| 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_free(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 = CODEC_CAP_DR1, |
| 188 | }; |