Technical Background Document: 3ivx D4 4.5.1

New Modules

3ivx DirectShow Video Encoder
* New DirectShow Video Encoder supports all the features of the VfW Encoder and more!
* Variable Frame Rate support, timestamps from original media are preserved
* Automatic PAR support. Automatically preserves media's DAR no matter what cropping or scaling is performed.
* DirectShow based means easy integration with any DirectShow application


New Features

Core
* Added support for an obscure MPEG-4 variant produced by some Digital Video Recorders

3ivx Video for Windows (VfW) Codec
* Encoding support for MPEG-4 PAR in AVI files.

3ivx DirectShow Video Decoder
* Decoding support for MPEG-4 PAR in AVI files.

3ivx DirectShow Media Muxer
* Muxing support for MPEG-4 PAR in AVI files.

3ivx DirectShow Media Splitter
* IChapterInfo support allows MP4 chapter lists to be used with many popular players.
* ChapterMarker support allows MP4 chapter lists to be used with other popular players.
* Support for AMR audio (as produced by some mobile phones). Note: 3ivx does not currently include an AMR audio decoder.

Win Installer
* M4A, MP4 and MOV are now registered as audio/video types with Windows Media Player
* M4A, MP4 and MOV can now be used in Windows Media Player's Media Library and Playlists.


Improvements

3ivx DirectShow Media Splitter
* Implements frame based seeking. It now works perfectly when the splitter is in "Frame accurate seeking"
* Fast seeking no longer causes frame stutter
* Large MP4/MOV files now open in seconds, rather than minutes.
* Uknown audio formats are not decoded as PCM

3ivx DirectShow Media Muxer
* Chunk buffer is now automatically enlarged if required.

3ivx DirectShow Audio Encoder
* Edit Text Fields were converted to Static Text
* VBR/ABR modes are now mutually exclusive
* FAAC was updated to 1.23.5

3ivx DirectShow Audio Decoder
* Audio Output buffer was enlarged, resulting in significantly less skips.

3ivx QuickTime Video Codec
* Now plays bitstreams which use a bpp of 12


Bugs Fixed

3ivx DirectShow Media Splitter
* Fixed crash when using frame based seeking
* Compaact AAC malformed MP4 files no longer crash the splitter
* PCM bug: "my video plays to fast and the audio is just noisy static"

3ivx DirectShow Media Muxer
* Fixed crash on large frame sizes, or >8mbps streams

3ivx DirectShow Audio Encoder
* Property Dialog's text fields no longer appear to have any effect

3ivx DirectShow Audio Decoder
* Fixed a registery validation bug


Known Bugs

Core
* Inter4v Bframe MBs are not always correctly decoded
* Some high bitrate Sorenson MPEG-4 video bitstreams decode highly blockily.

3ivx QuickTime Video Codec
* The QT codec does not encode correctly with Adobe Premiere. The resulting video only shows keyframes. Work-arounds, configure 3ivx for all keyframes, or preferably use the 3ivx VfW codec.

3ivx QuickTime Video Codec for Windows
* When one movie has two or more video tracks, each encoded with 3ivx there may be problems playing the video when DirectDraw Acceleration is enabled in the QuickTime settings control panel. Work-arounds, disable DirectDraw acceleration, or DirectDraw.

3ivx DirectShow Media Muxer
* The muxer is currently limited to muxing streams no more than approximately 9.942 hours in length. If you attempt to mux a stream longer than this the resulting MP4 will be corrupt.


Unknown Bugs

3ivx DirectShow Media Muxer
* The DS Muxer probably can't mux streams over 4GB in size


Missing Features

Core
* >1 Warp-point GMC is not currently supported
* Interlaced decoding is not currently supported


Non Issues

3ivx DirectShow Media Muxer
* The muxer will not connect to a filewriter which does not have an .mp4 or .mov extension.
* The muxer can not be connected to the splitter.


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 QT6.4)

For further information see TBD:3ivx MPEG-4 4.5