mpeg2decode is our implementation of an ISO/IEC DIS 13818-2
decoder. It converts MPEG-1 and MPEG-2 video bitstreams into uncompressed
mpg2ppm takes one ISO/IEC DIS 13818-2  MPEG-2 video bitstream
and convert them to uncompressed video. Since MPEG-2 is (by definition)
forward compatible with MPEG-1, mpg2ppm also decodes MPEG-1 sequences
(ISO/IEC IS 11172-2 ).
The decoder is not optimized for speed, although some parts (e.g. variable
length decoding, inverse DCT) are based on relatively fast algorithms. The
emphasis was on correct implementation of the standard and simple structure
of the program. Its main purpose is to demonstrate a sample implementation of
an MPEG-2 decoder and to serve as an educational tool. Our hope is that this
implementation makes it easier to understand the relatively complex details
of the standard.
As you can deduce from the list of missing features, mpg2ppm is still under
development. However, we considered the current version to be complete
enough to justify a public release.
The decoder has been extensively tested on bitstreams produced by a variety
of encoders from the MPEG research community to ascertain validity of the
implementation. Of course we can't guarantee complete compliance with the
+ decodes non-scalable, spatial scalable, SNR scalable and data partitioning
MPEG-2 video bitstreams
+ supports Simple, Main, SNR Scalable and Spatially Scalable Profile streams
at all defined levels
+ decodes MPEG-1 (ISO/IEC IS 11172-2) video bitstreams (except D-picture
+ optional output of detailed decoding information
+ robustness against stream syntax errors
+ fast IEEE 1180-1990 compliant integer arithmetic inverse DCT
+ optional double precision floating point inverse DCT
+ Exports to Portable PixMap Image format as defined in PBMPLUS ,
a graphics package by Jef Poskanzer. Extension is .ppm.
- spatial scalability other than interlaced -> interlaced
- P/B/D-picture MPEG-1 sequences
- temporal scalability
- error concealment
- repeat_field_first and other mostly display process oriented features.
Go to The Project page for more info and downloads.