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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 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  * Pictor/PC Paint decoder
25  */
26 
27 #include "libavutil/imgutils.h"
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "cga_data.h"
31 #include "internal.h"
32 
33 typedef struct PicContext {
35  int width, height;
36  int nb_planes;
38 } PicContext;
39 
40 static void picmemset_8bpp(PicContext *s, int value, int run, int *x, int *y)
41 {
42  while (run > 0) {
43  uint8_t *d = s->frame.data[0] + *y * s->frame.linesize[0];
44  if (*x + run >= s->width) {
45  int n = s->width - *x;
46  memset(d + *x, value, n);
47  run -= n;
48  *x = 0;
49  *y -= 1;
50  if (*y < 0)
51  break;
52  } else {
53  memset(d + *x, value, run);
54  *x += run;
55  break;
56  }
57  }
58 }
59 
60 static void picmemset(PicContext *s, int value, int run,
61  int *x, int *y, int *plane, int bits_per_plane)
62 {
63  uint8_t *d;
64  int shift = *plane * bits_per_plane;
65  int mask = ((1 << bits_per_plane) - 1) << shift;
66  value <<= shift;
67 
68  while (run > 0) {
69  int j;
70  for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) {
71  d = s->frame.data[0] + *y * s->frame.linesize[0];
72  d[*x] |= (value >> j) & mask;
73  *x += 1;
74  if (*x == s->width) {
75  *y -= 1;
76  *x = 0;
77  if (*y < 0) {
78  *y = s->height - 1;
79  *plane += 1;
80  value <<= bits_per_plane;
81  mask <<= bits_per_plane;
82  if (*plane >= s->nb_planes)
83  break;
84  }
85  }
86  }
87  run--;
88  }
89 }
90 
91 static const uint8_t cga_mode45_index[6][4] = {
92  [0] = { 0, 3, 5, 7 }, // mode4, palette#1, low intensity
93  [1] = { 0, 2, 4, 6 }, // mode4, palette#2, low intensity
94  [2] = { 0, 3, 4, 7 }, // mode5, low intensity
95  [3] = { 0, 11, 13, 15 }, // mode4, palette#1, high intensity
96  [4] = { 0, 10, 12, 14 }, // mode4, palette#2, high intensity
97  [5] = { 0, 11, 12, 15 }, // mode5, high intensity
98 };
99 
101 {
102  PicContext *s = avctx->priv_data;
103 
105  return 0;
106 }
107 
108 static int decode_frame(AVCodecContext *avctx,
109  void *data, int *got_frame,
110  AVPacket *avpkt)
111 {
112  PicContext *s = avctx->priv_data;
113  uint32_t *palette;
114  int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
115  int i, x, y, plane, tmp, val;
116 
117  bytestream2_init(&s->g, avpkt->data, avpkt->size);
118 
119  if (bytestream2_get_bytes_left(&s->g) < 11)
120  return AVERROR_INVALIDDATA;
121 
122  if (bytestream2_get_le16u(&s->g) != 0x1234)
123  return AVERROR_INVALIDDATA;
124 
125  s->width = bytestream2_get_le16u(&s->g);
126  s->height = bytestream2_get_le16u(&s->g);
127  bytestream2_skip(&s->g, 4);
128  tmp = bytestream2_get_byteu(&s->g);
129  bits_per_plane = tmp & 0xF;
130  s->nb_planes = (tmp >> 4) + 1;
131  bpp = bits_per_plane * s->nb_planes;
132  if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
133  av_log_ask_for_sample(avctx, "unsupported bit depth\n");
134  return AVERROR_PATCHWELCOME;
135  }
136 
137  if (bytestream2_peek_byte(&s->g) == 0xFF || bpp == 1 || bpp == 4 || bpp == 8) {
138  bytestream2_skip(&s->g, 2);
139  etype = bytestream2_get_le16(&s->g);
140  esize = bytestream2_get_le16(&s->g);
141  if (bytestream2_get_bytes_left(&s->g) < esize)
142  return AVERROR_INVALIDDATA;
143  } else {
144  etype = -1;
145  esize = 0;
146  }
147 
148  avctx->pix_fmt = AV_PIX_FMT_PAL8;
149 
150  if (s->width != avctx->width && s->height != avctx->height) {
151  if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
152  return -1;
153  avcodec_set_dimensions(avctx, s->width, s->height);
154  if (s->frame.data[0])
155  avctx->release_buffer(avctx, &s->frame);
156  }
157 
158  if (ff_get_buffer(avctx, &s->frame) < 0){
159  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
