Fixes out of array accesses Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
		
			
				
	
	
		
			267 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			267 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * Microsoft RLE decoder
 | 
						|
 * Copyright (C) 2008 Konstantin Shishkov
 | 
						|
 *
 | 
						|
 * This file is part of FFmpeg.
 | 
						|
 *
 | 
						|
 * FFmpeg is free software; you can redistribute it and/or
 | 
						|
 * modify it under the terms of the GNU Lesser General Public
 | 
						|
 * License as published by the Free Software Foundation; either
 | 
						|
 * version 2.1 of the License, or (at your option) any later version.
 | 
						|
 *
 | 
						|
 * FFmpeg is distributed in the hope that it will be useful,
 | 
						|
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
						|
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | 
						|
 * Lesser General Public License for more details.
 | 
						|
 *
 | 
						|
 * You should have received a copy of the GNU Lesser General Public
 | 
						|
 * License along with FFmpeg; if not, write to the Free Software
 | 
						|
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 | 
						|
 */
 | 
						|
 | 
						|
/**
 | 
						|
 * @file
 | 
						|
 * MS RLE decoder based on decoder by Mike Melanson and my own for TSCC
 | 
						|
 * For more information about the MS RLE format, visit:
 | 
						|
 *   http://www.multimedia.cx/msrle.txt
 | 
						|
 */
 | 
						|
 | 
						|
#include "libavutil/intreadwrite.h"
 | 
						|
#include "avcodec.h"
 | 
						|
#include "msrledec.h"
 | 
						|
 | 
						|
static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
 | 
						|
                             GetByteContext *gb)
 | 
						|
{
 | 
						|
    unsigned char rle_code;
 | 
						|
    unsigned char extra_byte, odd_pixel;
 | 
						|
    unsigned char stream_byte;
 | 
						|
    unsigned int pixel_ptr = 0;
 | 
						|
    int row_dec = pic->linesize[0];
 | 
						|
    int row_ptr = (avctx->height - 1) * row_dec;
 | 
						|
    int frame_size = row_dec * avctx->height;
 | 
						|
    int i;
 | 
						|
 | 
						|
    while (row_ptr >= 0) {
 | 
						|
        if (bytestream2_get_bytes_left(gb) <= 0) {
 | 
						|
            av_log(avctx, AV_LOG_ERROR,
 | 
						|
                   "MS RLE: bytestream overrun, %d rows left\n",
 | 
						|
                   row_ptr);
 | 
						|
            return AVERROR_INVALIDDATA;
 | 
						|
        }
 | 
						|
        rle_code = stream_byte = bytestream2_get_byteu(gb);
 | 
						|
        if (rle_code == 0) {
 | 
						|
            /* fetch the next byte to see how to handle escape code */
 | 
						|
            stream_byte = bytestream2_get_byte(gb);
 | 
						|
            if (stream_byte == 0) {
 | 
						|
                /* line is done, goto the next one */
 | 
						|
                row_ptr -= row_dec;
 | 
						|
                pixel_ptr = 0;
 | 
						|
            } else if (stream_byte == 1) {
 | 
						|
                /* decode is done */
 | 
						|
                return 0;
 | 
						|
            } else if (stream_byte == 2) {
 | 
						|
                /* reposition frame decode coordinates */
 | 
						|
                stream_byte = bytestream2_get_byte(gb);
 | 
						|
                pixel_ptr += stream_byte;
 | 
						|
                stream_byte = bytestream2_get_byte(gb);
 | 
						|
                row_ptr -= stream_byte * row_dec;
 | 
						|
            } else {
 | 
						|
                // copy pixels from encoded stream
 | 
						|
                odd_pixel =  stream_byte & 1;
 | 
						|
                rle_code = (stream_byte + 1) / 2;
 | 
						|
                extra_byte = rle_code & 0x01;
 | 
						|
                if (row_ptr + pixel_ptr + stream_byte > frame_size ||
 | 
						|
                    bytestream2_get_bytes_left(gb) < rle_code) {
 | 
						|
                    av_log(avctx, AV_LOG_ERROR,
 | 
						|
                           "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
 | 
						|
                    return AVERROR_INVALIDDATA;
 | 
						|
                }
 | 
						|
 | 
						|
                for (i = 0; i < rle_code; i++) {
 | 
						|
                    if (pixel_ptr >= avctx->width)
 | 
						|
                        break;
 | 
						|
                    stream_byte = bytestream2_get_byteu(gb);
 | 
						|
                    pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
 | 
						|
                    pixel_ptr++;
 | 
						|
                    if (i + 1 == rle_code && odd_pixel)
 | 
						|
                        break;
 | 
						|
                    if (pixel_ptr >= avctx->width)
 | 
						|
                        break;
 | 
						|
                    pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
 | 
						|
