quicktime/ffmpeg/libavcodec/msvideo1.c

   1 /*
   2  * Microsoft Video-1 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 /**
  22  * @file msvideo1.c
  23  * Microsoft Video-1 Decoder by Mike Melanson (melanson@pcisys.net)
  24  * For more information about the MS Video-1 format, visit:
  25  *   http://www.pcisys.net/~melanson/codecs/
  26  *
  27  * This decoder outputs either PAL8 or RGB555 data, depending on the
  28  * whether a RGB palette was passed through palctrl;
  29  * if it's present, then the data is PAL8; RGB555 otherwise.
  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 #define PALETTE_COUNT 256
  42 #define CHECK_STREAM_PTR(n) \
  43   if ((stream_ptr + n) > s->size ) { \
  44     av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \
  45       stream_ptr + n, s->size); \
  46     return; \
  47   }
  48
  49 typedef struct Msvideo1Context {
  50
  51     AVCodecContext *avctx;
  52     DSPContext dsp;
  53     AVFrame frame;
  54
  55     unsigned char *buf;
  56     int size;
  57
  58     int mode_8bit;  /* if it's not 8-bit, it's 16-bit */
  59
  60 } Msvideo1Context;
  61
  62 static int msvideo1_decode_init(AVCodecContext *avctx)
  63 {
  64     Msvideo1Context *s = (Msvideo1Context *)avctx->priv_data;
  65
  66     s->avctx = avctx;
  67
  68     /* figure out the colorspace based on the presence of a palette */
  69     if (s->avctx->palctrl) {
  70         s->mode_8bit = 1;
  71         avctx->pix_fmt = PIX_FMT_PAL8;
  72     } else {
  73         s->mode_8bit = 0;
  74         avctx->pix_fmt = PIX_FMT_RGB555;
  75     }
  76
  77     avctx->has_b_frames = 0;
  78     dsputil_init(&s->dsp, avctx);
  79
  80     s->frame.data[0] = NULL;
  81
  82     return 0;
  83 }
  84
  85 static void msvideo1_decode_8bit(Msvideo1Context *s)
  86 {
  87     int block_ptr, pixel_ptr;
  88     int total_blocks;
  89     int pixel_x, pixel_y;  /* pixel width and height iterators */
  90     int block_x, block_y;  /* block width and height iterators */
  91     int blocks_wide, blocks_high;  /* width and height in 4x4 blocks */
  92     int block_inc;
  93     int row_dec;
  94
  95     /* decoding parameters */
  96     int stream_ptr;
  97     unsigned char byte_a, byte_b;
  98     unsigned short flags;
  99     int skip_blocks;
 100     unsigned char colors[8];
 101     unsigned char *pixels = s->frame.data[0];
 102     int stride = s->frame.linesize[0];
 103
 104     stream_ptr = 0;
 105     skip_blocks = 0;
 106     blocks_wide = s->avctx->width / 4;
 107     blocks_high = s->avctx->height / 4;
 108     total_blocks = blocks_wide * blocks_high;
 109     block_inc = 4;
 110     row_dec = stride + 4;
 111
 112     for (block_y = blocks_high; block_y > 0; block_y--) {
 113         block_ptr = ((block_y * 4) - 1) * stride;
 114         for (block_x = blocks_wide; block_x > 0; block_x--) {
 115             /* check if this block should be skipped */
 116             if (skip_blocks) {
 117                 block_ptr += block_inc;
 118                 skip_blocks--;
 119                 total_blocks--;
 120                 continue;
 121             }
 122
 123             pixel_ptr = block_ptr;
 124
 125             /* get the next two bytes in the encoded data stream */
 126             CHECK_STREAM_PTR(2);
 127             byte_a = s->buf[stream_ptr++];
 128             byte_b = s->buf[stream_ptr++];
 129
 130             /* check if the decode is finished */
 131             if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
 132                 return;
 133             else if ((byte_b & 0xFC) == 0x84) {
 134                 /* skip code, but don't count the current block */
 135                 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
 136             } else if (byte_b < 0x80) {
 137                 /* 2-color encoding */
 138                 flags = (byte_b << 8) | byte_a;
 139
 140                 CHECK_STREAM_PTR(2);
 141                 colors[0] = s->buf[stream_ptr++];
 142                 colors[1] = s->buf[stream_ptr++];
 143
 144                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 145                     for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
 146                         pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
 147                     pixel_ptr -= row_dec;
 148                 }
 149             } else if (byte_b >= 0x90) {
 150                 /* 8-color encoding */
 151                 flags = (byte_b << 8) | byte_a;
 152
 153                 CHECK_STREAM_PTR(8);
 154                 memcpy(colors, &s->buf[stream_ptr], 8);
 155                 stream_ptr += 8;
 156
 157                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 158                     for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
 159                         pixels[pixel_ptr++] =
 160                             colors[((pixel_y & 0x2) << 1) +
 161                                 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
 162                     pixel_ptr -= row_dec;
 163                 }
 164             } else {
 165                 /* 1-color encoding */
 166                 colors[0] = byte_a;
 167
 168                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 169                     for (pixel_x = 0; pixel_x < 4; pixel_x++)
 170                         pixels[pixel_ptr++] = colors[0];
 171                     pixel_ptr -= row_dec;
 172                 }
 173             }
 174
 175             block_ptr += block_inc;
 176             total_blocks--;
 177         }
 178     }
 179
 180     /* make the palette available on the way out */
 181     if (s->avctx->pix_fmt == PIX_FMT_PAL8) {
 182         memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
 183         if (s->avctx->palctrl->palette_changed) {
 184             s->frame.palette_has_changed = 1;
 185             s->avctx->palctrl->palette_changed = 0;
 186         }
 187     }
 188 }
 189
 190 static void msvideo1_decode_16bit(Msvideo1Context *s)
