1/*
2 * Brute Force & Ignorance (BFI) video decoder
3 * Copyright (c) 2008 Sisir Koppaka
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * @brief Brute Force & Ignorance (.bfi) video decoder
25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26 * @sa http://wiki.multimedia.cx/index.php?title=BFI
27 */
28
29#include "libavutil/common.h"
30#include "avcodec.h"
31#include "bytestream.h"
32
33typedef struct BFIContext {
34    AVCodecContext *avctx;
35    AVFrame frame;
36    uint8_t *dst;
37} BFIContext;
38
39static av_cold int bfi_decode_init(AVCodecContext * avctx)
40{
41    BFIContext *bfi = avctx->priv_data;
42    avctx->pix_fmt = PIX_FMT_PAL8;
43    bfi->dst = av_mallocz(avctx->width * avctx->height);
44    return 0;
45}
46
47static int bfi_decode_frame(AVCodecContext * avctx, void *data,
48                            int *data_size, AVPacket *avpkt)
49{
50    const uint8_t *buf = avpkt->data;
51    int buf_size = avpkt->size;
52    BFIContext *bfi = avctx->priv_data;
53    uint8_t *dst = bfi->dst;
54    uint8_t *src, *dst_offset, colour1, colour2;
55    uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
56    uint32_t *pal;
57    int i, j, height = avctx->height;
58
59    if (bfi->frame.data[0])
60        avctx->release_buffer(avctx, &bfi->frame);
61
62    bfi->frame.reference = 1;
63
64    if (avctx->get_buffer(avctx, &bfi->frame) < 0) {
65        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
66        return -1;
67    }
68
69    /* Set frame parameters and palette, if necessary */
70    if (!avctx->frame_number) {
71        bfi->frame.pict_type = FF_I_TYPE;
72        bfi->frame.key_frame = 1;
73        /* Setting the palette */
74        if(avctx->extradata_size>768) {
75            av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
76            return -1;
77        }
78        pal = (uint32_t *) bfi->frame.data[1];
79        for (i = 0; i < avctx->extradata_size / 3; i++) {
80            int shift = 16;
81            *pal = 0;
82            for (j = 0; j < 3; j++, shift -= 8)
83                *pal +=
84                    ((avctx->extradata[i * 3 + j] << 2) |
85                    (avctx->extradata[i * 3 + j] >> 4)) << shift;
86            pal++;
87        }
88        bfi->frame.palette_has_changed = 1;
89    } else {
90        bfi->frame.pict_type = FF_P_TYPE;
91        bfi->frame.key_frame = 0;
92    }
93
94    buf += 4; //Unpacked size, not required.
95
96    while (dst != frame_end) {
97        static const uint8_t lentab[4]={0,2,0,1};
98        unsigned int byte = *buf++, av_uninit(offset);
99        unsigned int code = byte >> 6;
100        unsigned int length = byte & ~0xC0;
101
102        /* Get length and offset(if required) */
103        if (length == 0) {
104            if (code == 1) {
105                length = bytestream_get_byte(&buf);
106                offset = bytestream_get_le16(&buf);
107            } else {
108                length = bytestream_get_le16(&buf);
109                if (code == 2 && length == 0)
110                    break;
111            }
112        } else {
113            if (code == 1)
114                offset = bytestream_get_byte(&buf);
115        }
116
117        /* Do boundary check */
118        if (dst + (length<<lentab[code]) > frame_end)
119            break;
120
121        switch (code) {
122
123        case 0:                //Normal Chain
124            bytestream_get_buffer(&buf, dst, length);
125            dst += length;
126            break;
127
128        case 1:                //Back Chain
129            dst_offset = dst - offset;
130            length *= 4;        //Convert dwords to bytes.
131            if (dst_offset < bfi->dst)
132                break;
133            while (length--)
134                *dst++ = *dst_offset++;
135            break;
136
137        case 2:                //Skip Chain
138            dst += length;
139            break;
140
141        case 3:                //Fill Chain
142            colour1 = bytestream_get_byte(&buf);
143            colour2 = bytestream_get_byte(&buf);
144            while (length--) {
145                *dst++ = colour1;
146                *dst++ = colour2;
147            }
148            break;
149
150        }
151    }
152
153    src = bfi->dst;
154    dst = bfi->frame.data[0];
155    while (height--) {
156        memcpy(dst, src, avctx->width);
157        src += avctx->width;
158        dst += bfi->frame.linesize[0];
159    }
160    *data_size = sizeof(AVFrame);
161    *(AVFrame *) data = bfi->frame;
162    return buf_size;
163}
164
165static av_cold int bfi_decode_close(AVCodecContext * avctx)
166{
167    BFIContext *bfi = avctx->priv_data;
168    if (bfi->frame.data[0])
169        avctx->release_buffer(avctx, &bfi->frame);
170    av_free(bfi->dst);
171    return 0;
172}
173
174AVCodec bfi_decoder = {
175    .name = "bfi",
176    .type = AVMEDIA_TYPE_VIDEO,
177    .id = CODEC_ID_BFI,
178    .priv_data_size = sizeof(BFIContext),
179    .init = bfi_decode_init,
180    .close = bfi_decode_close,
181    .decode = bfi_decode_frame,
182    .capabilities = CODEC_CAP_DR1,
183    .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
184};
185