/*
  * XVideo Motion Compensation
  * Copyright (c) 2003 Ivan Kalvachev
  *

  * 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

  */
 

 #include <limits.h>

 #include <X11/extensions/XvMC.h>

 
 #include "avcodec.h"
 #include "mpegvideo.h"
 
 #undef NDEBUG
 #include <assert.h>
 

 #include "xvmc.h"

 #include "xvmc_internal.h"

 /**

  * Initialize the block field of the MpegEncContext pointer passed as

  * parameter after making sure that the data is not corrupted.

  * In order to implement something like direct rendering instead of decoding
  * coefficients in s->blocks and then copying them, copy them directly

  * into the data_blocks array provided by xvmc.

  */

 void ff_xvmc_init_block(MpegEncContext *s)

 {

     struct xvmc_pix_fmt *render = (struct xvmc_pix_fmt*)s->current_picture.f.data[2];

     assert(render && render->xvmc_id == AV_XVMC_ID);

     s->block = (int16_t (*)[64])(render->data_blocks + render->next_free_data_block_num * 64);

 }
 

 /**

  * Fill individual block pointers, so there are no gaps in the data_block array

  * in case not all blocks in the macroblock are coded.

  */

 void ff_xvmc_pack_pblocks(MpegEncContext *s, int cbp)

 {

     int i, j = 0;

     const int mb_block_count = 4 + (1 << s->chroma_format);

     cbp <<= 12-mb_block_count;
     for (i = 0; i < mb_block_count; i++) {

         if (cbp & (1 << 11))

             s->pblocks[i] = &s->block[j++];

         else

             s->pblocks[i] = NULL;

         cbp += cbp;

     }

 }
 

 /**

  * Find and store the surfaces that are used as reference frames.

  * This function should be called for every new field and/or frame.
  * It should be safe to call the function a few times for the same field.
  */

 int ff_xvmc_field_start(MpegEncContext *s, AVCodecContext *avctx)

 {

     struct xvmc_pix_fmt *last, *next, *render = (struct xvmc_pix_fmt*)s->current_picture.f.data[2];

     const int mb_block_count = 4 + (1 << s->chroma_format);

     assert(avctx);

     if (!render || render->xvmc_id != AV_XVMC_ID ||

         !render->data_blocks || !render->mv_blocks ||
         (unsigned int)render->allocated_mv_blocks   > INT_MAX/(64*6) ||
         (unsigned int)render->allocated_data_blocks > INT_MAX/64     ||
         !render->p_surface) {

         av_log(avctx, AV_LOG_ERROR,
                "Render token doesn't look as expected.\n");

         return -1; // make sure that this is a render packet

     }

     if (render->filled_mv_blocks_num) {

         av_log(avctx, AV_LOG_ERROR,

                "Rendering surface contains %i unprocessed blocks.\n",

                render->filled_mv_blocks_num);

         return -1;

     }

     if (render->allocated_mv_blocks   < 1 ||

         render->allocated_data_blocks <  render->allocated_mv_blocks*mb_block_count ||
         render->start_mv_blocks_num   >= render->allocated_mv_blocks                ||
         render->next_free_data_block_num >
                         render->allocated_data_blocks -
                         mb_block_count*(render->allocated_mv_blocks-render->start_mv_blocks_num)) {

         av_log(avctx, AV_LOG_ERROR,
                "Rendering surface doesn't provide enough block structures to work with.\n");
         return -1;
     }

     render->picture_structure = s->picture_structure;
     render->flags             = s->first_field ? 0 : XVMC_SECOND_FIELD;

     render->p_future_surface  = NULL;
     render->p_past_surface    = NULL;

     switch(s->pict_type) {

         case  AV_PICTURE_TYPE_I:

             return 0; // no prediction from other frames

         case  AV_PICTURE_TYPE_B:

             next = (struct xvmc_pix_fmt*)s->next_picture.f.data[2];

             if (!next)

                 return -1;

             if (next->xvmc_id != AV_XVMC_ID)

                 return -1;

             render->p_future_surface = next->p_surface;

             // no return here, going to set forward prediction

         case  AV_PICTURE_TYPE_P:

             last = (struct xvmc_pix_fmt*)s->last_picture.f.data[2];

             if (!last)

                 last = render; // predict second field from the first

             if (last->xvmc_id != AV_XVMC_ID)

                 return -1;

             render->p_past_surface = last->p_surface;
             return 0;

     }

 
 return -1;
 }
 

 /**

  * Complete frame/field rendering by passing any remaining blocks.

