How do I re-size a binary file?

Josh · 2015-11-06T01:19:29

Hii I'm trying to re-size a binary file. It's seems when I do this it's off by 8 bytes. If I use a different file it might be 3 or 5 bytes. Here is my re-size code: // index the beginning of the new .bik file int index = 2160640; // files to load std::ifstream readFile("baa_logo_run_v5_h264.bik", std::ifstream::binary); std::ifstream readFile2("riddeler.bik", std::ifstream::binary); // length of old file long length = 9972608; // get size of readFile readFile.seekg(0, readFile.end); long size = readFile.tellg(); readFile.seekg(0); // get size of readFile2 readFile2.seekg(0, readFile2.end); long size2 = readFile2.tellg(); readFile2.seekg(0); // allocate memory for file content char* readBuffer1 = new char[size]; char* readBuffer2 = new char[size2]; // read contents in buffer readFile.read(readBuffer1, size); readFile2.read(readBuffer2, size2); readFile.close(); readFile2.close(); // file to write to std::ofstream WriteFile("myfile.ty", std::ofstream::binary); // update new bik files // .bik file size is less than current bik length if (size2 < length) { // re-size writeBuffer long newSize = size - (length - size2); char* writeBuffer = new char[newSize]; // rebuild file again for (int i = 0; i < newSize; i++) { writeBuffer[i] = readBuffer1[i]; } // counters and flag int num = 0; int num2 = 0; int flag = 0; // length of the whole file for (int i = index; i < newSize; i++) { // length of the new bik file if (num < size2) { writeBuffer[i] = readBuffer2[num]; } num++; // if the new bik is stored then flag = 1 if (num > size2) { flag = 1; } // write the rest of the other files. if (flag == 1) { if (num2 < newSize && index + length + num2 < newSize) { writeBuffer[i] = readBuffer1[(index + length + num2)]; } num2++; } } // write to file WriteFile.write(writeBuffer, newSize); WriteFile.close(); delete[] writeBuffer; } // end of rebuild file

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Started by SlashC++Programmer November 01, 2015 05:27 AM

10 comments, last by SlashC++Programmer 9 years, 1 month ago

fastcall22

10,918

November 02, 2015 04:29 AM

He said something about trying to put a riddler video in the place of a batman video, but "it was off by 8 places"

Oh, that's easy.

Most that do games package assets into a single archive, tend to have two sections: The directory index and the actual file data. You can generally just overwrite the existing content of the file, provided it's the same size or smaller. (And since it's a video, you'd need to check the video and audio codec.) Otherwise, you might be able to append the video file to the end of the archive, and update the directory index with the new location and size. Or you could rearrange everything and update every entry in the directory index...

SlashC++Programmer

Author

139

November 06, 2015 01:19 AM

Hi guys thanks. So I can't just load the whole thing in memory? Loading the whole thing in memory causes prolems? Yes I'm making a file.ty that has a lot of batman assets in it. The reason I hardcoded it at the top was to give you an idea what I'm facing.

How do I re-size a binary file?

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How do I re-size a binary file?

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