Multimedia Data Read in Problem

[azntekkan]

Hi, I currenty looking at making a multimedia player which plays DV format videos. I have been experimenting with different ways to read in the file. i.e fread, ReadFile, mmioRead.

But these functions seem to have trouble when it comes to large files(currently using a 300 meg file for testing). The functions are eraddic when reading in the files.

I'm reading in the files in 15 megs chunks into unsigned char pointers(buffers).

The functions start off reading fast, at about 30 mb/s but then after reading in about 45 meg(3 read in's) it starts to slow down to about 7 megs a second and then when it reaches the end of the file it speeds up again.

My program requires at least a 20 meg/s read in. i'm looking for any suggestions to help me out. Any new io functions for reading in large files quickly will be greatly appreciated.

 

[mishou]

try playing with the size of the chunk, but 20meg/s are hard to achieve (take into consideration the hard-drive, its fragmentation status a.s.o)