extern/ffmpeg/libavcodec/msrle.c

   1 /*
   2  * Micrsoft RLE Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 /**
  21  * @file msrle.c
  22  * MS RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
  23  * For more information about the MS RLE format, visit:
  24  *   http://www.pcisys.net/~melanson/codecs/
  25  *
  26  * The MS RLE decoder outputs PAL8 colorspace data.
  27  *
  28  * Note that this decoder expects the palette colors from the end of the
  29  * BITMAPINFO header passed through palctrl.
  30  */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36
  37 #include "common.h"
  38 #include "avcodec.h"
  39 #include "dsputil.h"
  40
  41 typedef struct MsrleContext {
  42     AVCodecContext *avctx;
  43     AVFrame frame;
  44
  45     unsigned char *buf;
  46     int size;
  47
  48 } MsrleContext;
  49
  50 #define FETCH_NEXT_STREAM_BYTE() \
  51     if (stream_ptr >= s->size) \
  52     { \
  53       av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
  54       return; \
  55     } \
  56     stream_byte = s->buf[stream_ptr++];
  57
  58 static void msrle_decode_pal4(MsrleContext *s)
  59 {
  60     int stream_ptr = 0;
  61     unsigned char rle_code;
  62     unsigned char extra_byte, odd_pixel;
  63     unsigned char stream_byte;
  64     int pixel_ptr = 0;
  65     int row_dec = s->frame.linesize[0];
  66     int row_ptr = (s->avctx->height - 1) * row_dec;
  67     int frame_size = row_dec * s->avctx->height;
  68     int i;
  69
  70     /* make the palette available */
  71     memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
  72     if (s->avctx->palctrl->palette_changed) {
  73         s->frame.palette_has_changed = 1;
  74         s->avctx->palctrl->palette_changed = 0;
  75     }
  76
  77     while (row_ptr >= 0) {
  78         FETCH_NEXT_STREAM_BYTE();
  79         rle_code = stream_byte;
  80         if (rle_code == 0) {
  81             /* fetch the next byte to see how to handle escape code */
  82             FETCH_NEXT_STREAM_BYTE();
  83             if (stream_byte == 0) {
  84                 /* line is done, goto the next one */
  85                 row_ptr -= row_dec;
  86                 pixel_ptr = 0;
  87             } else if (stream_byte == 1) {
  88                 /* decode is done */
  89                 return;
  90             } else if (stream_byte == 2) {
  91                 /* reposition frame decode coordinates */
  92                 FETCH_NEXT_STREAM_BYTE();
  93                 pixel_ptr += stream_byte;
  94                 FETCH_NEXT_STREAM_BYTE();
  95                 row_ptr -= stream_byte * row_dec;
  96         } else {
  97             // copy pixels from encoded stream
  98             odd_pixel =  stream_byte & 1;
  99             rle_code = (stream_byte + 1) / 2;
 100             extra_byte = rle_code & 0x01;
 101             if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
 102                 (row_ptr < 0)) {
 103                 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
 104                 return;
 105             }
 106
 107             for (i = 0; i < rle_code; i++) {
 108                 if (pixel_ptr >= s->avctx->width)
 109                     break;
 110                 FETCH_NEXT_STREAM_BYTE();
 111                 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
 112                 pixel_ptr++;
 113                 if (i + 1 == rle_code && odd_pixel)
 114                     break;
 115                 if (pixel_ptr >= s->avctx->width)
 116                     break;
 117                 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
 118                 pixel_ptr++;
 119             }
 120
 121             // if the RLE code is odd, skip a byte in the stream
 122             if (extra_byte)
 123               stream_ptr++;
 124             }
 125         } else {
 126             // decode a run of data
 127             if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
 128                 (row_ptr < 0)) {
 129                 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
 130                 return;
 131             }
 132             FETCH_NEXT_STREAM_BYTE();
 133             for (i = 0; i < rle_code; i++) {
 134                 if (pixel_ptr >= s->avctx->width)
 135                     break;
 136                 if ((i & 1) == 0)
 137                     s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
 138                 else
 139                     s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
 140                 pixel_ptr++;
 141             }
 142         }
 143     }
 144
 145     /* one last sanity check on the way out */
 146     if (stream_ptr < s->size)
 147         av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
 148             stream_ptr, s->size);
 149 }
 150
 151
 152
 153 static void msrle_decode_pal8(MsrleContext *s)
 154 {
 155     int stream_ptr = 0;
 156     unsigned char rle_code;
 157     unsigned char extra_byte;
 158     unsigned char stream_byte;
 159     int pixel_ptr = 0;
 160     int row_dec = s->frame.linesize[0];
