libavcodec/rpza.c

   1 /*
   2  * Quicktime Video (RPZA) Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  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 libavcodec documentation states that RGB555
  34  * pixels shall be stored in native CPU endianness.
  35  */
  36
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include "libavutil/internal.h"
  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             if (s->size - stream_ptr < n_blocks * 4)
 188                 return;
 189             while (n_blocks--) {
 190                 block_ptr = row_ptr + pixel_ptr;
 191                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 192                     index = s->buf[stream_ptr++];
 193                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 194                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 195                         pixels[block_ptr] = color4[idx];
 196                         block_ptr++;
 197                     }
 198                     block_ptr += row_inc;
 199                 }
 200                 ADVANCE_BLOCK();
 201             }
 202             break;
 203
 204         /* Fill block with 16 colors */
 205         case 0x00:
 206             if (s->size - stream_ptr < 16)
 207                 return;
 208             block_ptr = row_ptr + pixel_ptr;
 209             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 210                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 211                     /* We already have color of upper left pixel */
 212                     if ((pixel_y != 0) || (pixel_x !=0)) {
 213                         colorA = AV_RB16 (&s->buf[stream_ptr]);
 214                         stream_ptr += 2;
 215                     }
 216                     pixels[block_ptr] = colorA;
 217                     block_ptr++;
 218                 }
 219                 block_ptr += row_inc;
 220             }
 221             ADVANCE_BLOCK();
 222             break;
 223
 224         /* Unknown opcode */
 225         default:
 226             av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
 227                  " Skip remaining %d bytes of chunk data.\n", opcode,
 228                  chunk_size - stream_ptr);
 229             return;
 230         } /* Opcode switch */
 231     }
 232 }
 233
 234 static av_cold int rpza_decode_init(AVCodecContext *avctx)
 235 {
 236     RpzaContext *s = avctx->priv_data;
 237
 238     s->avctx = avctx;
 239     avctx->pix_fmt = AV_PIX_FMT_RGB555;
 240
 241     s->frame.data[0] = NULL;
 242
 243     return 0;
 244 }
 245
 246 static int rpza_decode_frame(AVCodecContext *avctx,
 247                              void *data, int *got_frame,
 248                              AVPacket *avpkt)
 249 {
 250     const uint8_t *buf = avpkt->data;
 251     int buf_size = avpkt->size;
 252     RpzaContext *s = avctx->priv_data;
 253     int ret;
 254
 255     s->buf = buf;
 256     s->size = buf_size;
 257
 258     s->frame.reference = 1;
 259     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 260     if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0) {
 261         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 262         return ret;
 263     }
 264
 265     rpza_decode_stream(s);
 266
 267     *got_frame      = 1;
 268     *(AVFrame*)data = s->frame;
 269
 270     /* always report that the buffer was completely consumed */
 271     return buf_size;
 272 }
 273
 274 static av_cold int rpza_decode_end(AVCodecContext *avctx)
 275 {
 276     RpzaContext *s = avctx->priv_data;
 277
 278     if (s->frame.data[0])
 279         avctx->release_buffer(avctx, &s->frame);
 280
 281     return 0;
 282 }
 283
 284 AVCodec ff_rpza_decoder = {
 285     .name           = "rpza",
 286     .type           = AVMEDIA_TYPE_VIDEO,
 287     .id             = AV_CODEC_ID_RPZA,
 288     .priv_data_size = sizeof(RpzaContext),
 289     .init           = rpza_decode_init,
 290     .close          = rpza_decode_end,
 291     .decode         = rpza_decode_frame,
 292     .capabilities   = CODEC_CAP_DR1,
 293     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
 294 };