

     } else { \
         AV_WN16A(dst                 , \

                  (AV_RN16(dst                 ) + delta_tab->deltas[dyad1]) & 0x7F7F);\

         AV_WN16A(dst + 2             , \

                  (AV_RN16(dst + 2             ) + delta_tab->deltas[dyad2]) & 0x7F7F);\

         AV_WN16A(dst + row_offset    , \

                  (AV_RN16(dst + row_offset    ) + delta_tab->deltas[dyad1]) & 0x7F7F);\

         AV_WN16A(dst + row_offset + 2, \

                  (AV_RN16(dst + row_offset + 2) + delta_tab->deltas[dyad2]) & 0x7F7F);\

     }

 static int decode_cell_data(Indeo3DecodeContext *ctx, Cell *cell,
                             uint8_t *block, uint8_t *ref_block,

                             ptrdiff_t row_offset, int h_zoom, int v_zoom, int mode,

                             const vqEntry *delta[2], int swap_quads[2],
                             const uint8_t **data_ptr, const uint8_t *last_ptr)
 {
     int           x, y, line, num_lines;
     int           rle_blocks = 0;
     uint8_t       code, *dst, *ref;
     const vqEntry *delta_tab;
     unsigned int  dyad1, dyad2;
     uint64_t      pix64;
     int           skip_flag = 0, is_top_of_cell, is_first_row = 1;

     int           blk_row_offset, line_offset;

 
     blk_row_offset = (row_offset << (2 + v_zoom)) - (cell->width << 2);
     line_offset    = v_zoom ? row_offset : 0;
 

     if (cell->height & v_zoom || cell->width & h_zoom)
         return IV3_BAD_DATA;
 

     for (y = 0; y < cell->height; is_first_row = 0, y += 1 + v_zoom) {
         for (x = 0; x < cell->width; x += 1 + h_zoom) {
             ref = ref_block;
             dst = block;
 
             if (rle_blocks > 0) {
                 if (mode <= 4) {
                     RLE_BLOCK_COPY;
                 } else if (mode == 10 && !cell->mv_ptr) {
                     RLE_BLOCK_COPY_8;

                 }

                 rle_blocks--;
             } else {
                 for (line = 0; line < 4;) {
                     num_lines = 1;
                     is_top_of_cell = is_first_row && !line;
 
                     /* select primary VQ table for odd, secondary for even lines */
                     if (mode <= 4)
                         delta_tab = delta[line & 1];
                     else
                         delta_tab = delta[1];
                     BUFFER_PRECHECK;
                     code = bytestream_get_byte(data_ptr);
                     if (code < 248) {
                         if (code < delta_tab->num_dyads) {
                             BUFFER_PRECHECK;
                             dyad1 = bytestream_get_byte(data_ptr);
                             dyad2 = code;

                             if (dyad1 >= delta_tab->num_dyads || dyad1 >= 248)

                                 return IV3_BAD_DATA;
                         } else {
                             /* process QUADS */
                             code -= delta_tab->num_dyads;
                             dyad1 = code / delta_tab->quad_exp;
                             dyad2 = code % delta_tab->quad_exp;
                             if (swap_quads[line & 1])
                                 FFSWAP(unsigned int, dyad1, dyad2);
                         }
                         if (mode <= 4) {
                             APPLY_DELTA_4;
                         } else if (mode == 10 && !cell->mv_ptr) {
                             APPLY_DELTA_8;
                         } else {
                             APPLY_DELTA_1011_INTER;
                         }
                     } else {
                         /* process RLE codes */
                         switch (code) {
                         case RLE_ESC_FC:
                             skip_flag  = 0;
                             rle_blocks = 1;
                             code       = 253;
                             /* FALLTHROUGH */
                         case RLE_ESC_FF:
                         case RLE_ESC_FE:
                         case RLE_ESC_FD:
                             num_lines = 257 - code - line;
                             if (num_lines <= 0)
                                 return IV3_BAD_RLE;
                             if (mode <= 4) {
                                 RLE_LINES_COPY;
                             } else if (mode == 10 && !cell->mv_ptr) {
                                 RLE_LINES_COPY_M10;
                             }
                             break;
                         case RLE_ESC_FB:
                             BUFFER_PRECHECK;
                             code = bytestream_get_byte(data_ptr);
                             rle_blocks = (code & 0x1F) - 1; /* set block counter */
                             if (code >= 64 || rle_blocks < 0)
                                 return IV3_BAD_COUNTER;
                             skip_flag = code & 0x20;
                             num_lines = 4 - line; /* enforce next block processing */
                             if (mode >= 10 || (cell->mv_ptr || !skip_flag)) {
                                 if (mode <= 4) {
                                     RLE_LINES_COPY;
                                 } else if (mode == 10 && !cell->mv_ptr) {
                                     RLE_LINES_COPY_M10;

