1/*
2 * PC Paintbrush PCX (.pcx) image encoder
3 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * PCX image encoder
24 * @file
25 * @author Daniel Verkamp
26 * @sa http://www.qzx.com/pc-gpe/pcx.txt
27 */
28
29#include "avcodec.h"
30#include "bytestream.h"
31
32typedef struct PCXContext {
33    AVFrame picture;
34} PCXContext;
35
36static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
37
38static av_cold int pcx_encode_init(AVCodecContext *avctx)
39{
40    PCXContext *s = avctx->priv_data;
41
42    avcodec_get_frame_defaults(&s->picture);
43    avctx->coded_frame = &s->picture;
44
45    return 0;
46}
47
48/**
49 * PCX run-length encoder
50 * @param dst output buffer
51 * @param dst_size size of output buffer
52 * @param src input buffer
53 * @param src_plane_size size of one plane of input buffer in bytes
54 * @param nplanes number of planes in input buffer
55 * @return number of bytes written to dst or -1 on error
56 * @bug will not work for nplanes != 1 && bpp != 8
57 */
58static int pcx_rle_encode(      uint8_t *dst, int dst_size,
59                          const uint8_t *src, int src_plane_size, int nplanes)
60{
61    int p;
62    const uint8_t *dst_start = dst;
63
64    // check worst-case upper bound on dst_size
65    if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
66        return -1;
67
68    for (p = 0; p < nplanes; p++) {
69        int count = 1;
70        const uint8_t *src_plane = src + p;
71        const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
72        uint8_t prev = *src_plane;
73        src_plane += nplanes;
74
75        for (; ; src_plane += nplanes) {
76            if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
77                // current byte is same as prev
78                ++count;
79            } else {
80                // output prev * count
81                if (count != 1 || prev >= 0xC0)
82                    *dst++ = 0xC0 | count;
83                *dst++ = prev;
84
85                if (src_plane == src_plane_end)
86                    break;
87
88                // start new run
89                count = 1;
90                prev = *src_plane;
91            }
92        }
93    }
94
95    return dst - dst_start;
96}
97
98static int pcx_encode_frame(AVCodecContext *avctx,
99                            unsigned char *buf, int buf_size, void *data)
100{
101    PCXContext *s = avctx->priv_data;
102    AVFrame *const pict = &s->picture;
103    const uint8_t *buf_start = buf;
104    const uint8_t *buf_end   = buf + buf_size;
105
106    int bpp, nplanes, i, y, line_bytes, written;
107    const uint32_t *pal = NULL;
108    const uint8_t *src;
109
110    *pict = *(AVFrame *)data;
111    pict->pict_type = FF_I_TYPE;
112    pict->key_frame = 1;
113
114    if (avctx->width > 65535 || avctx->height > 65535) {
115        av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
116        return -1;
117    }
118
119    switch (avctx->pix_fmt) {
120    case PIX_FMT_RGB24:
121        bpp = 8;
122        nplanes = 3;
123        break;
124    case PIX_FMT_RGB8:
125    case PIX_FMT_BGR8:
126    case PIX_FMT_RGB4_BYTE:
127    case PIX_FMT_BGR4_BYTE:
128    case PIX_FMT_GRAY8:
129    case PIX_FMT_PAL8:
130        bpp = 8;
131        nplanes = 1;
132        pal = (uint32_t *)pict->data[1];
133        break;
134    case PIX_FMT_MONOBLACK:
135        bpp = 1;
136        nplanes = 1;
137        pal = monoblack_pal;
138        break;
139    default:
140        av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
141        return -1;
142    }
143
144    line_bytes = (avctx->width * bpp + 7) >> 3;
145    line_bytes = (line_bytes + 1) & ~1;
146
147    bytestream_put_byte(&buf, 10);                  // manufacturer
148    bytestream_put_byte(&buf, 5);                   // version
149    bytestream_put_byte(&buf, 1);                   // encoding
150    bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
151    bytestream_put_le16(&buf, 0);                   // x min
152    bytestream_put_le16(&buf, 0);                   // y min
153    bytestream_put_le16(&buf, avctx->width - 1);    // x max
154    bytestream_put_le16(&buf, avctx->height - 1);   // y max
155    bytestream_put_le16(&buf, 0);                   // horizontal DPI
156    bytestream_put_le16(&buf, 0);                   // vertical DPI
157    for (i = 0; i < 16; i++)
158        bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
159    bytestream_put_byte(&buf, 0);                   // reserved
160    bytestream_put_byte(&buf, nplanes);             // number of planes
161    bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
162
163    while (buf - buf_start < 128)
164        *buf++= 0;
165
166    src = pict->data[0];
167
168    for (y = 0; y < avctx->height; y++) {
169        if ((written = pcx_rle_encode(buf, buf_end - buf,
170                                      src, line_bytes, nplanes)) < 0) {
171            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
172            return -1;
173        }
174        buf += written;
175        src += pict->linesize[0];
176    }
177
178    if (nplanes == 1 && bpp == 8) {
179        if (buf_end - buf < 257) {
180            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
181            return -1;
182        }
183        bytestream_put_byte(&buf, 12);
184        for (i = 0; i < 256; i++) {
185            bytestream_put_be24(&buf, pal[i]);
186        }
187    }
188
189    return buf - buf_start;
190}
191
192AVCodec pcx_encoder = {
193    "pcx",
194    AVMEDIA_TYPE_VIDEO,
195    CODEC_ID_PCX,
196    sizeof(PCXContext),
197    pcx_encode_init,
198    pcx_encode_frame,
199    NULL,
200    .pix_fmts = (const enum PixelFormat[]){
201        PIX_FMT_RGB24,
202        PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
203        PIX_FMT_MONOBLACK,
204        PIX_FMT_NONE},
205    .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
206};
207