2174184bced855155772a505aa4c73a9e4a20f37
[libav.git] / libavcodec / pcx.c
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 "avcodec.h"
26 #include "bytestream.h"
27 #include "get_bits.h"
28
29 typedef struct PCXContext {
30 AVFrame picture;
31 } PCXContext;
32
33 static av_cold int pcx_init(AVCodecContext *avctx) {
34 PCXContext *s = avctx->priv_data;
35
36 avcodec_get_frame_defaults(&s->picture);
37 avctx->coded_frame= &s->picture;
38
39 return 0;
40 }
41
42 /**
43 * @return advanced src pointer
44 */
45 static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst,
46 unsigned int bytes_per_scanline, int compressed) {
47 unsigned int i = 0;
48 unsigned char run, value;
49
50 if (compressed) {
51 while (i<bytes_per_scanline) {
52 run = 1;
53 value = *src++;
54 if (value >= 0xc0) {
55 run = value & 0x3f;
56 value = *src++;
57 }
58 while (i<bytes_per_scanline && run--)
59 dst[i++] = value;
60 }
61 } else {
62 memcpy(dst, src, bytes_per_scanline);
63 src += bytes_per_scanline;
64 }
65
66 return src;
67 }
68
69 static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
70 unsigned int i;
71
72 for (i=0; i<pallen; i++)
73 *dst++ = bytestream_get_be24(src);
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 *data_size,
79 AVPacket *avpkt) {
80 const uint8_t *buf = avpkt->data;
81 int buf_size = avpkt->size;
82 PCXContext * const s = avctx->priv_data;
83 AVFrame *picture = data;
84 AVFrame * const p = &s->picture;
85 int compressed, xmin, ymin, xmax, ymax;
86 unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
87 bytes_per_scanline;
88 uint8_t *ptr;
89 uint8_t const *bufstart = buf;
90
91 if (buf[0] != 0x0a || buf[1] > 5) {
92 av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
93 return -1;
94 }
95
96 compressed = buf[2];
97 xmin = AV_RL16(buf+ 4);
98 ymin = AV_RL16(buf+ 6);
99 xmax = AV_RL16(buf+ 8);
100 ymax = AV_RL16(buf+10);
101
102 if (xmax < xmin || ymax < ymin) {
103 av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
104 return -1;
105 }
106
107 w = xmax - xmin + 1;
108 h = ymax - ymin + 1;
109
110 bits_per_pixel = buf[3];
111 bytes_per_line = AV_RL16(buf+66);
112 nplanes = buf[65];
113 bytes_per_scanline = nplanes * bytes_per_line;
114
115 if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
116 av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
117 return -1;
118 }
119
120 switch ((nplanes<<8) + bits_per_pixel) {
121 case 0x0308:
122 avctx->pix_fmt = PIX_FMT_RGB24;
123 break;
124 case 0x0108:
125 case 0x0104:
126 case 0x0102:
127 case 0x0101:
128 case 0x0401:
129 case 0x0301:
130 case 0x0201:
131 avctx->pix_fmt = PIX_FMT_PAL8;
132 break;
133 default:
134 av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
135 return -1;
136 }
137
138 buf += 128;
139
140 if (p->data[0])
141 avctx->release_buffer(avctx, p);
142
143 if (avcodec_check_dimensions(avctx, w, h))
144 return -1;
145 if (w != avctx->width || h != avctx->height)
146 avcodec_set_dimensions(avctx, w, h);
147 if (avctx->get_buffer(avctx, p) < 0) {
148 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
149 return -1;
150 }
151
152 p->pict_type = FF_I_TYPE;
153
154 ptr = p->data[0];
155 stride = p->linesize[0];
156
157 if (nplanes == 3 && bits_per_pixel == 8) {
158 uint8_t scanline[bytes_per_scanline];
159
160 for (y=0; y<h; y++) {
161 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
162
163 for (x=0; x<w; x++) {
164 ptr[3*x ] = scanline[x ];
165 ptr[3*x+1] = scanline[x+ bytes_per_line ];
166 ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
167 }
168
169 ptr += stride;
170 }
171
172 } else if (nplanes == 1 && bits_per_pixel == 8) {
173 uint8_t scanline[bytes_per_scanline];
174 const uint8_t *palstart = bufstart + buf_size - 769;
175
176 for (y=0; y<h; y++, ptr+=stride) {
177 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
178 memcpy(ptr, scanline, w);
179 }
180
181 if (buf != palstart) {
182 av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
183 buf = palstart;
184 }
185 if (*buf++ != 12) {
186 av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
187 return -1;
188 }
189
190 } else if (nplanes == 1) { /* all packed formats, max. 16 colors */
191 uint8_t scanline[bytes_per_scanline];
192 GetBitContext s;
193
194 for (y=0; y<h; y++) {
195 init_get_bits(&s, scanline, bytes_per_scanline<<3);
196
197 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
198
199 for (x=0; x<w; x++)
200 ptr[x] = get_bits(&s, bits_per_pixel);
201 ptr += stride;
202 }
203
204 } else { /* planar, 4, 8 or 16 colors */
205 uint8_t scanline[bytes_per_scanline];
206 int i;
207
208 for (y=0; y<h; y++) {
209 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed);
210
211 for (x=0; x<w; x++) {
212 int m = 0x80 >> (x&7), v = 0;
213 for (i=nplanes - 1; i>=0; i--) {
214 v <<= 1;
215 v += !!(scanline[i*bytes_per_line + (x>>3)] & m);
216 }
217 ptr[x] = v;
218 }
219 ptr += stride;
220 }
221 }
222
223 if (nplanes == 1 && bits_per_pixel == 8) {
224 pcx_palette(&buf, (uint32_t *) p->data[1], 256);
225 } else if (bits_per_pixel < 8) {
226 const uint8_t *palette = bufstart+16;
227 pcx_palette(&palette, (uint32_t *) p->data[1], 16);
228 }
229
230 *picture = s->picture;
231 *data_size = sizeof(AVFrame);
232
233 return buf - bufstart;
234 }
235
236 static av_cold int pcx_end(AVCodecContext *avctx) {
237 PCXContext *s = avctx->priv_data;
238
239 if(s->picture.data[0])
240 avctx->release_buffer(avctx, &s->picture);
241
242 return 0;
243 }
244
245 AVCodec pcx_decoder = {
246 "pcx",
247 AVMEDIA_TYPE_VIDEO,
248 CODEC_ID_PCX,
249 sizeof(PCXContext),
250 pcx_init,
251 NULL,
252 pcx_end,
253 pcx_decode_frame,
254 CODEC_CAP_DR1,
255 NULL,
256 .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
257 };