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