2 * Brute Force & Ignorance (BFI) video decoder
3 * Copyright (c) 2008 Sisir Koppaka
5 * This file is part of FFmpeg.
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.
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.
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
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
29 #include "libavutil/common.h"
31 #include "bytestream.h"
34 typedef struct BFIContext {
35 AVCodecContext *avctx;
40 static av_cold int bfi_decode_init(AVCodecContext *avctx)
42 BFIContext *bfi = avctx->priv_data;
43 avctx->pix_fmt = AV_PIX_FMT_PAL8;
44 bfi->dst = av_mallocz(avctx->width * avctx->height);
48 static int bfi_decode_frame(AVCodecContext *avctx, void *data,
49 int *got_frame, AVPacket *avpkt)
51 AVFrame *frame = data;
53 int buf_size = avpkt->size;
54 BFIContext *bfi = avctx->priv_data;
55 uint8_t *dst = bfi->dst;
56 uint8_t *src, *dst_offset, colour1, colour2;
57 uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
59 int i, j, ret, height = avctx->height;
61 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
64 bytestream2_init(&g, avpkt->data, buf_size);
66 /* Set frame parameters and palette, if necessary */
67 if (!avctx->frame_number) {
68 frame->pict_type = AV_PICTURE_TYPE_I;
70 /* Setting the palette */
71 if (avctx->extradata_size > 768) {
72 av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
73 return AVERROR_INVALIDDATA;
75 pal = (uint32_t *)frame->data[1];
76 for (i = 0; i < avctx->extradata_size / 3; i++) {
79 for (j = 0; j < 3; j++, shift -= 8)
80 *pal += ((avctx->extradata[i * 3 + j] << 2) |
81 (avctx->extradata[i * 3 + j] >> 4)) << shift;
84 memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
85 frame->palette_has_changed = 1;
87 frame->pict_type = AV_PICTURE_TYPE_P;
89 frame->palette_has_changed = 0;
90 memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
93 bytestream2_skip(&g, 4); // Unpacked size, not required.
95 while (dst != frame_end) {
96 static const uint8_t lentab[4] = { 0, 2, 0, 1 };
97 unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
98 unsigned int code = byte >> 6;
99 unsigned int length = byte & ~0xC0;
101 if (!bytestream2_get_bytes_left(&g)) {
102 av_log(avctx, AV_LOG_ERROR,
103 "Input resolution larger than actual frame.\n");
104 return AVERROR_INVALIDDATA;
107 /* Get length and offset (if required) */
110 length = bytestream2_get_byte(&g);
111 offset = bytestream2_get_le16(&g);
113 length = bytestream2_get_le16(&g);
114 if (code == 2 && length == 0)
119 offset = bytestream2_get_byte(&g);
122 /* Do boundary check */
123 if (dst + (length << lentab[code]) > frame_end)
127 case 0: // normal chain
128 if (length >= bytestream2_get_bytes_left(&g)) {
129 av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
130 return AVERROR_INVALIDDATA;
132 bytestream2_get_buffer(&g, dst, length);
135 case 1: // back chain
136 dst_offset = dst - offset;
137 length *= 4; // Convert dwords to bytes.
138 if (dst_offset < bfi->dst)
141 *dst++ = *dst_offset++;
143 case 2: // skip chain
146 case 3: // fill chain
147 colour1 = bytestream2_get_byte(&g);
148 colour2 = bytestream2_get_byte(&g);
158 dst = frame->data[0];
160 memcpy(dst, src, avctx->width);
162 dst += frame->linesize[0];
169 static av_cold int bfi_decode_close(AVCodecContext *avctx)
171 BFIContext *bfi = avctx->priv_data;
176 AVCodec ff_bfi_decoder = {
178 .type = AVMEDIA_TYPE_VIDEO,
179 .id = AV_CODEC_ID_BFI,
180 .priv_data_size = sizeof(BFIContext),
181 .init = bfi_decode_init,
182 .close = bfi_decode_close,
183 .decode = bfi_decode_frame,
184 .capabilities = CODEC_CAP_DR1,
185 .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),