  * Normally ff_draw_horiz_band() is called for each slice, however,
  * some leftover blocks, for example from error_resilience(), may remain.

  * It should be safe to call the function a few times for the same field.
  */

 void ff_xvmc_field_end(MpegEncContext *s)

 {

     struct xvmc_pix_fmt *render = (struct xvmc_pix_fmt*)s->current_picture.f.data[2];

     assert(render);

     if (render->filled_mv_blocks_num > 0)

         ff_mpeg_draw_horiz_band(s, 0, 0);

 }
 

 /**

  * Synthesize the data needed by XvMC to render one macroblock of data.
  * Fill all relevant fields, if necessary do IDCT.

  */

 void ff_xvmc_decode_mb(MpegEncContext *s)

 {

     XvMCMacroBlock *mv_block;

     struct xvmc_pix_fmt *render;

     int i, cbp, blocks_per_mb;

     const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;

     if (s->encoding) {

         av_log(s->avctx, AV_LOG_ERROR, "XVMC doesn't support encoding!!!\n");

         return;

     }
 

     // from MPV_decode_mb(), update DC predictors for P macroblocks

     if (!s->mb_intra) {
         s->last_dc[0] =
         s->last_dc[1] =
         s->last_dc[2] =  128 << s->intra_dc_precision;
     }
 

     // MC doesn't skip blocks

     s->mb_skipped = 0;

     // Do I need to export quant when I could not perform postprocessing?
     // Anyway, it doesn't hurt.

     s->current_picture.qscale_table[mb_xy] = s->qscale;

     // start of XVMC-specific code

     render = (struct xvmc_pix_fmt*)s->current_picture.f.data[2];

     assert(render);

     assert(render->xvmc_id == AV_XVMC_ID);

     assert(render->mv_blocks);

     // take the next free macroblock

     mv_block = &render->mv_blocks[render->start_mv_blocks_num +

                                   render->filled_mv_blocks_num];

     mv_block->x        = s->mb_x;
     mv_block->y        = s->mb_y;

     mv_block->dct_type = s->interlaced_dct; // XVMC_DCT_TYPE_FRAME/FIELD;

     if (s->mb_intra) {

         mv_block->macroblock_type = XVMC_MB_TYPE_INTRA; // no MC, all done

     } else {

         mv_block->macroblock_type = XVMC_MB_TYPE_PATTERN;
 

         if (s->mv_dir & MV_DIR_FORWARD) {

             mv_block->macroblock_type |= XVMC_MB_TYPE_MOTION_FORWARD;

             // PMV[n][dir][xy] = mv[dir][n][xy]

             mv_block->PMV[0][0][0] = s->mv[0][0][0];
             mv_block->PMV[0][0][1] = s->mv[0][0][1];
             mv_block->PMV[1][0][0] = s->mv[0][1][0];
             mv_block->PMV[1][0][1] = s->mv[0][1][1];
         }

         if (s->mv_dir & MV_DIR_BACKWARD) {

             mv_block->macroblock_type |= XVMC_MB_TYPE_MOTION_BACKWARD;

             mv_block->PMV[0][1][0] = s->mv[1][0][0];
             mv_block->PMV[0][1][1] = s->mv[1][0][1];
             mv_block->PMV[1][1][0] = s->mv[1][1][0];
             mv_block->PMV[1][1][1] = s->mv[1][1][1];
         }
 

         switch(s->mv_type) {

             case  MV_TYPE_16X16:
                 mv_block->motion_type = XVMC_PREDICTION_FRAME;
                 break;
             case  MV_TYPE_16X8:
                 mv_block->motion_type = XVMC_PREDICTION_16x8;
                 break;
             case  MV_TYPE_FIELD:
                 mv_block->motion_type = XVMC_PREDICTION_FIELD;

                 if (s->picture_structure == PICT_FRAME) {
                     mv_block->PMV[0][0][1] <<= 1;
                     mv_block->PMV[1][0][1] <<= 1;
                     mv_block->PMV[0][1][1] <<= 1;
                     mv_block->PMV[1][1][1] <<= 1;

