protected ulong ReadBoxSize(BoxBinaryReader reader)
{
ulong size = 0;
size = reader.ReadUInt32();
if (size == 1)
{
reader.BaseStream.Seek(4, SeekOrigin.Current); // Skip over the box type
size = reader.ReadUInt64();
}
return size;
}
/// <summary>
/// This method of building the mfra will make web requests in order to download the data
/// from the online source.
/// </summary>
/// <param name="callback">The action that should be notified when the process is complete.</param>
private async Task ReadMovieFragmentRandomAccess()
{
#if !RANGESUFFIXSUPPORTED // not all backend services support range suffixes. For example, Azure Blobs. Here is a way around this but it requires an extra request to get the length and therefore does not perform as well.
var fileSize = await WebRequestor.GetFileSizeAsync(this.fileUri);
#endif
// grab the mfra offset
#if RANGESUFFIXSUPPORTED
var offsetStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, -4);
#else
var offsetStream = await WebRequestor.GetStreamRangeNoSuffixAsync(this.fileUri, -4, fileSize);
#endif
uint mfraOffset = 0;
using (var reader = new BoxBinaryReader(offsetStream))
{
mfraOffset = reader.ReadUInt32();
}
// grab the mfra data
#if RANGESUFFIXSUPPORTED
var mfraStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, -mfraOffset);
#else
var mfraStream = await WebRequestor.GetStreamRangeNoSuffixAsync(this.fileUri, -mfraOffset, fileSize);
#endif
// Write the bytes to our TOC file
using (var reader = new BoxBinaryReader(mfraStream))
{
reader.GotoPosition(0);
Box box = null;
do
{
box = reader.ReadNextBox();
if (box != null)
{
this.Boxes.Add(box);
}
} while (box != null);
}
}