Technical Background Document:

3ivx MPEG-4 5.0.5

New Features

• OS X
  • Now Mountain Lion compatible
  • Mountain Lion GateKeeper Support
  • Retina Display Support
    

Improvements

• QT Video Codec
  
  • Now compatible with Mountain Lion's QuickTime Player X (10.2)
    
    
• QT Exporter
• Added Retina Graphics
• OS X Preference Pane
• Added Retina Graphics
• OS X Register Application
  • Added Retina Graphics
• OS X Installer
  • Added Retina Graphics
  • Installation packages are now a flat package so they can be signed
  • Code-signed with 3ivx's developer license, which makes GateKeeper happy

Bugs Fixed

• Core
  • Fixed an incompatibility issue caused by Mountain Lion's sandbox protection
    
    

Missing Features

• Core
  
  • Interlaced decoding is not implemented for S-frames (GMC)
    
    
    

Permanent Issues

• Core
  
  • XviD streams prior to build0000 (ie up to and including 0.9 stable series) with non-multiples of 16 are not MPEG-4 compliant and exhibit occasional glitches. There is no work-around.
    
  • NVops (not coded PVops) can be used to more efficiently represent dropped frames or frames which are identical to the previous frame. NVops are not correctly handled by the QuickTime MPEG-4 Stream hinter and will cause a -5402 error when attempting to hint a file which contains NVops. The solution is to not use NVop coding. The 3ivx DirectShow Media Muxer can be used to remove NVops from an already coded bitstream. (This is currently still an issue with QT6.5)
    
  • As decoder delay has been reduced by 1 frame, if the clip playing does not correctly indicate low_delay field - the first B span will jitter.
    
    
• QT Codec
  
  • QuickTime 7's native datarate setting is now in kilobits/sec. There are
    1000 bits in a kilobit, and 1024 bytes in a kilobyte, according to the
    QuickTime Player. Due to a work-around for an error in QT7's kilobit->byte conversion, third party applications which do not use the QT7 codec selection dialog to obtain a datarate from the user (in kilobits/sec) may end up undershooting by a factor 1.024 (roughly 2.5%). In order to correct for this multiply the datarate you enter into affected applications by 1.024. This is only an issue when using QT7.
    
  • Quicktime does not allow decoding GMC in mp4 files, error 2010 dialog would generally pop out
    
  • In certain versions of QuickTime Player, if using a CTTS enabled MP4 file, the first frame displayed will be black.
    
  • If the first frame produced is black, the last frame displayed will be mis-predicted.
    
    

For further information see TBD:3ivx MPEG-4 5.0.4