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qtrle.c
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1 /*
2  * Quicktime Animation (RLE) Video Decoder
3  * Copyright (C) 2004 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
24  * QT RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
25  * For more information about the QT RLE format, visit:
26  * http://www.pcisys.net/~melanson/codecs/
27  *
28  * The QT RLE decoder has seven modes of operation:
29  * 1, 2, 4, 8, 16, 24, and 32 bits per pixel. For modes 1, 2, 4, and 8
30  * the decoder outputs PAL8 colorspace data. 16-bit data yields RGB555
31  * data. 24-bit data is RGB24 and 32-bit data is RGB32.
32  */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "avcodec.h"
39 #include "bytestream.h"
40 
41 typedef struct QtrleContext {
44 
46  uint32_t pal[256];
47 } QtrleContext;
48 
49 #define CHECK_PIXEL_PTR(n) \
50  if ((pixel_ptr + n > pixel_limit) || (pixel_ptr + n < 0)) { \
51  av_log (s->avctx, AV_LOG_ERROR, "Problem: pixel_ptr = %d, pixel_limit = %d\n",\
52  pixel_ptr + n, pixel_limit); \
53  return; \
54  } \
55 
56 static void qtrle_decode_1bpp(QtrleContext *s, int row_ptr, int lines_to_change)
57 {
58  int rle_code;
59  int pixel_ptr;
60  int row_inc = s->frame.linesize[0];
61  unsigned char pi0, pi1; /* 2 8-pixel values */
62  unsigned char *rgb = s->frame.data[0];
63  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
64  int skip;
65  /* skip & 0x80 appears to mean 'start a new line', which can be interpreted
66  * as 'go to next line' during the decoding of a frame but is 'go to first
67  * line' at the beginning. Since we always interpret it as 'go to next line'
68  * in the decoding loop (which makes code simpler/faster), the first line
69  * would not be counted, so we count one more.
70  * See: https://ffmpeg.org/trac/ffmpeg/ticket/226
71  * In the following decoding loop, row_ptr will be the position of the
72  * current row. */
73 
74  row_ptr -= row_inc;
75  pixel_ptr = row_ptr;
76  lines_to_change++;
77  while (lines_to_change) {
78  skip = bytestream2_get_byte(&s->g);
79  rle_code = (signed char)bytestream2_get_byte(&s->g);
80  if (rle_code == 0)
81  break;
82  if(skip & 0x80) {
83  lines_to_change--;
84  row_ptr += row_inc;
85  pixel_ptr = row_ptr + 2 * (skip & 0x7f);
86  } else
87  pixel_ptr += 2 * skip;
88  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
89 
90  if(rle_code == -1)
91  continue;
92 
93  if (rle_code < 0) {
94  /* decode the run length code */
95  rle_code = -rle_code;
96  /* get the next 2 bytes from the stream, treat them as groups
97  * of 8 pixels, and output them rle_code times */
98 
99  pi0 = bytestream2_get_byte(&s->g);
100  pi1 = bytestream2_get_byte(&s->g);
101  CHECK_PIXEL_PTR(rle_code * 2);
102 
103  while (rle_code--) {
104  rgb[pixel_ptr++] = pi0;
105  rgb[pixel_ptr++] = pi1;
106  }
107  } else {
108  /* copy the same pixel directly to output 2 times */
109  rle_code *= 2;
110  CHECK_PIXEL_PTR(rle_code);
111 
112  while (rle_code--)
113  rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
114  }
115  }
116 }
117 
118 static inline void qtrle_decode_2n4bpp(QtrleContext *s, int row_ptr,
119  int lines_to_change, int bpp)
120 {
121  int rle_code, i;
122  int pixel_ptr;
123  int row_inc = s->frame.linesize[0];
124  unsigned char pi[16]; /* 16 palette indices */
125  unsigned char *rgb = s->frame.data[0];
126  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
127  int num_pixels = (bpp == 4) ? 8 : 16;
128 
129  while (lines_to_change--) {
130  pixel_ptr = row_ptr + (num_pixels * (bytestream2_get_byte(&s->g) - 1));
