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 * @see http://wiki.multimedia.cx/index.php?title=BFI
27 */
28
29 #include "libavutil/common.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33
34 typedef struct BFIContext {
35 AVCodecContext *avctx;
36 uint8_t *dst;
37 uint32_t pal[256];
38 } BFIContext;
39
bfi_decode_init(AVCodecContext * avctx)40 static av_cold int bfi_decode_init(AVCodecContext *avctx)
41 {
42 BFIContext *bfi = avctx->priv_data;
43 avctx->pix_fmt = AV_PIX_FMT_PAL8;
44 bfi->dst = av_mallocz(avctx->width * avctx->height);
45 if (!bfi->dst)
46 return AVERROR(ENOMEM);
47 return 0;
48 }
49
bfi_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)50 static int bfi_decode_frame(AVCodecContext *avctx, void *data,
51 int *got_frame, AVPacket *avpkt)
52 {
53 AVFrame *frame = data;
54 GetByteContext g;
55 int buf_size = avpkt->size;
56 BFIContext *bfi = avctx->priv_data;
57 uint8_t *dst = bfi->dst;
58 uint8_t *src, *dst_offset, colour1, colour2;
59 uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
60 uint32_t *pal;
61 int i, j, ret, height = avctx->height;
62
63 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
64 return ret;
65
66 bytestream2_init(&g, avpkt->data, buf_size);
67
68 /* Set frame parameters and palette, if necessary */
69 if (!avctx->frame_number) {
70 frame->pict_type = AV_PICTURE_TYPE_I;
71 frame->key_frame = 1;
72 /* Setting the palette */
73 if (avctx->extradata_size > 768) {
74 av_log(avctx, AV_LOG_ERROR, "Palette is too large.\n");
75 return AVERROR_INVALIDDATA;
76 }
77 pal = (uint32_t *)frame->data[1];
78 for (i = 0; i < avctx->extradata_size / 3; i++) {
79 int shift = 16;
80 *pal = 0xFFU << 24;
81 for (j = 0; j < 3; j++, shift -= 8)
82 *pal += ((avctx->extradata[i * 3 + j] << 2) |
83 (avctx->extradata[i * 3 + j] >> 4)) << shift;
84 pal++;
85 }
86 memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
87 frame->palette_has_changed = 1;
88 } else {
89 frame->pict_type = AV_PICTURE_TYPE_P;
90 frame->key_frame = 0;
91 frame->palette_has_changed = 0;
92 memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
93 }
94
95 bytestream2_skip(&g, 4); // Unpacked size, not required.
96
97 while (dst != frame_end) {
98 static const uint8_t lentab[4] = { 0, 2, 0, 1 };
99 unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
100 unsigned int code = byte >> 6;
101 unsigned int length = byte & ~0xC0;
102
103 if (!bytestream2_get_bytes_left(&g)) {
104 av_log(avctx, AV_LOG_ERROR,
105 "Input resolution larger than actual frame.\n");
106 return AVERROR_INVALIDDATA;
107 }
108
109 /* Get length and offset (if required) */
110 if (length == 0) {
111 if (code == 1) {
112 length = bytestream2_get_byte(&g);
113 offset = bytestream2_get_le16(&g);
114 } else {
115 length = bytestream2_get_le16(&g);
116 if (code == 2 && length == 0)
117 break;
118 }
119 } else {
120 if (code == 1)
121 offset = bytestream2_get_byte(&g);
122 }
123
124 /* Do boundary check */
125 if (dst + (length << lentab[code]) > frame_end)
126 break;
127
128 switch (code) {
129 case 0: // normal chain
130 if (length >= bytestream2_get_bytes_left(&g)) {
131 av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
132 return AVERROR_INVALIDDATA;
133 }
134 bytestream2_get_buffer(&g, dst, length);
135 dst += length;
136 break;
137 case 1: // back chain
138 dst_offset = dst - offset;
139 length *= 4; // Convert dwords to bytes.
140 if (dst_offset < bfi->dst)
141 break;
142 while (length--)
143 *dst++ = *dst_offset++;
144 break;
145 case 2: // skip chain
146 dst += length;
147 break;
148 case 3: // fill chain
149 colour1 = bytestream2_get_byte(&g);
150 colour2 = bytestream2_get_byte(&g);
151 while (length--) {
152 *dst++ = colour1;
153 *dst++ = colour2;
154 }
155 break;
156 }
157 }
158
159 src = bfi->dst;
160 dst = frame->data[0];
161 while (height--) {
162 memcpy(dst, src, avctx->width);
163 src += avctx->width;
164 dst += frame->linesize[0];
165 }
166 *got_frame = 1;
167
168 return buf_size;
169 }
170
bfi_decode_close(AVCodecContext * avctx)171 static av_cold int bfi_decode_close(AVCodecContext *avctx)
172 {
173 BFIContext *bfi = avctx->priv_data;
174 av_freep(&bfi->dst);
175 return 0;
176 }
177
178 AVCodec ff_bfi_decoder = {
179 .name = "bfi",
180 .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
181 .type = AVMEDIA_TYPE_VIDEO,
182 .id = AV_CODEC_ID_BFI,
183 .priv_data_size = sizeof(BFIContext),
184 .init = bfi_decode_init,
185 .close = bfi_decode_close,
186 .decode = bfi_decode_frame,
187 .capabilities = AV_CODEC_CAP_DR1,
188 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
189 };
190