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 34typedef struct BFIContext { 35 AVCodecContext *avctx; 36 uint8_t *dst; 37 uint32_t pal[256]; 38} BFIContext; 39 40static 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 50static 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 171static av_cold int bfi_decode_close(AVCodecContext *avctx) 172{ 173 BFIContext *bfi = avctx->priv_data; 174 av_free(bfi->dst); 175 return 0; 176} 177 178AVCodec 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 = CODEC_CAP_DR1, 188}; 189