libavcodec/rpza.c

   1 /*
   2  * Quicktime Video (RPZA) Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file libavcodec/rpza.c
  24  * QT RPZA Video Decoder by Roberto Togni
  25  * For more information about the RPZA format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * The RPZA decoder outputs RGB555 colorspace data.
  29  *
  30  * Note that this decoder reads big endian RGB555 pixel values from the
  31  * bytestream, arranges them in the host's endian order, and outputs
  32  * them to the final rendered map in the same host endian order. This is
  33  * intended behavior as the ffmpeg documentation states that RGB555 pixels
  34  * shall be stored in native CPU endianness.
  35  */
  36
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #include "libavutil/intreadwrite.h"
  43 #include "avcodec.h"
  44
  45 typedef struct RpzaContext {
  46
  47     AVCodecContext *avctx;
  48     AVFrame frame;
  49
  50     const unsigned char *buf;
  51     int size;
  52
  53 } RpzaContext;
  54
  55 #define ADVANCE_BLOCK() \
  56 { \
  57     pixel_ptr += 4; \
  58     if (pixel_ptr >= width) \
  59     { \
  60         pixel_ptr = 0; \
  61         row_ptr += stride * 4; \
  62     } \
  63     total_blocks--; \
  64     if (total_blocks < 0) \
  65     { \
  66         av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
  67         return; \
  68     } \
  69 }
  70
  71 static void rpza_decode_stream(RpzaContext *s)
  72 {
  73     int width = s->avctx->width;
  74     int stride = s->frame.linesize[0] / 2;
  75     int row_inc = stride - 4;
  76     int stream_ptr = 0;
  77     int chunk_size;
  78     unsigned char opcode;
  79     int n_blocks;
  80     unsigned short colorA = 0, colorB;
  81     unsigned short color4[4];
  82     unsigned char index, idx;
  83     unsigned short ta, tb;
  84     unsigned short *pixels = (unsigned short *)s->frame.data[0];
  85
  86     int row_ptr = 0;
  87     int pixel_ptr = 0;
  88     int block_ptr;
  89     int pixel_x, pixel_y;
  90     int total_blocks;
  91
  92     /* First byte is always 0xe1. Warn if it's different */
  93     if (s->buf[stream_ptr] != 0xe1)
  94         av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
  95             s->buf[stream_ptr]);
  96
  97     /* Get chunk size, ingnoring first byte */
  98     chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
  99     stream_ptr += 4;
 100
 101     /* If length mismatch use size from MOV file and try to decode anyway */
 102     if (chunk_size != s->size)
 103         av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
 104
 105     chunk_size = s->size;
 106
 107     /* Number of 4x4 blocks in frame. */
 108     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
 109
 110     /* Process chunk data */
 111     while (stream_ptr < chunk_size) {
 112         opcode = s->buf[stream_ptr++]; /* Get opcode */
 113
 114         n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
 115
 116         /* If opcode MSbit is 0, we need more data to decide what to do */
 117         if ((opcode & 0x80) == 0) {
 118             colorA = (opcode << 8) | (s->buf[stream_ptr++]);
 119             opcode = 0;
 120             if ((s->buf[stream_ptr] & 0x80) != 0) {
 121                 /* Must behave as opcode 110xxxxx, using colorA computed
 122                  * above. Use fake opcode 0x20 to enter switch block at
 123                  * the right place */
 124                 opcode = 0x20;
 125                 n_blocks = 1;
 126             }
 127         }
 128
 129         switch (opcode & 0xe0) {
 130
 131         /* Skip blocks */
 132         case 0x80:
 133             while (n_blocks--) {
 134               ADVANCE_BLOCK();
 135             }
 136             break;
 137
 138         /* Fill blocks with one color */
 139         case 0xa0:
 140             colorA = AV_RB16 (&s->buf[stream_ptr]);
 141             stream_ptr += 2;
 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] = colorA;
 147                         block_ptr++;
 148                     }
 149                     block_ptr += row_inc;
 150                 }
 151                 ADVANCE_BLOCK();
 152             }
 153             break;
 154
 155         /* Fill blocks with 4 colors */
 156         case 0xc0:
 157             colorA = AV_RB16 (&s->buf[stream_ptr]);
 158             stream_ptr += 2;
 159         case 0x20:
