summaryrefslogtreecommitdiff
path: root/libavcodec/aliaspixenc.c
blob: 1fcea084159c7a359dcae079f3657267f1389860 (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
/*
 * Alias PIX image encoder
 * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
 *
 * 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 "libavutil/intreadwrite.h"

#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"

#define ALIAS_HEADER_SIZE 10

static av_cold int encode_init(AVCodecContext *avctx)
{
    avctx->coded_frame = av_frame_alloc();
    if (!avctx->coded_frame)
        return AVERROR(ENOMEM);
    return 0;
}

static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                        const AVFrame *frame, int *got_packet)
{
    int width, height, bits_pixel, i, j, length, ret;
    uint8_t *in_buf, *buf;

    avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
    avctx->coded_frame->key_frame = 1;

    width  = avctx->width;
    height = avctx->height;

    if (width > 65535 || height > 65535 ||
        width * height >= INT_MAX / 4 - ALIAS_HEADER_SIZE) {
        av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", width, height);
        return AVERROR_INVALIDDATA;
    }

    switch (avctx->pix_fmt) {
    case AV_PIX_FMT_GRAY8:
        bits_pixel = 8;
        break;
    case AV_PIX_FMT_BGR24:
        bits_pixel = 24;
        break;
    default:
        return AVERROR(EINVAL);
    }

    length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible
    if ((ret = ff_alloc_packet(pkt, length)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", length);
        return ret;
    }

    buf = pkt->data;

    /* Encode header. */
    bytestream_put_be16(&buf, width);
    bytestream_put_be16(&buf, height);
    bytestream_put_be32(&buf, 0); /* X, Y offset */
    bytestream_put_be16(&buf, bits_pixel);

    for (j = 0; j < height; j++) {
        in_buf = frame->data[0] + frame->linesize[0] * j;
        for (i = 0; i < width; ) {
            int count = 0;
            int pixel;

            if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
                pixel = *in_buf;
                while (count < 255 && count + i < width && pixel == *in_buf) {
                    count++;
                    in_buf++;
                }
                bytestream_put_byte(&buf, count);
                bytestream_put_byte(&buf, pixel);
            } else { /* AV_PIX_FMT_BGR24 */
                pixel = AV_RB24(in_buf);
                while (count < 255 && count + i < width &&
                       pixel == AV_RB24(in_buf)) {
                    count++;
                    in_buf += 3;
                }
                bytestream_put_byte(&buf, count);
                bytestream_put_be24(&buf, pixel);
            }
            i += count;
        }
    }

    /* Total length */
    av_shrink_packet(pkt, buf - pkt->data);
    pkt->flags |= AV_PKT_FLAG_KEY;
    *got_packet = 1;

    return 0;
}

static av_cold int encode_close(AVCodecContext *avctx)
{
    av_frame_free(&avctx->coded_frame);
    return 0;
}

AVCodec ff_alias_pix_encoder = {
    .name      = "alias_pix",
    .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
    .type      = AVMEDIA_TYPE_VIDEO,
    .id        = AV_CODEC_ID_ALIAS_PIX,
    .init      = encode_init,
    .encode2   = encode_frame,
    .close     = encode_close,
    .pix_fmts  = (const enum AVPixelFormat[]) {
        AV_PIX_FMT_BGR24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
    },
};