 161     int row_ptr = (s->avctx->height - 1) * row_dec;
 162     int frame_size = row_dec * s->avctx->height;
 163
 164     /* make the palette available */
 165     memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
 166     if (s->avctx->palctrl->palette_changed) {
 167         s->frame.palette_has_changed = 1;
 168         s->avctx->palctrl->palette_changed = 0;
 169     }
 170
 171     while (row_ptr >= 0) {
 172         FETCH_NEXT_STREAM_BYTE();
 173         rle_code = stream_byte;
 174         if (rle_code == 0) {
 175             /* fetch the next byte to see how to handle escape code */
 176             FETCH_NEXT_STREAM_BYTE();
 177             if (stream_byte == 0) {
 178                 /* line is done, goto the next one */
 179                 row_ptr -= row_dec;
 180                 pixel_ptr = 0;
 181             } else if (stream_byte == 1) {
 182                 /* decode is done */
 183                 return;
 184             } else if (stream_byte == 2) {
 185                 /* reposition frame decode coordinates */
 186                 FETCH_NEXT_STREAM_BYTE();
 187                 pixel_ptr += stream_byte;
 188                 FETCH_NEXT_STREAM_BYTE();
 189                 row_ptr -= stream_byte * row_dec;
 190             } else {
 191                 /* copy pixels from encoded stream */
 192                 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
 193                     (row_ptr < 0)) {
 194                     av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
 195                     return;
 196                 }
 197
 198                 rle_code = stream_byte;
 199                 extra_byte = stream_byte & 0x01;
 200                 if (stream_ptr + rle_code + extra_byte > s->size) {
 201                     av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (2)\n");
 202                     return;
 203                 }
 204
 205                 while (rle_code--) {
 206                     FETCH_NEXT_STREAM_BYTE();
 207                     s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
 208                     pixel_ptr++;
 209                 }
 210
 211                 /* if the RLE code is odd, skip a byte in the stream */
 212                 if (extra_byte)
 213                     stream_ptr++;
 214             }
 215         } else {
 216             /* decode a run of data */
 217             if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
 218                 (row_ptr < 0)) {
 219                 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (2)\n");
 220                 return;
 221             }
 222
 223             FETCH_NEXT_STREAM_BYTE();
 224
 225             while(rle_code--) {
 226                 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
 227                 pixel_ptr++;
 228             }
 229         }
 230     }
 231
 232     /* one last sanity check on the way out */
 233     if (stream_ptr < s->size)
 234         av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
 235             stream_ptr, s->size);
 236 }
 237
 238 static int msrle_decode_init(AVCodecContext *avctx)
 239 {
 240     MsrleContext *s = (MsrleContext *)avctx->priv_data;
 241
 242     s->avctx = avctx;
 243
 244     avctx->pix_fmt = PIX_FMT_PAL8;
 245     avctx->has_b_frames = 0;
 246     s->frame.data[0] = NULL;
 247
 248     return 0;
 249 }
 250
 251 static int msrle_decode_frame(AVCodecContext *avctx,
 252                               void *data, int *data_size,
 253                               uint8_t *buf, int buf_size)
 254 {
 255     MsrleContext *s = (MsrleContext *)avctx->priv_data;
 256
 257     s->buf = buf;
 258     s->size = buf_size;
 259
 260     s->frame.reference = 1;
 261     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 262     if (avctx->reget_buffer(avctx, &s->frame)) {
 263         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 264         return -1;
 265     }
 266
 267     switch (avctx->bits_per_sample) {
 268         case 8:
 269             msrle_decode_pal8(s);
 270             break;
 271         case 4:
 272             msrle_decode_pal4(s);
 273             break;
 274         default:
 275             av_log(avctx, AV_LOG_ERROR, "Don't know how to decode depth %u.\n",
 276                    avctx->bits_per_sample);
 277     }
 278
 279     *data_size = sizeof(AVFrame);
 280     *(AVFrame*)data = s->frame;
 281
 282     /* report that the buffer was completely consumed */
 283     return buf_size;
 284 }
 285
 286 static int msrle_decode_end(AVCodecContext *avctx)
 287 {
 288     MsrleContext *s = (MsrleContext *)avctx->priv_data;
 289
 290     /* release the last frame */
 291     if (s->frame.data[0])
 292         avctx->release_buffer(avctx, &s->frame);
 293
 294     return 0;
 295 }
 296
 297 AVCodec msrle_decoder = {
 298     "msrle",
 299     CODEC_TYPE_VIDEO,
 300     CODEC_ID_MSRLE,
 301     sizeof(MsrleContext),
 302     msrle_decode_init,
 303     NULL,
 304     msrle_decode_end,
 305     msrle_decode_frame,
 306     CODEC_CAP_DR1,
 307 };