                                 }

                             }
                             break;
                         case RLE_ESC_F9:
                             skip_flag  = 1;
                             rle_blocks = 1;
                             /* FALLTHROUGH */
                         case RLE_ESC_FA:
                             if (line)
                                 return IV3_BAD_RLE;
                             num_lines = 4; /* enforce next block processing */
                             if (cell->mv_ptr) {
                                 if (mode <= 4) {
                                     RLE_LINES_COPY;
                                 } else if (mode == 10 && !cell->mv_ptr) {
                                     RLE_LINES_COPY_M10;

                                 }
                             }

                             break;
                         default:
                             return IV3_UNSUPPORTED;

                         }
                     }

                     line += num_lines;
                     ref  += row_offset * (num_lines << v_zoom);
                     dst  += row_offset * (num_lines << v_zoom);

                 }

             }

             /* move to next horizontal block */
             block     += 4 << h_zoom;
             ref_block += 4 << h_zoom;
         }

         /* move to next line of blocks */
         ref_block += blk_row_offset;
         block     += blk_row_offset;
     }
     return IV3_NOERR;
 }

 /**
  *  Decode a vector-quantized cell.
  *  It consists of several routines, each of which handles one or more "modes"
  *  with which a cell can be encoded.
  *
  *  @param ctx      pointer to the decoder context
  *  @param avctx    ptr to the AVCodecContext
  *  @param plane    pointer to the plane descriptor
  *  @param cell     pointer to the cell  descriptor
  *  @param data_ptr pointer to the compressed data
  *  @param last_ptr pointer to the last byte to catch reads past end of buffer
  *  @return         number of consumed bytes or negative number in case of error
  */
 static int decode_cell(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
                        Plane *plane, Cell *cell, const uint8_t *data_ptr,
                        const uint8_t *last_ptr)
 {
     int           x, mv_x, mv_y, mode, vq_index, prim_indx, second_indx;
     int           zoom_fac;
     int           offset, error = 0, swap_quads[2];
     uint8_t       code, *block, *ref_block = 0;
     const vqEntry *delta[2];
     const uint8_t *data_start = data_ptr;
 
     /* get coding mode and VQ table index from the VQ descriptor byte */
     code     = *data_ptr++;
     mode     = code >> 4;
     vq_index = code & 0xF;
 
     /* setup output and reference pointers */
     offset = (cell->ypos << 2) * plane->pitch + (cell->xpos << 2);
     block  =  plane->pixels[ctx->buf_sel] + offset;

     if (!cell->mv_ptr) {
         /* use previous line as reference for INTRA cells */
         ref_block = block - plane->pitch;
     } else if (mode >= 10) {
         /* for mode 10 and 11 INTER first copy the predicted cell into the current one */
         /* so we don't need to do data copying for each RLE code later */

         int ret = copy_cell(ctx, plane, cell);
         if (ret < 0)
             return ret;

     } else {
         /* set the pointer to the reference pixels for modes 0-4 INTER */
         mv_y      = cell->mv_ptr[0];
         mv_x      = cell->mv_ptr[1];

 
         /* -1 because there is an extra line on top for prediction */
         if ((cell->ypos << 2) + mv_y < -1 || (cell->xpos << 2) + mv_x < 0 ||

             ((cell->ypos + cell->height) << 2) + mv_y > plane->height     ||
             ((cell->xpos + cell->width)  << 2) + mv_x > plane->width) {

             av_log(ctx->avctx, AV_LOG_ERROR,
                    "Motion vectors point out of the frame.\n");
             return AVERROR_INVALIDDATA;
         }
 

         offset   += mv_y * plane->pitch + mv_x;
         ref_block = plane->pixels[ctx->buf_sel ^ 1] + offset;
     }