160  return -1;
161  }
162  memset(s->frame.data[0], 0, s->height * s->frame.linesize[0]);
164  s->frame.palette_has_changed = 1;
165 
166  pos_after_pal = bytestream2_tell(&s->g) + esize;
167  palette = (uint32_t*)s->frame.data[1];
168  if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
169  int idx = bytestream2_get_byte(&s->g);
170  npal = 4;
171  for (i = 0; i < npal; i++)
172  palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
173  } else if (etype == 2) {
174  npal = FFMIN(esize, 16);
175  for (i = 0; i < npal; i++) {
176  int pal_idx = bytestream2_get_byte(&s->g);
177  palette[i] = ff_cga_palette[FFMIN(pal_idx, 15)];
178  }
179  } else if (etype == 3) {
180  npal = FFMIN(esize, 16);
181  for (i = 0; i < npal; i++) {
182  int pal_idx = bytestream2_get_byte(&s->g);
183  palette[i] = ff_ega_palette[FFMIN(pal_idx, 63)];
184  }
185  } else if (etype == 4 || etype == 5) {
186  npal = FFMIN(esize / 3, 256);
187  for (i = 0; i < npal; i++) {
188  palette[i] = bytestream2_get_be24(&s->g) << 2;
189  palette[i] |= 0xFFU << 24 | palette[i] >> 6 & 0x30303;
190  }
191  } else {
192  if (bpp == 1) {
193  npal = 2;
194  palette[0] = 0xFF000000;
195  palette[1] = 0xFFFFFFFF;
196  } else if (bpp == 2) {
197  npal = 4;
198  for (i = 0; i < npal; i++)
199  palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
200  } else {
201  npal = 16;
202  memcpy(palette, ff_cga_palette, npal * 4);
203  }
204  }
205  // fill remaining palette entries
206  memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
207  // skip remaining palette bytes
208  bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
209 
210  val = 0;
211  y = s->height - 1;
212  if (bytestream2_get_le16(&s->g)) {
213  x = 0;
214  plane = 0;
215  while (y >= 0 && bytestream2_get_bytes_left(&s->g) >= 6) {
216  int stop_size, marker, t1, t2;
217 
218  t1 = bytestream2_get_bytes_left(&s->g);
219  t2 = bytestream2_get_le16(&s->g);
220  stop_size = t1 - FFMIN(t1, t2);
221  // ignore uncompressed block size
222  bytestream2_skip(&s->g, 2);
223  marker = bytestream2_get_byte(&s->g);
224 
225  while (plane < s->nb_planes && y >= 0 &&
226  bytestream2_get_bytes_left(&s->g) > stop_size) {
227  int run = 1;
228  val = bytestream2_get_byte(&s->g);
229  if (val == marker) {
230  run = bytestream2_get_byte(&s->g);
231  if (run == 0)
232  run = bytestream2_get_le16(&s->g);
233  val = bytestream2_get_byte(&s->g);
234  }
235  if (!bytestream2_get_bytes_left(&s->g))
236  break;
237 
238  if (bits_per_plane == 8) {
239  picmemset_8bpp(s, val, run, &x, &y);
240  } else {
241  picmemset(s, val, run, &x, &y, &plane, bits_per_plane);
242  }
243  }
244  }
245 
246  if (x < avctx->width && y >= 0) {
247  int run = (y + 1) * avctx->width - x;
248  if (bits_per_plane == 8)
249  picmemset_8bpp(s, val, run, &x, &y);
250  else
251  picmemset(s, val, run / (8 / bits_per_plane), &x, &y, &plane, bits_per_plane);
252  }
253  } else {
254  while (y >= 0 && bytestream2_get_bytes_left(&s->g) > 0) {
255  memcpy(s->frame.data[0] + y * s->frame.linesize[0], s->g.buffer, FFMIN(avctx->width, bytestream2_get_bytes_left(&s->g)));
256  bytestream2_skip(&s->g, avctx->width);
257  y--;
258  }
259  }
260 
261  *got_frame = 1;
262  *(AVFrame*)data = s->frame;
263  return avpkt->size;
264 }
265 
267 {
268  PicContext *s = avctx->priv_data;
269  if (s->frame.data[0])
270  avctx->release_buffer(avctx, &s->frame);
271  return 0;
272 }
273 
275  .name = "pictor",
276  .type = AVMEDIA_TYPE_VIDEO,
277  .id = AV_CODEC_ID_PICTOR,
278  .priv_data_size = sizeof(PicContext),
279  .init = decode_init,
280  .close = decode_end,
281  .decode = decode_frame,
282  .capabilities = CODEC_CAP_DR1,
283  .long_name = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),
284 };