1/*
2 * SGI image encoder
3 * Todd Kirby <doubleshot@pacbell.net>
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#include "avcodec.h"
23#include "bytestream.h"
24#include "sgi.h"
25#include "rle.h"
26
27#define SGI_SINGLE_CHAN 2
28#define SGI_MULTI_CHAN 3
29
30typedef struct SgiContext {
31    AVFrame picture;
32} SgiContext;
33
34static av_cold int encode_init(AVCodecContext *avctx){
35    SgiContext *s = avctx->priv_data;
36
37    avcodec_get_frame_defaults(&s->picture);
38    avctx->coded_frame = &s->picture;
39
40    return 0;
41}
42
43static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
44                        int buf_size, void *data) {
45    SgiContext *s = avctx->priv_data;
46    AVFrame * const p = &s->picture;
47    uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
48    int x, y, z, length, tablesize;
49    unsigned int width, height, depth, dimension;
50    unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
51
52    *p = *(AVFrame*)data;
53    p->pict_type = FF_I_TYPE;
54    p->key_frame = 1;
55
56    width = avctx->width;
57    height = avctx->height;
58
59    switch (avctx->pix_fmt) {
60        case PIX_FMT_GRAY8:
61            dimension = SGI_SINGLE_CHAN;
62            depth = SGI_GRAYSCALE;
63            break;
64        case PIX_FMT_RGB24:
65            dimension = SGI_MULTI_CHAN;
66            depth = SGI_RGB;
67            break;
68        case PIX_FMT_RGBA:
69            dimension = SGI_MULTI_CHAN;
70            depth = SGI_RGBA;
71            break;
72        default:
73            return AVERROR_INVALIDDATA;
74    }
75
76    tablesize = depth * height * 4;
77    length = tablesize * 2 + SGI_HEADER_SIZE;
78
79    if (buf_size < length) {
80        av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
81        return -1;
82    }
83
84    /* Encode header. */
85    bytestream_put_be16(&buf, SGI_MAGIC);
86    bytestream_put_byte(&buf, 1); /* RLE */
87    bytestream_put_byte(&buf, 1); /* bytes_per_channel */
88    bytestream_put_be16(&buf, dimension);
89    bytestream_put_be16(&buf, width);
90    bytestream_put_be16(&buf, height);
91    bytestream_put_be16(&buf, depth);
92
93    /* The rest are constant in this implementation. */
94    bytestream_put_be32(&buf, 0L); /* pixmin */
95    bytestream_put_be32(&buf, 255L); /* pixmax */
96    bytestream_put_be32(&buf, 0L); /* dummy */
97
98    /* name */
99    memset(buf, 0, SGI_HEADER_SIZE);
100    buf += 80;
101
102     /* colormap */
103    bytestream_put_be32(&buf, 0L);
104
105    /* The rest of the 512 byte header is unused. */
106    buf += 404;
107    offsettab = buf;
108
109    /* Skip RLE offset table. */
110    buf += tablesize;
111    lengthtab = buf;
112
113    /* Skip RLE length table. */
114    buf += tablesize;
115
116    /* Make an intermediate consecutive buffer. */
117    if ((encode_buf = av_malloc(width)) == NULL)
118        return -1;
119
120    for (z = 0; z < depth; z++) {
121        in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
122
123        for (y = 0; y < height; y++) {
124            bytestream_put_be32(&offsettab, buf - orig_buf);
125
126            for (x = 0; x < width; x++)
127                encode_buf[x] = in_buf[depth * x];
128
129            if((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
130                av_free(encode_buf);
131                return -1;
132            }
133
134            buf += length;
135            bytestream_put_byte(&buf, 0);
136            bytestream_put_be32(&lengthtab, length + 1);
137            in_buf -= p->linesize[0];
138        }
139    }
140
141    av_free(encode_buf);
142    /* total length */
143    return buf - orig_buf;
144}
145
146AVCodec sgi_encoder = {
147    "sgi",
148    CODEC_TYPE_VIDEO,
149    CODEC_ID_SGI,
150    sizeof(SgiContext),
151    encode_init,
152    encode_frame,
153    NULL,
154    .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_NONE},
155    .long_name= NULL_IF_CONFIG_SMALL("SGI image"),
156};
157
158