context.Response.WriteFile(fullpath, fp, length);
context.Response.Flush();
context.Response.Close();

Without Flush, my code was throwing an error.

When using this code to load videos that are a couple Gigs in size.

the second last line

—————
context.Response.WriteFile(fullpath, fp, length);
—————

would throw an error saying length can only be between 0 and Int32.MaxValue. in that case, a file of 2.2Gb would trigger this error.

I have worked around this by sending the data in blocks of 2Mb ( you can customize the block size). The following is my modification. Use it over the line above.

—————
long blockSize = 1024 * 1024 * 2; //2mb
while(length > 0)
{
if(length > blockSize)
{
context.Response.WriteFile(fullpath, fp, blockSize);
context.Response.Flush();
fp += blockSize;
length -= blockSize;
}
else
{
context.Response.WriteFile(fullpath, fp, length);
context.Response.Flush();
fp += length;
length -= length;
}
Thread.Sleep(10);
}
—————

I haven’t tested it, but that does sound like a good enhancement – I would think it would work.

I use your code for delivering large files. Thanks for the code! Sometimes I do receive an error in the IIS log: not enough storage is available to proccess this command.

Wouldn’t it make sense to use
context.Response.TransmitFile(fullpath, fp, sizeThreshold);
instead of
context.Response.WriteFile(fullpath, fp, sizeThreshold);
to release memory and not buffering the file before writing the file to the output stream?

The HttpContext is a variable that’s available when your ASP.NET application is handling a web request. Check the project on Github, there is a sample application showing it’s use:

http://videostreamer.codeplex.com/SourceControl/latest#SampleWebApplication/VideoStreamer.ashx

// If the range starts with an ‘-‘ we start from the beginning
// If not, we forward the file pointer
// And make sure to get the end byte if spesified
if (range.StartsWith(“-“))
{
// The n-number of the last bytes is requested
anotherStart = size – Convert.ToInt64(range.Substring(1));
}

I believe you want to set anotherEnd here. From my testing I never saw a request start started with -, but I wanted to point it out since it could cause a problem in some specific case.