| 1 | /* |
| 2 | * Microsoft RLE decoder |
| 3 | * Copyright (C) 2008 Konstantin Shishkov |
| 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 | * MS RLE decoder based on decoder by Mike Melanson and my own for TSCC |
| 25 | * For more information about the MS RLE format, visit: |
| 26 | * http://www.multimedia.cx/msrle.txt |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/intreadwrite.h" |
| 30 | #include "avcodec.h" |
| 31 | #include "msrledec.h" |
| 32 | |
| 33 | static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic, |
| 34 | GetByteContext *gb) |
| 35 | { |
| 36 | unsigned char rle_code; |
| 37 | unsigned char extra_byte, odd_pixel; |
| 38 | unsigned char stream_byte; |
| 39 | unsigned int pixel_ptr = 0; |
| 40 | int row_dec = pic->linesize[0]; |
| 41 | int row_ptr = (avctx->height - 1) * row_dec; |
| 42 | int frame_size = row_dec * avctx->height; |
| 43 | int i; |
| 44 | |
| 45 | while (row_ptr >= 0) { |
| 46 | if (bytestream2_get_bytes_left(gb) <= 0) { |
| 47 | av_log(avctx, AV_LOG_ERROR, |
| 48 | "MS RLE: bytestream overrun, %d rows left\n", |
| 49 | row_ptr); |
| 50 | return AVERROR_INVALIDDATA; |
| 51 | } |
| 52 | rle_code = stream_byte = bytestream2_get_byteu(gb); |
| 53 | if (rle_code == 0) { |
| 54 | /* fetch the next byte to see how to handle escape code */ |
| 55 | stream_byte = bytestream2_get_byte(gb); |
| 56 | if (stream_byte == 0) { |
| 57 | /* line is done, goto the next one */ |
| 58 | row_ptr -= row_dec; |
| 59 | pixel_ptr = 0; |
| 60 | } else if (stream_byte == 1) { |
| 61 | /* decode is done */ |
| 62 | return 0; |
| 63 | } else if (stream_byte == 2) { |
| 64 | /* reposition frame decode coordinates */ |
| 65 | stream_byte = bytestream2_get_byte(gb); |
| 66 | pixel_ptr += stream_byte; |
| 67 | stream_byte = bytestream2_get_byte(gb); |
| 68 | row_ptr -= stream_byte * row_dec; |
| 69 | } else { |
| 70 | // copy pixels from encoded stream |
| 71 | odd_pixel = stream_byte & 1; |
| 72 | rle_code = (stream_byte + 1) / 2; |
| 73 | extra_byte = rle_code & 0x01; |
| 74 | if (row_ptr + pixel_ptr + stream_byte > frame_size || |
| 75 | bytestream2_get_bytes_left(gb) < rle_code) { |
| 76 | av_log(avctx, AV_LOG_ERROR, |
| 77 | "MS RLE: frame/stream ptr just went out of bounds (copy)\n"); |
| 78 | return AVERROR_INVALIDDATA; |
| 79 | } |
| 80 | |
| 81 | for (i = 0; i < rle_code; i++) { |
| 82 | if (pixel_ptr >= avctx->width) |
| 83 | break; |
| 84 | stream_byte = bytestream2_get_byteu(gb); |
| 85 | pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4; |
| 86 | pixel_ptr++; |
| 87 | if (i + 1 == rle_code && odd_pixel) |
| 88 | break; |
| 89 | if (pixel_ptr >= avctx->width) |
| 90 | break; |
| 91 | pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F; |
| 92 | pixel_ptr++; |
| 93 | } |
| 94 | |
| 95 | // if the RLE code is odd, skip a byte in the stream |
| 96 | if (extra_byte) |
| 97 | bytestream2_skip(gb, 1); |
| 98 | } |
| 99 | } else { |
| 100 | // decode a run of data |
| 101 | if (row_ptr + pixel_ptr + stream_byte > frame_size) { |
| 102 | av_log(avctx, AV_LOG_ERROR, |
| 103 | "MS RLE: frame ptr just went out of bounds (run)\n"); |
| 104 | return AVERROR_INVALIDDATA; |
| 105 | } |
| 106 | stream_byte = bytestream2_get_byte(gb); |
| 107 | for (i = 0; i < rle_code; i++) { |
| 108 | if (pixel_ptr >= avctx->width) |
| 109 | break; |
| 110 | if ((i & 1) == 0) |
| 111 | pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4; |
| 112 | else |
| 113 | pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F; |
| 114 | pixel_ptr++; |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | /* one last sanity check on the way out */ |
| 120 | if (bytestream2_get_bytes_left(gb)) { |
| 121 | av_log(avctx, AV_LOG_ERROR, |
| 122 | "MS RLE: ended frame decode with %d bytes left over\n", |
| 123 | bytestream2_get_bytes_left(gb)); |
| 124 | return AVERROR_INVALIDDATA; |
| 125 | } |
| 126 | |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | |
| 131 | static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic, |
| 132 | int depth, GetByteContext *gb) |
| 133 | { |
| 134 | uint8_t *output, *output_end; |
| 135 | int p1, p2, line=avctx->height - 1, pos=0, i; |
| 136 | uint16_t pix16; |
