1/*
2 * Pictor/PC Paint decoder
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * Pictor/PC Paint decoder
25 */
26
27#include "libavutil/imgutils.h"
28#include "avcodec.h"
29#include "bytestream.h"
30#include "cga_data.h"
31
32typedef struct PicContext {
33    AVFrame frame;
34    int width, height;
35    int nb_planes;
36    GetByteContext g;
37} PicContext;
38
39static void picmemset_8bpp(PicContext *s, int value, int run, int *x, int *y)
40{
41    while (run > 0) {
42        uint8_t *d = s->frame.data[0] + *y * s->frame.linesize[0];
43        if (*x + run >= s->width) {
44            int n = s->width - *x;
45            memset(d + *x, value, n);
46            run -= n;
47            *x = 0;
48            *y -= 1;
49            if (*y < 0)
50                break;
51        } else {
52            memset(d + *x, value, run);
53            *x += run;
54            break;
55        }
56    }
57}
58
59static void picmemset(PicContext *s, int value, int run,
60                      int *x, int *y, int *plane, int bits_per_plane)
61{
62    uint8_t *d;
63    int shift = *plane * bits_per_plane;
64    int mask  = ((1 << bits_per_plane) - 1) << shift;
65    value   <<= shift;
66
67    while (run > 0) {
68        int j;
69        for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) {
70            d = s->frame.data[0] + *y * s->frame.linesize[0];
71            d[*x] |= (value >> j) & mask;
72            *x += 1;
73            if (*x == s->width) {
74                *y -= 1;
75                *x = 0;
76                if (*y < 0) {
77                   *y = s->height - 1;
78                   *plane += 1;
79                   value <<= bits_per_plane;
80                   mask  <<= bits_per_plane;
81                   if (*plane >= s->nb_planes)
82                       break;
83                }
84            }
85        }
86        run--;
87    }
88}
89
90static const uint8_t cga_mode45_index[6][4] = {
91    [0] = { 0, 3,  5,   7 }, // mode4, palette#1, low intensity
92    [1] = { 0, 2,  4,   6 }, // mode4, palette#2, low intensity
93    [2] = { 0, 3,  4,   7 }, // mode5, low intensity
94    [3] = { 0, 11, 13, 15 }, // mode4, palette#1, high intensity
95    [4] = { 0, 10, 12, 14 }, // mode4, palette#2, high intensity
96    [5] = { 0, 11, 12, 15 }, // mode5, high intensity
97};
98
99static int decode_frame(AVCodecContext *avctx,
100                        void *data, int *data_size,
101                        AVPacket *avpkt)
102{
103    PicContext *s = avctx->priv_data;
104    uint32_t *palette;
105    int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
106    int i, x, y, plane, tmp;
107
108    bytestream2_init(&s->g, avpkt->data, avpkt->size);
109
110    if (bytestream2_get_bytes_left(&s->g) < 11)
111        return AVERROR_INVALIDDATA;
112
113    if (bytestream2_get_le16u(&s->g) != 0x1234)
114        return AVERROR_INVALIDDATA;
115
116    s->width       = bytestream2_get_le16u(&s->g);
117    s->height      = bytestream2_get_le16u(&s->g);
118    bytestream2_skip(&s->g, 4);
119    tmp            = bytestream2_get_byteu(&s->g);
120    bits_per_plane = tmp & 0xF;
121    s->nb_planes   = (tmp >> 4) + 1;
122    bpp            = bits_per_plane * s->nb_planes;
123    if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
124        av_log_ask_for_sample(s, "unsupported bit depth\n");
125        return AVERROR_INVALIDDATA;
126    }
127
128    if (bytestream2_peek_byte(&s->g) == 0xFF) {
129        bytestream2_skip(&s->g, 2);
130        etype = bytestream2_get_le16(&s->g);
131        esize = bytestream2_get_le16(&s->g);
132        if (bytestream2_get_bytes_left(&s->g) < esize)
133            return AVERROR_INVALIDDATA;
134    } else {
135        etype = -1;
136        esize = 0;
137    }
138
139    avctx->pix_fmt = PIX_FMT_PAL8;
140
141    if (s->width != avctx->width && s->height != avctx->height) {
142        if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
143            return -1;
144        avcodec_set_dimensions(avctx, s->width, s->height);
145        if (s->frame.data[0])
146            avctx->release_buffer(avctx, &s->frame);
147    }
148
149    if (avctx->get_buffer(avctx, &s->frame) < 0){
