extern/ffmpeg/libavcodec/avs.c

   1 /*
   2  * AVS video decoder.
   3  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #include "avcodec.h"
  21 #include "bitstream.h"
  22
  23
  24 typedef struct {
  25     AVFrame picture;
  26 } avs_context_t;
  27
  28 typedef enum {
  29     AVS_VIDEO     = 0x01,
  30     AVS_AUDIO     = 0x02,
  31     AVS_PALETTE   = 0x03,
  32     AVS_GAME_DATA = 0x04,
  33 } avs_block_type_t;
  34
  35 typedef enum {
  36     AVS_I_FRAME     = 0x00,
  37     AVS_P_FRAME_3X3 = 0x01,
  38     AVS_P_FRAME_2X2 = 0x02,
  39     AVS_P_FRAME_2X3 = 0x03,
  40 } avs_video_sub_type_t;
  41
  42
  43 static int
  44 avs_decode_frame(AVCodecContext * avctx,
  45                  void *data, int *data_size, uint8_t * buf, int buf_size)
  46 {
  47     avs_context_t *const avs = avctx->priv_data;
  48     AVFrame *picture = data;
  49     AVFrame *const p = (AVFrame *) & avs->picture;
  50     uint8_t *table, *vect, *out;
  51     int i, j, x, y, stride, vect_w = 3, vect_h = 3;
  52     int sub_type;
  53     avs_block_type_t type;
  54     GetBitContext change_map;
  55
  56     if (avctx->reget_buffer(avctx, p)) {
  57         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
  58         return -1;
  59     }
  60     p->reference = 1;
  61     p->pict_type = FF_P_TYPE;
  62     p->key_frame = 0;
  63
  64     out = avs->picture.data[0];
  65     stride = avs->picture.linesize[0];
  66
  67     sub_type = buf[0];
  68     type = buf[1];
  69     buf += 4;
  70
  71     if (type == AVS_PALETTE) {
  72         int first, last;
  73         uint32_t *pal = (uint32_t *) avs->picture.data[1];
  74
  75         first = LE_16(buf);
  76         last = first + LE_16(buf + 2);
  77         buf += 4;
  78         for (i=first; i<last; i++, buf+=3)
  79             pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);
  80
  81         sub_type = buf[0];
  82         type = buf[1];
  83         buf += 4;
  84     }
  85
  86     if (type != AVS_VIDEO)
  87         return -1;
  88
  89     switch (sub_type) {
  90     case AVS_I_FRAME:
  91         p->pict_type = FF_I_TYPE;
  92         p->key_frame = 1;
  93     case AVS_P_FRAME_3X3:
  94         vect_w = 3;
  95         vect_h = 3;
  96         break;
  97
  98     case AVS_P_FRAME_2X2:
  99         vect_w = 2;
 100         vect_h = 2;
 101         break;
 102
 103     case AVS_P_FRAME_2X3:
 104         vect_w = 2;
 105         vect_h = 3;
 106         break;
 107
 108     default:
 109       return -1;
 110     }
 111
 112     table = buf + (256 * vect_w * vect_h);
 113     if (sub_type != AVS_I_FRAME) {
 114         int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);
 115         init_get_bits(&change_map, table, map_size);
 116         table += map_size;
 117     }
 118
 119     for (y=0; y<198; y+=vect_h) {
 120         for (x=0; x<318; x+=vect_w) {
 121             if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) {
 122                 vect = &buf[*table++ * (vect_w * vect_h)];
 123                 for (j=0; j<vect_w; j++) {
 124                     out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];
 125                     out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];
 126                     if (vect_h == 3)
 127                         out[(y + 2) * stride + x + j] =
 128                             vect[(2 * vect_w) + j];
 129                 }
 130             }
 131         }
 132         if (sub_type != AVS_I_FRAME)
 133             align_get_bits(&change_map);
 134     }
 135
 136     *picture = *(AVFrame *) & avs->picture;
 137     *data_size = sizeof(AVPicture);
 138
 139     return buf_size;
 140 }
 141
 142 static int avs_decode_init(AVCodecContext * avctx)
 143 {
 144     avctx->pix_fmt = PIX_FMT_PAL8;
 145     return 0;
 146 }
 147
 148 AVCodec avs_decoder = {
 149     "avs",
 150     CODEC_TYPE_VIDEO,
 151     CODEC_ID_AVS,
 152     sizeof(avs_context_t),
 153     avs_decode_init,
 154     NULL,
 155     NULL,
 156     avs_decode_frame,
 157     CODEC_CAP_DR1,
 158 };