blob: 233a1d27a8f1f961dc7b59d3ab2a481c2012f784
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 | |
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 | |
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(NULL, 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 | |
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 |