     /* select VQ tables as follows: */
     /* modes 0 and 3 use only the primary table for all lines in a block */
     /* while modes 1 and 4 switch between primary and secondary tables on alternate lines */
     if (mode == 1 || mode == 4) {
         code        = ctx->alt_quant[vq_index];
         prim_indx   = (code >> 4)  + ctx->cb_offset;
         second_indx = (code & 0xF) + ctx->cb_offset;
     } else {
         vq_index += ctx->cb_offset;
         prim_indx = second_indx = vq_index;
     }

     if (prim_indx >= 24 || second_indx >= 24) {
         av_log(avctx, AV_LOG_ERROR, "Invalid VQ table indexes! Primary: %d, secondary: %d!\n",
                prim_indx, second_indx);
         return AVERROR_INVALIDDATA;
     }

     delta[0] = &vq_tab[second_indx];
     delta[1] = &vq_tab[prim_indx];
     swap_quads[0] = second_indx >= 16;
     swap_quads[1] = prim_indx   >= 16;

     /* requantize the prediction if VQ index of this cell differs from VQ index */
     /* of the predicted cell in order to avoid overflows. */
     if (vq_index >= 8 && ref_block) {
         for (x = 0; x < cell->width << 2; x++)

             ref_block[x] = requant_tab[vq_index & 7][ref_block[x] & 127];

     }

     error = IV3_NOERR;

     switch (mode) {
     case 0: /*------------------ MODES 0 & 1 (4x4 block processing) --------------------*/
     case 1:
     case 3: /*------------------ MODES 3 & 4 (4x8 block processing) --------------------*/
     case 4:
         if (mode >= 3 && cell->mv_ptr) {
             av_log(avctx, AV_LOG_ERROR, "Attempt to apply Mode 3/4 to an INTER cell!\n");
             return AVERROR_INVALIDDATA;
         }

         zoom_fac = mode >= 3;

         error = decode_cell_data(ctx, cell, block, ref_block, plane->pitch,
                                  0, zoom_fac, mode, delta, swap_quads,
                                  &data_ptr, last_ptr);

         break;
     case 10: /*-------------------- MODE 10 (8x8 block processing) ---------------------*/
     case 11: /*----------------- MODE 11 (4x8 INTER block processing) ------------------*/
         if (mode == 10 && !cell->mv_ptr) { /* MODE 10 INTRA processing */

             error = decode_cell_data(ctx, cell, block, ref_block, plane->pitch,
                                      1, 1, mode, delta, swap_quads,
                                      &data_ptr, last_ptr);

         } else { /* mode 10 and 11 INTER processing */
             if (mode == 11 && !cell->mv_ptr) {
                av_log(avctx, AV_LOG_ERROR, "Attempt to use Mode 11 for an INTRA cell!\n");
                return AVERROR_INVALIDDATA;

             }

 
             zoom_fac = mode == 10;

             error = decode_cell_data(ctx, cell, block, ref_block, plane->pitch,

                                      zoom_fac, 1, mode, delta, swap_quads,
                                      &data_ptr, last_ptr);

         }

         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unsupported coding mode: %d\n", mode);
         return AVERROR_INVALIDDATA;
     }//switch mode
 
     switch (error) {
     case IV3_BAD_RLE:
         av_log(avctx, AV_LOG_ERROR, "Mode %d: RLE code %X is not allowed at the current line\n",
                mode, data_ptr[-1]);
         return AVERROR_INVALIDDATA;
     case IV3_BAD_DATA:
         av_log(avctx, AV_LOG_ERROR, "Mode %d: invalid VQ data\n", mode);
         return AVERROR_INVALIDDATA;
     case IV3_BAD_COUNTER:
         av_log(avctx, AV_LOG_ERROR, "Mode %d: RLE-FB invalid counter: %d\n", mode, code);
         return AVERROR_INVALIDDATA;
     case IV3_UNSUPPORTED:
         av_log(avctx, AV_LOG_ERROR, "Mode %d: unsupported RLE code: %X\n", mode, data_ptr[-1]);
         return AVERROR_INVALIDDATA;
     case IV3_OUT_OF_DATA:
         av_log(avctx, AV_LOG_ERROR, "Mode %d: attempt to read past end of buffer\n", mode);
         return AVERROR_INVALIDDATA;
     }

     return data_ptr - data_start; /* report number of bytes consumed from the input buffer */
 }
 
