Perceived video quality measurement technologies
AccepTV has developped several video quality measurement technologies (commonly called "video quality metrics") :
- a Full Reference metric which is generic (designed to work for any codec)
- a No Reference metric designed for MPEG-2
- a No Reference metric designed for H.264
- a Parametric metric designed for MPEG-2
- a Parametric metric designed for H.264
- an Hybrid metric designed for MPEG-2
- an Hybrid metric designed for H.264
All these metrics are the result of many years of research in the fields of human vision modeling, perceived quality evaluation and video processing.
To design a perceived video quality metric, we develop vision models in order to reproduce human perception of video. Then we apply these models to videos from which we extract features which are relevant to human judgment of video quality. At last, we combine several measures performed on these features in order to compute video quality scores. These video quality scores are compared to the ones which are given by human observers during subjective video quality assessment tests (these tests are performed in normalized viewing conditions).
A metric is validated only if it provides video quality scores which are well correlated to subjective video judgment over an important number of videos.
Other technologies
AccepTV has also developped C/C++ libraries to decode video files using DirectShow filters. For example, these libraries enable to:
- decode video and/or decode audio
- process video with DirectShow filters (including codecs)
- capture videos from SDI/HDSDI/HDMI or IP interfaces (UDP, RTP)
- capture to memory or directly to disk (this may require fast hard disk drives arrays)
- play videos on SDI/HDSDI/HDMI
- perform simultaneous play and capture operations
AccepTV has also skills:
- in network and web technologies: TCP, UDP, SNMP, FTP, SMTP, HTTP, PHP, javascript, etc.
- in DirectShow applications for Windows Mobile devices (capture, playing, video processing, video filtering)
At last, AccepTV has developed software libraries to process audio and video streaming in real time under Linux.