 160             colorB = AV_RB16 (&s->buf[stream_ptr]);
 161             stream_ptr += 2;
 162
 163             /* sort out the colors */
 164             color4[0] = colorB;
 165             color4[1] = 0;
 166             color4[2] = 0;
 167             color4[3] = colorA;
 168
 169             /* red components */
 170             ta = (colorA >> 10) & 0x1F;
 171             tb = (colorB >> 10) & 0x1F;
 172             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
 173             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
 174
 175             /* green components */
 176             ta = (colorA >> 5) & 0x1F;
 177             tb = (colorB >> 5) & 0x1F;
 178             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
 179             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
 180
 181             /* blue components */
 182             ta = colorA & 0x1F;
 183             tb = colorB & 0x1F;
 184             color4[1] |= ((11 * ta + 21 * tb) >> 5);
 185             color4[2] |= ((21 * ta + 11 * tb) >> 5);
 186
 187             while (n_blocks--) {
 188                 block_ptr = row_ptr + pixel_ptr;
 189                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 190                     index = s->buf[stream_ptr++];
 191                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 192                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 193                         pixels[block_ptr] = color4[idx];
 194                         block_ptr++;
 195                     }
 196                     block_ptr += row_inc;
 197                 }
 198                 ADVANCE_BLOCK();
 199             }
 200             break;
 201
 202         /* Fill block with 16 colors */
 203         case 0x00:
 204             block_ptr = row_ptr + pixel_ptr;
 205             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 206                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 207                     /* We already have color of upper left pixel */
 208                     if ((pixel_y != 0) || (pixel_x !=0)) {
 209                         colorA = AV_RB16 (&s->buf[stream_ptr]);
 210                         stream_ptr += 2;
 211                     }
 212                     pixels[block_ptr] = colorA;
 213                     block_ptr++;
 214                 }
 215                 block_ptr += row_inc;
 216             }
 217             ADVANCE_BLOCK();
 218             break;
 219
 220         /* Unknown opcode */
 221         default:
 222             av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
 223                  " Skip remaining %d bytes of chunk data.\n", opcode,
 224                  chunk_size - stream_ptr);
 225             return;
 226         } /* Opcode switch */
 227     }
 228 }
 229
 230 static av_cold int rpza_decode_init(AVCodecContext *avctx)
 231 {
 232     RpzaContext *s = avctx->priv_data;
 233
 234     s->avctx = avctx;
 235     avctx->pix_fmt = PIX_FMT_RGB555;
 236
 237     s->frame.data[0] = NULL;
 238
 239     return 0;
 240 }
 241
 242 static int rpza_decode_frame(AVCodecContext *avctx,
 243                              void *data, int *data_size,
 244                              const uint8_t *buf, int buf_size)
 245 {
 246     RpzaContext *s = avctx->priv_data;
 247
 248     s->buf = buf;
 249     s->size = buf_size;
 250
 251     s->frame.reference = 1;
 252     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 253     if (avctx->reget_buffer(avctx, &s->frame)) {
 254         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 255         return -1;
 256     }
 257
 258     rpza_decode_stream(s);
 259
 260     *data_size = sizeof(AVFrame);
 261     *(AVFrame*)data = s->frame;
 262
 263     /* always report that the buffer was completely consumed */
 264     return buf_size;
 265 }
 266
 267 static av_cold int rpza_decode_end(AVCodecContext *avctx)
 268 {
 269     RpzaContext *s = avctx->priv_data;
 270
 271     if (s->frame.data[0])
 272         avctx->release_buffer(avctx, &s->frame);
 273
 274     return 0;
 275 }
 276
 277 AVCodec rpza_decoder = {
 278     "rpza",
 279     CODEC_TYPE_VIDEO,
 280     CODEC_ID_RPZA,
 281     sizeof(RpzaContext),
 282     rpza_decode_init,
 283     NULL,
 284     rpza_decode_end,
 285     rpza_decode_frame,
 286     CODEC_CAP_DR1,
 287     .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
 288 };