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                         AVPacket *avpkt)
  44 {
  45     const uint8_t *buf = avpkt->data;
  46     int buf_size = avpkt->size;
  47     VideoXLContext * const a = avctx->priv_data;
  48     AVFrame * const p= (AVFrame*)&a->pic;
  49     uint8_t *Y, *U, *V;
  50     int i, j;
  51     int stride;
  52     uint32_t val;
  53     int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
  54
  55     if(p->data[0])
  56         avctx->release_buffer(avctx, p);
  57
  58     p->reference = 0;
  59     if(avctx->get_buffer(avctx, p) < 0){
  60         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  61         return -1;
  62     }
  63     p->pict_type= FF_I_TYPE;
  64     p->key_frame= 1;
  65
  66     Y = a->pic.data[0];
  67     U = a->pic.data[1];
  68     V = a->pic.data[2];
  69
  70     stride = avctx->width - 4;
  71     for (i = 0; i < avctx->height; i++) {
  72         /* lines are stored in reversed order */
  73         buf += stride;
  74
  75         for (j = 0; j < avctx->width; j += 4) {
  76             /* value is stored in LE dword with word swapped */
  77             val = AV_RL32(buf);
  78             buf -= 4;
  79             val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
  80
  81             if(!j)
  82                 y0 = (val & 0x1F) << 2;
  83             else
  84                 y0 = y3 + xl_table[val & 0x1F];
  85             val >>= 5;
  86             y1 = y0 + xl_table[val & 0x1F];
  87             val >>= 5;
  88             y2 = y1 + xl_table[val & 0x1F];
  89             val >>= 6; /* align to word */
  90             y3 = y2 + xl_table[val & 0x1F];
  91             val >>= 5;
  92             if(!j)
  93                 c0 = (val & 0x1F) << 2;
  94             else
  95                 c0 += xl_table[val & 0x1F];
  96             val >>= 5;
  97             if(!j)
  98                 c1 = (val & 0x1F) << 2;
  99             else
 100                 c1 += xl_table[val & 0x1F];
 101
 102             Y[j + 0] = y0 << 1;
 103             Y[j + 1] = y1 << 1;
 104             Y[j + 2] = y2 << 1;
 105             Y[j + 3] = y3 << 1;
 106
 107             U[j >> 2] = c0 << 1;
 108             V[j >> 2] = c1 << 1;
 109         }
 110
 111         buf += avctx->width + 4;
 112         Y += a->pic.linesize[0];
 113         U += a->pic.linesize[1];
 114         V += a->pic.linesize[2];
 115     }
 116
 117     *data_size = sizeof(AVFrame);
 118     *(AVFrame*)data = a->pic;
 119
 120     return buf_size;
 121 }
 122
 123 static av_cold int decode_init(AVCodecContext *avctx){
 124 //    VideoXLContext * const a = avctx->priv_data;
 125
 126     avctx->pix_fmt= PIX_FMT_YUV411P;
 127
 128     return 0;
 129 }
 130
 131 AVCodec xl_decoder = {
 132     "xl",
 133     CODEC_TYPE_VIDEO,
 134     CODEC_ID_VIXL,
 135     sizeof(VideoXLContext),
 136     decode_init,
 137     NULL,
 138     NULL,
 139     decode_frame,
 140     CODEC_CAP_DR1,
 141     .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
 142 };