 191 {
 192     int block_ptr, pixel_ptr;
 193     int total_blocks;
 194     int pixel_x, pixel_y;  /* pixel width and height iterators */
 195     int block_x, block_y;  /* block width and height iterators */
 196     int blocks_wide, blocks_high;  /* width and height in 4x4 blocks */
 197     int block_inc;
 198     int row_dec;
 199
 200     /* decoding parameters */
 201     int stream_ptr;
 202     unsigned char byte_a, byte_b;
 203     unsigned short flags;
 204     int skip_blocks;
 205     unsigned short colors[8];
 206     unsigned short *pixels = (unsigned short *)s->frame.data[0];
 207     int stride = s->frame.linesize[0] / 2;
 208
 209     stream_ptr = 0;
 210     skip_blocks = 0;
 211     blocks_wide = s->avctx->width / 4;
 212     blocks_high = s->avctx->height / 4;
 213     total_blocks = blocks_wide * blocks_high;
 214     block_inc = 4;
 215     row_dec = stride + 4;
 216
 217     for (block_y = blocks_high; block_y > 0; block_y--) {
 218         block_ptr = ((block_y * 4) - 1) * stride;
 219         for (block_x = blocks_wide; block_x > 0; block_x--) {
 220             /* check if this block should be skipped */
 221             if (skip_blocks) {
 222                 block_ptr += block_inc;
 223                 skip_blocks--;
 224                 total_blocks--;
 225                 continue;
 226             }
 227
 228             pixel_ptr = block_ptr;
 229
 230             /* get the next two bytes in the encoded data stream */
 231             CHECK_STREAM_PTR(2);
 232             byte_a = s->buf[stream_ptr++];
 233             byte_b = s->buf[stream_ptr++];
 234
 235             /* check if the decode is finished */
 236             if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
 237                 return;
 238             } else if ((byte_b & 0xFC) == 0x84) {
 239                 /* skip code, but don't count the current block */
 240                 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
 241             } else if (byte_b < 0x80) {
 242                 /* 2- or 8-color encoding modes */
 243                 flags = (byte_b << 8) | byte_a;
 244
 245                 CHECK_STREAM_PTR(4);
 246                 colors[0] = LE_16(&s->buf[stream_ptr]);
 247                 stream_ptr += 2;
 248                 colors[1] = LE_16(&s->buf[stream_ptr]);
 249                 stream_ptr += 2;
 250
 251                 if (colors[0] & 0x8000) {
 252                     /* 8-color encoding */
 253                     CHECK_STREAM_PTR(12);
 254                     colors[2] = LE_16(&s->buf[stream_ptr]);
 255                     stream_ptr += 2;
 256                     colors[3] = LE_16(&s->buf[stream_ptr]);
 257                     stream_ptr += 2;
 258                     colors[4] = LE_16(&s->buf[stream_ptr]);
 259                     stream_ptr += 2;
 260                     colors[5] = LE_16(&s->buf[stream_ptr]);
 261                     stream_ptr += 2;
 262                     colors[6] = LE_16(&s->buf[stream_ptr]);
 263                     stream_ptr += 2;
 264                     colors[7] = LE_16(&s->buf[stream_ptr]);
 265                     stream_ptr += 2;
 266
 267                     for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 268                         for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
 269                             pixels[pixel_ptr++] =
 270                                 colors[((pixel_y & 0x2) << 1) +
 271                                     (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
 272                         pixel_ptr -= row_dec;
 273                     }
 274                 } else {
 275                     /* 2-color encoding */
 276                     for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 277                         for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
 278                             pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
 279                         pixel_ptr -= row_dec;
 280                     }
 281                 }
 282             } else {
 283                 /* otherwise, it's a 1-color block */
 284                 colors[0] = (byte_b << 8) | byte_a;
 285
 286                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 287                     for (pixel_x = 0; pixel_x < 4; pixel_x++)
 288                         pixels[pixel_ptr++] = colors[0];
 289                     pixel_ptr -= row_dec;
 290                 }
 291             }
 292
 293             block_ptr += block_inc;
 294             total_blocks--;
 295         }
 296     }
 297 }
 298
 299 static int msvideo1_decode_frame(AVCodecContext *avctx,
 300                                 void *data, int *data_size,
 301                                 uint8_t *buf, int buf_size)
 302 {
 303     Msvideo1Context *s = (Msvideo1Context *)avctx->priv_data;
 304
 305     s->buf = buf;
 306     s->size = buf_size;
 307
 308     s->frame.reference = 1;
 309     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 310     if (avctx->reget_buffer(avctx, &s->frame)) {
 311         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 312         return -1;
 313     }
 314
 315     if (s->mode_8bit)
 316         msvideo1_decode_8bit(s);
 317     else
 318         msvideo1_decode_16bit(s);
 319
 320     *data_size = sizeof(AVFrame);
 321     *(AVFrame*)data = s->frame;
 322
 323     /* report that the buffer was completely consumed */
 324     return buf_size;
 325 }
 326
 327 static int msvideo1_decode_end(AVCodecContext *avctx)
 328 {
 329     Msvideo1Context *s = (Msvideo1Context *)avctx->priv_data;
 330
 331     if (s->frame.data[0])
 332         avctx->release_buffer(avctx, &s->frame);
 333
 334     return 0;
 335 }
 336
 337 AVCodec msvideo1_decoder = {
 338     "msvideo1",
 339     CODEC_TYPE_VIDEO,
 340     CODEC_ID_MSVIDEO1,
 341     sizeof(Msvideo1Context),
 342     msvideo1_decode_init,
 343     NULL,
 344     msvideo1_decode_end,
 345     msvideo1_decode_frame,
 346     CODEC_CAP_DR1,
 347 };