summaryrefslogtreecommitdiff
path: root/libavcodec/sgirledec.c
blob: 69d012e8e464c69ff390e14ace73fbaa567a9a48 (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
150
151
152
153
154
155
156
157
158
159
160
/*
 * Silicon Graphics RLE 8-bit video decoder
 * Copyright (c) 2012 Peter Ross
 *
 * 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
 */

/**
 * @file
 * Silicon Graphics RLE 8-bit video decoder
 * @note Data is packed in rbg323 with rle, contained in mv or mov.
 * The algorithm and pixfmt are subtly different from SGI images.
 */

#include "libavutil/common.h"

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

typedef struct SGIRLEContext {
    AVFrame *frame;
} SGIRLEContext;

static av_cold int sgirle_decode_init(AVCodecContext *avctx)
{
    SGIRLEContext *s = avctx->priv_data;
    avctx->pix_fmt = AV_PIX_FMT_BGR8;
    s->frame = av_frame_alloc();
    if (!s->frame)
        return AVERROR(ENOMEM);
    return 0;
}

/**
 * Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8
 * SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb)
 */
#define RBG323_TO_BGR8(x) ((((x) << 3) & 0xC0) |                                \
                           (((x) << 3) & 0x38) |                                \
                           (((x) >> 5) & 7))
static av_always_inline
void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
{
    int i;
    for (i = 0; i < size; i++)
        dst[i] = RBG323_TO_BGR8(src[i]);
}

/**
 * @param[out] dst Destination buffer
 * @param[in] src  Source buffer
 * @param src_size Source buffer size (bytes)
 * @param width    Width of destination buffer (pixels)
 * @param height   Height of destination buffer (pixels)
 * @param linesize Line size of destination buffer (bytes)
 *
 * @return <0 on error
 */
static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst,
                          const uint8_t *src, int src_size,
                          int width, int height, ptrdiff_t linesize)
{
    const uint8_t *src_end = src + src_size;
    int x = 0, y = 0;

#define INC_XY(n)                                                             \
    x += n;                                                                   \
    if (x >= width) {                                                         \
        y++;                                                                  \
        if (y >= height)                                                      \
            return 0;                                                         \
        x = 0;                                                                \
    }

    while (src_end - src >= 2) {
        uint8_t v = *src++;
        if (v > 0 && v < 0xC0) {
            do {
                int length = FFMIN(v, width - x);
                if (length <= 0)
                    break;
                memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length);
                INC_XY(length);
                v -= length;
            } while (v > 0);
            src++;
        } else if (v >= 0xC1) {
            v -= 0xC0;
            do {
                int length = FFMIN3(v, width - x, src_end - src);
                if (src_end - src < length || length <= 0)
                    break;
                rbg323_to_bgr8(dst + y * linesize + x, src, length);
                INC_XY(length);
                src += length;
                v   -= length;
            } while (v > 0);
        } else {
            avpriv_request_sample(avctx, "opcode %d", v);
            return AVERROR_PATCHWELCOME;
        }
    }
    return 0;
}

static int sgirle_decode_frame(AVCodecContext *avctx, void *data,
                               int *got_frame, AVPacket *avpkt)
{
    SGIRLEContext *s = avctx->priv_data;
    int ret;

    if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
        return ret;

    ret = decode_sgirle8(avctx, s->frame->data[0], avpkt->data, avpkt->size,
                         avctx->width, avctx->height, s->frame->linesize[0]);
    if (ret < 0)
        return ret;

    *got_frame = 1;
    if ((ret = av_frame_ref(data, s->frame)) < 0)
        return ret;

    return avpkt->size;
}

static av_cold int sgirle_decode_end(AVCodecContext *avctx)
{
    SGIRLEContext *s = avctx->priv_data;

    av_frame_free(&s->frame);

    return 0;
}

AVCodec ff_sgirle_decoder = {
    .name           = "sgirle",
    .long_name      = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_SGIRLE,
    .priv_data_size = sizeof(SGIRLEContext),
    .init           = sgirle_decode_init,
    .close          = sgirle_decode_end,
    .decode         = sgirle_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};