xref: /third_party/ffmpeg/libavcodec/xbmenc.c (revision cabdff1a)
1/*
2 * XBM image format
3 *
4 * Copyright (c) 2012 Paul B Mahol
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "libavutil/reverse.h"
24#include "avcodec.h"
25#include "codec_internal.h"
26#include "encode.h"
27#include "mathops.h"
28
29#define ANSI_MIN_READLINE 509
30
31static int xbm_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
32                            const AVFrame *p, int *got_packet)
33{
34    int i, j, l, commas, ret, size, linesize, lineout, rowsout;
35    uint8_t *ptr, *buf;
36
37    linesize = lineout = (avctx->width + 7) / 8;
38    commas   = avctx->height * linesize;
39
40    /* ANSI worst case minimum readline is 509 chars. */
41    rowsout  = avctx->height;
42    if (lineout > (ANSI_MIN_READLINE / 6)) {
43        lineout = ANSI_MIN_READLINE / 6;
44        rowsout = (commas + lineout - 1) / lineout;
45    }
46
47    size     = rowsout * (lineout * 6 + 1) + 106;
48    if ((ret = ff_alloc_packet(avctx, pkt, size)) < 0)
49        return ret;
50
51    buf = pkt->data;
52    ptr = p->data[0];
53
54    buf += snprintf(buf, 32, "#define image_width %u\n", avctx->width);
55    buf += snprintf(buf, 33, "#define image_height %u\n", avctx->height);
56    buf += snprintf(buf, 39, "static unsigned char image_bits[] = {\n");
57    for (i = 0, l = lineout; i < avctx->height; i++) {
58        for (j = 0; j < linesize; j++) {
59            buf += snprintf(buf, 6, " 0x%02X", ff_reverse[*ptr++]);
60            if (--commas <= 0) {
61                buf += snprintf(buf, 2, "\n");
62                break;
63            }
64            buf += snprintf(buf, 2, ",");
65            if (--l <= 0) {
66                buf += snprintf(buf, 2, "\n");
67                l = lineout;
68            }
69        }
70        ptr += p->linesize[0] - linesize;
71    }
72    buf += snprintf(buf, 5, " };\n");
73
74    pkt->size   = buf - pkt->data;
75    *got_packet = 1;
76    return 0;
77}
78
79const FFCodec ff_xbm_encoder = {
80    .p.name       = "xbm",
81    .p.long_name  = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
82    .p.type       = AVMEDIA_TYPE_VIDEO,
83    .p.id         = AV_CODEC_ID_XBM,
84    FF_CODEC_ENCODE_CB(xbm_encode_frame),
85    .p.pix_fmts   = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE,
86                                                   AV_PIX_FMT_NONE },
87};
88