bfi.c 6.08 KB
Newer Older
Sisir Koppaka's avatar
Sisir Koppaka committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 * Brute Force & Ignorance (BFI) video decoder
 * Copyright (c) 2008 Sisir Koppaka
 *
 * 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
 */

/**
23
 * @file
Sisir Koppaka's avatar
Sisir Koppaka committed
24 25
 * @brief Brute Force & Ignorance (.bfi) video decoder
 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26
 * @see http://wiki.multimedia.cx/index.php?title=BFI
Sisir Koppaka's avatar
Sisir Koppaka committed
27 28
 */

29
#include "libavutil/common.h"
Sisir Koppaka's avatar
Sisir Koppaka committed
30 31 32 33 34 35 36
#include "avcodec.h"
#include "bytestream.h"

typedef struct BFIContext {
    AVCodecContext *avctx;
    AVFrame frame;
    uint8_t *dst;
37
    uint32_t pal[256];
Sisir Koppaka's avatar
Sisir Koppaka committed
38 39
} BFIContext;

Aneesh Dogra's avatar
Aneesh Dogra committed
40
static av_cold int bfi_decode_init(AVCodecContext *avctx)
Sisir Koppaka's avatar
Sisir Koppaka committed
41 42 43
{
    BFIContext *bfi = avctx->priv_data;
    avctx->pix_fmt = PIX_FMT_PAL8;
44
    avcodec_get_frame_defaults(&bfi->frame);
Sisir Koppaka's avatar
Sisir Koppaka committed
45 46 47 48
    bfi->dst = av_mallocz(avctx->width * avctx->height);
    return 0;
}

Aneesh Dogra's avatar
Aneesh Dogra committed
49
static int bfi_decode_frame(AVCodecContext *avctx, void *data,
50
                            int *data_size, AVPacket *avpkt)
Sisir Koppaka's avatar
Sisir Koppaka committed
51
{
52
    GetByteContext g;
53
    int buf_size = avpkt->size;
Sisir Koppaka's avatar
Sisir Koppaka committed
54 55 56 57 58 59 60 61 62 63
    BFIContext *bfi = avctx->priv_data;
    uint8_t *dst = bfi->dst;
    uint8_t *src, *dst_offset, colour1, colour2;
    uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
    uint32_t *pal;
    int i, j, height = avctx->height;

    if (bfi->frame.data[0])
        avctx->release_buffer(avctx, &bfi->frame);

64
    bfi->frame.reference = 3;
Sisir Koppaka's avatar
Sisir Koppaka committed
65 66 67 68 69 70

    if (avctx->get_buffer(avctx, &bfi->frame) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

71 72
    bytestream2_init(&g, avpkt->data, buf_size);

Sisir Koppaka's avatar
Sisir Koppaka committed
73 74
    /* Set frame parameters and palette, if necessary */
    if (!avctx->frame_number) {
75
        bfi->frame.pict_type = AV_PICTURE_TYPE_I;
Sisir Koppaka's avatar
Sisir Koppaka committed
76 77
        bfi->frame.key_frame = 1;
        /* Setting the palette */
Aneesh Dogra's avatar
Aneesh Dogra committed
78
        if (avctx->extradata_size > 768) {
Sisir Koppaka's avatar
Sisir Koppaka committed
79 80 81
            av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
            return -1;
        }
Aneesh Dogra's avatar
Aneesh Dogra committed
82
        pal = (uint32_t *)bfi->frame.data[1];
Sisir Koppaka's avatar
Sisir Koppaka committed
83 84
        for (i = 0; i < avctx->extradata_size / 3; i++) {
            int shift = 16;
85
            *pal = 0xFF << 24;
Sisir Koppaka's avatar
Sisir Koppaka committed
86 87 88 89 90 91
            for (j = 0; j < 3; j++, shift -= 8)
                *pal +=
                    ((avctx->extradata[i * 3 + j] << 2) |
                    (avctx->extradata[i * 3 + j] >> 4)) << shift;
            pal++;
        }
92
        memcpy(bfi->pal, bfi->frame.data[1], sizeof(bfi->pal));
Sisir Koppaka's avatar
Sisir Koppaka committed
93 94
        bfi->frame.palette_has_changed = 1;
    } else {
95
        bfi->frame.pict_type = AV_PICTURE_TYPE_P;
Sisir Koppaka's avatar
Sisir Koppaka committed
96
        bfi->frame.key_frame = 0;
97 98
        bfi->frame.palette_has_changed = 0;
        memcpy(bfi->frame.data[1], bfi->pal, sizeof(bfi->pal));
Sisir Koppaka's avatar
Sisir Koppaka committed
99 100
    }

