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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 ADVANCE_BLOCK() \
  57 { \
  58     pixel_ptr += 4; \
  59     if (pixel_ptr >= width) \
  60     { \
  61         pixel_ptr = 0; \
  62         row_ptr += stride * 4; \
  63     } \
  64     total_blocks--; \
  65     if (total_blocks < 0) \
  66     { \
  67         av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
  68         return; \
  69     } \
  70 }
  71
  72 static void rpza_decode_stream(RpzaContext *s)
  73 {
  74     int width = s->avctx->width;
  75     int stride = s->frame.linesize[0] / 2;
  76     int row_inc = stride - 4;
  77     int stream_ptr = 0;
  78     int chunk_size;
  79     unsigned char opcode;
  80     int n_blocks;
  81     unsigned short colorA = 0, colorB;
  82     unsigned short color4[4];
  83     unsigned char index, idx;
  84     unsigned short ta, tb;
  85     unsigned short *pixels = (unsigned short *)s->frame.data[0];
  86
  87     int row_ptr = 0;
  88     int pixel_ptr = 0;
  89     int block_ptr;
  90     int pixel_x, pixel_y;
  91     int total_blocks;
  92
  93     /* First byte is always 0xe1. Warn if it's different */
  94     if (s->buf[stream_ptr] != 0xe1)
  95         av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
  96             s->buf[stream_ptr]);
  97
  98     /* Get chunk size, ingnoring first byte */
  99     chunk_size = BE_32(&s->buf[stream_ptr]) & 0x00FFFFFF;
 100     stream_ptr += 4;
 101
 102     /* If length mismatch use size from MOV file and try to decode anyway */
 103     if (chunk_size != s->size)
 104         av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
 105
 106     chunk_size = s->size;
 107
 108     /* Number of 4x4 blocks in frame. */
 109     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
 110
 111     /* Process chunk data */
 112     while (stream_ptr < chunk_size) {
 113         opcode = s->buf[stream_ptr++]; /* Get opcode */
 114
 115         n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
 116
 117         /* If opcode MSbit is 0, we need more data to decide what to do */
 118         if ((opcode & 0x80) == 0) {
 119             colorA = (opcode << 8) | (s->buf[stream_ptr++]);
 120             opcode = 0;
 121             if ((s->buf[stream_ptr] & 0x80) != 0) {
 122                 /* Must behave as opcode 110xxxxx, using colorA computed
 123                  * above. Use fake opcode 0x20 to enter switch block at
 124                  * the right place */
 125                 opcode = 0x20;
 126                 n_blocks = 1;
 127             }
 128         }
 129
 130         switch (opcode & 0xe0) {
 131
 132         /* Skip blocks */
 133         case 0x80:
 134             while (n_blocks--) {
 135               ADVANCE_BLOCK();
 136             }
 137             break;
 138
 139         /* Fill blocks with one color */
 140         case 0xa0:
 141             colorA = BE_16 (&s->buf[stream_ptr]);
 142             stream_ptr += 2;
 143             while (n_blocks--) {
 144                 block_ptr = row_ptr + pixel_ptr;
 145                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 146                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 147                         pixels[block_ptr] = colorA;
 148                         block_ptr++;
 149                     }
 150                     block_ptr += row_inc;
 151                 }
 152                 ADVANCE_BLOCK();
 153             }
 154             break;
 155
 156         /* Fill blocks with 4 colors */
 157         case 0xc0:
 158             colorA = BE_16 (&s->buf[stream_ptr]);
 159             stream_ptr += 2;
 160         case 0x20:
 161             colorB = BE_16 (&s->buf[stream_ptr]);
 162             stream_ptr += 2;
 163
 164             /* sort out the colors */
 165             color4[0] = colorB;
 166             color4[1] = 0;
 167             color4[2] = 0;
 168             color4[3] = colorA;
 169
 170             /* red components */
 171             ta = (colorA >> 10) & 0x1F;
 172             tb = (colorB >> 10) & 0x1F;
 173             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
 174             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
 175
 176             /* green components */
 177             ta = (colorA >> 5) & 0x1F;
 178             tb = (colorB >> 5) & 0x1F;
 179             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
 180             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
 181
 182             /* blue components */
 183             ta = colorA & 0x1F;
 184             tb = colorB & 0x1F;
 185             color4[1] |= ((11 * ta + 21 * tb) >> 5);
 186             color4[2] |= ((21 * ta + 11 * tb) >> 5);
 187
 188             while (n_blocks--) {
 189                 block_ptr = row_ptr + pixel_ptr;
 190                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 191                     index = s->buf[stream_ptr++];
 192                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 193                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 194                         pixels[block_ptr] = color4[idx];
 195                         block_ptr++;
 196                     }
 197                     block_ptr += row_inc;
 198                 }
 199                 ADVANCE_BLOCK();
 200             }
 201             break;
 202
 203         /* Fill block with 16 colors */
 204         case 0x00:
 205             block_ptr = row_ptr + pixel_ptr;
 206             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 207                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 208                     /* We already have color of upper left pixel */
 209                     if ((pixel_y != 0) || (pixel_x !=0)) {
 210                         colorA = BE_16 (&s->buf[stream_ptr]);
 211                         stream_ptr += 2;
 212                     }
 213                     pixels[block_ptr] = colorA;
 214                     block_ptr++;
 215                 }
 216                 block_ptr += row_inc;
 217             }
 218             ADVANCE_BLOCK();
 219             break;
 220
 221         /* Unknown opcode */
 222         default:
 223             av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
 224                  " Skip remaining %d bytes of chunk data.\n", opcode,
 225                  chunk_size - stream_ptr);
 226             return;
 227         } /* Opcode switch */
 228     }
 229 }
 230
 231 static int rpza_decode_init(AVCodecContext *avctx)
 232 {
 233     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 234
 235     s->avctx = avctx;
 236     avctx->pix_fmt = PIX_FMT_RGB555;
 237     avctx->has_b_frames = 0;
 238     dsputil_init(&s->dsp, avctx);
 239
 240     s->frame.data[0] = NULL;
 241
 242     return 0;
 243 }
 244
 245 static int rpza_decode_frame(AVCodecContext *avctx,
 246                              void *data, int *data_size,
 247                              uint8_t *buf, int buf_size)
 248 {
 249     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 250
 251     s->buf = buf;
 252     s->size = buf_size;
 253
 254     s->frame.reference = 1;
 255     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 256     if (avctx->reget_buffer(avctx, &s->frame)) {
 257         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 258         return -1;
 259     }
 260
 261     rpza_decode_stream(s);
 262
 263     *data_size = sizeof(AVFrame);
 264     *(AVFrame*)data = s->frame;
 265
 266     /* always report that the buffer was completely consumed */
 267     return buf_size;
 268 }
 269
 270 static int rpza_decode_end(AVCodecContext *avctx)
 271 {
 272     RpzaContext *s = (RpzaContext *)avctx->priv_data;
 273
 274     if (s->frame.data[0])
 275         avctx->release_buffer(avctx, &s->frame);
 276
 277     return 0;
 278 }
 279
 280 AVCodec rpza_decoder = {
 281     "rpza",
 282     CODEC_TYPE_VIDEO,
 283     CODEC_ID_RPZA,
 284     sizeof(RpzaContext),
 285     rpza_decode_init,
 286     NULL,
 287     rpza_decode_end,
 288     rpza_decode_frame,
 289     CODEC_CAP_DR1,
 290 };