                    pixel_ptr++;
 | 
						|
                }
 | 
						|
 | 
						|
                // if the RLE code is odd, skip a byte in the stream
 | 
						|
                if (extra_byte)
 | 
						|
                    bytestream2_skip(gb, 1);
 | 
						|
            }
 | 
						|
        } else {
 | 
						|
            // decode a run of data
 | 
						|
            if (row_ptr + pixel_ptr + stream_byte > frame_size) {
 | 
						|
                av_log(avctx, AV_LOG_ERROR,
 | 
						|
                       "MS RLE: frame ptr just went out of bounds (run)\n");
 | 
						|
                return AVERROR_INVALIDDATA;
 | 
						|
            }
 | 
						|
            stream_byte = bytestream2_get_byte(gb);
 | 
						|
            for (i = 0; i < rle_code; i++) {
 | 
						|
                if (pixel_ptr >= avctx->width)
 | 
						|
                    break;
 | 
						|
                if ((i & 1) == 0)
 | 
						|
                    pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
 | 
						|
                else
 | 
						|
                    pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
 | 
						|
                pixel_ptr++;
 | 
						|
            }
 | 
						|
        }
 | 
						|
    }
 | 
						|
 | 
						|
    /* one last sanity check on the way out */
 | 
						|
    if (bytestream2_get_bytes_left(gb)) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR,
 | 
						|
               "MS RLE: ended frame decode with %d bytes left over\n",
 | 
						|
               bytestream2_get_bytes_left(gb));
 | 
						|
        return AVERROR_INVALIDDATA;
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
 | 
						|
                                   int depth, GetByteContext *gb)
 | 
						|
{
 | 
						|
    uint8_t *output, *output_end;
 | 
						|
    int p1, p2, line=avctx->height - 1, pos=0, i;
 | 
						|
    uint16_t pix16;
 | 
						|
    uint32_t pix32;
 | 
						|
    unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
 | 
						|
 | 
						|
    output     = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
 | 
						|
    output_end = output + FFABS(pic->linesize[0]);
 | 
						|
 | 
						|
    while (bytestream2_get_bytes_left(gb) > 0) {
 | 
						|
        p1 = bytestream2_get_byteu(gb);
 | 
						|
        if(p1 == 0) { //Escape code
 | 
						|
            p2 = bytestream2_get_byte(gb);
 | 
						|
            if(p2 == 0) { //End-of-line
 | 
						|
                if (--line < 0) {
 | 
						|
                    if (bytestream2_get_be16(gb) == 1) { // end-of-picture
 | 
						|
                        return 0;
 | 
						|
                    } else {
 | 
						|
                        av_log(avctx, AV_LOG_ERROR,
 | 
						|
                               "Next line is beyond picture bounds (%d bytes left)\n",
 | 
						|
                               bytestream2_get_bytes_left(gb));
 | 
						|
                        return AVERROR_INVALIDDATA;
 | 
						|
                    }
 | 
						|
                }
 | 
						|
                output = pic->data[0] + line * pic->linesize[0];
 | 
						|
                output_end = output + FFABS(pic->linesize[0]);
 | 
						|
                pos = 0;
 | 
						|
                continue;
 | 
						|
            } else if(p2 == 1) { //End-of-picture
 | 
						|
                return 0;
 | 
						|
            } else if(p2 == 2) { //Skip
 | 
						|
                p1 = bytestream2_get_byte(gb);
 | 
						|
                p2 = bytestream2_get_byte(gb);
 | 
						|
                line -= p2;
 | 
						|
                pos += p1;
 | 
						|
                if (line < 0 || pos >= width){
 | 
						|
                    av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
 | 
						|
                    return -1;
 | 
						|
                }
 | 
						|
                output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
 | 
						|
                output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]);
 | 
						|
                continue;
 | 
						|
            }
 | 
						|
            // Copy data
 | 
						|
            if (output + p2 * (depth >> 3) > output_end) {
 | 
						|
                bytestream2_skip(gb, 2 * (depth >> 3));
 | 
						|
                continue;
 | 
						|
            } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
 | 
						|
                av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
 | 
						|
                return AVERROR_INVALIDDATA;
 | 
						|
            }
 | 
						|
 | 
						|
            if ((depth == 8) || (depth == 24)) {
 | 
						|
                for(i = 0; i < p2 * (depth >> 3); i++) {
 | 
						|
                    *output++ = bytestream2_get_byteu(gb);
 | 
						|
                }
 | 
						|
                // RLE8 copy is actually padded - and runs are not!
