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 #define PCX_HEADER_SIZE 128
32
pcx_rle_decode(GetByteContext * gb,uint8_t * dst,unsigned int bytes_per_scanline,int compressed)33 static int pcx_rle_decode(GetByteContext *gb,
34 uint8_t *dst,
35 unsigned int bytes_per_scanline,
36 int compressed)
37 {
38 unsigned int i = 0;
39 unsigned char run, value;
40
41 if (bytestream2_get_bytes_left(gb) < 1)
42 return AVERROR_INVALIDDATA;
43
44 if (compressed) {
45 while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
46 run = 1;
47 value = bytestream2_get_byte(gb);
48 if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
49 run = value & 0x3f;
50 value = bytestream2_get_byte(gb);
51 }
52 while (i < bytes_per_scanline && run--)
53 dst[i++] = value;
54 }
55 } else {
56 bytestream2_get_buffer(gb, dst, bytes_per_scanline);
57 }
58 return 0;
59 }
60
pcx_palette(GetByteContext * gb,uint32_t * dst,int pallen)61 static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
62 {
63 int i;
64
65 pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
66 for (i = 0; i < pallen; i++)
67 *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
68 if (pallen < 256)
69 memset(dst, 0, (256 - pallen) * sizeof(*dst));
70 }
71
pcx_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)72 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
73 AVPacket *avpkt)
74 {
75 GetByteContext gb;
76 AVFrame * const p = data;
77 int compressed, xmin, ymin, xmax, ymax;
78 int ret;
79 unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
80 bytes_per_scanline;
81 uint8_t *ptr, *scanline;
82
83 if (avpkt->size < PCX_HEADER_SIZE) {
84 av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
85 return AVERROR_INVALIDDATA;
86 }
87
88 bytestream2_init(&gb, avpkt->data, avpkt->size);
89
90 if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
91 av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
92 return AVERROR_INVALIDDATA;
93 }
94
95 compressed = bytestream2_get_byteu(&gb);
96 bits_per_pixel = bytestream2_get_byteu(&gb);
97 xmin = bytestream2_get_le16u(&gb);
98 ymin = bytestream2_get_le16u(&gb);
99 xmax = bytestream2_get_le16u(&gb);
100 ymax = bytestream2_get_le16u(&gb);
101 avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
102 avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
103
104 if (xmax < xmin || ymax < ymin) {
105 av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
106 return AVERROR_INVALIDDATA;
107 }
108
109 w = xmax - xmin + 1;
110 h = ymax - ymin + 1;
111
112 bytestream2_skipu(&gb, 49);
113 nplanes = bytestream2_get_byteu(&gb);
114 bytes_per_line = bytestream2_get_le16u(&gb);
115 bytes_per_scanline = nplanes * bytes_per_line;
116
117 if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
118 (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
119 av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
120 return AVERROR_INVALIDDATA;
121 }
122
123 switch ((nplanes << 8) + bits_per_pixel) {
124 case 0x0308:
125 avctx->pix_fmt = AV_PIX_FMT_RGB24;
126 break;
127 case 0x0108:
128 case 0x0104:
129 case 0x0102:
130 case 0x0101:
131 case 0x0401:
132 case 0x0301:
133 case 0x0201:
134 avctx->pix_fmt = AV_PIX_FMT_PAL8;
135 break;
136 default:
137 av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
138 return AVERROR_INVALIDDATA;
139 }
140
141 bytestream2_skipu(&gb, 60);
142
143 if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
144 return ret;
145
146 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
147 return ret;
148
149 p->pict_type = AV_PICTURE_TYPE_I;
150
151 ptr = p->data[0];
152 stride = p->linesize[0];
153
154 scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);
155 if (!scanline)
156 return AVERROR(ENOMEM);
157
158 if (nplanes == 3 && bits_per_pixel == 8) {
159 for (y = 0; y < h; y++) {
160 ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
161 if (ret < 0)
162 goto end;
163
164 for (x = 0; x < w; x++) {
165 ptr[3 * x] = scanline[x];
166 ptr[3 * x + 1] = scanline[x + bytes_per_line];
167 ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];
168 }
169
170 ptr += stride;
171 }
172 } else if (nplanes == 1 && bits_per_pixel == 8) {
173 int palstart = avpkt->size - 769;
174
175 if (avpkt->size < 769) {
176 av_log(avctx, AV_LOG_ERROR, "File is too short\n");
177 ret = avctx->err_recognition & AV_EF_EXPLODE ?
178 AVERROR_INVALIDDATA : avpkt->size;
179 goto end;
180 }
181
182 for (y = 0; y < h; y++, ptr += stride) {
183 ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
184 if (ret < 0)
185 goto end;
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 = avctx->err_recognition & AV_EF_EXPLODE ?
196 AVERROR_INVALIDDATA : avpkt->size;
197 goto end;
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_bits8(&s, scanline, bytes_per_scanline);
204
205 ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
206 if (ret < 0)
207 goto end;
208
209 for (x = 0; x < w; x++)
210 ptr[x] = get_bits(&s, bits_per_pixel);
211 ptr += stride;
212 }
213 } else { /* planar, 4, 8 or 16 colors */
214 int i;
215
216 for (y = 0; y < h; y++) {
217 ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
218 if (ret < 0)
219 goto end;
220
221 for (x = 0; x < w; x++) {
222 int m = 0x80 >> (x & 7), v = 0;
223 for (i = nplanes - 1; i >= 0; i--) {
224 v <<= 1;
225 v += !!(scanline[i * bytes_per_line + (x >> 3)] & m);
226 }
227 ptr[x] = v;
228 }
229 ptr += stride;
230 }
231 }
232
233 ret = bytestream2_tell(&gb);
234 if (nplanes == 1 && bits_per_pixel == 8) {
235 pcx_palette(&gb, (uint32_t *)p->data[1], 256);
236 ret += 256 * 3;
237 } else if (bits_per_pixel * nplanes == 1) {
238 AV_WN32A(p->data[1] , 0xFF000000);
239 AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
240 } else if (bits_per_pixel < 8) {
241 bytestream2_seek(&gb, 16, SEEK_SET);
242 pcx_palette(&gb, (uint32_t *)p->data[1], 16);
243 }
244
245 *got_frame = 1;
246
247 end:
248 av_free(scanline);
249 return ret;
250 }
251
252 AVCodec ff_pcx_decoder = {
253 .name = "pcx",
254 .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
255 .type = AVMEDIA_TYPE_VIDEO,
256 .id = AV_CODEC_ID_PCX,
257 .decode = pcx_decode_frame,
258 .capabilities = AV_CODEC_CAP_DR1,
259 };
260