- Simultaneous encode/decode/preview in a robust, compact unit
- Low preview latency
- H.264 HP@L3, MPEG-4 ASP, MJPEG video compression
- AAC, G.711 audio compression, uncompressed PCM
- Unicode text and graphic overlay
- Closed caption/VBI support for H.264 streams
- GPS receiver and two incremental encoder interfaces/dual GPIO
- Incremental encoder counts and GPS data can be overlaid onto video
- Ideal for video pipeline inspection, radar processing and video surveillance applications
Model 2253P is a USB device that combines the functions of a model 2253 A/V codec, GPS receiver, and two multifunction ports in a compact and robust metal enclosure. All operating power is supplied by a single USB port.
Each multifunction port can operate as an incremental quadrature encoder interface or as dual general purpose digital inputs (GPIO). Encoder counts, GPS data, and GPIO states can be monitored over USB. Real-time encoder counts and GPS data can be overlaid onto any video stream and GPIOs can pause and start streams, all without host intervention.
Multiple, independent video processors allow the unit to simultaneously produce two different video streams from its single composite input and send the streams out over USB. One of the streams can be a low-latency uncompressed stream (useful for real time previewing) and the other compressed, or both streams may be compressed. Image transformations (resolution, rotation, mirroring) are independently configurable for each stream, as well as compression type and bit rate in the case of compressed streams.
Up to 1024 bytes of application-supplied data can be inserted in the H.264 or MPEG stream at regular frame intervals or single shot. Closed captions are supported for H.264 streams.
Port inputs are compatible with both TTL/CMOS and differential RS-422 signals. Incremental encoders may be powered by the 2253P or an external power supply. When a port is used as dual GPIOs, the host can manually monitor GPIO states or the port can automatically send notifications over USB upon state changes. Also, each GPIO can be used to control the flow of any stream.
An integral GPS receiver produces NMEA data and sends it out over USB. If desired, the host may send GPS information back to the 2253P to be overlaid on the preview or compressed video, or the 2253P can automatically overlay GPS data onto the video in real time. Power is provided for an external active antenna through the 2253P's threaded SMA antenna connector.
Video and audio are available as elementary streams or may be multiplexed in MP4 container format.
The 2253P supports transport streams by packaging elementary streams with error correction and stream synchronization to help maintain integrity when the signal is degraded. The transport stream uses AAC audio and H.264 for MPEG-4.
Hardware-generated timestamps are employed to keep audio synchronized to the video, thus eliminating "lip sync" problems. MP4 files can be edited in Adobe Premiere Pro with A/V sync preserved.
Real-Time Text Overlay
The overlay generators can position up to 160 characters of text anywhere in the video frame. A unique text string, consisting of mixed constant and variable text, may be defined for each overlay generator. Text variables are automatically updated every video frame. Supported variables include time, date, GPS position, incremental encoder counts, and frame count.
Graphics Overlay with Unicode Text
Overlay images can be displayed on top of the composite video output, compressed streams, or the preview stream (but not low latency preview stream). BMP and PNG image formats are supported, with 24 or 32 bits per pixel and up to eight transparancy levels.
High quality, styled unicode text (bold, italic, underline, outline and shadow) can be overlaid on any video stream. Up to 256 full-color overlay regions are supported on the composite output, and up to eight monochrome regions are supported for capture or preview.
The 2253P can also perform as a decoder, converting a USB-supplied compressed audio/video stream into standard analog video and audio signals. (Note: Decoding is guaranteed only for streams captured with the 2253). The following formats are supported for decoding: MPEG-4, H.264, MP4 and MJPEG. The composite output video can be sourced from either the composite video input or a decoded compressed stream.
Low Latency Preview
Model 2253P supports a low latency preview mode for real-time applications. When capturing in native resolution (704x480 for NTSC or 704x576 for PAL) this mode reduces the overall latency by approximately one frame time.
Model 2253P features a sturdy metal enclosure with connectors for video, audio, USB, GPS antenna, and multifunction ports.
A USB cable is supplied with model 2253P.
A GPS antenna and video cables must be purchased separately.
||1 NTSC/PAL composite, 75 Ohm
||1 NTSC/PAL composite, 75 Ohm
||640x480@ 30 fps (NTSC); 720x576@25 fps (PAL); YUV4:2:2, GREY8, JPEG, RGB
||See timing diagrams below
||1 line stereo + 1 microphone mono
Software selectable (only one may be active)
||1 line stereo
||Up to 160 characters for full resolution images
|Video Output Overlay
||Up to 256 regions of BMP and PNG (with 24 or 32 bits/pixel), or unicode text.
16-bit color, 3-bit alpha channel
|Video Capture Overlay
||Up to 8 monochrome regions of BMP and PNG (with 24 or 32 bits/pixel), or unicode text
||2 independent image transformers:
Resize to various resolutions
Mirror horizontally or vertically
||Video: H.264 HP@L3, MPEG-4 ASP, JPEG;
Audio: G.711, AAC
|Output stream format
||Elementary audio/video, MPEG-4 program stream (.MP4), MJPEG AVI, Transport Stream
||32-bit incremental encoder interface, 10 MHz maximum count rate;
Dual digital inputs with edge detection
||Differential: RS-422, < 7v CMV; Single-ended: 5V TTL/CMOS compatible, w/integral 3.3 KΩ pull-up
||5V for external encoder/contact loads, 100 mA maximum
||RJ-45 receptacle per channel
||Decoded: latitude, longitude, speed, heading, time, date;
Undecoded: all raw data, in conformance with NMEA 0183
||GPS active antenna (not included)
||USB 2.0 High-speed
||1 input, galvanically coupled or optically isolated
1 output, optically isolated
||< 1.5 w (300 mA @ 5 V) from USB port (excluding 2253P encoder power)
||Standard version: 0 to 70 °C
||2253P: 5.14" x 3.28" x 1.14"
Preview Latency Timing