101
    bytestream2_skip(&g, 4); // Unpacked size, not required.
Sisir Koppaka's avatar
Sisir Koppaka committed
102 103

    while (dst != frame_end) {
Aneesh Dogra's avatar
Aneesh Dogra committed
104
        static const uint8_t lentab[4] = { 0, 2, 0, 1 };
105
        unsigned int byte   = bytestream2_get_byte(&g), av_uninit(offset);
Aneesh Dogra's avatar
Aneesh Dogra committed
106
        unsigned int code   = byte >> 6;
Sisir Koppaka's avatar
Sisir Koppaka committed
107 108
        unsigned int length = byte & ~0xC0;

109
        if (!bytestream2_get_bytes_left(&g)) {
Aneesh Dogra's avatar
Aneesh Dogra committed
110 111
            av_log(avctx, AV_LOG_ERROR,
                   "Input resolution larger than actual frame.\n");
112 113 114
            return -1;
        }

Sisir Koppaka's avatar
Sisir Koppaka committed
115 116 117
        /* Get length and offset(if required) */
        if (length == 0) {
            if (code == 1) {
118 119
                length = bytestream2_get_byte(&g);
                offset = bytestream2_get_le16(&g);
Sisir Koppaka's avatar
Sisir Koppaka committed
120
            } else {
121
                length = bytestream2_get_le16(&g);
Sisir Koppaka's avatar
Sisir Koppaka committed
122 123 124 125 126
                if (code == 2 && length == 0)
                    break;
            }
        } else {
            if (code == 1)
127
                offset = bytestream2_get_byte(&g);
Sisir Koppaka's avatar
Sisir Koppaka committed
128 129 130
        }

        /* Do boundary check */
Aneesh Dogra's avatar
Aneesh Dogra committed
131
        if (dst + (length << lentab[code]) > frame_end)
Sisir Koppaka's avatar
Sisir Koppaka committed
132 133 134 135 136
            break;

        switch (code) {

        case 0:                //Normal Chain
137
            if (length >= bytestream2_get_bytes_left(&g)) {
138 139 140
                av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
                return -1;
            }
141
            bytestream2_get_buffer(&g, dst, length);
Sisir Koppaka's avatar
Sisir Koppaka committed
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
            dst += length;
            break;

        case 1:                //Back Chain
            dst_offset = dst - offset;
            length *= 4;        //Convert dwords to bytes.
            if (dst_offset < bfi->dst)
                break;
            while (length--)
                *dst++ = *dst_offset++;
            break;

        case 2:                //Skip Chain
            dst += length;
            break;

        case 3:                //Fill Chain
159 160
            colour1 = bytestream2_get_byte(&g);
            colour2 = bytestream2_get_byte(&g);
Sisir Koppaka's avatar
Sisir Koppaka committed
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177
            while (length--) {
                *dst++ = colour1;
                *dst++ = colour2;
            }
            break;

        }
    }

    src = bfi->dst;
    dst = bfi->frame.data[0];
    while (height--) {
        memcpy(dst, src, avctx->width);
        src += avctx->width;
        dst += bfi->frame.linesize[0];
    }
    *data_size = sizeof(AVFrame);
Aneesh Dogra's avatar
Aneesh Dogra committed
178
    *(AVFrame *)data = bfi->frame;
Sisir Koppaka's avatar
Sisir Koppaka committed
179 180 181
    return buf_size;
}

182
static av_cold int bfi_decode_close(AVCodecContext * avctx)
Sisir Koppaka's avatar
Sisir Koppaka committed
183 184 185 186 187 188 189 190
{
    BFIContext *bfi = avctx->priv_data;
    if (bfi->frame.data[0])
        avctx->release_buffer(avctx, &bfi->frame);
    av_free(bfi->dst);
    return 0;
}

191
AVCodec ff_bfi_decoder = {
Sisir Koppaka's avatar
Sisir Koppaka committed
192
    .name = "bfi",
193
    .type = AVMEDIA_TYPE_VIDEO,
Sisir Koppaka's avatar
Sisir Koppaka committed
194 195 196 197 198
    .id = CODEC_ID_BFI,
    .priv_data_size = sizeof(BFIContext),
    .init = bfi_decode_init,
    .close = bfi_decode_close,
    .decode = bfi_decode_frame,
199
    .capabilities = CODEC_CAP_DR1,
200
    .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
Sisir Koppaka's avatar
Sisir Koppaka committed
201
};