/*
  * RV30 decoder
  * Copyright (c) 2007 Konstantin Shishkov
  *
  * 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

  * RV30 decoder

  */
 
 #include "avcodec.h"
 #include "mpegvideo.h"

 #include "golomb.h"

 
 #include "rv34.h"
 #include "rv30data.h"
 
 
 static int rv30_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
 {
     int mb_bits;
     int w = r->s.width, h = r->s.height;
     int mb_size;

     int rpr;

 
     memset(si, 0, sizeof(SliceInfo));

     if(get_bits(gb, 3))
         return -1;

     si->type = get_bits(gb, 2);
     if(si->type == 1) si->type = 0;
     if(get_bits1(gb))
         return -1;
     si->quant = get_bits(gb, 5);
     skip_bits1(gb);

     si->pts = get_bits(gb, 13);

     rpr = get_bits(gb, r->rpr);

     if (r->s.avctx->extradata_size < 8 + rpr*2) {
         av_log(r->s.avctx, AV_LOG_WARNING,
                "Extradata does not contain selected resolution\n");
         rpr = 0;
     }

     if(rpr){
         w = r->s.avctx->extradata[6 + rpr*2] << 2;
         h = r->s.avctx->extradata[7 + rpr*2] << 2;

     }

     si->width  = w;
     si->height = h;

     mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
     mb_bits = ff_rv34_get_start_offset(gb, mb_size);
     si->start = get_bits(gb, mb_bits);
     skip_bits1(gb);
     return 0;
 }
 
 /**

  * Decode 4x4 intra types array.

  */

 static int rv30_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)

 {
     int i, j, k;
 

     for(i = 0; i < 4; i++, dst += r->intra_types_stride - 4){

         for(j = 0; j < 4; j+= 2){

             unsigned code = svq3_get_ue_golomb(gb) << 1;

             if (code > 80U*2U) {

                 av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction code\n");
                 return -1;
             }
             for(k = 0; k < 2; k++){

                 int A = dst[-r->intra_types_stride] + 1;

                 int B = dst[-1] + 1;
                 *dst++ = rv30_itype_from_context[A * 90 + B * 9 + rv30_itype_code[code + k]];
                 if(dst[-1] == 9){
                     av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction mode\n");
                     return -1;
                 }
             }
         }
     }
     return 0;
 }
 
 /**

  * Decode macroblock information.

  */
 static int rv30_decode_mb_info(RV34DecContext *r)
 {
     static const int rv30_p_types[6] = { RV34_MB_SKIP, RV34_MB_P_16x16, RV34_MB_P_8x8, -1, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
     static const int rv30_b_types[6] = { RV34_MB_SKIP, RV34_MB_B_DIRECT, RV34_MB_B_FORWARD, RV34_MB_B_BACKWARD, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
     MpegEncContext *s = &r->s;
     GetBitContext *gb = &s->gb;

     unsigned code     = svq3_get_ue_golomb(gb);

     if (code > 11) {

         av_log(s->avctx, AV_LOG_ERROR, "Incorrect MB type code\n");
         return -1;
     }
     if(code > 5){
         av_log(s->avctx, AV_LOG_ERROR, "dquant needed\n");
         code -= 6;
     }

     if(s->pict_type != AV_PICTURE_TYPE_B)

         return rv30_p_types[code];
     else
         return rv30_b_types[code];
 }
 

 static inline void rv30_weak_loop_filter(uint8_t *src, const int step,
                                          const int stride, const int lim)
 {

     const uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;

     int i, diff;
 
     for(i = 0; i < 4; i++){
         diff = ((src[-2*step] - src[1*step]) - (src[-1*step] - src[0*step])*4) >> 3;
         diff = av_clip(diff, -lim, lim);
         src[-1*step] = cm[src[-1*step] + diff];
         src[ 0*step] = cm[src[ 0*step] - diff];
         src += stride;
     }
 }
 
 static void rv30_loop_filter(RV34DecContext *r, int row)
 {
     MpegEncContext *s = &r->s;
     int mb_pos, mb_x;
     int i, j, k;
     uint8_t *Y, *C;
     int loc_lim, cur_lim, left_lim = 0, top_lim = 0;
 
     mb_pos = row * s->mb_stride;
     for(mb_x = 0; mb_x < s->mb_width; mb_x++, mb_pos++){

         int mbtype = s->current_picture_ptr->mb_type[mb_pos];

         if(IS_INTRA(mbtype) || IS_SEPARATE_DC(mbtype))
             r->deblock_coefs[mb_pos] = 0xFFFF;
         if(IS_INTRA(mbtype))
             r->cbp_chroma[mb_pos] = 0xFF;
     }
 
     /* all vertical edges are filtered first
      * and horizontal edges are filtered on the next iteration
      */
     mb_pos = row * s->mb_stride;
     for(mb_x = 0; mb_x < s->mb_width; mb_x++, mb_pos++){

         cur_lim = rv30_loop_filt_lim[s->current_picture_ptr->qscale_table[mb_pos]];

         if(mb_x)

             left_lim = rv30_loop_filt_lim[s->current_picture_ptr->qscale_table[mb_pos - 1]];

         for(j = 0; j < 16; j += 4){

             Y = s->current_picture_ptr->f.data[0] + mb_x*16 + (row*16 + j) * s->linesize + 4 * !mb_x;

             for(i = !mb_x; i < 4; i++, Y += 4){
                 int ij = i + j;
                 loc_lim = 0;
                 if(r->deblock_coefs[mb_pos] & (1 << ij))
                     loc_lim = cur_lim;
                 else if(!i && r->deblock_coefs[mb_pos - 1] & (1 << (ij + 3)))
                     loc_lim = left_lim;
                 else if( i && r->deblock_coefs[mb_pos]     & (1 << (ij - 1)))
                     loc_lim = cur_lim;
                 if(loc_lim)
                     rv30_weak_loop_filter(Y, 1, s->linesize, loc_lim);
             }
         }
         for(k = 0; k < 2; k++){
             int cur_cbp, left_cbp = 0;
             cur_cbp = (r->cbp_chroma[mb_pos] >> (k*4)) & 0xF;
             if(mb_x)
                 left_cbp = (r->cbp_chroma[mb_pos - 1] >> (k*4)) & 0xF;
             for(j = 0; j < 8; j += 4){

