summaryrefslogtreecommitdiffstats
path: root/libavcodec/targaenc.c
blob: 007a79591cc43f0f206d2a55477db820ae2399fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * Targa (.tga) image encoder
 * Copyright (c) 2007 Bobby Bingham
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include "avcodec.h"
#include "rle.h"

/**
 * RLE compress the image, with maximum size of out_size
 * @param outbuf Output buffer
 * @param out_size Maximum output size
 * @param pic Image to compress
 * @param bpp Bytes per pixel
 * @param w Image width
 * @param h Image height
 * @return Size of output in bytes, or -1 if larger than out_size
 */
static int targa_encode_rle(uint8_t *outbuf, int out_size, AVFrame *pic,
                            int bpp, int w, int h)
{
    int y,ret;
    uint8_t *out;

    out = outbuf;

    for(y = 0; y < h; y ++) {
        ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
        if(ret == -1){
            return -1;
        }
        out+= ret;
        out_size -= ret;
    }

    return out - outbuf;
}

static int targa_encode_normal(uint8_t *outbuf, AVFrame *pic, int bpp, int w, int h)
{
    int i, n = bpp * w;
    uint8_t *out = outbuf;
    uint8_t *ptr = pic->data[0];

    for(i=0; i < h; i++) {
        memcpy(out, ptr, n);
        out += n;
        ptr += pic->linesize[0];
    }

    return out - outbuf;
}

static int targa_encode_frame(AVCodecContext *avctx,
                              unsigned char *outbuf,
                              int buf_size, void *data){
    AVFrame *p = data;
    int bpp, picsize, datasize;
    uint8_t *out;

    if(avctx->width > 0xffff || avctx->height > 0xffff) {
        av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
        return -1;
    }
    picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
    if(buf_size < picsize + 45) {
        av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
        return -1;
    }

    p->pict_type= FF_I_TYPE;
    p->key_frame= 1;

    /* zero out the header and only set applicable fields */
    memset(outbuf, 0, 11);
    AV_WL16(outbuf+12, avctx->width);
    AV_WL16(outbuf+14, avctx->height);
    outbuf[17] = 0x20;           /* origin is top-left. no alpha */

    /* TODO: support alpha channel */
    switch(avctx->pix_fmt) {
    case PIX_FMT_GRAY8:
        outbuf[2] = 3;           /* uncompressed grayscale image */
        outbuf[16] = 8;          /* bpp */
        break;
    case PIX_FMT_RGB555:
        outbuf[2] = 2;           /* uncompresses true-color image */
        outbuf[16] = 16;         /* bpp */
        break;
    case PIX_FMT_BGR24:
        outbuf[2] = 2;           /* uncompressed true-color image */
        outbuf[16] = 24;         /* bpp */
        break;
    default:
        return -1;
    }
    bpp = outbuf[16] >> 3;

    out = outbuf + 18;  /* skip past the header we just output */

    /* try RLE compression */
    datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);

    /* if that worked well, mark the picture as RLE compressed */
    if(datasize >= 0)
        outbuf[2] |= 8;

    /* if RLE didn't make it smaller, go back to no compression */
    else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);

    out += datasize;

    /* The standard recommends including this section, even if we don't use
     * any of the features it affords. TODO: take advantage of the pixel
     * aspect ratio and encoder ID fields available? */
    memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);

    return out + 26 - outbuf;
}

static av_cold int targa_encode_init(AVCodecContext *avctx)
{
    return 0;
}

AVCodec targa_encoder = {
    .name = "targa",
    .type = CODEC_TYPE_VIDEO,
    .id = CODEC_ID_TARGA,
    .priv_data_size = 0,
    .init = targa_encode_init,
    .encode = targa_encode_frame,
    .pix_fmts= (enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB555, PIX_FMT_GRAY8, -1},
};
OpenPOWER on IntegriCloud