Emc Corporation

Michel Noury

Sorin Faibish

Daniel Gardere

Wayne William Duso

Peter C Bixby

John Forecast

Seyfullah H Oguz

Jie Wang

Sebastian Keller

Sebastien Keller

Raymond Mantchala

Jean Louis Rochette

To produce a paused MPEG coded video stream from an original MPEG coded video stream, an I frame is extracted from the original stream, and a Group of Pictures for a 'pause' (a pause GOP) is constructed containing the extracted I frame, some 'frozen' frames, and padding. Each &#x201c;frozen&#x201d; frame is a P frame that repeats the I frame. When a pause is requested in the original stream, a seamless transition is made from the I frame to the pause GOP, and the pause GOP is played in a loop until a resume is requested. To resume, the pause GOP is completed and a seamless transition is made to continue in the original stream from the I frame where the pause had begun.

Method of pausing an MPEG coded video stream

MPEG coded video data includes groups of pictures (GOPs). Each group of pictures includes one or more I-frames and a plurality of B- or P-frames. To produce an MPEG slow-forward coded video stream, the coding type of each frame in the MPEG coded video data is identified, and freeze frames are inserted as a predefined function of the identified coding type and as a predefined function of a desired slow down factor. In a preferred implementation, for a slow-down factor of n, for each original I- or P-frame, (n&#x2212;1) backward-predicted freeze frames are inserted, and for each original B-frame, (n&#x2212;1) copies of the original B-frames are added, and a selected amount of padding is added to each copy of each original B-frame in order to obtain a normal play bit rate and avoid video buffer overflow or underflow.

Generation of MPEG slow motion playout

Coded video from an on-line MPEG video encoder is stored as a clip in a video server or is otherwise received in the video server and prepared or used for splicing. In order to reduce apparent frame inaccuracy that may result from the splicing process, the on-line MPEG video encoder and the server are coordinated so that the group-of-picture (GOP) structure in the encoder provides specified In-points and Out-points that are valid and desirable for splicing. An encoder control protocol is also provided for remote control of the on-line MPEG video encoder in order to coordinate the on-line MPEG video encoder with the video server.

MPEG encoder control protocol for on-line encoding and MPEG data storage

Original-quality MPEG coded video is processed to produce reduced-quality MPEG coded video for trick mode operation by removing non-zero AC DCT coefficients from the 8&#xd7;8 blocks of I-frames of the MPEG coded video to produce I-frames of reduced-quality MPEG coded video, and inserting freeze frames in the reduced-quality MPEG coded video. Preferably, the coded video is stored in a main file, a fast-forward file and a fast-reverse file. The fast forward file and the fast reverse files contain reduced-quality I frames corresponding to original-quality I frames in the main file. A reading of the main file produces an MPEG transport stream for an audio-visual presentation at a normal rate, a reading of the fast-forward file produces an MPEG transport stream of the audio-visual presentation in a forward direction at a fast rate, and a reading of the fast-reverse file produces an MPEG transport stream of the audio-visual presentation in a reverse direction at a fast rate. Preferably, the files share a volume that includes at least one GOP index associating the corresponding I frames of the files.

Processing of MPEG encoded video for trick mode operation

Predictive analysis is performed upon encoded digital motion video (such as an MPEG Transport Stream) to facilitate real-time splicing. The predictive analysis includes estimation of upper and lower bounds of the data levels in a decoder's video and audio buffers for splicing in such a way as to prevent buffer overflow and underflow. This enables buffer management techniques including padding or stuffing, micro-restamping, freeze or repeat of frames, skip or drop of frames, alignment of audio with video. The predictive analysis also includes analysis of the structure of the encoded audio including audio access units (AAUs) and compression windows (AFs), prediction in the compressed domain of initial conditions of the decoder buffer levels for every single Elementary Stream (ES) component of a Transport Stream (TS), and identification of valid splicing In Points and Out Points based on the predicted buffer levels without any special encoder. This permits splicing of different compressed audio types without consideration of the details of the compression mechanism. The predictive analysis may also include recommendations or marking. The analysis is performed on ingest of the data as a pre-processing in preparation for splicing of a new file on early queuing in a data storage system before streaming.

Growing community of inventors

Villebon sur Yvette, France

Michel Noury