v0.51.0

Added

• Copy methods for FtypBox and StypBox
• StreamFile for decoding a stream of fragmented mp4
  • BoxSeekReader to make an io.Reader available for lazy mdat processing
  • examples/stream-encrypt showing how to read and process a multi-segment file
    • On an HTTP request, a file is read, optionally further fragmented, and then encrypted
• New functions DecodeBoxBody and similar to allow for two-step header and body parsing
• Support for FLAC audio including fLaC and dfLa boxes
• Support for ID32 (ID3v2) box
• Support Spherical Video V1 Metadata

Fixed

• AddEmptyTrack returns reference to newly added track
• duration is printed by MdhdBox.Info()
• extended size usage only allowed for mdat boxes
• trackID is checked when decrypting content
• Proper handling of trailing bytes in avc1 (VisualSampleEntryBox). Issue 444
• Proper removal of boxes when decrypting PR 464
• More robust decode of malformed files