Media pipeline with multichannel video processing and playback

DETAILED DESCRIPTION The present invention will be more completely understood through the following detailed description which should be read in conjunction with the attached drawing in which similar reference numbers indicate similar structures.
All references cited herein, including pending patent applications, are hereby expressly incorporated by reference.
A media pipeline 35 with two channels of digital video for providing effects will now be described in connection with FIG.
2.
The media pipeline 30 shown in FIG.
1 is modified to include a compression/decompression (CODEC) unit 58 which is a modification of compression/decompression system 44 of FIG.
1.
The CODEC unit 58 has two CODEC channels 50 and 52.
One is used for compression and decompression, i.
e.
, for both recording and playback, while the other is used only for playback.
The outputs of these channels are fed to a blender 54 which combines them according to the desired effect.
It is not necessary to use compressed data; however, compression is preferable to reduce storage requirements.
This compression/decompression unit 58 is described in more detail in British provisional specification 9307894.
7, filed Apr.
16, 1993, under U.
S.
foreign filing license 504287 granted Apr.
13, 1993.
This CODEC unit 58 will now be described in more detail in connection with FIG.
3.
In this figure, a control unit 60 controls two channels of coder/decoders.
The modification to the media pipeline 30 is made by assigning, in the control unit 60, different sections of the compressed data buffer 42 to each channel.
A sequence of digital still images is also assigned to a channel.
Thus, when the sequence is read into the compressed data buffer 42, it is input to the section assigned to the channel for that sequence.
Thus, reading and writing of data into the FIFO 62 and 64 for the CODECs 66 and 68 is based on the assignment of a channel to a selected sequence of digital still images.
Each channel has a separate CODEC, either a first CODEC 66 or a second CODEC 68