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pcx.c
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1 /*
2  * PC Paintbrush PCX (.pcx) image decoder
3  * Copyright (c) 2007, 2008 Ivo van Poorten
4  *
5  * This decoder does not support CGA palettes. I am unable to find samples
6  * and Netpbm cannot generate them.
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #include "libavutil/imgutils.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "get_bits.h"
29 #include "internal.h"
30 
31 typedef struct PCXContext {
33 } PCXContext;
34 
35 static av_cold int pcx_init(AVCodecContext *avctx)
36 {
37  PCXContext *s = avctx->priv_data;
38 
40  avctx->coded_frame= &s->picture;
41 
42  return 0;
43 }
44 
46  unsigned int bytes_per_scanline, int compressed)
47 {
48  unsigned int i = 0;
49  unsigned char run, value;
50 
51  if (compressed) {
52  while (i<bytes_per_scanline) {
53  run = 1;
54  value = bytestream2_get_byte(gb);
55  if (value >= 0xc0) {
56  run = value & 0x3f;
57  value = bytestream2_get_byte(gb);
58  }
59  while (i<bytes_per_scanline && run--)
60  dst[i++] = value;
61  }
62  } else {
63  bytestream2_get_buffer(gb, dst, bytes_per_scanline);
64  }
65 }
66 
67 static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
68 {
69  int i;
70 
71  pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
72  for (i=0; i<pallen; i++)
73  *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
74  if (pallen < 256)
75  memset(dst, 0, (256 - pallen) * sizeof(*dst));
76 }
77 
78 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
79  AVPacket *avpkt)
80 {
81  PCXContext * const s = avctx->priv_data;
82  AVFrame *picture = data;
83  AVFrame * const p = &s->picture;
84  GetByteContext gb;
85  int compressed, xmin, ymin, xmax, ymax, ret;
86  unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
87  bytes_per_scanline;
88  uint8_t *ptr, *scanline;
89 
90  if (avpkt->size < 128)
91  return AVERROR_INVALIDDATA;
92 
93  bytestream2_init(&gb, avpkt->data, avpkt->size);
94 
95  if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
96  av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
97  return AVERROR_INVALIDDATA;
98  }
99 
100  compressed = bytestream2_get_byteu(&gb);
101  bits_per_pixel = bytestream2_get_byteu(&gb);
102  xmin = bytestream2_get_le16u(&gb);
103  ymin = bytestream2_get_le16u(&gb);
104  xmax = bytestream2_get_le16u(&gb);
105  ymax = bytestream2_get_le16u(&gb);
106  avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
107  avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
108 
109  if (xmax < xmin || ymax < ymin) {
110  av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
111  return AVERROR_INVALIDDATA;
112  }
113 
114  w = xmax - xmin + 1;
115  h = ymax - ymin + 1;
116 
117  bytestream2_skipu(&gb, 49);
118  nplanes = bytestream2_get_byteu(&gb);
119  bytes_per_line = bytestream2_get_le16u(&gb);
120  bytes_per_scanline = nplanes * bytes_per_line;
121 
122  if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
123  av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
124  return AVERROR_INVALIDDATA;
125  }
126 
127  switch ((nplanes<<8) + bits_per_pixel) {
128  case 0x0308:
129  avctx->pix_fmt = AV_PIX_FMT_RGB24;
130  break;
131  case 0x0108:
132  case 0x0104:
133  case 0x0102:
134  case 0x0101:
135  case 0x0401:
136  case 0x0301:
137  case 0x0201:
138  avctx->pix_fmt = AV_PIX_FMT_PAL8;
139  break;
140  default:
141  av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
142  return AVERROR_INVALIDDATA;
143  }
144 
145  bytestream2_skipu(&gb, 60);
146 
147  if (p->data[0])
148  avctx->release_buffer(avctx, p);
149 
150  if (av_image_check_size(w, h, 0, avctx))
151  return AVERROR_INVALIDDATA;
152  if (w != avctx->width || h != avctx->height)
153  avcodec_set_dimensions(avctx, w, h);
154  if ((ret = ff_get_buffer(avctx, p)) < 0) {
155  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
156  return ret;
157  }
158 
160 
161  ptr = p->data[0];
162  stride = p->linesize[0];
163 
164  scanline = av_malloc(bytes_per_scanline);
165  if (!scanline)
166  return AVERROR(ENOMEM);
167 
168  if (nplanes == 3 && bits_per_pixel == 8) {
169  for (y=0; y<h; y++) {
170  pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
171 
172  for (x=0; x<w; x++) {
173  ptr[3*x ] = scanline[x ];
174  ptr[3*x+1] = scanline[x+ bytes_per_line ];
175  ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
176  }
177 
178  ptr += stride;
179  }
180 
181  } else if (nplanes == 1 && bits_per_pixel == 8) {
182  int palstart = avpkt->size - 769;
183 
184  for (y=0; y<h; y++, ptr+=stride) {
185  pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
186  memcpy(ptr, scanline, w);
187  }
188 
189  if (bytestream2_tell(&gb) != palstart) {
190  av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
191  bytestream2_seek(&gb, palstart, SEEK_SET);
192  }
193  if (bytestream2_get_byte(&gb) != 12) {
194  av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
195  ret = AVERROR_INVALIDDATA;
196  goto end;
197  }
198 
199  } else if (nplanes == 1) { /* all packed formats, max. 16 colors */
200  GetBitContext s;
201 
202  for (y=0; y<h; y++) {
203  init_get_bits(&s, scanline, bytes_per_scanline<<3);
204 
205  pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
206 
207  for (x=0; x<w; x++)
208  ptr[x] = get_bits(&s, bits_per_pixel);
209  ptr += stride;
210  }
211 
212  } else { /* planar, 4, 8 or 16 colors */
213  int i;
214 
215  for (y=0; y<h; y++) {
216  pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
217 
218  for (x=0; x<w; x++) {
219  int m = 0x80 >> (x&7), v = 0;
220  for (i=nplanes - 1; i>=0; i--) {
221  v <<= 1;
222  v += !!(scanline[i*bytes_per_line + (x>>3)] & m);
223  }
224  ptr[x] = v;
225  }
226  ptr += stride;
227  }
228  }
229 
230  ret = bytestream2_tell(&gb);
231  if (nplanes == 1 && bits_per_pixel == 8) {
232  pcx_palette(&gb, (uint32_t *) p->data[1], 256);
233  ret += 256 * 3;
234  } else if (bits_per_pixel * nplanes == 1) {
235  AV_WN32A(p->data[1] , 0xFF000000);
236  AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
237  } else if (bits_per_pixel < 8) {
238  bytestream2_seek(&gb, 16, SEEK_SET);
239  pcx_palette(&gb, (uint32_t *) p->data[1], 16);
240  }
241 
242  *picture = s->picture;
243  *got_frame = 1;
244 
245 end:
246  av_free(scanline);
247  return ret;
248 }
249 
250 static av_cold int pcx_end(AVCodecContext *avctx)
251 {
252  PCXContext *s = avctx->priv_data;
253 
254  if(s->picture.data[0])
255  avctx->release_buffer(avctx, &s->picture);
256 
257  return 0;
258 }
259 
261  .name = "pcx",
262  .type = AVMEDIA_TYPE_VIDEO,
263  .id = AV_CODEC_ID_PCX,
264  .priv_data_size = sizeof(PCXContext),
265  .init = pcx_init,
266  .close = pcx_end,
268  .capabilities = CODEC_CAP_DR1,
269  .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
270 };