 
 /* Binary tree codes. */
 enum {
     H_SPLIT    = 0,
     V_SPLIT    = 1,
     INTRA_NULL = 2,
     INTER_DATA = 3
 };
 
 
 #define SPLIT_CELL(size, new_size) (new_size) = ((size) > 2) ? ((((size) + 2) >> 2) << 1) : 1
 
 #define UPDATE_BITPOS(n) \
     ctx->skip_bits  += (n); \
     ctx->need_resync = 1
 
 #define RESYNC_BITSTREAM \
     if (ctx->need_resync && !(get_bits_count(&ctx->gb) & 7)) { \
         skip_bits_long(&ctx->gb, ctx->skip_bits);              \
         ctx->skip_bits   = 0;                                  \
         ctx->need_resync = 0;                                  \
     }
 
 #define CHECK_CELL \
     if (curr_cell.xpos + curr_cell.width > (plane->width >> 2) ||               \
         curr_cell.ypos + curr_cell.height > (plane->height >> 2)) {             \
         av_log(avctx, AV_LOG_ERROR, "Invalid cell: x=%d, y=%d, w=%d, h=%d\n",   \
                curr_cell.xpos, curr_cell.ypos, curr_cell.width, curr_cell.height); \
         return AVERROR_INVALIDDATA;                                                              \
     }
 
 
 static int parse_bintree(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
                          Plane *plane, int code, Cell *ref_cell,
                          const int depth, const int strip_width)
 {
     Cell    curr_cell;

     int     bytes_used, ret;

 
     if (depth <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Stack overflow (corrupted binary tree)!\n");
         return AVERROR_INVALIDDATA; // unwind recursion
     }
 
     curr_cell = *ref_cell; // clone parent cell
     if (code == H_SPLIT) {
         SPLIT_CELL(ref_cell->height, curr_cell.height);
         ref_cell->ypos   += curr_cell.height;
         ref_cell->height -= curr_cell.height;

         if (ref_cell->height <= 0 || curr_cell.height <= 0)
             return AVERROR_INVALIDDATA;

     } else if (code == V_SPLIT) {
         if (curr_cell.width > strip_width) {
             /* split strip */
             curr_cell.width = (curr_cell.width <= (strip_width << 1) ? 1 : 2) * strip_width;
         } else
             SPLIT_CELL(ref_cell->width, curr_cell.width);
         ref_cell->xpos  += curr_cell.width;
         ref_cell->width -= curr_cell.width;

         if (ref_cell->width <= 0 || curr_cell.width <= 0)
             return AVERROR_INVALIDDATA;

     }
 

     while (get_bits_left(&ctx->gb) >= 2) { /* loop until return */

         RESYNC_BITSTREAM;
         switch (code = get_bits(&ctx->gb, 2)) {
         case H_SPLIT:
         case V_SPLIT:
             if (parse_bintree(ctx, avctx, plane, code, &curr_cell, depth - 1, strip_width))
                 return AVERROR_INVALIDDATA;
             break;
         case INTRA_NULL:
             if (!curr_cell.tree) { /* MC tree INTRA code */
                 curr_cell.mv_ptr = 0; /* mark the current strip as INTRA */
                 curr_cell.tree   = 1; /* enter the VQ tree */
             } else { /* VQ tree NULL code */
                 RESYNC_BITSTREAM;
                 code = get_bits(&ctx->gb, 2);
                 if (code >= 2) {
                     av_log(avctx, AV_LOG_ERROR, "Invalid VQ_NULL code: %d\n", code);
                     return AVERROR_INVALIDDATA;

                 }

                 if (code == 1)
                     av_log(avctx, AV_LOG_ERROR, "SkipCell procedure not implemented yet!\n");
 
                 CHECK_CELL

                 if (!curr_cell.mv_ptr)

                     return AVERROR_INVALIDDATA;

                 ret = copy_cell(ctx, plane, &curr_cell);
                 return ret;

