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
29typedef struct PCXContext {
30    AVFrame picture;
31} PCXContext;
32
33static 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 */
45static 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
69static 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
78static 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
236static 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
245AVCodec 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};
258