 | 
						|
                if(depth == 8 && (p2 & 1)) {
 | 
						|
                    bytestream2_skip(gb, 1);
 | 
						|
                }
 | 
						|
            } else if (depth == 16) {
 | 
						|
                for(i = 0; i < p2; i++) {
 | 
						|
                    *(uint16_t*)output = bytestream2_get_le16u(gb);
 | 
						|
                    output += 2;
 | 
						|
                }
 | 
						|
            } else if (depth == 32) {
 | 
						|
                for(i = 0; i < p2; i++) {
 | 
						|
                    *(uint32_t*)output = bytestream2_get_le32u(gb);
 | 
						|
                    output += 4;
 | 
						|
                }
 | 
						|
            }
 | 
						|
            pos += p2;
 | 
						|
        } else { //run of pixels
 | 
						|
            uint8_t pix[3]; //original pixel
 | 
						|
            if (output + p1 * (depth >> 3) > output_end)
 | 
						|
                continue;
 | 
						|
 | 
						|
            switch(depth){
 | 
						|
            case  8:
 | 
						|
                pix[0] = bytestream2_get_byte(gb);
 | 
						|
                for(i = 0; i < p1; i++)
 | 
						|
                        *output++ = pix[0];
 | 
						|
                break;
 | 
						|
            case 16:
 | 
						|
                pix16  = bytestream2_get_le16(gb);
 | 
						|
                for(i = 0; i < p1; i++) {
 | 
						|
                        *(uint16_t*)output = pix16;
 | 
						|
                        output += 2;
 | 
						|
                }
 | 
						|
                break;
 | 
						|
            case 24:
 | 
						|
                pix[0] = bytestream2_get_byte(gb);
 | 
						|
                pix[1] = bytestream2_get_byte(gb);
 | 
						|
                pix[2] = bytestream2_get_byte(gb);
 | 
						|
                for(i = 0; i < p1; i++) {
 | 
						|
                        *output++ = pix[0];
 | 
						|
                        *output++ = pix[1];
 | 
						|
                        *output++ = pix[2];
 | 
						|
                }
 | 
						|
                break;
 | 
						|
            case 32:
 | 
						|
                pix32  = bytestream2_get_le32(gb);
 | 
						|
                for(i = 0; i < p1; i++) {
 | 
						|
                        *(uint32_t*)output = pix32;
 | 
						|
                        output += 4;
 | 
						|
                }
 | 
						|
                break;
 | 
						|
            }
 | 
						|
            pos += p1;
 | 
						|
        }
 | 
						|
    }
 | 
						|
 | 
						|
    av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
 | 
						|
                    int depth, GetByteContext *gb)
 | 
						|
{
 | 
						|
    switch(depth){
 | 
						|
    case  4:
 | 
						|
        return msrle_decode_pal4(avctx, pic, gb);
 | 
						|
    case  8:
 | 
						|
    case 16:
 | 
						|
    case 24:
 | 
						|
    case 32:
 | 
						|
        return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
 | 
						|
    default:
 | 
						|
        av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
 | 
						|
        return -1;
 | 
						|
    }
 | 
						|
}
 |