Given the way file compression works, I don't think it's possible to get an accurate value. There are probably compression programs that can give you a best guesstimation by analyzing a chunk of the file. The only compression program I ever use is 7zip, and it doesn't do it, so I can't tell you what would.
No its not about prediction model but Benchmark applications that calculate compression Speed and rate somehow and result the compressed size I made some test with 7z but it doesn't give the compressed size Code: RAM size: 4095 MB, # CPU hardware threads: 4 RAM usage: 882 MB, # Benchmark threads: 4 Compressing | Decompressing Dict Speed Usage R/U Rating | Speed Usage R/U Rating KiB/s % MIPS MIPS | KiB/s % MIPS MIPS 22: 6119 274 2176 5953 | 74918 382 1673 6392 23: 6072 289 2141 6187 | 74534 382 1688 6449 24: 5930 293 2175 6376 | 74245 385 1694 6518 25: 5828 302 2202 6655 | 74168 389 1697 6601 22: 6300 289 2119 6129 | 75685 385 1676 6457 23: 5871 294 2032 5983 | 74714 385 1680 6465 24: 5897 299 2120 6341 | 74618 387 1694 6550 25: 5686 302 2149 6493 | 72879 385 1683 6486 ---------------------------------- | ------------------------------ Avr: 293 2139 6265 | 385 1686 6490 Tot: 339 1912 6377
WinRAR can do at least an estimation: Open WinRAR - select File - Info - compression prognosis Example: h ttp://w ww.tahionic.com/computers/how%20to%20use%20winrar/WR_P4.gif