libavcodec/rpza.c

   1 /*
   2  * Quicktime Video (RPZA) 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 /**
  22  * @file rpza.c
  23  * QT RPZA Video Decoder by Roberto Togni <rtogni@bresciaonline.it>
  24  * For more information about the RPZA format, visit:
  25  *   http://www.pcisys.net/~melanson/codecs/
  26  *
  27  * The RPZA decoder outputs RGB555 colorspace data.
  28  *
  29  * Note that this decoder reads big endian RGB555 pixel values from the
  30  * bytestream, arranges them in the host's endian order, and outputs
  31  * them to the final rendered map in the same host endian order. This is
  32  * intended behavior as the ffmpeg documentation states that RGB555 pixels
  33  * shall be stored in native CPU endianness.
  34  */
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40
  41 #include "common.h"
  42 #include "avcodec.h"
  43 #include "dsputil.h"
  44
  45 typedef struct RpzaContext {
  46
  47     AVCodecContext *avctx;
  48     DSPContext dsp;
  49     AVFrame frame;
  50     AVFrame prev_frame;
  51
  52     unsigned char *buf;
  53     int size;
  54
  55 } RpzaContext;
  56
  57 #define BE_16(x)  ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
  58 #define BE_32(x)  ((((uint8_t*)(x))[0] << 24) | \
  59                    (((uint8_t*)(x))[1] << 16) | \
  60                    (((uint8_t*)(x))[2] << 8) | \
  61                     ((uint8_t*)(x))[3])
  62
  63 #define ADVANCE_BLOCK() \
  64 { \
  65     pixel_ptr += 4; \
  66     if (pixel_ptr >= width) \
  67     { \
  68         pixel_ptr = 0; \
  69         row_ptr += stride * 4; \
  70     } \
  71     total_blocks--; \
  72     if (total_blocks < 0) \
  73     { \
  74         printf("warning: block counter just went negative (this should not happen)\n"); \
  75         return; \
  76     } \
  77 }
  78
  79 static void rpza_decode_stream(RpzaContext *s)
  80 {
  81     int width = s->avctx->width;
  82     int stride = s->frame.linesize[0] / 2;
  83     int row_inc = stride - 4;
  84     int stream_ptr = 0;
  85     int chunk_size;
  86     unsigned char opcode;
  87     int n_blocks;
  88     unsigned short colorA = 0, colorB;
  89     unsigned short color4[4];
  90     unsigned char index, idx;
  91     unsigned short ta, tb;
  92     unsigned short *pixels = (unsigned short *)s->frame.data[0];
  93     unsigned short *prev_pixels = (unsigned short *)s->prev_frame.data[0];
  94
  95     int row_ptr = 0;
  96     int pixel_ptr = 0;
  97     int block_ptr;
  98     int pixel_x, pixel_y;
  99     int total_blocks;
 100
 101     /* First byte is always 0xe1. Warn if it's different */
 102     if (s->buf[stream_ptr] != 0xe1)
 103         printf("First chunk byte is 0x%02x instead of 0x1e\n",
 104             s->buf[stream_ptr]);
 105
 106     /* Get chunk size, ingnoring first byte */
 107     chunk_size = BE_32(&s->buf[stream_ptr]) & 0x00FFFFFF;
 108     stream_ptr += 4;
 109
 110     /* If length mismatch use size from MOV file and try to decode anyway */
 111     if (chunk_size != s->size)
 112         printf("MOV chunk size != encoded chunk size; using MOV chunk size\n");
 113
 114     chunk_size = s->size;
 115
 116     /* Number of 4x4 blocks in frame. */
 117     total_blocks = (s->avctx->width * s->avctx->height) / (4 * 4);
 118
 119     /* Process chunk data */
 120     while (stream_ptr < chunk_size) {
 121         opcode = s->buf[stream_ptr++]; /* Get opcode */
 122
 123         n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
 124
 125         /* If opcode MSbit is 0, we need more data to decide what to do */
 126         if ((opcode & 0x80) == 0) {
 127             colorA = (opcode << 8) | (s->buf[stream_ptr++]);
 128             opcode = 0;
 129             if ((s->buf[stream_ptr] & 0x80) != 0) {
 130                 /* Must behave as opcode 110xxxxx, using colorA computed
 131                  * above. Use fake opcode 0x20 to enter switch block at
 132                  * the right place */
 133                 opcode = 0x20;
 134                 n_blocks = 1;
 135             }
 136         }
 137
 138         switch (opcode & 0xe0) {
 139
 140         /* Skip blocks */
 141         case 0x80:
 142             while (n_blocks--) {
 143                 block_ptr = row_ptr + pixel_ptr;
 144                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 145                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 146                         pixels[block_ptr] = prev_pixels[block_ptr];
 147                         block_ptr++;
 148                     }
 149                     block_ptr += row_inc;
 150                 }
 151                 ADVANCE_BLOCK();
 152             }
 153             break;
 154
 155         /* Fill blocks with one color */
 156         case 0xa0:
 157             colorA = BE_16 (&s->buf[stream_ptr]);
 158             stream_ptr += 2;
 159             while (n_blocks--) {
 160                 block_ptr = row_ptr + pixel_ptr;
