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
  51     unsigned char *buf;
  52     int size;
  53
  54 } RpzaContext;
  55
  56 #define BE_16(x)  ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
  57 #define BE_32(x)  ((((uint8_t*)(x))[0] << 24) | \
  58                    (((uint8_t*)(x))[1] << 16) | \
  59                    (((uint8_t*)(x))[2] << 8) | \
  60                     ((uint8_t*)(x))[3])
  61
  62 #define ADVANCE_BLOCK() \
  63 { \
  64     pixel_ptr += 4; \
  65     if (pixel_ptr >= width) \
  66     { \
  67         pixel_ptr = 0; \
  68         row_ptr += stride * 4; \
  69     } \
  70     total_blocks--; \
  71     if (total_blocks < 0) \
  72     { \
  73         av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
  74         return; \
  75     } \
  76 }
  77
  78 static void rpza_decode_stream(RpzaContext *s)
  79 {
  80     int width = s->avctx->width;
  81     int stride = s->frame.linesize[0] / 2;
  82     int row_inc = stride - 4;
  83     int stream_ptr = 0;
  84     int chunk_size;
  85     unsigned char opcode;
  86     int n_blocks;
  87     unsigned short colorA = 0, colorB;
  88     unsigned short color4[4];
  89     unsigned char index, idx;
  90     unsigned short ta, tb;
  91     unsigned short *pixels = (unsigned short *)s->frame.data[0];
  92
  93     int row_ptr = 0;
  94     int pixel_ptr = 0;
  95     int block_ptr;
  96     int pixel_x, pixel_y;
  97     int total_blocks;
  98
  99     /* First byte is always 0xe1. Warn if it's different */
 100     if (s->buf[stream_ptr] != 0xe1)
 101         av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0x1e\n",
 102             s->buf[stream_ptr]);
 103
 104     /* Get chunk size, ingnoring first byte */
 105     chunk_size = BE_32(&s->buf[stream_ptr]) & 0x00FFFFFF;
 106     stream_ptr += 4;
 107
 108     /* If length mismatch use size from MOV file and try to decode anyway */
 109     if (chunk_size != s->size)
 110         av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
 111
 112     chunk_size = s->size;
 113
 114     /* Number of 4x4 blocks in frame. */
 115     total_blocks = (s->avctx->width * s->avctx->height) / (4 * 4);
 116
 117     /* Process chunk data */
 118     while (stream_ptr < chunk_size) {
 119         opcode = s->buf[stream_ptr++]; /* Get opcode */
 120
 121         n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
 122
 123         /* If opcode MSbit is 0, we need more data to decide what to do */
 124         if ((opcode & 0x80) == 0) {
 125             colorA = (opcode << 8) | (s->buf[stream_ptr++]);
 126             opcode = 0;
 127             if ((s->buf[stream_ptr] & 0x80) != 0) {
 128                 /* Must behave as opcode 110xxxxx, using colorA computed
 129                  * above. Use fake opcode 0x20 to enter switch block at
 130                  * the right place */
 131                 opcode = 0x20;
 132                 n_blocks = 1;
 133             }
 134         }
 135
 136         switch (opcode & 0xe0) {
 137
 138         /* Skip blocks */
 139         case 0x80:
 140             while (n_blocks--) {
 141               ADVANCE_BLOCK();
 142             }
 143             break;
 144
 145         /* Fill blocks with one color */
 146         case 0xa0:
 147             colorA = BE_16 (&s->buf[stream_ptr]);
 148             stream_ptr += 2;
 149             while (n_blocks--) {
 150                 block_ptr = row_ptr + pixel_ptr;
 151                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 152                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 153                         pixels[block_ptr] = colorA;
 154                         block_ptr++;
 155                     }
 156                     block_ptr += row_inc;
 157                 }
 158                 ADVANCE_BLOCK();
 159             }
 160             break;
 161
 162         /* Fill blocks with 4 colors */
 163         case 0xc0:
 164             colorA = BE_16 (&s->buf[stream_ptr]);
 165             stream_ptr += 2;
 166         case 0x20:
 167             colorB = BE_16 (&s->buf[stream_ptr]);
 168             stream_ptr += 2;
 169
 170             /* sort out the colors */
 171             color4[0] = colorB;
 172             color4[1] = 0;
 173             color4[2] = 0;
 174             color4[3] = colorA;