                 C = s->current_picture_ptr->f.data[k + 1] + mb_x*8 + (row*8 + j) * s->uvlinesize + 4 * !mb_x;

                 for(i = !mb_x; i < 2; i++, C += 4){
                     int ij = i + (j >> 1);
                     loc_lim = 0;

                     if (cur_cbp & (1 << ij))

                         loc_lim = cur_lim;
                     else if(!i && left_cbp & (1 << (ij + 1)))
                         loc_lim = left_lim;
                     else if( i && cur_cbp  & (1 << (ij - 1)))
                         loc_lim = cur_lim;
                     if(loc_lim)
                         rv30_weak_loop_filter(C, 1, s->uvlinesize, loc_lim);
                 }
             }
         }
     }
     mb_pos = row * s->mb_stride;
     for(mb_x = 0; mb_x < s->mb_width; mb_x++, mb_pos++){

         cur_lim = rv30_loop_filt_lim[s->current_picture_ptr->qscale_table[mb_pos]];

         if(row)

             top_lim = rv30_loop_filt_lim[s->current_picture_ptr->qscale_table[mb_pos - s->mb_stride]];

         for(j = 4*!row; j < 16; j += 4){

             Y = s->current_picture_ptr->f.data[0] + mb_x*16 + (row*16 + j) * s->linesize;

             for(i = 0; i < 4; i++, Y += 4){
                 int ij = i + j;
                 loc_lim = 0;
                 if(r->deblock_coefs[mb_pos] & (1 << ij))
                     loc_lim = cur_lim;
                 else if(!j && r->deblock_coefs[mb_pos - s->mb_stride] & (1 << (ij + 12)))
                     loc_lim = top_lim;
                 else if( j && r->deblock_coefs[mb_pos]                & (1 << (ij - 4)))
                     loc_lim = cur_lim;
                 if(loc_lim)
                     rv30_weak_loop_filter(Y, s->linesize, 1, loc_lim);
             }
         }
         for(k = 0; k < 2; k++){
             int cur_cbp, top_cbp = 0;
             cur_cbp = (r->cbp_chroma[mb_pos] >> (k*4)) & 0xF;
             if(row)
                 top_cbp = (r->cbp_chroma[mb_pos - s->mb_stride] >> (k*4)) & 0xF;
             for(j = 4*!row; j < 8; j += 4){

                 C = s->current_picture_ptr->f.data[k+1] + mb_x*8 + (row*8 + j) * s->uvlinesize;

                 for(i = 0; i < 2; i++, C += 4){
                     int ij = i + (j >> 1);
                     loc_lim = 0;

                     if (r->cbp_chroma[mb_pos] & (1 << ij))

                         loc_lim = cur_lim;
                     else if(!j && top_cbp & (1 << (ij + 2)))
                         loc_lim = top_lim;
                     else if( j && cur_cbp & (1 << (ij - 2)))
                         loc_lim = cur_lim;
                     if(loc_lim)
                         rv30_weak_loop_filter(C, s->uvlinesize, 1, loc_lim);
                 }
             }
         }
     }
 }
 

 /**

  * Initialize decoder.

  */

 static av_cold int rv30_decode_init(AVCodecContext *avctx)

 {
     RV34DecContext *r = avctx->priv_data;

     int ret;

 
     r->rv30 = 1;

     if ((ret = ff_rv34_decode_init(avctx)) < 0)

         return ret;

     if(avctx->extradata_size < 2){

         av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");

         return -1;
     }
     r->rpr = (avctx->extradata[1] & 7) >> 1;
     r->rpr = FFMIN(r->rpr + 1, 3);

     if(avctx->extradata_size - 8 < (r->rpr - 1) * 2){
         av_log(avctx, AV_LOG_ERROR, "Insufficient extradata - need at least %d bytes, got %d\n",
                6 + r->rpr * 2, avctx->extradata_size);
     }

     r->parse_slice_header = rv30_parse_slice_header;
     r->decode_intra_types = rv30_decode_intra_types;
     r->decode_mb_info     = rv30_decode_mb_info;

     r->loop_filter        = rv30_loop_filter;

     r->luma_dc_quant_i = rv30_luma_dc_quant;
     r->luma_dc_quant_p = rv30_luma_dc_quant;
     return 0;
 }
 

 AVCodec ff_rv30_decoder = {

     .name                  = "rv30",

     .long_name             = NULL_IF_CONFIG_SMALL("RealVideo 3.0"),

     .type                  = AVMEDIA_TYPE_VIDEO,

     .id                    = AV_CODEC_ID_RV30,

     .priv_data_size        = sizeof(RV34DecContext),
     .init                  = rv30_decode_init,
     .close                 = ff_rv34_decode_end,
     .decode                = ff_rv34_decode_frame,
     .capabilities          = CODEC_CAP_DR1 | CODEC_CAP_DELAY |
                              CODEC_CAP_FRAME_THREADS,
     .flush                 = ff_mpeg_flush,
     .pix_fmts              = ff_pixfmt_list_420,

     .init_thread_copy      = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_update_thread_context),

 };