summaryrefslogtreecommitdiff
path: root/libavcodec/msrle.c
blob: b6fa7f7abb993d0929f3f81b4123ac326a55f4b8 (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
161
162
163
164
165
166
167
168
169
170
/*
 * Microsoft RLE video decoder
 * Copyright (C) 2003 The FFmpeg project
 *
 * 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
 * MS RLE video decoder by Mike Melanson (melanson@pcisys.net)
 * For more information about the MS RLE format, visit:
 *   http://www.pcisys.net/~melanson/codecs/
 *
 * The MS RLE decoder outputs PAL8 colorspace data.
 */

#include <string.h>

#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "msrledec.h"
#include "libavutil/imgutils.h"

typedef struct MsrleContext {
    AVCodecContext *avctx;
    AVFrame *frame;

    GetByteContext gb;

    uint32_t pal[256];
} MsrleContext;

static av_cold int msrle_decode_init(AVCodecContext *avctx)
{
    MsrleContext *s = avctx->priv_data;
    int i;

    s->avctx = avctx;

    switch (avctx->bits_per_coded_sample) {
    case 1:
        avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
        break;
    case 4:
    case 8:
        avctx->pix_fmt = AV_PIX_FMT_PAL8;
        break;
    case 24:
        avctx->pix_fmt = AV_PIX_FMT_BGR24;
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
        return AVERROR_INVALIDDATA;
    }

    s->frame = av_frame_alloc();
    if (!s->frame)
        return AVERROR(ENOMEM);

    if (avctx->extradata_size >= 4)
        for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
            s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);

    return 0;
}

static int msrle_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
                              int *got_frame, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    MsrleContext *s = avctx->priv_data;
    int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
    int ret;

    if (buf_size < 2) //Minimally a end of picture code should be there
        return AVERROR_INVALIDDATA;

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

    if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
        s->frame->palette_has_changed = ff_copy_palette(s->pal, avpkt, avctx);

        /* make the palette available */
        memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
    }

    /* FIXME how to correctly detect RLE ??? */
    if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
        int linesize = av_image_get_linesize(avctx->pix_fmt, avctx->width, 0);
        uint8_t *ptr = s->frame->data[0];
        const uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
        int i, j;

        if (linesize < 0)
            return linesize;

        for (i = 0; i < avctx->height; i++) {
            if (avctx->bits_per_coded_sample == 4) {
                for (j = 0; j < avctx->width - 1; j += 2) {
                    ptr[j+0] = buf[j>>1] >> 4;
                    ptr[j+1] = buf[j>>1] & 0xF;
                }
                if (avctx->width & 1)
                    ptr[j+0] = buf[j>>1] >> 4;
            } else {
                memcpy(ptr, buf, linesize);
            }
            buf -= istride;
            ptr += s->frame->linesize[0];
        }
    } else {
        bytestream2_init(&s->gb, buf, buf_size);
        ff_msrle_decode(avctx, s->frame, avctx->bits_per_coded_sample, &s->gb);
    }

    if ((ret = av_frame_ref(rframe, s->frame)) < 0)
        return ret;

    *got_frame      = 1;

    /* report that the buffer was completely consumed */
    return buf_size;
}

static void msrle_decode_flush(AVCodecContext *avctx)
{
    MsrleContext *s = avctx->priv_data;

    av_frame_unref(s->frame);
}

static av_cold int msrle_decode_end(AVCodecContext *avctx)
{
    MsrleContext *s = avctx->priv_data;

    /* release the last frame */
    av_frame_free(&s->frame);

    return 0;
}

const FFCodec ff_msrle_decoder = {
    .p.name         = "msrle",
    CODEC_LONG_NAME("Microsoft RLE"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_MSRLE,
    .priv_data_size = sizeof(MsrleContext),
    .init           = msrle_decode_init,
    .close          = msrle_decode_end,
    FF_CODEC_DECODE_CB(msrle_decode_frame),
    .flush          = msrle_decode_flush,
    .p.capabilities = AV_CODEC_CAP_DR1,
};