             }
             break;
         case INTER_DATA:
             if (!curr_cell.tree) { /* MC tree INTER code */

                 unsigned mv_idx;

                 /* get motion vector index and setup the pointer to the mv set */
                 if (!ctx->need_resync)
                     ctx->next_cell_data = &ctx->gb.buffer[(get_bits_count(&ctx->gb) + 7) >> 3];

                 if (ctx->next_cell_data >= ctx->last_byte) {
                     av_log(avctx, AV_LOG_ERROR, "motion vector out of array\n");
                     return AVERROR_INVALIDDATA;
                 }

                 mv_idx = *(ctx->next_cell_data++);

                 if (mv_idx >= ctx->num_vectors) {
                     av_log(avctx, AV_LOG_ERROR, "motion vector index out of range\n");
                     return AVERROR_INVALIDDATA;
                 }

                 curr_cell.mv_ptr = &ctx->mc_vectors[mv_idx << 1];

                 curr_cell.tree   = 1; /* enter the VQ tree */
                 UPDATE_BITPOS(8);
             } else { /* VQ tree DATA code */
                 if (!ctx->need_resync)
                     ctx->next_cell_data = &ctx->gb.buffer[(get_bits_count(&ctx->gb) + 7) >> 3];
 
                 CHECK_CELL
                 bytes_used = decode_cell(ctx, avctx, plane, &curr_cell,
                                          ctx->next_cell_data, ctx->last_byte);
                 if (bytes_used < 0)
                     return AVERROR_INVALIDDATA;
 
                 UPDATE_BITPOS(bytes_used << 3);
                 ctx->next_cell_data += bytes_used;
                 return 0;

             }

             break;

         }

     }//while
 

     return AVERROR_INVALIDDATA;

 }
 

 
 static int decode_plane(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
                         Plane *plane, const uint8_t *data, int32_t data_size,
                         int32_t strip_width)

 {

     Cell            curr_cell;

     unsigned        num_vectors;

     /* each plane data starts with mc_vector_count field, */
     /* an optional array of motion vectors followed by the vq data */

     num_vectors = bytestream_get_le32(&data); data_size -= 4;

     if (num_vectors > 256) {
         av_log(ctx->avctx, AV_LOG_ERROR,
                "Read invalid number of motion vectors %d\n", num_vectors);

         return AVERROR_INVALIDDATA;

     }

     if (num_vectors * 2 > data_size)

         return AVERROR_INVALIDDATA;

 
     ctx->num_vectors = num_vectors;

     ctx->mc_vectors  = num_vectors ? data : 0;
 
     /* init the bitreader */

     init_get_bits(&ctx->gb, &data[num_vectors * 2], (data_size - num_vectors * 2) << 3);

     ctx->skip_bits   = 0;
     ctx->need_resync = 0;
 

     ctx->last_byte = data + data_size;

     /* initialize the 1st cell and set its dimensions to whole plane */
     curr_cell.xpos   = curr_cell.ypos = 0;
     curr_cell.width  = plane->width  >> 2;
     curr_cell.height = plane->height >> 2;
     curr_cell.tree   = 0; // we are in the MC tree now
     curr_cell.mv_ptr = 0; // no motion vector = INTRA cell

     return parse_bintree(ctx, avctx, plane, INTRA_NULL, &curr_cell, CELL_STACK_MAX, strip_width);

 }
 

 
 #define OS_HDR_ID   MKBETAG('F', 'R', 'M', 'H')
 
 static int decode_frame_headers(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
                                 const uint8_t *buf, int buf_size)

 {

     GetByteContext gb;
     const uint8_t   *bs_hdr;

     uint32_t        frame_num, word2, check_sum, data_size;

     int             y_offset, u_offset, v_offset;
     uint32_t        starts[3], ends[3];

     uint16_t        height, width;
     int             i, j;
 

     bytestream2_init(&gb, buf, buf_size);
 

     /* parse and check the OS header */

     frame_num = bytestream2_get_le32(&gb);
     word2     = bytestream2_get_le32(&gb);
     check_sum = bytestream2_get_le32(&gb);
     data_size = bytestream2_get_le32(&gb);

 
     if ((frame_num ^ word2 ^ data_size ^ OS_HDR_ID) != check_sum) {
         av_log(avctx, AV_LOG_ERROR, "OS header checksum mismatch!\n");
         return AVERROR_INVALIDDATA;