                 }
                 break;
             case  MV_TYPE_DMV:
                 mv_block->motion_type = XVMC_PREDICTION_DUAL_PRIME;

                 if (s->picture_structure == PICT_FRAME) {

                     mv_block->PMV[0][0][0] = s->mv[0][0][0];      // top from top

                     mv_block->PMV[0][0][1] = s->mv[0][0][1] << 1;

                     mv_block->PMV[0][1][0] = s->mv[0][0][0];      // bottom from bottom

                     mv_block->PMV[0][1][1] = s->mv[0][0][1] << 1;

                     mv_block->PMV[1][0][0] = s->mv[0][2][0];      // dmv00, top from bottom

                     mv_block->PMV[1][0][1] = s->mv[0][2][1] << 1; // dmv01

                     mv_block->PMV[1][1][0] = s->mv[0][3][0];      // dmv10, bottom from top

                     mv_block->PMV[1][1][1] = s->mv[0][3][1] << 1; // dmv11

                 } else {

                     mv_block->PMV[0][1][0] = s->mv[0][2][0];      // dmv00
                     mv_block->PMV[0][1][1] = s->mv[0][2][1];      // dmv01

                 }
                 break;
             default:
                 assert(0);
         }
 
         mv_block->motion_vertical_field_select = 0;
 

         // set correct field references

         if (s->mv_type == MV_TYPE_FIELD || s->mv_type == MV_TYPE_16X8) {

             mv_block->motion_vertical_field_select |= s->field_select[0][0];

             mv_block->motion_vertical_field_select |= s->field_select[1][0] << 1;
             mv_block->motion_vertical_field_select |= s->field_select[0][1] << 2;
             mv_block->motion_vertical_field_select |= s->field_select[1][1] << 3;

         }

     } // !intra

     // time to handle data blocks

     mv_block->index = render->next_free_data_block_num;

     blocks_per_mb = 6;

     if (s->chroma_format >= 2) {

         blocks_per_mb = 4 + (1 << s->chroma_format);

     }

     // calculate cbp

     cbp = 0;

     for (i = 0; i < blocks_per_mb; i++) {

         cbp += cbp;

         if (s->block_last_index[i] >= 0)

             cbp++;
     }

     if (s->flags & CODEC_FLAG_GRAY) {

         if (s->mb_intra) {                                   // intra frames are always full chroma blocks

             for (i = 4; i < blocks_per_mb; i++) {

                 memset(s->pblocks[i], 0, sizeof(*s->pblocks[i]));  // so we need to clear them

                 if (!render->unsigned_intra)

                     *s->pblocks[i][0] = 1 << 10;

             }

         } else {

             cbp &= 0xf << (blocks_per_mb - 4);

             blocks_per_mb = 4;                               // luminance blocks only

         }

     }

     mv_block->coded_block_pattern = cbp;

     if (cbp == 0)

         mv_block->macroblock_type &= ~XVMC_MB_TYPE_PATTERN;
 

     for (i = 0; i < blocks_per_mb; i++) {
         if (s->block_last_index[i] >= 0) {

             // I do not have unsigned_intra MOCO to test, hope it is OK.

             if (s->mb_intra && (render->idct || !render->unsigned_intra))

                 *s->pblocks[i][0] -= 1 << 10;

             if (!render->idct) {

                 s->dsp.idct(*s->pblocks[i]);

                 /* It is unclear if MC hardware requires pixel diff values to be
                  * in the range [-255;255]. TODO: Clipping if such hardware is
                  * ever found. As of now it would only be an unnecessary
                  * slowdown. */

             }

             // copy blocks only if the codec doesn't support pblocks reordering

             if (s->avctx->xvmc_acceleration == 1) {

                 memcpy(&render->data_blocks[render->next_free_data_block_num*64],

                        s->pblocks[i], sizeof(*s->pblocks[i]));

             }
             render->next_free_data_block_num++;

         }
     }
     render->filled_mv_blocks_num++;
 

     assert(render->filled_mv_blocks_num     <= render->allocated_mv_blocks);
     assert(render->next_free_data_block_num <= render->allocated_data_blocks);
     /* The above conditions should not be able to fail as long as this function
      * is used and the following 'if ()' automatically calls a callback to free
      * blocks. */

     if (render->filled_mv_blocks_num == render->allocated_mv_blocks)

         ff_mpeg_draw_horiz_band(s, 0, 0);

 }