Showing papers by "Noel Murphy published in 2002"

Rhythm detection for speech-music discrimination in MPEG compressed domain

Abstract: A novel approach to speech-music discrimination based on rhythm (or beat) detection is introduced. Rhythmic pulses are detected by applying a long-term autocorrelation method on band-passed signals. This approach is combined with another, in which the features describe the energy peaks of the signal. The discriminator uses just three features that are computed from data directly taken from an MPEG-1 bitstream. The discriminator was tested on more than 3 hours of audio data. Average recognition rate is 97.7%.

Temporal video segmentation for real-time key frame extraction

Abstract: The extensive amount of media coverage today, generates difficulties in identifying and selecting desired information. Browsing and retrieval systems become more and more necessary in order to support users with powerful and easy-to-use tools for searching, browsing and summarization of information content. The starting point for these tasks in video browsing and retrieval systems is the low level analysis of video content, especially the segmentation of video content into shots. This paper presents a fast and efficient way to detect shot changes using only the temporal distribution of macroblock types in MPEG compressed video. The notion of a dominant reference frame is introduced here. A dominant frame denotes the reference frame (I or P) used as prediction reference for most of the macroblocks from a subsequent B frame.

MPEG audio bitstream processing towards the automatic generation of sports programme summaries

Abstract: The frequency subband scale-factors are fundamental components of MPEG-1 audio encoded bitstreams. Examination of scale-factor weights is sufficient for the establishment of an audio amplitude profile of an audio track. If, for sports programme TV broadcasts, the audio amplitude is assumed to primarily reflect the noise level exhibited by the commentator (and/or attending spectators), then, this vocal reaction to the significance of unfolding events may be used as a basis for summarisation. i.e. by relying on the exhilaration, or otherwise, expressed by the commentator/spectators, individual clips of the programme (e.g. camera shots), may be ranked according to their relative significance. A summary may then be produced by amalgamating (chronologically) any number of these clips corresponding to selected audio peaks.

Dublin City University video track experiments for TREC 2002

Abstract: Dublin City University participated in the Feature Extraction task and the Search task of the TREC-2002 Video Track. In the Feature Extraction task, we submitted 3 features: Face, Speech, and Music. In the Search task, we developed an interactive video retrieval system, which incorporated the 40 hours of the video search test collection and supported user searching using our own feature extraction data along with the donated feature data and ASR transcript from other Video Track groups. This video retrieval system allows a user to specify a query based on the 10 features and ASR transcript, and the query result is a ranked list of videos that can be further browsed at the shot level. To evaluate the usefulness of the feature-based query, we have developed a second system interface that provides only ASR transcript-based querying, and we conducted an experiment with 12 test users to compare these 2 systems. Results were submitted to NIST and we are currently conducting further analysis of user performance with these 2 systems.

Audio processing for automatic TV sports program highlights detection

Abstract: In today's fast paced world, the time available to watch long sports programmes is decreasing, while the number of sports channels is rapidly increasing. Many viewers desire the facility to watch just the highlights of sports events. This paper presents a simple, but effective, method for generating sports video highlights summaries. Our method detects semantically important events in sports programmes by using the Scale Factors in the MPEG audio bitstream to generate an audio amplitude profile of the program. The Scale Factors for the sub- bands corresponding to the voice bandwidth give a strong indication of the level of commentator and/or spectator excitement. When periods of sustained high audio amplitude have been detected and ranked, the corresponding video shots may be concatenated to produce a summary of the program highlights. Our method uses only the Scale Factor information that is directly accessible from the MPEG bitstream, without any decoding, leading to highly efficient computation. It is also rather more generic than many existing techniques, being particularly suitable for the more popular sports televised in Ireland such as soccer, Gaelic football, hurling, rugby, horse racing and motor racing.

Low Power Techniques for Video Compression

Abstract: This paper gives an overview of low-power techniques proposed in the literature for mobile multimedia and Internet appli- cations. Exploitable aspects are discussed in the behavior of dier- ent video compression tools. These power-ecient solutions are then classified by synthesis domain and level of abstraction. As this paper is meant to be a starting point for further research in the area, a low- power hardware& software co-design methodology is outlined in the end as a possible scenario for video-codec-on-a-chip implementations on future mobile multimedia platforms. Keywords — mobile multimedia, video compression, low power, hardware acceleration

MPEG-1 Bitstreams Processing for Audio Content Analysis

Abstract: In this paper, we present the MPEG-1 Audio bitstreams processing work which our research group is involved in. This work is primarily based on the processing of the encoded bitstream, and the extraction of useful audio features for the purposes of analysis and browsing. In order to prepare for the discussion of these features, the MPEG-1 audio bitstream format is first described. The Application Interface Protocol (API) which we have been developing in C++ is then introduced, before completing