Statistics
| Branch: | Revision:

ffmpeg / libavcodec / pcx.c @ 9106a698

History | View | Annotate | Download (6.89 KB)

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) {
47
    unsigned int i = 0;
48
    unsigned char run, value;
49

    
50
    while (i<bytes_per_scanline) {
51
        run = 1;
52
        value = *src++;
53
        if (value >= 0xc0) {
54
            run = value & 0x3f;
55
            value = *src++;
56
        }
57
        while (i<bytes_per_scanline && run--)
58
            dst[i++] = value;
59
    }
60

    
61
    return src;
62
}
63

    
64
static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
65
    unsigned int i;
66

    
67
    for (i=0; i<pallen; i++)
68
        *dst++ = bytestream_get_be24(src);
69
    memset(dst, 0, (256 - pallen) * sizeof(*dst));
70
}
71

    
72
static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
73
                            AVPacket *avpkt) {
74
    const uint8_t *buf = avpkt->data;
75
    int buf_size = avpkt->size;
76
    PCXContext * const s = avctx->priv_data;
77
    AVFrame *picture = data;
78
    AVFrame * const p = &s->picture;
79
    int xmin, ymin, xmax, ymax;
80
    unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
81
                 bytes_per_scanline;
82
    uint8_t *ptr;
83
    uint8_t const *bufstart = buf;
84

    
85
    if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) {
86
        av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
87
        return -1;
88
    }
89

    
90
    xmin = AV_RL16(buf+ 4);
91
    ymin = AV_RL16(buf+ 6);
92
    xmax = AV_RL16(buf+ 8);
93
    ymax = AV_RL16(buf+10);
94

    
95
    if (xmax < xmin || ymax < ymin) {
96
        av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
97
        return -1;
98
    }
99

    
100
    w = xmax - xmin + 1;
101
    h = ymax - ymin + 1;
102

    
103
    bits_per_pixel     = buf[3];
104
    bytes_per_line     = AV_RL16(buf+66);
105
    nplanes            = buf[65];
106
    bytes_per_scanline = nplanes * bytes_per_line;
107

    
108
    if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
109
        av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
110
        return -1;
111
    }
112

    
113
    switch ((nplanes<<8) + bits_per_pixel) {
114
        case 0x0308:
115
            avctx->pix_fmt = PIX_FMT_RGB24;
116
            break;
117
        case 0x0108:
118
        case 0x0104:
119
        case 0x0102:
120
        case 0x0101:
121
        case 0x0401:
122
        case 0x0301:
123
        case 0x0201:
124
            avctx->pix_fmt = PIX_FMT_PAL8;
125
            break;
126
        default:
127
            av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
128
            return -1;
129
    }
130

    
131
    buf += 128;
132

    
133
    if (p->data[0])
134
        avctx->release_buffer(avctx, p);
135

    
136
    if (avcodec_check_dimensions(avctx, w, h))
137
        return -1;
138
    if (w != avctx->width || h != avctx->height)
139
        avcodec_set_dimensions(avctx, w, h);
140
    if (avctx->get_buffer(avctx, p) < 0) {
141
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
142
        return -1;
143
    }
144

    
145
    p->pict_type = FF_I_TYPE;
146

    
147
    ptr    = p->data[0];
148
    stride = p->linesize[0];
149

    
150
    if (nplanes == 3 && bits_per_pixel == 8) {
151
        uint8_t scanline[bytes_per_scanline];
152

    
153
        for (y=0; y<h; y++) {
154
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
155

    
156
            for (x=0; x<w; x++) {
157
                ptr[3*x  ] = scanline[x                    ];
158
                ptr[3*x+1] = scanline[x+ bytes_per_line    ];
159
                ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
160
            }
161

    
162
            ptr += stride;
163
        }
164

    
165
    } else if (nplanes == 1 && bits_per_pixel == 8) {
166
        uint8_t scanline[bytes_per_scanline];
167
        const uint8_t *palstart = bufstart + buf_size - 769;
168

    
169
        for (y=0; y<h; y++, ptr+=stride) {
170
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
171
            memcpy(ptr, scanline, w);
172
        }
173

    
174
        if (buf != palstart) {
175
            av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
176
            buf = palstart;
177
        }
178
        if (*buf++ != 12) {
179
            av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
180
            return -1;
181
        }
182

    
183
    } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
184
        uint8_t scanline[bytes_per_scanline];
185
        GetBitContext s;
186

    
187
        for (y=0; y<h; y++) {
188
            init_get_bits(&s, scanline, bytes_per_scanline<<3);
189

    
190
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
191

    
192
            for (x=0; x<w; x++)
193
                ptr[x] = get_bits(&s, bits_per_pixel);
194
            ptr += stride;
195
        }
196

    
197
    } else {    /* planar, 4, 8 or 16 colors */
198
        uint8_t scanline[bytes_per_scanline];
199
        int i;
200

    
201
        for (y=0; y<h; y++) {
202
            buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
203

    
204
            for (x=0; x<w; x++) {
205
                int m = 0x80 >> (x&7), v = 0;
206
                for (i=nplanes - 1; i>=0; i--) {
207
                    v <<= 1;
208
                    v  += !!(scanline[i*bytes_per_line + (x>>3)] & m);
209
                }
210
                ptr[x] = v;
211
            }
212
            ptr += stride;
213
        }
214
    }
215

    
216
    if (nplanes == 1 && bits_per_pixel == 8) {
217
        pcx_palette(&buf, (uint32_t *) p->data[1], 256);
218
    } else if (bits_per_pixel < 8) {
219
        const uint8_t *palette = bufstart+16;
220
        pcx_palette(&palette, (uint32_t *) p->data[1], 16);
221
    }
222

    
223
    *picture = s->picture;
224
    *data_size = sizeof(AVFrame);
225

    
226
    return buf - bufstart;
227
}
228

    
229
static av_cold int pcx_end(AVCodecContext *avctx) {
230
    PCXContext *s = avctx->priv_data;
231

    
232
    if(s->picture.data[0])
233
        avctx->release_buffer(avctx, &s->picture);
234

    
235
    return 0;
236
}
237

    
238
AVCodec pcx_decoder = {
239
    "pcx",
240
    CODEC_TYPE_VIDEO,
241
    CODEC_ID_PCX,
242
    sizeof(PCXContext),
243
    pcx_init,
244
    NULL,
245
    pcx_end,
246
    pcx_decode_frame,
247
    0,
248
    NULL,
249
    .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
250
};