     }

     /* parse the bitstream header */

     bs_hdr = gb.buffer;

     if (bytestream2_get_le16(&gb) != 32) {

         av_log(avctx, AV_LOG_ERROR, "Unsupported codec version!\n");
         return AVERROR_INVALIDDATA;

     }
 

     ctx->frame_num   =  frame_num;

     ctx->frame_flags =  bytestream2_get_le16(&gb);
     ctx->data_size   = (bytestream2_get_le32(&gb) + 7) >> 3;
     ctx->cb_offset   =  bytestream2_get_byte(&gb);

 
     if (ctx->data_size == 16)
         return 4;

     ctx->data_size = FFMIN(ctx->data_size, buf_size - 16);

     bytestream2_skip(&gb, 3); // skip reserved byte and checksum

 
     /* check frame dimensions */

     height = bytestream2_get_le16(&gb);
     width  = bytestream2_get_le16(&gb);

     if (av_image_check_size(width, height, 0, avctx))
         return AVERROR_INVALIDDATA;
 
     if (width != ctx->width || height != ctx->height) {

         int res;
 

         ff_dlog(avctx, "Frame dimensions changed!\n");

         if (width  < 16 || width  > 640 ||
             height < 16 || height > 480 ||
             width  &  3 || height &   3) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid picture dimensions: %d x %d!\n", width, height);
             return AVERROR_INVALIDDATA;
         }

         free_frame_buffers(ctx);

         if ((res = allocate_frame_buffers(ctx, avctx, width, height)) < 0)

              return res;

         if ((res = ff_set_dimensions(avctx, width, height)) < 0)
             return res;

     }
 

     y_offset = bytestream2_get_le32(&gb);
     v_offset = bytestream2_get_le32(&gb);
     u_offset = bytestream2_get_le32(&gb);
     bytestream2_skip(&gb, 4);

 
     /* unfortunately there is no common order of planes in the buffer */
     /* so we use that sorting algo for determining planes data sizes  */
     starts[0] = y_offset;
     starts[1] = v_offset;
     starts[2] = u_offset;
 
     for (j = 0; j < 3; j++) {
         ends[j] = ctx->data_size;
         for (i = 2; i >= 0; i--)
             if (starts[i] < ends[j] && starts[i] > starts[j])
                 ends[j] = starts[i];

     }
 

     ctx->y_data_size = ends[0] - starts[0];
     ctx->v_data_size = ends[1] - starts[1];
     ctx->u_data_size = ends[2] - starts[2];

     if (FFMIN3(y_offset, v_offset, u_offset) < 0 ||
         FFMAX3(y_offset, v_offset, u_offset) >= ctx->data_size - 16 ||

         FFMIN3(y_offset, v_offset, u_offset) < gb.buffer - bs_hdr + 16 ||

         FFMIN3(ctx->y_data_size, ctx->v_data_size, ctx->u_data_size) <= 0) {
         av_log(avctx, AV_LOG_ERROR, "One of the y/u/v offsets is invalid\n");
         return AVERROR_INVALIDDATA;

     }

     ctx->y_data_ptr = bs_hdr + y_offset;
     ctx->v_data_ptr = bs_hdr + v_offset;
     ctx->u_data_ptr = bs_hdr + u_offset;

     ctx->alt_quant  = gb.buffer;

     if (ctx->data_size == 16) {
         av_log(avctx, AV_LOG_DEBUG, "Sync frame encountered!\n");
         return 16;
     }

     if (ctx->frame_flags & BS_8BIT_PEL) {

         avpriv_request_sample(avctx, "8-bit pixel format");

         return AVERROR_PATCHWELCOME;
     }
 
     if (ctx->frame_flags & BS_MV_X_HALF || ctx->frame_flags & BS_MV_Y_HALF) {

         avpriv_request_sample(avctx, "Halfpel motion vectors");

         return AVERROR_PATCHWELCOME;
     }
 
     return 0;
 }

 /**
  *  Convert and output the current plane.
  *  All pixel values will be upsampled by shifting right by one bit.
  *
  *  @param[in]  plane        pointer to the descriptor of the plane being processed
  *  @param[in]  buf_sel      indicates which frame buffer the input data stored in
  *  @param[out] dst          pointer to the buffer receiving converted pixels
  *  @param[in]  dst_pitch    pitch for moving to the next y line