131  CHECK_PIXEL_PTR(0);
132 
133  while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {
134  if (rle_code == 0) {
135  /* there's another skip code in the stream */
136  pixel_ptr += (num_pixels * (bytestream2_get_byte(&s->g) - 1));
137  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
138  } else if (rle_code < 0) {
139  /* decode the run length code */
140  rle_code = -rle_code;
141  /* get the next 4 bytes from the stream, treat them as palette
142  * indexes, and output them rle_code times */
143  for (i = num_pixels-1; i >= 0; i--) {
144  pi[num_pixels-1-i] = (bytestream2_peek_byte(&s->g) >> ((i*bpp) & 0x07)) & ((1<<bpp)-1);
145  bytestream2_skip(&s->g, ((i & ((num_pixels>>2)-1)) == 0));
146  }
147  CHECK_PIXEL_PTR(rle_code * num_pixels);
148  while (rle_code--) {
149  for (i = 0; i < num_pixels; i++)
150  rgb[pixel_ptr++] = pi[i];
151  }
152  } else {
153  /* copy the same pixel directly to output 4 times */
154  rle_code *= 4;
155  CHECK_PIXEL_PTR(rle_code*(num_pixels>>2));
156  while (rle_code--) {
157  if(bpp == 4) {
158  int x = bytestream2_get_byte(&s->g);
159  rgb[pixel_ptr++] = (x >> 4) & 0x0f;
160  rgb[pixel_ptr++] = x & 0x0f;
161  } else {
162  int x = bytestream2_get_byte(&s->g);
163  rgb[pixel_ptr++] = (x >> 6) & 0x03;
164  rgb[pixel_ptr++] = (x >> 4) & 0x03;
165  rgb[pixel_ptr++] = (x >> 2) & 0x03;
166  rgb[pixel_ptr++] = x & 0x03;
167  }
168  }
169  }
170  }
171  row_ptr += row_inc;
172  }
173 }
174 
175 static void qtrle_decode_8bpp(QtrleContext *s, int row_ptr, int lines_to_change)
176 {
177  int rle_code;
178  int pixel_ptr;
179  int row_inc = s->frame.linesize[0];
180  unsigned char pi1, pi2, pi3, pi4; /* 4 palette indexes */
181  unsigned char *rgb = s->frame.data[0];
182  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
183 
184  while (lines_to_change--) {
185  pixel_ptr = row_ptr + (4 * (bytestream2_get_byte(&s->g) - 1));
186  CHECK_PIXEL_PTR(0);
187 
188  while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {
189  if (rle_code == 0) {
190  /* there's another skip code in the stream */
191  pixel_ptr += (4 * (bytestream2_get_byte(&s->g) - 1));
192  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
193  } else if (rle_code < 0) {
194  /* decode the run length code */
195  rle_code = -rle_code;
196  /* get the next 4 bytes from the stream, treat them as palette
197  * indexes, and output them rle_code times */
198  pi1 = bytestream2_get_byte(&s->g);
199  pi2 = bytestream2_get_byte(&s->g);
200  pi3 = bytestream2_get_byte(&s->g);
201  pi4 = bytestream2_get_byte(&s->g);
202 
203  CHECK_PIXEL_PTR(rle_code * 4);
204 
205  while (rle_code--) {
206  rgb[pixel_ptr++] = pi1;
207  rgb[pixel_ptr++] = pi2;
208  rgb[pixel_ptr++] = pi3;
209  rgb[pixel_ptr++] = pi4;
210  }
211  } else {
212  /* copy the same pixel directly to output 4 times */
213  rle_code *= 4;
214  CHECK_PIXEL_PTR(rle_code);
215 
216  while (rle_code--) {
217  rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
218  }
219  }
220  }
221  row_ptr += row_inc;
222  }
223 }
224 
225 static void qtrle_decode_16bpp(QtrleContext *s, int row_ptr, int lines_to_change)
226 {
227  int rle_code;
228  int pixel_ptr;
229  int row_inc = s->frame.linesize[0];
230  unsigned short rgb16;
231  unsigned char *rgb = s->frame.data[0];
232  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
233 
234  while (lines_to_change--) {
235  pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 2;
236  CHECK_PIXEL_PTR(0);
237 
238  while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {
239  if (rle_code == 0) {
240  /* there's another skip code in the stream */
241  pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 2;
242  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
243  } else if (rle_code < 0) {
244  /* decode the run length code */
245  rle_code = -rle_code;
246  rgb16 = bytestream2_get_be16(&s->g);
247 
248  CHECK_PIXEL_PTR(rle_code * 2);
249 
250  while (rle_code--) {
251  *(unsigned short *)(&rgb[pixel_ptr]) = rgb16;
252  pixel_ptr += 2;
253  }
254  } else {
255  CHECK_PIXEL_PTR(rle_code * 2);
256 
257  /* copy pixels directly to output */
258  while (rle_code--) {
259  rgb16 = bytestream2_get_be16(&s->g);
260  *(unsigned short *)(&rgb[pixel_ptr]) = rgb16;
261  pixel_ptr += 2;
262  }
263  }
264  }
265  row_ptr += row_inc;
266  }
267 }
268 
269 static void qtrle_decode_24bpp(QtrleContext *s, int row_ptr, int lines_to_change)
270 {
271  int rle_code;
272  int pixel_ptr;
273  int row_inc = s->frame.linesize[0];
274  unsigned char r, g, b;
275  unsigned char *rgb = s->frame.data[0];
276  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
277 
278  while (lines_to_change--) {
279  pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 3;
280  CHECK_PIXEL_PTR(0);
281 
282  while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {
283  if (rle_code == 0) {
284  /* there's another skip code in the stream */
285  pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 3;
286  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
287  } else if (rle_code < 0) {
288  /* decode the run length code */
289  rle_code = -rle_code;
290  r = bytestream2_get_byte(&s->g);
291  g = bytestream2_get_byte(&s->g);
292  b = bytestream2_get_byte(&s->g);
293 
294  CHECK_PIXEL_PTR(rle_code * 3);
295 
296  while (rle_code--) {
297  rgb[pixel_ptr++] = r;
298  rgb[pixel_ptr++] = g;
299  rgb[pixel_ptr++] = b;
300  }
301  } else {
302  CHECK_PIXEL_PTR(rle_code * 3);
303 
304  /* copy pixels directly to output */
305  while (rle_code--) {
306  rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
307  rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
308  rgb[pixel_ptr++] = bytestream2_get_byte(&s->g);
309  }
310  }
311  }
312  row_ptr += row_inc;
313  }
314 }
315 
316 static void qtrle_decode_32bpp(QtrleContext *s, int row_ptr, int lines_to_change)
317 {
318  int rle_code;
319  int pixel_ptr;
320  int row_inc = s->frame.linesize[0];
321  unsigned int argb;
322  unsigned char *rgb = s->frame.data[0];
323  int pixel_limit = s->frame.linesize[0] * s->avctx->height;
324 
325  while (lines_to_change--) {
326  pixel_ptr = row_ptr + (bytestream2_get_byte(&s->g) - 1) * 4;
327  CHECK_PIXEL_PTR(0);
328 
329  while ((rle_code = (signed char)bytestream2_get_byte(&s->g)) != -1) {
330  if (rle_code == 0) {
331  /* there's another skip code in the stream */
332  pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 4;
333  CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
334  } else if (rle_code < 0) {
335  /* decode the run length code */
336  rle_code = -rle_code;
337  argb = bytestream2_get_be32(&s->g);
338 
339  CHECK_PIXEL_PTR(rle_code * 4);
340 
341  while (rle_code--) {
342  AV_WN32A(rgb + pixel_ptr, argb);
343  pixel_ptr += 4;
344  }
345  } else {
346  CHECK_PIXEL_PTR(rle_code * 4);
347 
348  /* copy pixels directly to output */
349  while (rle_code--) {
350  argb = bytestream2_get_be32(&s->g);
351  AV_WN32A(rgb + pixel_ptr, argb);
352  pixel_ptr += 4;
353  }
354  }
355  }
356  row_ptr += row_inc;
357  }
358 }
359 
361 {
362  QtrleContext *s = avctx->priv_data;
363 
364  s->avctx = avctx;
365  switch (avctx->bits_per_coded_sample) {
