libavcodec/rv30.c

   1 /*
   2  * RV30 decoder
   3  * Copyright (c) 2007 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file rv30.c
  24  * RV30 decoder
  25  */
  26
  27 #include "avcodec.h"
  28 #include "dsputil.h"
  29 #include "mpegvideo.h"
  30 #include "golomb.h"
  31
  32 #include "rv34.h"
  33 #include "rv30data.h"
  34
  35
  36 static int rv30_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
  37 {
  38     int mb_bits;
  39     int w = r->s.width, h = r->s.height;
  40     int mb_size;
  41
  42     memset(si, 0, sizeof(SliceInfo));
  43     skip_bits(gb, 3);
  44     si->type = get_bits(gb, 2);
  45     if(si->type == 1) si->type = 0;
  46     if(get_bits1(gb))
  47         return -1;
  48     si->quant = get_bits(gb, 5);
  49     skip_bits1(gb);
  50     si->pts = get_bits(gb, 13);
  51     skip_bits(gb, r->rpr);
  52     si->width  = w;
  53     si->height = h;
  54     mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
  55     mb_bits = ff_rv34_get_start_offset(gb, mb_size);
  56     si->start = get_bits(gb, mb_bits);
  57     skip_bits1(gb);
  58     return 0;
  59 }
  60
  61 /**
  62  * Decode 4x4 intra types array.
  63  */
  64 static int rv30_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
  65 {
  66     int i, j, k;
  67
  68     for(i = 0; i < 4; i++, dst += r->s.b4_stride - 4){
  69         for(j = 0; j < 4; j+= 2){
  70             int code = svq3_get_ue_golomb(gb) << 1;
  71             if(code >= 81*2){
  72                 av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction code\n");
  73                 return -1;
  74             }
  75             for(k = 0; k < 2; k++){
  76                 int A = dst[-r->s.b4_stride] + 1;
  77                 int B = dst[-1] + 1;
  78                 *dst++ = rv30_itype_from_context[A * 90 + B * 9 + rv30_itype_code[code + k]];
  79                 if(dst[-1] == 9){
  80                     av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction mode\n");
  81                     return -1;
  82                 }
  83             }
  84         }
  85     }
  86     return 0;
  87 }
  88
  89 /**
  90  * Decode macroblock information.
  91  */
  92 static int rv30_decode_mb_info(RV34DecContext *r)
  93 {
  94     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 };
  95     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 };
  96     MpegEncContext *s = &r->s;
  97     GetBitContext *gb = &s->gb;
  98     int code = svq3_get_ue_golomb(gb);
  99
 100     if(code > 11){
 101         av_log(s->avctx, AV_LOG_ERROR, "Incorrect MB type code\n");
 102         return -1;
 103     }
 104     if(code > 5){
 105         av_log(s->avctx, AV_LOG_ERROR, "dquant needed\n");
 106         code -= 6;
 107     }
 108     if(s->pict_type != FF_B_TYPE)
 109         return rv30_p_types[code];
 110     else
 111         return rv30_b_types[code];
 112 }
 113
 114 /**
 115  * Initialize decoder.
 116  */
 117 static av_cold int rv30_decode_init(AVCodecContext *avctx)
 118 {
 119     RV34DecContext *r = avctx->priv_data;
 120
 121     r->rv30 = 1;
 122     ff_rv34_decode_init(avctx);
 123     if(avctx->extradata_size < 2){
 124         av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
 125         return -1;
 126     }
 127     r->rpr = (avctx->extradata[1] & 7) >> 1;
 128     r->rpr = FFMIN(r->rpr + 1, 3);
 129     r->parse_slice_header = rv30_parse_slice_header;
 130     r->decode_intra_types = rv30_decode_intra_types;
 131     r->decode_mb_info     = rv30_decode_mb_info;
 132     r->luma_dc_quant_i = rv30_luma_dc_quant;
 133     r->luma_dc_quant_p = rv30_luma_dc_quant;
 134     return 0;
 135 }
 136
 137 AVCodec rv30_decoder = {
 138     "rv30",
 139     CODEC_TYPE_VIDEO,
 140     CODEC_ID_RV30,
 141     sizeof(RV34DecContext),
 142     rv30_decode_init,
 143     NULL,
 144     ff_rv34_decode_end,
 145     ff_rv34_decode_frame,
 146     CODEC_CAP_DR1 | CODEC_CAP_DELAY,
 147     .long_name = NULL_IF_CONFIG_SMALL("RealVideo 3.0"),
 148 };