 161                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 162                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 163                         pixels[block_ptr] = colorA;
 164                         block_ptr++;
 165                     }
 166                     block_ptr += row_inc;
 167                 }
 168                 ADVANCE_BLOCK();
 169             }
 170             break;
 171
 172         /* Fill blocks with 4 colors */
 173         case 0xc0:
 174             colorA = BE_16 (&s->buf[stream_ptr]);
 175             stream_ptr += 2;
 176         case 0x20:
 177             colorB = BE_16 (&s->buf[stream_ptr]);
 178             stream_ptr += 2;
 179
 180             /* sort out the colors */
 181             color4[0] = colorB;
 182             color4[1] = 0;
 183             color4[2] = 0;
 184             color4[3] = colorA;
 185
 186             /* red components */
 187             ta = (colorA >> 10) & 0x1F;
 188             tb = (colorB >> 10) & 0x1F;
 189             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
 190             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
 191
 192             /* green components */
 193             ta = (colorA >> 5) & 0x1F;
 194             tb = (colorB >> 5) & 0x1F;
 195             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
 196             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
 197
 198             /* blue components */
 199             ta = colorA & 0x1F;
 200             tb = colorB & 0x1F;
 201             color4[1] |= ((11 * ta + 21 * tb) >> 5);
 202             color4[2] |= ((21 * ta + 11 * tb) >> 5);
 203
 204             while (n_blocks--) {
 205                 block_ptr = row_ptr + pixel_ptr;
 206                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 207                     index = s->buf[stream_ptr++];
 208                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 209                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 210                         pixels[block_ptr] = color4[idx];
 211                         block_ptr++;
 212                     }
 213                     block_ptr += row_inc;
 214                 }
 215                 ADVANCE_BLOCK();
 216             }
 217             break;
 218
 219         /* Fill block with 16 colors */
 220         case 0x00:
 221             block_ptr = row_ptr + pixel_ptr;
 222             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 223                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 224                     /* We already have color of upper left pixel */
 225                     if ((pixel_y != 0) || (pixel_x !=0)) {
 226                         colorA = BE_16 (&s->buf[stream_ptr]);
 227                         stream_ptr += 2;
 228                     }
 229                     pixels[block_ptr] = colorA;
 230                     block_ptr++;
 231                 }
 232                 block_ptr += row_inc;
 233             }
 234             ADVANCE_BLOCK();
 235             break;
 236
 237         /* Unknown opcode */
 238         default:
 239             printf("Unknown opcode %d in rpza chunk."
 240                  " Skip remaining %d bytes of chunk data.\n", opcode,
 241                  chunk_size - stream_ptr);
 242             return;
 243         } /* Opcode switch */
 244     }
 245 }
 246
 247 static int rpza_decode_init(AVCodecContext *avctx)
 248 {
 249     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 250
 251     s->avctx = avctx;
 252     avctx->pix_fmt = PIX_FMT_RGB555;
 253     avctx->has_b_frames = 0;
 254     dsputil_init(&s->dsp, avctx);
 255
 256     s->frame.data[0] = s->prev_frame.data[0] = NULL;
 257
 258     return 0;
 259 }
 260
 261 static int rpza_decode_frame(AVCodecContext *avctx,
 262                              void *data, int *data_size,
 263                              uint8_t *buf, int buf_size)
 264 {
 265     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 266
 267     s->buf = buf;
 268     s->size = buf_size;
 269
 270     if (avctx->get_buffer(avctx, &s->frame)) {
 271         printf ("  RPZA Video: get_buffer() failed\n");
 272         return -1;
 273     }
 274
 275     rpza_decode_stream(s);
 276
 277     if (s->prev_frame.data[0])
 278         avctx->release_buffer(avctx, &s->prev_frame);
 279
 280     /* shuffle frames */
 281     s->prev_frame = s->frame;
 282
 283     *data_size = sizeof(AVFrame);
 284     *(AVFrame*)data = s->frame;
 285
 286     /* always report that the buffer was completely consumed */
 287     return buf_size;
 288 }
 289
 290 static int rpza_decode_end(AVCodecContext *avctx)
 291 {
 292     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 293
 294     if (s->prev_frame.data[0])
 295         avctx->release_buffer(avctx, &s->prev_frame);
 296
 297     return 0;
 298 }
 299
 300 AVCodec rpza_decoder = {
 301     "rpza",
 302     CODEC_TYPE_VIDEO,
 303     CODEC_ID_RPZA,
 304     sizeof(RpzaContext),
 305     rpza_decode_init,
 306     NULL,
 307     rpza_decode_end,
 308     rpza_decode_frame,
 309     CODEC_CAP_DR1,
 310 };