xref: /third_party/ffmpeg/libavcodec/pcxenc.c (revision cabdff1a)
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://bespin.org/~qz/pc-gpe/pcx.txt
27 */
28
29#include "avcodec.h"
30#include "bytestream.h"
31#include "libavutil/imgutils.h"
32#include "codec_internal.h"
33#include "encode.h"
34
35static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
36
37/**
38 * PCX run-length encoder
39 * @param dst output buffer
40 * @param dst_size size of output buffer
41 * @param src input buffer
42 * @param src_plane_size size of one plane of input buffer in bytes
43 * @param nplanes number of planes in input buffer
44 * @return number of bytes written to dst or -1 on error
45 * @bug will not work for nplanes != 1 && bpp != 8
46 */
47static int pcx_rle_encode(      uint8_t *dst, int dst_size,
48                          const uint8_t *src, int src_plane_size, int nplanes)
49{
50    int p;
51    const uint8_t *dst_start = dst;
52
53    // check worst-case upper bound on dst_size
54    if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
55        return AVERROR(EINVAL);
56
57    for (p = 0; p < nplanes; p++) {
58        int count = 1;
59        const uint8_t *src_plane = src + p;
60        const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
61        uint8_t prev = *src_plane;
62        src_plane += nplanes;
63
64        for (; ; src_plane += nplanes) {
65            if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
66                // current byte is same as prev
67                ++count;
68            } else {
69                // output prev * count
70                if (count != 1 || prev >= 0xC0)
71                    *dst++ = 0xC0 | count;
72                *dst++ = prev;
73
74                if (src_plane == src_plane_end)
75                    break;
76
77                // start new run
78                count = 1;
79                prev = *src_plane;
80            }
81        }
82    }
83
84    return dst - dst_start;
85}
86
87static int pcx_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
88                            const AVFrame *frame, int *got_packet)
89{
90    const uint8_t *buf_end;
91    uint8_t *buf;
92
93    int bpp, nplanes, i, y, line_bytes, written, ret, max_pkt_size, sw, sh;
94    const uint32_t *pal = NULL;
95    uint32_t palette256[256];
96    const uint8_t *src;
97
98    if (avctx->width > 65535 || avctx->height > 65535) {
99        av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
100        return AVERROR(EINVAL);
101    }
102
103    switch (avctx->pix_fmt) {
104    case AV_PIX_FMT_RGB24:
105        bpp = 8;
106        nplanes = 3;
107        break;
108    case AV_PIX_FMT_RGB8:
109    case AV_PIX_FMT_BGR8:
110    case AV_PIX_FMT_RGB4_BYTE:
111    case AV_PIX_FMT_BGR4_BYTE:
112    case AV_PIX_FMT_GRAY8:
113        bpp = 8;
114        nplanes = 1;
115        avpriv_set_systematic_pal2(palette256, avctx->pix_fmt);
116        pal = palette256;
117        break;
118    case AV_PIX_FMT_PAL8:
119        bpp = 8;
120        nplanes = 1;
121        pal = (uint32_t *)frame->data[1];
122        break;
123    case AV_PIX_FMT_MONOBLACK:
124        bpp = 1;
125        nplanes = 1;
126        pal = monoblack_pal;
127        break;
128    default:
129        av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
130        return AVERROR(EINVAL);
131    }
132
133    line_bytes = (avctx->width * bpp + 7) >> 3;
134    line_bytes = (line_bytes + 1) & ~1;
135
136    max_pkt_size = 128 + avctx->height * 2 * line_bytes * nplanes + (pal ? 256*3 + 1 : 0);
137    if ((ret = ff_alloc_packet(avctx, pkt, max_pkt_size)) < 0)
138        return ret;
139    buf     = pkt->data;
140    buf_end = pkt->data + pkt->size;
141
142    sw = avctx->sample_aspect_ratio.num;
143    sh = avctx->sample_aspect_ratio.den;
144    if (sw > 0xFFFFu || sh > 0xFFFFu)
145        av_reduce(&sw, &sh, sw, sh, 0xFFFFu);
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, sw);                  // horizontal DPI
156    bytestream_put_le16(&buf, sh);                  // 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 - pkt->data < 128)
164        *buf++= 0;
165
166    src = frame->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 AVERROR_BUG;
173        }
174        buf += written;
175        src += frame->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 AVERROR_BUG;
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    pkt->size   = buf - pkt->data;
190    *got_packet = 1;
191
192    return 0;
193}
194
195const FFCodec ff_pcx_encoder = {
196    .p.name         = "pcx",
197    .p.long_name    = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
198    .p.type         = AVMEDIA_TYPE_VIDEO,
199    .p.id           = AV_CODEC_ID_PCX,
200    FF_CODEC_ENCODE_CB(pcx_encode_frame),
201    .p.pix_fmts     = (const enum AVPixelFormat[]){
202        AV_PIX_FMT_RGB24,
203        AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
204        AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8,
205        AV_PIX_FMT_MONOBLACK,
206        AV_PIX_FMT_NONE
207    },
208    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
209};
210