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/intreadwrite.h"
42 #include "avcodec.h"
43 
44 typedef struct RpzaContext {
45 
48 
49  const unsigned char *buf;
50  int size;
51 
52 } RpzaContext;
53 
54 #define ADVANCE_BLOCK() \
55 { \
56  pixel_ptr += 4; \
57  if (pixel_ptr >= width) \
58  { \
59  pixel_ptr = 0; \
60  row_ptr += stride * 4; \
61  } \
62  total_blocks--; \
63  if (total_blocks < 0) \
64  { \
65  av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
66  return; \
67  } \
68 }
69 
71 {
72  int width = s->avctx->width;
73  int stride = s->frame.linesize[0] / 2;
74  int row_inc = stride - 4;
75  int stream_ptr = 0;
76  int chunk_size;
77  unsigned char opcode;
78  int n_blocks;
79  unsigned short colorA = 0, colorB;
80  unsigned short color4[4];
81  unsigned char index, idx;
82  unsigned short ta, tb;
83  unsigned short *pixels = (unsigned short *)s->frame.data[0];
84 
85  int row_ptr = 0;
86  int pixel_ptr = 0;
87  int block_ptr;
88  int pixel_x, pixel_y;
89  int total_blocks;
90 
91  /* First byte is always 0xe1. Warn if it's different */
92  if (s->buf[stream_ptr] != 0xe1)
93  av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
94  s->buf[stream_ptr]);
95 
96  /* Get chunk size, ingnoring first byte */
97  chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
98  stream_ptr += 4;
99 
100  /* If length mismatch use size from MOV file and try to decode anyway */
101  if (chunk_size != s->size)
102  av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
103 
104  chunk_size = s->size;
105 
106  /* Number of 4x4 blocks in frame. */
107  total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
108 
109  /* Process chunk data */
110  while (stream_ptr < chunk_size) {
111  opcode = s->buf[stream_ptr++]; /* Get opcode */
112 
113  n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
114 
115  /* If opcode MSbit is 0, we need more data to decide what to do */
116  if ((opcode & 0x80) == 0) {
117  colorA = (opcode << 8) | (s->buf[stream_ptr++]);
118  opcode = 0;
119  if ((s->buf[stream_ptr] & 0x80) != 0) {
120  /* Must behave as opcode 110xxxxx, using colorA computed
121  * above. Use fake opcode 0x20 to enter switch block at
122  * the right place */
123  opcode = 0x20;
124  n_blocks = 1;
125  }
126  }
127 
128  switch (opcode & 0xe0) {
129 
130  /* Skip blocks */
131  case 0x80:
132  while (n_blocks--) {
133  ADVANCE_BLOCK();
134  }
135  break;
136 
137  /* Fill blocks with one color */
138  case 0xa0:
139  colorA = AV_RB16 (&s->buf[stream_ptr]);
140  stream_ptr += 2;
141  while (n_blocks--) {
142  block_ptr = row_ptr + pixel_ptr;
143  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
144  for (pixel_x = 0; pixel_x < 4; pixel_x++){
145  pixels[block_ptr] = colorA;
146  block_ptr++;
147  }
148  block_ptr += row_inc;
149  }
150  ADVANCE_BLOCK();
151  }
152  break;
153 
154  /* Fill blocks with 4 colors */
155  case 0xc0:
156  colorA = AV_RB16 (&s->buf[stream_ptr]);
157  stream_ptr += 2;
158  case 0x20:
159  colorB = AV_RB16 (&s->buf[stream_ptr]);
160  stream_ptr += 2;
161 
162  /* sort out the colors */
163  color4[0] = colorB;
164  color4[1] = 0;
165  color4[2] = 0;
166  color4[3] = colorA;
167 
168  /* red components */
169  ta = (colorA >> 10) & 0x1F;
170  tb = (colorB >> 10) & 0x1F;
171  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
172  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
173 
174  /* green components */
175  ta = (colorA >> 5) & 0x1F;
176  tb = (colorB >> 5) & 0x1F;
177  color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
178  color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
179 
180  /* blue components */
181  ta = colorA & 0x1F;
182  tb = colorB & 0x1F;
183  color4[1] |= ((11 * ta + 21 * tb) >> 5);
184  color4[2] |= ((21 * ta + 11 * tb) >> 5);
185 
186  if (s->size - stream_ptr < n_blocks * 4)
187  return;
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  if (s->size - stream_ptr < 16)
206  return;
207  block_ptr = row_ptr + pixel_ptr;
208  for (pixel_y = 0; pixel_y < 4; pixel_y++) {
209  for (pixel_x = 0; pixel_x < 4; pixel_x++){
210  /* We already have color of upper left pixel */
211  if ((pixel_y != 0) || (pixel_x !=0)) {
212  colorA = AV_RB16 (&s->buf[stream_ptr]);
213  stream_ptr += 2;
214  }
215  pixels[block_ptr] = colorA;
216  block_ptr++;
217  }
218  block_ptr += row_inc;
219  }
220  ADVANCE_BLOCK();
221  break;
222 
223  /* Unknown opcode */
224  default:
225  av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
226  " Skip remaining %d bytes of chunk data.\n", opcode,
227  chunk_size - stream_ptr);
228  return;
229  } /* Opcode switch */
230  }
231 }
232 
234 {
235  RpzaContext *s = avctx->priv_data;
236 
237  s->avctx = avctx;
238  avctx->pix_fmt = PIX_FMT_RGB555;
239 
240  s->frame.data[0] = NULL;
241 
242  return 0;
243 }
244 
246  void *data, int *data_size,
247  AVPacket *avpkt)
248 {
249  const uint8_t *buf = avpkt->data;
250  int buf_size = avpkt->size;
251  RpzaContext *s = avctx->priv_data;
252 
253  s->buf = buf;
254  s->size = buf_size;
255 
256  s->frame.reference = 1;
258  if (avctx->reget_buffer(avctx, &s->frame)) {
259  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
260  return -1;
261  }
262 
264 
265  *data_size = sizeof(AVFrame);
266  *(AVFrame*)data = s->frame;
267 
268  /* always report that the buffer was completely consumed */
269  return buf_size;
270 }
271 
273 {
274  RpzaContext *s = avctx->priv_data;
275 
276  if (s->frame.data[0])
277  avctx->release_buffer(avctx, &s->frame);
278 
279  return 0;
280 }
281 
283  .name = "rpza",
284  .type = AVMEDIA_TYPE_VIDEO,
285  .id = CODEC_ID_RPZA,
286  .priv_data_size = sizeof(RpzaContext),
290  .capabilities = CODEC_CAP_DR1,
291  .long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
292 };