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 libavcodec/xl.c
  24  * Miro VideoXL codec.
  25  */
  26
  27 #include "libavutil/intreadwrite.h"
  28 #include "avcodec.h"
  29
  30 typedef struct VideoXLContext{
  31     AVCodecContext *avctx;
  32     AVFrame pic;
  33 } VideoXLContext;
  34
  35 static const int xl_table[32] = {
  36    0,   1,   2,   3,   4,   5,   6,   7,
  37    8,   9,  12,  15,  20,  25,  34,  46,
  38   64,  82,  94, 103, 108, 113, 116, 119,
  39  120, 121, 122, 123, 124, 125, 126, 127};
  40
  41 static int decode_frame(AVCodecContext *avctx,
  42                         void *data, int *data_size,
  43                         const uint8_t *buf, int buf_size)
  44 {
  45     VideoXLContext * const a = avctx->priv_data;
  46     AVFrame * const p= (AVFrame*)&a->pic;
  47     uint8_t *Y, *U, *V;
  48     int i, j;
  49     int stride;
  50     uint32_t val;
  51     int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
  52
  53     if(p->data[0])
  54         avctx->release_buffer(avctx, p);
  55
  56     p->reference = 0;
  57     if(avctx->get_buffer(avctx, p) < 0){
  58         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  59         return -1;
  60     }
  61     p->pict_type= FF_I_TYPE;
  62     p->key_frame= 1;
  63
  64     Y = a->pic.data[0];
  65     U = a->pic.data[1];
  66     V = a->pic.data[2];
  67
  68     stride = avctx->width - 4;
  69     for (i = 0; i < avctx->height; i++) {
  70         /* lines are stored in reversed order */
  71         buf += stride;
  72
  73         for (j = 0; j < avctx->width; j += 4) {
  74             /* value is stored in LE dword with word swapped */
  75             val = AV_RL32(buf);
  76             buf -= 4;
  77             val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
  78
  79             if(!j)
  80                 y0 = (val & 0x1F) << 2;
  81             else
  82                 y0 = y3 + xl_table[val & 0x1F];
  83             val >>= 5;
  84             y1 = y0 + xl_table[val & 0x1F];
  85             val >>= 5;
  86             y2 = y1 + xl_table[val & 0x1F];
  87             val >>= 6; /* align to word */
  88             y3 = y2 + xl_table[val & 0x1F];
  89             val >>= 5;
  90             if(!j)
  91                 c0 = (val & 0x1F) << 2;
  92             else
  93                 c0 += xl_table[val & 0x1F];
  94             val >>= 5;
  95             if(!j)
  96                 c1 = (val & 0x1F) << 2;
  97             else
  98                 c1 += xl_table[val & 0x1F];
  99
 100             Y[j + 0] = y0 << 1;
 101             Y[j + 1] = y1 << 1;
 102             Y[j + 2] = y2 << 1;
 103             Y[j + 3] = y3 << 1;
 104
 105             U[j >> 2] = c0 << 1;
 106             V[j >> 2] = c1 << 1;
 107         }
 108
 109         buf += avctx->width + 4;
 110         Y += a->pic.linesize[0];
 111         U += a->pic.linesize[1];
 112         V += a->pic.linesize[2];
 113     }
 114
 115     *data_size = sizeof(AVFrame);
 116     *(AVFrame*)data = a->pic;
 117
 118     return buf_size;
 119 }
 120
 121 static av_cold int decode_init(AVCodecContext *avctx){
 122 //    VideoXLContext * const a = avctx->priv_data;
 123
 124     avctx->pix_fmt= PIX_FMT_YUV411P;
 125
 126     return 0;
 127 }
 128
 129 AVCodec xl_decoder = {
 130     "xl",
 131     CODEC_TYPE_VIDEO,
 132     CODEC_ID_VIXL,
 133     sizeof(VideoXLContext),
 134     decode_init,
 135     NULL,
 136     NULL,
 137     decode_frame,
 138     CODEC_CAP_DR1,
 139     .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
 140 };