/// <summary>
/// Opens a local (offline) file and initializes the CFF data that can be used for
/// manifest generation.
/// </summary>
/// <param name="path">The file URI of the resource to be opened. i.e. ms-appx:////Big_Buck_Bunny.uvu </param>
public override async Task Parse(Uri path)
{
if (StorageFile == null)
{
StorageFile = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(path);
}
using (var fileStream = await StorageFile.OpenStreamForReadAsync())
{
var reader = new BoxBinaryReader(fileStream);
Box box = null;
do
{
box = reader.ReadNextBox();
if (box != null)
{
this.Boxes.Add(box);
if (box.Type == BoxType.Moov)
{
// There may be an mdat after the moov, if so parse it
if (reader.PeekNextBoxType() == BoxType.Mdat)
{
box = reader.ReadNextBox();
this.Boxes.Add(box);
}
// After parsing the moov and optional mdat after it, skip to the mfra
// this will jump past the moof and mdats which we don't need to process
reader.GotoMovieFragmentRandomAccess();
}
}
} while (box != null);
}
this.InitializeTrackRegistry();
}
private static Stream HackFragment(Stream stream)
{
long offset = 0;
long versionBitOffset = 0;
BoxBinaryReader reader = new BoxBinaryReader(stream);
Box box = null;
do
{
box = reader.ReadNextBox();
if (box != null)
{
if (box.Type == BoxType.Moof)
{
offset = box.Offset;
var traf = box.InnerBoxes.FirstOrDefault(b => b.Type == BoxType.Traf) as TrackFragmentBox;
if (traf != null)
{
var trun = traf.InnerBoxes.First(b => b.Type == BoxType.Trun) as TrackFragmentRunFullBox;
if (trun != null && trun.Version != 0)
{
versionBitOffset = trun.Offset + 8;
}
}
break;
}
}
} while (box != null);
if (offset == 0 && versionBitOffset == 0)
{
return stream;
}
else
{
stream.Seek(offset, SeekOrigin.Begin);
var buffer = new byte[stream.Length - offset];
stream.Read(buffer, 0, buffer.Length);
if (versionBitOffset != 0)
{
versionBitOffset -= offset;
buffer[versionBitOffset] = 0;
}
return new MemoryStream(buffer);
}
}
private static Stream TrimToBox(Stream stream, BoxType boxType)
{
long offset = 0;
BoxBinaryReader reader = new BoxBinaryReader(stream);
Box box = null;
do
{
box = reader.ReadNextBox();
if (box != null && box.Type == boxType)
{
offset = box.Offset;
break;
}
} while (box != null);
if (offset == 0)
{
return stream;
}
else
{
stream.Seek(offset, SeekOrigin.Begin);
var buffer = new byte[stream.Length - offset];
stream.Read(buffer, 0, buffer.Length);
return new MemoryStream(buffer);
}
}
/// <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);
}
}
private async Task<Box> GetBox(BoxType boxType)
{
// get the box size
var size = await this.GetBoxSize(this.fileOffset);
// gets the box
var stream = await WebRequestor.GetStreamRangeAsync(this.fileUri, this.fileOffset, this.fileOffset + (long)size);
Box box = null;
using (var boxReader = new BoxBinaryReader(stream))
{
box = boxReader.ReadNextBox();
this.fileOffset += (long)size;
}
if (box.Type == boxType)
{
return box;
}
else
{
return await this.GetBox(boxType);
}
}
private async Task<Box> GetNextBox()
{
var size = await this.GetBoxSize(this.fileOffset);
var boxStream = await WebRequestor.GetStreamRangeAsync(this.fileUri, this.fileOffset, this.fileOffset + (long)size);
Box box = null;
using (var boxReader = new BoxBinaryReader(boxStream))
{
box = boxReader.ReadNextBox();
this.fileOffset += (long)size;
}
return box;
}
