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
31static void pcx_rle_decode(GetByteContext *gb,
32                           uint8_t *dst,
33                           unsigned int bytes_per_scanline,
34                           int compressed)
35{
36    unsigned int i = 0;
37    unsigned char run, value;
38
39    if (compressed) {
40        while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
41            run   = 1;
42            value = bytestream2_get_byte(gb);
43            if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
44                run   = value & 0x3f;
45                value = bytestream2_get_byte(gb);
46            }
47            while (i < bytes_per_scanline && run--)
48                dst[i++] = value;
49        }
50    } else {
51        bytestream2_get_buffer(gb, dst, bytes_per_scanline);
52    }
53}
54
55static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
56{
57    int i;
58
59    pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
60    for (i = 0; i < pallen; i++)
61        *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
62    if (pallen < 256)
63        memset(dst, 0, (256 - pallen) * sizeof(*dst));
64}
65
66static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
67                            AVPacket *avpkt)
68{
69    GetByteContext gb;
70    AVFrame * const p  = data;
71    int compressed, xmin, ymin, xmax, ymax;
72    int ret;
73    unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
74                 bytes_per_scanline;
75    uint8_t *ptr, *scanline;
76
77    if (avpkt->size < 128)
78        return AVERROR_INVALIDDATA;
79
80    bytestream2_init(&gb, avpkt->data, avpkt->size);
81
82    if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
83        av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
84        return AVERROR_INVALIDDATA;
85    }
86
87    compressed                     = bytestream2_get_byteu(&gb);
88    bits_per_pixel                 = bytestream2_get_byteu(&gb);
89    xmin                           = bytestream2_get_le16u(&gb);
90    ymin                           = bytestream2_get_le16u(&gb);
91    xmax                           = bytestream2_get_le16u(&gb);
92    ymax                           = bytestream2_get_le16u(&gb);
93    avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
94    avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
95
96    if (xmax < xmin || ymax < ymin) {
97        av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
98        return AVERROR_INVALIDDATA;
99    }
100
101    w = xmax - xmin + 1;
102    h = ymax - ymin + 1;
103
104    bytestream2_skipu(&gb, 49);
105    nplanes            = bytestream2_get_byteu(&gb);
106    bytes_per_line     = bytestream2_get_le16u(&gb);
107    bytes_per_scanline = nplanes * bytes_per_line;
108
109    if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
110        (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
111        av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
112        return AVERROR_INVALIDDATA;
113    }
114
115    switch ((nplanes << 8) + bits_per_pixel) {
116    case 0x0308:
117        avctx->pix_fmt = AV_PIX_FMT_RGB24;
118        break;
119    case 0x0108:
120    case 0x0104:
121    case 0x0102:
122    case 0x0101:
123    case 0x0401:
124    case 0x0301:
125    case 0x0201:
126        avctx->pix_fmt = AV_PIX_FMT_PAL8;
127        break;
128    default:
129        av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
130        return AVERROR_INVALIDDATA;
131    }
132
133    bytestream2_skipu(&gb, 60);
134
135    if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
136        return ret;
137
138    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
139        return ret;
140
141    p->pict_type = AV_PICTURE_TYPE_I;
142
143    ptr    = p->data[0];
144    stride = p->linesize[0];
145
146    scanline = av_malloc(bytes_per_scanline + FF_INPUT_BUFFER_PADDING_SIZE);
147    if (!scanline)
148        return AVERROR(ENOMEM);
149
150    if (nplanes == 3 && bits_per_pixel == 8) {
151        for (y = 0; y < h; y++) {
152            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
153
154            for (x = 0; x < w; x++) {
155                ptr[3 * x]     = scanline[x];
156                ptr[3 * x + 1] = scanline[x + bytes_per_line];
157                ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];
158            }
159
160            ptr += stride;
161        }
162    } else if (nplanes == 1 && bits_per_pixel == 8) {
163        int palstart = avpkt->size - 769;
164
165        if (avpkt->size < 769) {
166            av_log(avctx, AV_LOG_ERROR, "File is too short\n");
167            ret = avctx->err_recognition & AV_EF_EXPLODE ?
168                  AVERROR_INVALIDDATA : avpkt->size;
169            goto end;
170        }
171
172        for (y = 0; y < h; y++, ptr += stride) {
173            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
174            memcpy(ptr, scanline, w);
175        }
176
177        if (bytestream2_tell(&gb) != palstart) {
178            av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
179            bytestream2_seek(&gb, palstart, SEEK_SET);
180        }
181        if (bytestream2_get_byte(&gb) != 12) {
182            av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
183            ret = avctx->err_recognition & AV_EF_EXPLODE ?
184                  AVERROR_INVALIDDATA : avpkt->size;
185            goto end;
186        }
187    } else if (nplanes == 1) {   /* all packed formats, max. 16 colors */
188        GetBitContext s;
189
190        for (y = 0; y < h; y++) {
191            init_get_bits8(&s, scanline, bytes_per_scanline);
192
193            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
194
195            for (x = 0; x < w; x++)
196                ptr[x] = get_bits(&s, bits_per_pixel);
197            ptr += stride;
198        }
199    } else {    /* planar, 4, 8 or 16 colors */
200        int i;
201
202        for (y = 0; y < h; y++) {
203            pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
204
205            for (x = 0; x < w; x++) {
206                int m = 0x80 >> (x & 7), v = 0;
207                for (i = nplanes - 1; i >= 0; i--) {
208                    v <<= 1;
209                    v  += !!(scanline[i * bytes_per_line + (x >> 3)] & m);
210                }
211                ptr[x] = v;
212            }
213            ptr += stride;
214        }
215    }
216
217    ret = bytestream2_tell(&gb);
218    if (nplanes == 1 && bits_per_pixel == 8) {
219        pcx_palette(&gb, (uint32_t *)p->data[1], 256);
220        ret += 256 * 3;
221    } else if (bits_per_pixel * nplanes == 1) {
222        AV_WN32A(p->data[1]  , 0xFF000000);
223        AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
224    } else if (bits_per_pixel < 8) {
225        bytestream2_seek(&gb, 16, SEEK_SET);
226        pcx_palette(&gb, (uint32_t *)p->data[1], 16);
227    }
228
229    *got_frame = 1;
230
231end:
232    av_free(scanline);
233    return ret;
234}
235
236AVCodec ff_pcx_decoder = {
237    .name         = "pcx",
238    .long_name    = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
239    .type         = AVMEDIA_TYPE_VIDEO,
240    .id           = AV_CODEC_ID_PCX,
241    .decode       = pcx_decode_frame,
242    .capabilities = CODEC_CAP_DR1,
243};
244