6d17987d03fe0d208e5b27e2f739ad09e2f14d28
[libav.git] / libavcodec / pcxenc.c
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 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 * PCX image encoder
25 * @author Daniel Verkamp
26 * @see http://www.qzx.com/pc-gpe/pcx.txt
27 */
28
29 #include "avcodec.h"
30 #include "bytestream.h"
31
32 typedef struct PCXContext {
33 AVFrame picture;
34 } PCXContext;
35
36 static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
37
38 static 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 */
58 static 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
98 static 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 = AV_PICTURE_TYPE_I;
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
192 AVCodec ff_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 };