  *  @param[in]  dst_height   output plane height

  */

 static void output_plane(const Plane *plane, int buf_sel, uint8_t *dst,

                          ptrdiff_t dst_pitch, int dst_height)

 {
     int             x,y;
     const uint8_t   *src  = plane->pixels[buf_sel];

     ptrdiff_t       pitch = plane->pitch;

     dst_height = FFMIN(dst_height, plane->height);
     for (y = 0; y < dst_height; y++) {

         /* convert four pixels at once using SWAR */
         for (x = 0; x < plane->width >> 2; x++) {
             AV_WN32A(dst, (AV_RN32A(src) & 0x7F7F7F7F) << 1);
             src += 4;
             dst += 4;

         }

         for (x <<= 2; x < plane->width; x++)
             *dst++ = *src++ << 1;

         src += pitch     - plane->width;
         dst += dst_pitch - plane->width;

     }

 }
 
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     Indeo3DecodeContext *ctx = avctx->priv_data;
 
     ctx->avctx     = avctx;

     avctx->pix_fmt = AV_PIX_FMT_YUV410P;

 
     build_requant_tab();
 

     ff_hpeldsp_init(&ctx->hdsp, avctx->flags);

     return allocate_frame_buffers(ctx, avctx, avctx->width, avctx->height);

 }
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

                         AVPacket *avpkt)

 {

     Indeo3DecodeContext *ctx = avctx->priv_data;

     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;

     AVFrame *frame     = data;

     int res;
 
     res = decode_frame_headers(ctx, avctx, buf, buf_size);
     if (res < 0)
         return res;
 
     /* skip sync(null) frames */
     if (res) {
         // we have processed 16 bytes but no data was decoded

         *got_frame = 0;

         return buf_size;
     }

     /* skip droppable INTER frames if requested */
     if (ctx->frame_flags & BS_NONREF &&
        (avctx->skip_frame >= AVDISCARD_NONREF))
         return 0;

     /* skip INTER frames if requested */
     if (!(ctx->frame_flags & BS_KEYFRAME) && avctx->skip_frame >= AVDISCARD_NONKEY)
         return 0;

     /* use BS_BUFFER flag for buffer switching */
     ctx->buf_sel = (ctx->frame_flags >> BS_BUFFER) & 1;

     if ((res = ff_get_buffer(avctx, frame, 0)) < 0)

         return res;
 

     /* decode luma plane */
     if ((res = decode_plane(ctx, avctx, ctx->planes, ctx->y_data_ptr, ctx->y_data_size, 40)))
         return res;

     /* decode chroma planes */
     if ((res = decode_plane(ctx, avctx, &ctx->planes[1], ctx->u_data_ptr, ctx->u_data_size, 10)))
         return res;

     if ((res = decode_plane(ctx, avctx, &ctx->planes[2], ctx->v_data_ptr, ctx->v_data_size, 10)))
         return res;
 

     output_plane(&ctx->planes[0], ctx->buf_sel,

                  frame->data[0], frame->linesize[0],

                  avctx->height);
     output_plane(&ctx->planes[1], ctx->buf_sel,

                  frame->data[1], frame->linesize[1],

                  (avctx->height + 3) >> 2);
     output_plane(&ctx->planes[2], ctx->buf_sel,

                  frame->data[2], frame->linesize[2],

                  (avctx->height + 3) >> 2);

     *got_frame = 1;

 
     return buf_size;
 }
 

 
 static av_cold int decode_close(AVCodecContext *avctx)

 {

     free_frame_buffers(avctx->priv_data);

 
     return 0;
 }
 

 AVCodec ff_indeo3_decoder = {

     .name           = "indeo3",

     .long_name      = NULL_IF_CONFIG_SMALL("Intel Indeo 3"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_INDEO3,

     .priv_data_size = sizeof(Indeo3DecodeContext),

     .init           = decode_init,
     .close          = decode_close,
     .decode         = decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };