pictordec.c
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1 /*
2  * Pictor/PC Paint decoder
3  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
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 
27 #include "libavutil/imgutils.h"
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "cga_data.h"
31 
32 typedef struct PicContext {
34  int width, height;
35  int nb_planes;
37 } PicContext;
38 
39 static void picmemset_8bpp(PicContext *s, int value, int run, int *x, int *y)
40 {
41  while (run > 0) {
42  uint8_t *d = s->frame.data[0] + *y * s->frame.linesize[0];
43  if (*x + run >= s->width) {
44  int n = s->width - *x;
45  memset(d + *x, value, n);
46  run -= n;
47  *x = 0;
48  *y -= 1;
49  if (*y < 0)
50  break;
51  } else {
52  memset(d + *x, value, run);
53  *x += run;
54  break;
55  }
56  }
57 }
58 
59 static void picmemset(PicContext *s, int value, int run,
60  int *x, int *y, int *plane, int bits_per_plane)
61 {
62  uint8_t *d;
63  int shift = *plane * bits_per_plane;
64  int mask = ((1 << bits_per_plane) - 1) << shift;
65  value <<= shift;
66 
67  while (run > 0) {
68  int j;
69  for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) {
70  d = s->frame.data[0] + *y * s->frame.linesize[0];
71  d[*x] |= (value >> j) & mask;
72  *x += 1;
73  if (*x == s->width) {
74  *y -= 1;
75  *x = 0;
76  if (*y < 0) {
77  *y = s->height - 1;
78  *plane += 1;
79  value <<= bits_per_plane;
80  mask <<= bits_per_plane;
81  if (*plane >= s->nb_planes)
82  break;
83  }
84  }
85  }
86  run--;
87  }
88 }
89 
90 static const uint8_t cga_mode45_index[6][4] = {
91  [0] = { 0, 3, 5, 7 }, // mode4, palette#1, low intensity
92  [1] = { 0, 2, 4, 6 }, // mode4, palette#2, low intensity
93  [2] = { 0, 3, 4, 7 }, // mode5, low intensity
94  [3] = { 0, 11, 13, 15 }, // mode4, palette#1, high intensity
95  [4] = { 0, 10, 12, 14 }, // mode4, palette#2, high intensity
96  [5] = { 0, 11, 12, 15 }, // mode5, high intensity
97 };
98 
99 static int decode_frame(AVCodecContext *avctx,
100  void *data, int *data_size,
101  AVPacket *avpkt)
102 {
103  PicContext *s = avctx->priv_data;
104  uint32_t *palette;
105  int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
106  int i, x, y, plane, tmp;
107 
108  bytestream2_init(&s->g, avpkt->data, avpkt->size);
109 
110  if (bytestream2_get_bytes_left(&s->g) < 11)
111  return AVERROR_INVALIDDATA;
112 
113  if (bytestream2_get_le16u(&s->g) != 0x1234)
114  return AVERROR_INVALIDDATA;
115 
116  s->width = bytestream2_get_le16u(&s->g);
117  s->height = bytestream2_get_le16u(&s->g);
118  bytestream2_skip(&s->g, 4);
119  tmp = bytestream2_get_byteu(&s->g);
120  bits_per_plane = tmp & 0xF;
121  s->nb_planes = (tmp >> 4) + 1;
122  bpp = bits_per_plane * s->nb_planes;
123  if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
124  av_log_ask_for_sample(avctx, "unsupported bit depth\n");
125  return AVERROR_INVALIDDATA;
126  }
127 
128  if (bytestream2_peek_byte(&s->g) == 0xFF) {
129  bytestream2_skip(&s->g, 2);
130  etype = bytestream2_get_le16(&s->g);
131  esize = bytestream2_get_le16(&s->g);
132  if (bytestream2_get_bytes_left(&s->g) < esize)
133  return AVERROR_INVALIDDATA;
134  } else {
135  etype = -1;
136  esize = 0;
137  }
138 
139  avctx->pix_fmt = PIX_FMT_PAL8;
140 
141  if (s->width != avctx->width && s->height != avctx->height) {
142  if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
143  return -1;
144  avcodec_set_dimensions(avctx, s->width, s->height);
