libavcodec/indeo2.c

   1 /*
   2  * Indel Indeo 2 codec
   3  * Copyright (c) 2005 Konstantin Shishkov
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 /**
  22  * @file indeo2.c
  23  * Intel Indeo 2 decoder.
  24  */
  25
  26 #include "avcodec.h"
  27 #include "bitstream.h"
  28 #include "indeo2data.h"
  29
  30 typedef struct Ir2Context{
  31     AVCodecContext *avctx;
  32     AVFrame picture;
  33     GetBitContext gb;
  34     int decode_delta;
  35 } Ir2Context;
  36
  37 #define CODE_VLC_BITS 14
  38 static VLC ir2_vlc;
  39
  40 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
  41 static inline int ir2_get_code(GetBitContext *gb)
  42 {
  43     int code;
  44
  45     code = get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
  46     if (code >= 0x80)
  47         return (code + 1);
  48     return code;
  49 }
  50 #define CLAMP_TO_BYTE(value) \
  51 if (value > 255) \
  52     value = 255; \
  53 else if (value < 0) \
  54     value = 0; \
  55
  56 static void ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
  57                              const uint8_t *table)
  58 {
  59     int i;
  60     int j;
  61     int out = 0;
  62     int c;
  63     int t;
  64
  65     /* first line contain absolute values, other lines contain deltas */
  66     while (out < width){
  67         c = ir2_get_code(&ctx->gb);
  68         if(c > 0x80) { /* we have a run */
  69             c -= 0x80;
  70             for (i = 0; i < c * 2; i++)
  71                 dst[out++] = 0x80;
  72         } else { /* copy two values from table */
  73             dst[out++] = table[c * 2];
  74             dst[out++] = table[(c * 2) + 1];
  75         }
  76     }
  77     dst += stride;
  78
  79     for (j = 1; j < height; j++){
  80         out = 0;
  81         while (out < width){
  82             c = ir2_get_code(&ctx->gb);
  83             if(c > 0x80) { /* we have a skip */
  84                 c -= 0x80;
  85                 for (i = 0; i < c * 2; i++) {
  86                     dst[out] = dst[out - stride];
  87                     out++;
  88                 }
  89             } else { /* add two deltas from table */
  90                 t = dst[out - stride] + (table[c * 2] - 128);
  91                 CLAMP_TO_BYTE(t);
  92                 dst[out] = t;
  93                 out++;
  94                 t = dst[out - stride] + (table[(c * 2) + 1] - 128);
  95                 CLAMP_TO_BYTE(t);
  96                 dst[out] = t;
  97                 out++;
  98             }
  99         }
 100         dst += stride;
 101     }
 102 }
 103
 104 static void ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
 105                              const uint8_t *table)
 106 {
 107     int j;
 108     int out = 0;
 109     int c;
 110     int t;
 111
 112     for (j = 0; j < height; j++){
 113         out = 0;
 114         while (out < width){
 115             c = ir2_get_code(&ctx->gb);
 116             if(c > 0x80) { /* we have a skip */
 117                 c -= 0x80;
 118                 out += c * 2;
 119             } else { /* add two deltas from table */
 120                 t = dst[out] + (table[c * 2] - 128);
 121                 CLAMP_TO_BYTE(t);
 122                 dst[out] = t;
 123                 out++;
 124                 t = dst[out] + (table[(c * 2) + 1] - 128);
 125                 CLAMP_TO_BYTE(t);
 126                 dst[out] = t;
 127                 out++;
 128             }
 129         }
 130         dst += stride;
 131     }
 132 }
 133
 134 static int ir2_decode_frame(AVCodecContext *avctx,
 135                         void *data, int *data_size,
 136                         uint8_t *buf, int buf_size)
 137 {
 138     Ir2Context * const s = avctx->priv_data;
 139     AVFrame *picture = data;
 140     AVFrame * const p= (AVFrame*)&s->picture;
 141     int start;
 142     int i;
 143
 144     if(p->data[0])
 145         avctx->release_buffer(avctx, p);
 146
 147     p->reference = 1;
 148     p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 149     if (avctx->reget_buffer(avctx, p)) {
 150         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 151         return -1;
 152     }
 153
 154     s->decode_delta = buf[18];
 155
 156     /* decide whether frame uses deltas or not */
 157
 158     for (i = 0; i < buf_size; i++)
 159         buf[i] = ff_reverse[buf[i]];
 160
 161     start = 48; /* hardcoded for now */
 162
 163     init_get_bits(&s->gb, buf + start, buf_size - start);
 164
 165     if (s->decode_delta) { /* intraframe */
 166         ir2_decode_plane(s, avctx->width, avctx->height,
 167                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
 168         /* swapped U and V */
 169         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
 170                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
 171         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
 172                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
 173     } else { /* interframe */
 174         ir2_decode_plane_inter(s, avctx->width, avctx->height,
 175                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
 176         /* swapped U and V */
 177         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
 178                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
 179         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
 180                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
 181     }
 182
 183     *picture= *(AVFrame*)&s->picture;
 184     *data_size = sizeof(AVPicture);
 185
 186     return buf_size;
 187 }
 188
 189 static int ir2_decode_init(AVCodecContext *avctx){
 190     Ir2Context * const ic = avctx->priv_data;
 191
 192     ic->avctx = avctx;
 193
 194     avctx->pix_fmt= PIX_FMT_YUV410P;
 195
 196     if (!ir2_vlc.table)
 197         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
 198                  &ir2_codes[0][1], 4, 2,
 199                  &ir2_codes[0][0], 4, 2, 1);
 200
 201     return 0;
 202 }
 203
 204 AVCodec indeo2_decoder = {
 205     "indeo2",
 206     CODEC_TYPE_VIDEO,
 207     CODEC_ID_INDEO2,
 208     sizeof(Ir2Context),
 209     ir2_decode_init,
 210     NULL,
 211     NULL,
 212     ir2_decode_frame,
 213     CODEC_CAP_DR1,
 214 };