libavcodec/indeo2.c

   1 /*
   2  * Intel Indeo 2 codec
   3  * Copyright (c) 2005 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/indeo2.c
  24  * Intel Indeo 2 decoder.
  25  */
  26 #define ALT_BITSTREAM_READER_LE
  27 #include "avcodec.h"
  28 #include "bitstream.h"
  29 #include "indeo2data.h"
  30
  31 typedef struct Ir2Context{
  32     AVCodecContext *avctx;
  33     AVFrame picture;
  34     GetBitContext gb;
  35     int decode_delta;
  36 } Ir2Context;
  37
  38 #define CODE_VLC_BITS 14
  39 static VLC ir2_vlc;
  40
  41 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
  42 static inline int ir2_get_code(GetBitContext *gb)
  43 {
  44     return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
  45 }
  46
  47 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
  48                              const uint8_t *table)
  49 {
  50     int i;
  51     int j;
  52     int out = 0;
  53     int c;
  54     int t;
  55
  56     if(width&1)
  57         return -1;
  58
  59     /* first line contain absolute values, other lines contain deltas */
  60     while (out < width){
  61         c = ir2_get_code(&ctx->gb);
  62         if(c >= 0x80) { /* we have a run */
  63             c -= 0x7F;
  64             if(out + c*2 > width)
  65                 return -1;
  66             for (i = 0; i < c * 2; i++)
  67                 dst[out++] = 0x80;
  68         } else { /* copy two values from table */
  69             dst[out++] = table[c * 2];
  70             dst[out++] = table[(c * 2) + 1];
  71         }
  72     }
  73     dst += stride;
  74
  75     for (j = 1; j < height; j++){
  76         out = 0;
  77         while (out < width){
  78             c = ir2_get_code(&ctx->gb);
  79             if(c >= 0x80) { /* we have a skip */
  80                 c -= 0x7F;
  81                 if(out + c*2 > width)
  82                     return -1;
  83                 for (i = 0; i < c * 2; i++) {
  84                     dst[out] = dst[out - stride];
  85                     out++;
  86                 }
  87             } else { /* add two deltas from table */
  88                 t = dst[out - stride] + (table[c * 2] - 128);
  89                 t= av_clip_uint8(t);
  90                 dst[out] = t;
  91                 out++;
  92                 t = dst[out - stride] + (table[(c * 2) + 1] - 128);
  93                 t= av_clip_uint8(t);
  94                 dst[out] = t;
  95                 out++;
  96             }
  97         }
  98         dst += stride;
  99     }
 100     return 0;
 101 }
 102
 103 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
 104                              const uint8_t *table)
 105 {
 106     int j;
 107     int out = 0;
 108     int c;
 109     int t;
 110
 111     if(width&1)
 112         return -1;
 113
 114     for (j = 0; j < height; j++){
 115         out = 0;
 116         while (out < width){
 117             c = ir2_get_code(&ctx->gb);
 118             if(c >= 0x80) { /* we have a skip */
 119                 c -= 0x7F;
 120                 out += c * 2;
 121             } else { /* add two deltas from table */
 122                 t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
 123                 t= av_clip_uint8(t);
 124                 dst[out] = t;
 125                 out++;
 126                 t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
 127                 t= av_clip_uint8(t);
 128                 dst[out] = t;
 129                 out++;
 130             }
 131         }
 132         dst += stride;
 133     }
 134     return 0;
 135 }
 136
 137 static int ir2_decode_frame(AVCodecContext *avctx,
 138                         void *data, int *data_size,
 139                         const uint8_t *buf, int buf_size)
 140 {
 141     Ir2Context * const s = avctx->priv_data;
 142     AVFrame *picture = data;
 143     AVFrame * const p= (AVFrame*)&s->picture;
 144     int start;
 145
 146     if(p->data[0])
 147         avctx->release_buffer(avctx, p);
 148
 149     p->reference = 1;
 150     p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 151     if (avctx->reget_buffer(avctx, p)) {
 152         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 153         return -1;
 154     }
 155
 156     s->decode_delta = buf[18];
 157
 158     /* decide whether frame uses deltas or not */
 159 #ifndef ALT_BITSTREAM_READER_LE
 160     for (i = 0; i < buf_size; i++)
 161         buf[i] = ff_reverse[buf[i]];
 162 #endif
 163     start = 48; /* hardcoded for now */
 164
 165     init_get_bits(&s->gb, buf + start, buf_size - start);
 166
 167     if (s->decode_delta) { /* intraframe */
 168         ir2_decode_plane(s, avctx->width, avctx->height,
 169                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
 170         /* swapped U and V */
 171         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
 172                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
 173         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
 174                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
 175     } else { /* interframe */
 176         ir2_decode_plane_inter(s, avctx->width, avctx->height,
 177                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
 178         /* swapped U and V */
 179         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
 180                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
 181         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
 182                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
 183     }
 184
 185     *picture= *(AVFrame*)&s->picture;
 186     *data_size = sizeof(AVPicture);
 187
 188     return buf_size;
 189 }
 190
 191 static av_cold int ir2_decode_init(AVCodecContext *avctx){
 192     Ir2Context * const ic = avctx->priv_data;
 193
 194     ic->avctx = avctx;
 195
 196     avctx->pix_fmt= PIX_FMT_YUV410P;
 197
 198     if (!ir2_vlc.table)
 199 #ifdef ALT_BITSTREAM_READER_LE
 200         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
 201                  &ir2_codes[0][1], 4, 2,
 202                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
 203 #else
 204         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
 205                  &ir2_codes[0][1], 4, 2,
 206                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC);
 207 #endif
 208
 209     return 0;
 210 }
 211
 212 AVCodec indeo2_decoder = {
 213     "indeo2",
 214     CODEC_TYPE_VIDEO,
 215     CODEC_ID_INDEO2,
 216     sizeof(Ir2Context),
 217     ir2_decode_init,
 218     NULL,
 219     NULL,
 220     ir2_decode_frame,
 221     CODEC_CAP_DR1,
 222     .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),
 223 };