145  if (s->frame.data[0])
146  avctx->release_buffer(avctx, &s->frame);
147  }
148 
149  if (avctx->get_buffer(avctx, &s->frame) < 0){
150  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
151  return -1;
152  }
153  memset(s->frame.data[0], 0, s->height * s->frame.linesize[0]);
155  s->frame.palette_has_changed = 1;
156 
157  pos_after_pal = bytestream2_tell(&s->g) + esize;
158  palette = (uint32_t*)s->frame.data[1];
159  if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
160  int idx = bytestream2_get_byte(&s->g);
161  npal = 4;
162  for (i = 0; i < npal; i++)
163  palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
164  } else if (etype == 2) {
165  npal = FFMIN(esize, 16);
166  for (i = 0; i < npal; i++) {
167  int pal_idx = bytestream2_get_byte(&s->g);
168  palette[i] = ff_cga_palette[FFMIN(pal_idx, 16)];
169  }
170  } else if (etype == 3) {
171  npal = FFMIN(esize, 16);
172  for (i = 0; i < npal; i++) {
173  int pal_idx = bytestream2_get_byte(&s->g);
174  palette[i] = ff_ega_palette[FFMIN(pal_idx, 63)];
175  }
176  } else if (etype == 4 || etype == 5) {
177  npal = FFMIN(esize / 3, 256);
178  for (i = 0; i < npal; i++)
179  palette[i] = bytestream2_get_be24(&s->g) << 2;
180  } else {
181  if (bpp == 1) {
182  npal = 2;
183  palette[0] = 0x000000;
184  palette[1] = 0xFFFFFF;
185  } else if (bpp == 2) {
186  npal = 4;
187  for (i = 0; i < npal; i++)
188  palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
189  } else {
190  npal = 16;
191  memcpy(palette, ff_cga_palette, npal * 4);
192  }
193  }
194  // fill remaining palette entries
195  memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
196  // skip remaining palette bytes
197  bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
198 
199  x = 0;
200  y = s->height - 1;
201  plane = 0;
202  if (bytestream2_get_le16(&s->g)) {
203  while (bytestream2_get_bytes_left(&s->g) >= 6) {
204  int stop_size, marker, t1, t2;
205 
206  t1 = bytestream2_get_bytes_left(&s->g);
207  t2 = bytestream2_get_le16(&s->g);
208  stop_size = t1 - FFMIN(t1, t2);
209  // ignore uncompressed block size
210  bytestream2_skip(&s->g, 2);
211  marker = bytestream2_get_byte(&s->g);
212 
213  while (plane < s->nb_planes &&
214  bytestream2_get_bytes_left(&s->g) > stop_size) {
215  int run = 1;
216  int val = bytestream2_get_byte(&s->g);
217  if (val == marker) {
218  run = bytestream2_get_byte(&s->g);
219  if (run == 0)
220  run = bytestream2_get_le16(&s->g);
221  val = bytestream2_get_byte(&s->g);
222  }
223  if (!bytestream2_get_bytes_left(&s->g))
224  break;
225 
226  if (bits_per_plane == 8) {
227  picmemset_8bpp(s, val, run, &x, &y);
228  if (y < 0)
229  goto finish;
230  } else {
231  picmemset(s, val, run, &x, &y, &plane, bits_per_plane);
232  }
233  }
234  }
235  } else {
236  av_log_ask_for_sample(avctx, "uncompressed image\n");
237  return avpkt->size;
238  }
239 finish:
240 
241  *data_size = sizeof(AVFrame);
242  *(AVFrame*)data = s->frame;
243  return avpkt->size;
244 }
245 
247 {
248  PicContext *s = avctx->priv_data;
249  if (s->frame.data[0])
250  avctx->release_buffer(avctx, &s->frame);
251  return 0;
252 }
253 
255  .name = "pictor",
256  .type = AVMEDIA_TYPE_VIDEO,
257  .id = CODEC_ID_PICTOR,
258  .priv_data_size = sizeof(PicContext),
259  .close = decode_end,
260  .decode = decode_frame,
261  .capabilities = CODEC_CAP_DR1,
262  .long_name = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),
263 };