libavcodec/xl.c

   1 /*
   2  * Miro VideoXL codec
   3  * Copyright (c) 2004 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 xl.c
  24  * Miro VideoXL codec.
  25  */
  26
  27 #include "avcodec.h"
  28
  29 typedef struct VideoXLContext{
  30     AVCodecContext *avctx;
  31     AVFrame pic;
  32 } VideoXLContext;
  33
  34 static const int xl_table[32] = {
  35    0,   1,   2,   3,   4,   5,   6,   7,
  36    8,   9,  12,  15,  20,  25,  34,  46,
  37   64,  82,  94, 103, 108, 113, 116, 119,
  38  120, 121, 122, 123, 124, 125, 126, 127};
  39
  40 static int decode_frame(AVCodecContext *avctx,
  41                         void *data, int *data_size,
  42                         const uint8_t *buf, int buf_size)
  43 {
  44     VideoXLContext * const a = avctx->priv_data;
  45     AVFrame * const p= (AVFrame*)&a->pic;
  46     uint8_t *Y, *U, *V;
  47     int i, j;
  48     int stride;
  49     uint32_t val;
  50     int y0, y1, y2, y3, c0, c1;
  51
  52     if(p->data[0])
  53         avctx->release_buffer(avctx, p);
  54
  55     p->reference = 0;
  56     if(avctx->get_buffer(avctx, p) < 0){
  57         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  58         return -1;
  59     }
  60     p->pict_type= FF_I_TYPE;
  61     p->key_frame= 1;
  62
  63     Y = a->pic.data[0];
  64     U = a->pic.data[1];
  65     V = a->pic.data[2];
  66
  67     stride = avctx->width - 4;
  68     for (i = 0; i < avctx->height; i++) {
  69         /* lines are stored in reversed order */
  70         buf += stride;
  71
  72         for (j = 0; j < avctx->width; j += 4) {
  73             /* value is stored in LE dword with word swapped */
  74             val = AV_RL32(buf);
  75             buf -= 4;
  76             val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
  77
  78             if(!j)
  79                 y0 = (val & 0x1F) << 2;
  80             else
  81                 y0 = y3 + xl_table[val & 0x1F];
  82             val >>= 5;
  83             y1 = y0 + xl_table[val & 0x1F];
  84             val >>= 5;
  85             y2 = y1 + xl_table[val & 0x1F];
  86             val >>= 6; /* align to word */
  87             y3 = y2 + xl_table[val & 0x1F];
  88             val >>= 5;
  89             if(!j)
  90                 c0 = (val & 0x1F) << 2;
  91             else
  92                 c0 += xl_table[val & 0x1F];
  93             val >>= 5;
  94             if(!j)
  95                 c1 = (val & 0x1F) << 2;
  96             else
  97                 c1 += xl_table[val & 0x1F];
  98
  99             Y[j + 0] = y0 << 1;
 100             Y[j + 1] = y1 << 1;
 101             Y[j + 2] = y2 << 1;
 102             Y[j + 3] = y3 << 1;
 103
 104             U[j >> 2] = c0 << 1;
 105             V[j >> 2] = c1 << 1;
 106         }
 107
 108         buf += avctx->width + 4;
 109         Y += a->pic.linesize[0];
 110         U += a->pic.linesize[1];
 111         V += a->pic.linesize[2];
 112     }
 113
 114     *data_size = sizeof(AVFrame);
 115     *(AVFrame*)data = a->pic;
 116
 117     return buf_size;
 118 }
 119
 120 static av_cold int decode_init(AVCodecContext *avctx){
 121 //    VideoXLContext * const a = avctx->priv_data;
 122
 123     avctx->pix_fmt= PIX_FMT_YUV411P;
 124
 125     return 0;
 126 }
 127
 128 AVCodec xl_decoder = {
 129     "xl",
 130     CODEC_TYPE_VIDEO,
 131     CODEC_ID_VIXL,
 132     sizeof(VideoXLContext),
 133     decode_init,
 134     NULL,
 135     NULL,
 136     decode_frame,
 137     CODEC_CAP_DR1,
 138     .long_name = "Miro VideoXL",
 139 };