rpza.c
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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 
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 #include "libavutil/common.h"
42 #include "libavutil/intreadwrite.h"
43 #include "avcodec.h"
44 
45 typedef struct RpzaContext {
46 
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 
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  n_blocks = FFMIN(n_blocks, total_blocks);
130 
131  switch (opcode & 0xe0) {
132 
133  /* Skip blocks */
134  case 0x80:
135  while (n_blocks--) {
136  ADVANCE_BLOCK();
137  }
138  break;
139 
140  /* Fill blocks with one color */
141  case 0xa0:
142  colorA = AV_RB16 (&s->buf[stream_ptr]);
143  stream_ptr += 2;
144  while (n_blocks--) {
145  block_ptr = row_ptr + pixel_ptr;
146  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
147  for (pixel_x = 0; pixel_x < 4; pixel_x++){
148  pixels[block_ptr] = colorA;
149  block_ptr++;
150  }
151  block_ptr += row_inc;
152  }
153  ADVANCE_BLOCK();
154  }
155  break;
156 
157  /* Fill blocks with 4 colors */
158  case 0xc0:
159  colorA = AV_RB16 (&s->buf[stream_ptr]);
160  stream_ptr += 2;
161  case 0x20:
162  colorB = AV_RB16 (&s->buf[stream_ptr]);
163  stream_ptr += 2;
164 
165  /* sort out the colors */
166  color4[0] = colorB;
167  color4[1] = 0;
168  color4[2] = 0;
169  color4[3] = colorA;
170 
171  /* red components */
172  ta = (colorA >> 10) & 0x1F;
173  tb = (colorB >> 10) & 0x1F;
174  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
175  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
176 
177  /* green components */
178  ta = (colorA >> 5) & 0x1F;
179  tb = (colorB >> 5) & 0x1F;
180  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
181  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
182 
183  /* blue components */
184  ta = colorA & 0x1F;
185  tb = colorB & 0x1F;
186  color4[1] |= ((11 * ta + 21 * tb) >> 5);
187  color4[2] |= ((21 * ta + 11 * tb) >> 5);
188 
189  if (s->size - stream_ptr < n_blocks * 4)
190  return;
191  while (n_blocks--) {
192  block_ptr = row_ptr + pixel_ptr;
193  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
194  index = s->buf[stream_ptr++];
195  for (pixel_x = 0; pixel_x < 4; pixel_x++){
196  idx = (index >> (2 * (3 - pixel_x))) & 0x03;
197  pixels[block_ptr] = color4[idx];
198  block_ptr++;
199  }
200  block_ptr += row_inc;
201  }
202  ADVANCE_BLOCK();
203  }
204  break;
205 
206  /* Fill block with 16 colors */
207  case 0x00:
208  if (s->size - stream_ptr < 30)
209  return;
210  block_ptr = row_ptr + pixel_ptr;
211  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
212  for (pixel_x = 0; pixel_x < 4; pixel_x++){
213  /* We already have color of upper left pixel */
214  if ((pixel_y != 0) || (pixel_x !=0)) {
215  colorA = AV_RB16 (&s->buf[stream_ptr]);
216  stream_ptr += 2;
217  }
218  pixels[block_ptr] = colorA;
219  block_ptr++;
220  }
221  block_ptr += row_inc;
222  }
223  ADVANCE_BLOCK();
224  break;
225 
226  /* Unknown opcode */
227  default:
228  av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
229  " Skip remaining %d bytes of chunk data.\n", opcode,
230  chunk_size - stream_ptr);
231  return;
232  } /* Opcode switch */
233  }
234 }
235 
237 {
238  RpzaContext *s = avctx->priv_data;
239 
240  s->avctx = avctx;
241  avctx->pix_fmt = PIX_FMT_RGB555;
242 
243  s->frame.data[0] = NULL;
244 
245  return 0;
246 }
247 
249  void *data, int *data_size,
250  AVPacket *avpkt)
251 {
252  const uint8_t *buf = avpkt->data;
253  int buf_size = avpkt->size;
254  RpzaContext *s = avctx->priv_data;
255 
256  s->buf = buf;
257  s->size = buf_size;
258 
259  s->frame.reference = 1;
261  if (avctx->reget_buffer(avctx, &s->frame)) {
262  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
263  return -1;
264  }
265 
267 
268  *data_size = sizeof(AVFrame);
269  *(AVFrame*)data = s->frame;
270 
271  /* always report that the buffer was completely consumed */
272  return buf_size;
273 }
274 
276 {
277  RpzaContext *s = avctx->priv_data;
278 
279  if (s->frame.data[0])
280  avctx->release_buffer(avctx, &s->frame);
281 
282  return 0;
283 }
284 
286  .name = "rpza",
287  .type = AVMEDIA_TYPE_VIDEO,
288  .id = CODEC_ID_RPZA,
289  .priv_data_size = sizeof(RpzaContext),
293  .capabilities = CODEC_CAP_DR1,
294  .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
295 };