 175
 176             /* red components */
 177             ta = (colorA >> 10) & 0x1F;
 178             tb = (colorB >> 10) & 0x1F;
 179             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
 180             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
 181
 182             /* green components */
 183             ta = (colorA >> 5) & 0x1F;
 184             tb = (colorB >> 5) & 0x1F;
 185             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
 186             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
 187
 188             /* blue components */
 189             ta = colorA & 0x1F;
 190             tb = colorB & 0x1F;
 191             color4[1] |= ((11 * ta + 21 * tb) >> 5);
 192             color4[2] |= ((21 * ta + 11 * tb) >> 5);
 193
 194             while (n_blocks--) {
 195                 block_ptr = row_ptr + pixel_ptr;
 196                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 197                     index = s->buf[stream_ptr++];
 198                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 199                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 200                         pixels[block_ptr] = color4[idx];
 201                         block_ptr++;
 202                     }
 203                     block_ptr += row_inc;
 204                 }
 205                 ADVANCE_BLOCK();
 206             }
 207             break;
 208
 209         /* Fill block with 16 colors */
 210         case 0x00:
 211             block_ptr = row_ptr + pixel_ptr;
 212             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 213                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 214                     /* We already have color of upper left pixel */
 215                     if ((pixel_y != 0) || (pixel_x !=0)) {
 216                         colorA = BE_16 (&s->buf[stream_ptr]);
 217                         stream_ptr += 2;
 218                     }
 219                     pixels[block_ptr] = colorA;
 220                     block_ptr++;
 221                 }
 222                 block_ptr += row_inc;
 223             }
 224             ADVANCE_BLOCK();
 225             break;
 226
 227         /* Unknown opcode */
 228         default:
 229             av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
 230                  " Skip remaining %d bytes of chunk data.\n", opcode,
 231                  chunk_size - stream_ptr);
 232             return;
 233         } /* Opcode switch */
 234     }
 235 }
 236
 237 static int rpza_decode_init(AVCodecContext *avctx)
 238 {
 239     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 240
 241     s->avctx = avctx;
 242     avctx->pix_fmt = PIX_FMT_RGB555;
 243     avctx->has_b_frames = 0;
 244     dsputil_init(&s->dsp, avctx);
 245
 246     s->frame.data[0] = NULL;
 247
 248     return 0;
 249 }
 250
 251 static int rpza_decode_frame(AVCodecContext *avctx,
 252                              void *data, int *data_size,
 253                              uint8_t *buf, int buf_size)
 254 {
 255     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 256
 257         /* no supplementary picture */
 258         if (buf_size == 0)
 259                 return 0;
 260
 261     s->buf = buf;
 262     s->size = buf_size;
 263
 264     s->frame.reference = 1;
 265         s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 266     if (avctx->reget_buffer(avctx, &s->frame)) {
 267         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 268         return -1;
 269     }
 270
 271     rpza_decode_stream(s);
 272
 273     *data_size = sizeof(AVFrame);
 274     *(AVFrame*)data = s->frame;
 275
 276     /* always report that the buffer was completely consumed */
 277     return buf_size;
 278 }
 279
 280 static int rpza_decode_end(AVCodecContext *avctx)
 281 {
 282     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 283
 284     if (s->frame.data[0])
 285         avctx->release_buffer(avctx, &s->frame);
 286
 287     return 0;
 288 }
 289
 290 AVCodec rpza_decoder = {
 291     "rpza",
 292     CODEC_TYPE_VIDEO,
 293     CODEC_ID_RPZA,
 294     sizeof(RpzaContext),
 295     rpza_decode_init,
 296     NULL,
 297     rpza_decode_end,
 298     rpza_decode_frame,
 299     CODEC_CAP_DR1,
 300 };