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 * @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#include "libavutil/imgutils.h"
32#include "internal.h"
33
34static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
35
36static av_cold int pcx_encode_init(AVCodecContext *avctx)
37{
38    avctx->coded_frame = av_frame_alloc();
39    if (!avctx->coded_frame)
40        return AVERROR(ENOMEM);
41
42    avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
43    avctx->coded_frame->key_frame = 1;
44
45    return 0;
46}
47
48static av_cold int pcx_encode_close(AVCodecContext *avctx)
49{
50    av_frame_free(&avctx->coded_frame);
51    return 0;
52}
53
54/**
55 * PCX run-length encoder
56 * @param dst output buffer
57 * @param dst_size size of output buffer
58 * @param src input buffer
59 * @param src_plane_size size of one plane of input buffer in bytes
60 * @param nplanes number of planes in input buffer
61 * @return number of bytes written to dst or -1 on error
62 * @bug will not work for nplanes != 1 && bpp != 8
63 */
64static int pcx_rle_encode(      uint8_t *dst, int dst_size,
65                          const uint8_t *src, int src_plane_size, int nplanes)
66{
67    int p;
68    const uint8_t *dst_start = dst;
69
70    // check worst-case upper bound on dst_size
71    if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
72        return -1;
73
74    for (p = 0; p < nplanes; p++) {
75        int count = 1;
76        const uint8_t *src_plane = src + p;
77        const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
78        uint8_t prev = *src_plane;
79        src_plane += nplanes;
80
81        for (; ; src_plane += nplanes) {
82            if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
83                // current byte is same as prev
84                ++count;
85            } else {
86                // output prev * count
87                if (count != 1 || prev >= 0xC0)
88                    *dst++ = 0xC0 | count;
89                *dst++ = prev;
90
91                if (src_plane == src_plane_end)
92                    break;
93
94                // start new run
95                count = 1;
96                prev = *src_plane;
97            }
98        }
99    }
100
101    return dst - dst_start;
102}
103
104static int pcx_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
105                            const AVFrame *frame, int *got_packet)
106{
107    const uint8_t *buf_end;
108    uint8_t *buf;
109
110    int bpp, nplanes, i, y, line_bytes, written, ret, max_pkt_size, sw, sh;
111    const uint32_t *pal = NULL;
112    uint32_t palette256[256];
113    const uint8_t *src;
114
115    if (avctx->width > 65535 || avctx->height > 65535) {
116        av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
117        return -1;
118    }
119
120    switch (avctx->pix_fmt) {
121    case AV_PIX_FMT_RGB24:
122        bpp = 8;
123        nplanes = 3;
124        break;
125    case AV_PIX_FMT_RGB8:
126    case AV_PIX_FMT_BGR8:
127    case AV_PIX_FMT_RGB4_BYTE:
128    case AV_PIX_FMT_BGR4_BYTE:
129    case AV_PIX_FMT_GRAY8:
130        bpp = 8;
131        nplanes = 1;
132        avpriv_set_systematic_pal2(palette256, avctx->pix_fmt);
133        pal = palette256;
134        break;
135    case AV_PIX_FMT_PAL8:
136        bpp = 8;
137        nplanes = 1;
138        pal = (uint32_t *)frame->data[1];
139        break;
140    case AV_PIX_FMT_MONOBLACK:
141        bpp = 1;
142        nplanes = 1;
143        pal = monoblack_pal;
144        break;
145    default:
146        av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
147        return -1;
148    }
149
150    line_bytes = (avctx->width * bpp + 7) >> 3;
151    line_bytes = (line_bytes + 1) & ~1;
152
153    max_pkt_size = 128 + avctx->height * 2 * line_bytes * nplanes + (pal ? 256*3 + 1 : 0);
154    if ((ret = ff_alloc_packet2(avctx, pkt, max_pkt_size)) < 0)
155        return ret;
156    buf     = pkt->data;
157    buf_end = pkt->data + pkt->size;
158
159    sw = avctx->sample_aspect_ratio.num;
160    sh = avctx->sample_aspect_ratio.den;
161    if (sw > 0xFFFFu || sh > 0xFFFFu)
162        av_reduce(&sw, &sh, sw, sh, 0xFFFFu);
163
164    bytestream_put_byte(&buf, 10);                  // manufacturer
165    bytestream_put_byte(&buf, 5);                   // version
166    bytestream_put_byte(&buf, 1);                   // encoding
167    bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
168    bytestream_put_le16(&buf, 0);                   // x min
169    bytestream_put_le16(&buf, 0);                   // y min
170    bytestream_put_le16(&buf, avctx->width - 1);    // x max
171    bytestream_put_le16(&buf, avctx->height - 1);   // y max
172    bytestream_put_le16(&buf, sw);                  // horizontal DPI
173    bytestream_put_le16(&buf, sh);                  // vertical DPI
174    for (i = 0; i < 16; i++)
175        bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
176    bytestream_put_byte(&buf, 0);                   // reserved
177    bytestream_put_byte(&buf, nplanes);             // number of planes
178    bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
179
180    while (buf - pkt->data < 128)
181        *buf++= 0;
182
183    src = frame->data[0];
184
185    for (y = 0; y < avctx->height; y++) {
186        if ((written = pcx_rle_encode(buf, buf_end - buf,
187                                      src, line_bytes, nplanes)) < 0) {
188            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
189            return -1;
190        }
191        buf += written;
192        src += frame->linesize[0];
193    }
194
195    if (nplanes == 1 && bpp == 8) {
196        if (buf_end - buf < 257) {
197            av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
198            return -1;
199        }
200        bytestream_put_byte(&buf, 12);
201        for (i = 0; i < 256; i++) {
202            bytestream_put_be24(&buf, pal[i]);
203        }
204    }
205
206    pkt->size   = buf - pkt->data;
207    pkt->flags |= AV_PKT_FLAG_KEY;
208    *got_packet = 1;
209
210    return 0;
211}
212
213AVCodec ff_pcx_encoder = {
214    .name           = "pcx",
215    .long_name      = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
216    .type           = AVMEDIA_TYPE_VIDEO,
217    .id             = AV_CODEC_ID_PCX,
218    .init           = pcx_encode_init,
219    .close          = pcx_encode_close,
220    .encode2        = pcx_encode_frame,
221    .pix_fmts       = (const enum AVPixelFormat[]){
222        AV_PIX_FMT_RGB24,
223        AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
224        AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8,
225        AV_PIX_FMT_MONOBLACK,
226        AV_PIX_FMT_NONE
227    },
228};
229