150        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
151        return -1;
152    }
153    memset(s->frame.data[0], 0, s->height * s->frame.linesize[0]);
154    s->frame.pict_type           = AV_PICTURE_TYPE_I;
155    s->frame.palette_has_changed = 1;
156
157    pos_after_pal = bytestream2_tell(&s->g) + esize;
158    palette = (uint32_t*)s->frame.data[1];
159    if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
160        int idx = bytestream2_get_byte(&s->g);
161        npal = 4;
162        for (i = 0; i < npal; i++)
163            palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
164    } else if (etype == 2) {
165        npal = FFMIN(esize, 16);
166        for (i = 0; i < npal; i++) {
167            int pal_idx = bytestream2_get_byte(&s->g);
168            palette[i]  = ff_cga_palette[FFMIN(pal_idx, 16)];
169        }
170    } else if (etype == 3) {
171        npal = FFMIN(esize, 16);
172        for (i = 0; i < npal; i++) {
173            int pal_idx = bytestream2_get_byte(&s->g);
174            palette[i]  = ff_ega_palette[FFMIN(pal_idx, 63)];
175        }
176    } else if (etype == 4 || etype == 5) {
177        npal = FFMIN(esize / 3, 256);
178        for (i = 0; i < npal; i++)
179            palette[i] = bytestream2_get_be24(&s->g) << 2;
180    } else {
181        if (bpp == 1) {
182            npal = 2;
183            palette[0] = 0x000000;
184            palette[1] = 0xFFFFFF;
185        } else if (bpp == 2) {
186            npal = 4;
187            for (i = 0; i < npal; i++)
188                palette[i] = ff_cga_palette[ cga_mode45_index[0][i] ];
189        } else {
190            npal = 16;
191            memcpy(palette, ff_cga_palette, npal * 4);
192        }
193    }
194    // fill remaining palette entries
195    memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
196    // skip remaining palette bytes
197    bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
198
199    x = 0;
200    y = s->height - 1;
201    plane = 0;
202    if (bytestream2_get_le16(&s->g)) {
203        while (bytestream2_get_bytes_left(&s->g) >= 6) {
204            int stop_size, marker, t1, t2;
205
206            t1        = bytestream2_get_bytes_left(&s->g);
207            t2        = bytestream2_get_le16(&s->g);
208            stop_size = t1 - FFMIN(t1, t2);
209            // ignore uncompressed block size
210            bytestream2_skip(&s->g, 2);
211            marker    = bytestream2_get_byte(&s->g);
212
213            while (plane < s->nb_planes &&
214                   bytestream2_get_bytes_left(&s->g) > stop_size) {
215                int run = 1;
216                int val = bytestream2_get_byte(&s->g);
217                if (val == marker) {
218                    run = bytestream2_get_byte(&s->g);
219                    if (run == 0)
220                        run = bytestream2_get_le16(&s->g);
221                    val = bytestream2_get_byte(&s->g);
222                }
223                if (!bytestream2_get_bytes_left(&s->g))
224                    break;
225
226                if (bits_per_plane == 8) {
227                    picmemset_8bpp(s, val, run, &x, &y);
228                    if (y < 0)
229                        break;
230                } else {
231                    picmemset(s, val, run, &x, &y, &plane, bits_per_plane);
232                }
233            }
234        }
235    } else {
236        av_log_ask_for_sample(s, "uncompressed image\n");
237        return avpkt->size;
238    }
239
240    *data_size = sizeof(AVFrame);
241    *(AVFrame*)data = s->frame;
242    return avpkt->size;
243}
244
245static av_cold int decode_end(AVCodecContext *avctx)
246{
247    PicContext *s = avctx->priv_data;
248    if (s->frame.data[0])
249        avctx->release_buffer(avctx, &s->frame);
250    return 0;
251}
252
253AVCodec ff_pictor_decoder = {
254    .name           = "pictor",
255    .type           = AVMEDIA_TYPE_VIDEO,
256    .id             = CODEC_ID_PICTOR,
257    .priv_data_size = sizeof(PicContext),
258    .close          = decode_end,
259    .decode         = decode_frame,
260    .capabilities   = CODEC_CAP_DR1,
261    .long_name = NULL_IF_CONFIG_SMALL("Pictor/PC Paint"),
262};
263