366  case 1:
367  case 33:
368  avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
369  break;
370 
371  case 2:
372  case 4:
373  case 8:
374  case 34:
375  case 36:
376  case 40:
377  avctx->pix_fmt = AV_PIX_FMT_PAL8;
378  break;
379 
380  case 16:
381  avctx->pix_fmt = AV_PIX_FMT_RGB555;
382  break;
383 
384  case 24:
385  avctx->pix_fmt = AV_PIX_FMT_RGB24;
386  break;
387 
388  case 32:
389  avctx->pix_fmt = AV_PIX_FMT_RGB32;
390  break;
391 
392  default:
393  av_log (avctx, AV_LOG_ERROR, "Unsupported colorspace: %d bits/sample?\n",
394  avctx->bits_per_coded_sample);
395  return AVERROR_INVALIDDATA;
396  }
397 
399  s->frame.data[0] = NULL;
400 
401  return 0;
402 }
403 
405  void *data, int *got_frame,
406  AVPacket *avpkt)
407 {
408  QtrleContext *s = avctx->priv_data;
409  int header, start_line;
410  int height, row_ptr;
411  int has_palette = 0;
412  int ret;
413 
414  bytestream2_init(&s->g, avpkt->data, avpkt->size);
415  s->frame.reference = 3;
418  if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0) {
419  av_log (s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
420  return ret;
421  }
422 
423  /* check if this frame is even supposed to change */
424  if (avpkt->size < 8)
425  goto done;
426 
427  /* start after the chunk size */
428  bytestream2_seek(&s->g, 4, SEEK_SET);
429 
430  /* fetch the header */
431  header = bytestream2_get_be16(&s->g);
432 
433  /* if a header is present, fetch additional decoding parameters */
434  if (header & 0x0008) {
435  if (avpkt->size < 14)
436  goto done;
437  start_line = bytestream2_get_be16(&s->g);
438  bytestream2_skip(&s->g, 2);
439  height = bytestream2_get_be16(&s->g);
440  bytestream2_skip(&s->g, 2);
441  if (height > s->avctx->height - start_line)
442  goto done;
443  } else {
444  start_line = 0;
445  height = s->avctx->height;
446  }
447  row_ptr = s->frame.linesize[0] * start_line;
448 
449  switch (avctx->bits_per_coded_sample) {
450  case 1:
451  case 33:
452  qtrle_decode_1bpp(s, row_ptr, height);
453  break;
454 
455  case 2:
456  case 34:
457  qtrle_decode_2n4bpp(s, row_ptr, height, 2);
458  has_palette = 1;
459  break;
460 
461  case 4:
462  case 36:
463  qtrle_decode_2n4bpp(s, row_ptr, height, 4);
464  has_palette = 1;
465  break;
466 
467  case 8:
468  case 40:
469  qtrle_decode_8bpp(s, row_ptr, height);
470  has_palette = 1;
471  break;
472 
473  case 16:
474  qtrle_decode_16bpp(s, row_ptr, height);
475  break;
476 
477  case 24:
478  qtrle_decode_24bpp(s, row_ptr, height);
479  break;
480 
481  case 32:
482  qtrle_decode_32bpp(s, row_ptr, height);
483  break;
484 
485  default:
486  av_log (s->avctx, AV_LOG_ERROR, "Unsupported colorspace: %d bits/sample?\n",
487  avctx->bits_per_coded_sample);
488  break;
489  }
490 
491  if(has_palette) {
493 
494  if (pal) {
495  s->frame.palette_has_changed = 1;
496  memcpy(s->pal, pal, AVPALETTE_SIZE);
497  }
498 
499  /* make the palette available on the way out */
500  memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
501  }
502 
503 done:
504  *got_frame = 1;
505  *(AVFrame*)data = s->frame;
506 
507  /* always report that the buffer was completely consumed */
508  return avpkt->size;
509 }
510 
512 {
513  QtrleContext *s = avctx->priv_data;
514 
515  if (s->frame.data[0])
516  avctx->release_buffer(avctx, &s->frame);
517 
518  return 0;
519 }
520 
522  .name = "qtrle",
523  .type = AVMEDIA_TYPE_VIDEO,
524  .id = AV_CODEC_ID_QTRLE,
525  .priv_data_size = sizeof(QtrleContext),
529  .capabilities = CODEC_CAP_DR1,
530  .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
531 };