| 137 | uint32_t pix32; |
| 138 | unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3); |
| 139 | |
| 140 | output = pic->data[0] + (avctx->height - 1) * pic->linesize[0]; |
| 141 | output_end = output + FFABS(pic->linesize[0]); |
| 142 | |
| 143 | while (bytestream2_get_bytes_left(gb) > 0) { |
| 144 | p1 = bytestream2_get_byteu(gb); |
| 145 | if(p1 == 0) { //Escape code |
| 146 | p2 = bytestream2_get_byte(gb); |
| 147 | if(p2 == 0) { //End-of-line |
| 148 | if (--line < 0) { |
| 149 | if (bytestream2_get_be16(gb) == 1) { // end-of-picture |
| 150 | return 0; |
| 151 | } else { |
| 152 | av_log(avctx, AV_LOG_ERROR, |
| 153 | "Next line is beyond picture bounds (%d bytes left)\n", |
| 154 | bytestream2_get_bytes_left(gb)); |
| 155 | return AVERROR_INVALIDDATA; |
| 156 | } |
| 157 | } |
| 158 | output = pic->data[0] + line * pic->linesize[0]; |
| 159 | output_end = output + FFABS(pic->linesize[0]); |
| 160 | pos = 0; |
| 161 | continue; |
| 162 | } else if(p2 == 1) { //End-of-picture |
| 163 | return 0; |
| 164 | } else if(p2 == 2) { //Skip |
| 165 | p1 = bytestream2_get_byte(gb); |
| 166 | p2 = bytestream2_get_byte(gb); |
| 167 | line -= p2; |
| 168 | pos += p1; |
| 169 | if (line < 0 || pos >= width){ |
| 170 | av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n"); |
| 171 | return -1; |
| 172 | } |
| 173 | output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3); |
| 174 | output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]); |
| 175 | continue; |
| 176 | } |
| 177 | // Copy data |
| 178 | if (output + p2 * (depth >> 3) > output_end) { |
| 179 | bytestream2_skip(gb, 2 * (depth >> 3)); |
| 180 | continue; |
| 181 | } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) { |
| 182 | av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n"); |
| 183 | return AVERROR_INVALIDDATA; |
| 184 | } |
| 185 | |
| 186 | if ((depth == 8) || (depth == 24)) { |
| 187 | bytestream2_get_bufferu(gb, output, p2 * (depth >> 3)); |
| 188 | output += p2 * (depth >> 3); |
| 189 | |
| 190 | // RLE8 copy is actually padded - and runs are not! |
| 191 | if(depth == 8 && (p2 & 1)) { |
| 192 | bytestream2_skip(gb, 1); |
| 193 | } |
| 194 | } else if (depth == 16) { |
| 195 | for(i = 0; i < p2; i++) { |
| 196 | *(uint16_t*)output = bytestream2_get_le16u(gb); |
| 197 | output += 2; |
| 198 | } |
| 199 | } else if (depth == 32) { |
| 200 | for(i = 0; i < p2; i++) { |
| 201 | *(uint32_t*)output = bytestream2_get_le32u(gb); |
| 202 | output += 4; |
| 203 | } |
| 204 | } |
| 205 | pos += p2; |
| 206 | } else { //run of pixels |
| 207 | uint8_t pix[3]; //original pixel |
| 208 | if (output + p1 * (depth >> 3) > output_end) |
| 209 | continue; |
| 210 | |
| 211 | switch(depth){ |
| 212 | case 8: |
| 213 | pix[0] = bytestream2_get_byte(gb); |
| 214 | memset(output, pix[0], p1); |
| 215 | output += p1; |
| 216 | break; |
| 217 | case 16: |
| 218 | pix16 = bytestream2_get_le16(gb); |
| 219 | for(i = 0; i < p1; i++) { |
| 220 | *(uint16_t*)output = pix16; |
| 221 | output += 2; |
| 222 | } |
| 223 | break; |
| 224 | case 24: |
| 225 | pix[0] = bytestream2_get_byte(gb); |
| 226 | pix[1] = bytestream2_get_byte(gb); |
| 227 | pix[2] = bytestream2_get_byte(gb); |
| 228 | for(i = 0; i < p1; i++) { |
| 229 | *output++ = pix[0]; |
| 230 | *output++ = pix[1]; |
| 231 | *output++ = pix[2]; |
| 232 | } |
| 233 | break; |
| 234 | case 32: |
| 235 | pix32 = bytestream2_get_le32(gb); |
| 236 | for(i = 0; i < p1; i++) { |
| 237 | *(uint32_t*)output = pix32; |
| 238 | output += 4; |
| 239 | } |
| 240 | break; |
| 241 | } |
| 242 | pos += p1; |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n"); |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | |
| 251 | int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic, |
| 252 | int depth, GetByteContext *gb) |
| 253 | { |
| 254 | switch(depth){ |
| 255 | case 4: |
| 256 | return msrle_decode_pal4(avctx, pic, gb); |
| 257 | case 8: |
| 258 | case 16: |
| 259 | case 24: |
| 260 | case 32: |
| 261 | return msrle_decode_8_16_24_32(avctx, pic, depth, gb); |
| 262 | default: |
| 263 | av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth); |
| 264 | return -1; |
| 265 | } |
| 266 | } |