MPEG-1/-2 coders from Canopus

By Sergey Demchenko, Larissa Bocharova

DVStrom 2 bundle

The Canopus Company from Japan releases a special device for coding/decoding of MPEG-1 and MPEG-2 streams, so and includes the functions of the coding/decoding in their own cards, intended for nonlinear editing.

The most popular Canopus card with coding and decoding feature is Canopus DVStorm 2. Additional module installed on base card allows to code the content in MPEG-1 and MPEG-2 stream practically in real time from time scale of Adobe Premiere applications directly and StormEdit, providing creation either a united mpg-file, or separate files for video and audio, which is possible to use for DVD authoring. Herewith Canopus DVStorm 2 gives the big choice of necessary adjustments, for instance, of video stream rate, video stream type (variable or permanent), GOP structures, program or elementary stream sign, type and rate of stream during audio coding etc. With Canopus DVStorm 2 a set of MPEG tools for editing and change of the MPEG files parameters is delivered: for trimmings, division on parts, reduction of stream rate, division on elementary streams. One of the particularities of the card DVStorm 2 is a possibility of the direct capture of the MPEG-1/-2 material through analogue and DV card inputs. These functions are executed by MediaCruise program which is included in the toolkit. Also, with this program it is possible to decode MPEG-files, residing on hard disk of the computer, and remove them on analogue outputs (decoding DVD is not supported).

The specific devices for coding/decoding MPEG-1/-2 streams, produced by Canopus, are realtime MPEG-coders of MPEGPRO EMR series and MPEGPRO MVR series, which are intended for compositing of DVD, VideoCD or MPEG-content for Internet applications. Additionally the same special device is the Amber card, providing MPEG- video coding in realtime for the consequent LAN transmission.

MPEGPRO EMR

Canopus MPEGPRO EMR is a high efficient hardware coder, representing an external block with analogue inputs (video: S-Video (Y/C) with standard connector or RCA with adapter; the audio: stereo, two RCA), connected to computer through USB interface. MPEGPRO EMR provides the high-quality realtime coding of video signal recepted from analogue sources in MPEG-1 and MPEG-2 streams. Files formed on coder output are ready for immediate use for DVD authoring. With this purpose the software of the supply software Ulead DVD Workshop SE package is used, which allows to realize the recording on DVD-R/-RW/+R/+RW or CD-R/-RW disks directly or for video archiving. MPEGPRO EMR supports the MPEG-2 streaming in the range from 4 to 15 Mbit/s for standard resolution (SIF is Standard Image Format; the horizontal resolution is 352×288 in PAL) and from 2 to 8 Mbit/s for HD1 (the HD1 picture has a horizontal resolution twice as little as compared with D1, and the resolution is 352×576 in PAL). The rate of MPEG-1 stream can be in a range from 1 to 1.8 Mbit/s for SIF. (For reception of the stream rate more than 6 Mbit/s it is necessary to connect via USB 2.0 bus). Besides, it is possible to use any constant (CBR) or variable (VBR) streaming (coding for one passage). As other coders of Canopus MPEGPRO series, the devices of EMR series provide the high quality MPEG streaming due to using of one-shot synchronizationing and special technology of noise reduction and prefiltering, including the dividing of Y/C to three vectors.

MPEGPRO MVR Card

Canopus coders of MPEGPRO MVR series (or named as MVR1000 SX), are similar to devices of EMR series, but herewith provide a PCI-card with analogue inputs (Y/C on video and stereo RCA on audio). One interesting particularity of MVR coders is the placing of noise-suppressing device inside, which reduces the noise level in analogue videosignal, provides keeping of the frames in intermediate buffer for stabilization of the stream, avoids the jitter of vertical line in frame, appearing from any instability of tape-drive mechanism, as well as realizes the digital reinforcement a level of enter signal for supporting of its level stability. MPEGPRO MVR coders allow not only to code the analogue signal to MPEG in realtime, but also by means of special DV-MPEG utility enable to code DV-files from hard disk of the computer in MPEG in a mode, which is almost in realtime. Besides, in MPEGPRO MVR kit the connected module for Adobe Premiere application is included, which allowsing to accelerate the export of the project from time scale of the program in MPEG-1/-2 stream. (For capturing from analogue sources the Canopus MediaCruise software program is used.)

User interface (top) and Amber coder card

For coding video in MPEG-2 (D1, HD1) and MPEG-1 in realtime with the following transmission on local-area networks the Canopus Company produces the Amber PCI-card, which is installed on video server and interacts with Canopus MediaEdge control program. For decoding video and audio the MPL-D2000 card on user computer is installed, which allows to display pictures both on screen of the computer, and on screen of the television set. It is a possibility to use the external block-decoder (Set Top Box), which is connected to video monitor or television set.

Being compatible not only with server applications, but also with system of the nonlinear editing (DVRex and DVRaptor), MPEG-coders of Amber series are an efficient instrument for high-quality processing, archiving and delivery of DV-content. Providing the possibility of the different compression using (I, B, P, MP@ML frames), these coders allow to choose the pictures with necessary quality which can be from high (PAL 720×576, NTSC 720×480, CCIR-601) up to very low, forming streaming from 1 to 15 Mbit/s. The use of constant or variable bit rate enables user to adjust the stream depending on picture parameteres. Amber coders also allow to realize the capture of the stereoaudio (up to 48 kHz, 16 bit), encoding him in MPEG Layer II format. (The capture and output of picture and audio are realized through analogue composite, S-video and stereo RCA input/output.)

Material is provided by ProViS Company