aboutsummaryrefslogtreecommitdiff
path: root/libavcodec/8bps.c
blob: fcb7b2bfcddf544958bd20e73adfdf41cc37ef28 (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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * Quicktime Planar RGB (8BPS) Video Decoder
 * Copyright (C) 2003 Roberto Togni
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * QT 8BPS Video Decoder by Roberto Togni
 * For more information about the 8BPS format, visit:
 *   http://www.pcisys.net/~melanson/codecs/
 *
 * Supports: PAL8 (RGB 8bpp, paletted)
 *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
 *         : RGB32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "internal.h"


static const enum AVPixelFormat pixfmt_rgb24[] = {
    AV_PIX_FMT_BGR24, AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE };

typedef struct EightBpsContext {
    AVCodecContext *avctx;

    unsigned char planes;
    unsigned char planemap[4];

    uint32_t pal[256];
} EightBpsContext;

static int decode_frame(AVCodecContext *avctx, void *data,
                        int *got_frame, AVPacket *avpkt)
{
    AVFrame *frame = data;
    const uint8_t *buf = avpkt->data;
    int buf_size       = avpkt->size;
    EightBpsContext * const c = avctx->priv_data;
    const unsigned char *encoded = buf;
    unsigned char *pixptr, *pixptr_end;
    unsigned int height = avctx->height; // Real image height
    unsigned int dlen, p, row;
    const unsigned char *lp, *dp;
    unsigned char count;
    unsigned int px_inc;
    unsigned int planes     = c->planes;
    unsigned char *planemap = c->planemap;
    int ret;

    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }

    /* Set data pointer after line lengths */
    dp = encoded + planes * (height << 1);

    /* Ignore alpha plane, don't know what to do with it */
    if (planes == 4)
        planes--;

    px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_RGB32);

    for (p = 0; p < planes; p++) {
        /* Lines length pointer for this plane */
        lp = encoded + p * (height << 1);

        /* Decode a plane */
        for (row = 0; row < height; row++) {
            pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
            pixptr_end = pixptr + frame->linesize[0];
            dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
            /* Decode a row of this plane */
            while (dlen > 0) {
                if (dp + 1 >= buf + buf_size)
                    return AVERROR_INVALIDDATA;
                if ((count = *dp++) <= 127) {
                    count++;
                    dlen -= count + 1;
                    if (pixptr + count * px_inc > pixptr_end)
                        break;
                    if (dp + count > buf + buf_size)
                        return AVERROR_INVALIDDATA;
                    while (count--) {
                        *pixptr = *dp++;
                        pixptr += px_inc;
                    }
                } else {
                    count = 257 - count;
                    if (pixptr + count * px_inc > pixptr_end)
                        break;
                    while (count--) {
                        *pixptr = *dp;
                        pixptr += px_inc;
                    }
                    dp++;
                    dlen -= 2;
                }
            }
        }
    }

    if (avctx->bits_per_coded_sample <= 8) {
        const uint8_t *pal = av_packet_get_side_data(avpkt,
                                                     AV_PKT_DATA_PALETTE,
                                                     NULL);
        if (pal) {
            frame->palette_has_changed = 1;
            memcpy(c->pal, pal, AVPALETTE_SIZE);
        }

        memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
    }

    *got_frame = 1;

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

static av_cold int decode_init(AVCodecContext *avctx)
{
    EightBpsContext * const c = avctx->priv_data;

    c->avctx       = avctx;

    switch (avctx->bits_per_coded_sample) {
    case 8:
        avctx->pix_fmt = AV_PIX_FMT_PAL8;
        c->planes      = 1;
        c->planemap[0] = 0; // 1st plane is palette indexes
        break;
    case 24:
        avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
        c->planes      = 3;
        c->planemap[0] = 2; // 1st plane is red
        c->planemap[1] = 1; // 2nd plane is green
        c->planemap[2] = 0; // 3rd plane is blue
        break;
    case 32:
        avctx->pix_fmt = AV_PIX_FMT_RGB32;
        c->planes      = 4;
#if HAVE_BIGENDIAN
        c->planemap[0] = 1; // 1st plane is red
        c->planemap[1] = 2; // 2nd plane is green
        c->planemap[2] = 3; // 3rd plane is blue
        c->planemap[3] = 0; // 4th plane is alpha???
#else
        c->planemap[0] = 2; // 1st plane is red
        c->planemap[1] = 1; // 2nd plane is green
        c->planemap[2] = 0; // 3rd plane is blue
        c->planemap[3] = 3; // 4th plane is alpha???
#endif
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
               avctx->bits_per_coded_sample);
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

AVCodec ff_eightbps_decoder = {
    .name           = "8bps",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_8BPS,
    .priv_data_size = sizeof(EightBpsContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
};