EP0676898B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Frame sampling scheme for video scanning in a video-on-demand system
Assignee: International Business Machines Corp
•
Filing: 1995-03-20
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Granted: 1999-10-20
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Expires: 2015-03-20
Abstract
Abstract A system and method for performing variable speed scanning or browsing, wherein a user controls the playout speed of a movie, which does not require additional disk or network bandwidth resources. In a preferred embodiment, the method provides for scanning operations for an MPEG video stream. The method satisfies the constraints of the MPEG decoder (in the users set-top box) and require a minimum of additional system resources. The embodiments of the present invention include (a) a storage method, (b1) a segment sampling method, (b2) a segment placement method, and (c) a playout method, where (b1) and (b2) are two alternatives for segment selection. Thus, two sets of solutions are provided to support vriable speed scanning in a disk-array-based video server: One using (a), (b1) and (c), and the other using (a), (b2) and (c). <IMAGE>
Inventors
- 👤 Ming-Syan Chen
- 👤 Dilip Dinkar Kandlur
- 👤 Philip Shi-Lung Yu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 15:20
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/20; H04N21/23; H04N21/238; H04N21/2387; H04N21/231; H04N21/2312; H04N21/40; H04N21/47; H04N21/472; H04N21/47202; H04N7/00; H04N7/16; H04N7/173; H04N7/17309; H04N7/17318; H04N7/17336
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
167 words
A method of performing any of variable speed scanning
operations in a video server wherein at least one data
stream is provided from a mass storage media, comprising
the steps of: receiving, by the video server, a performance request
from a viewer for showing a particular video; transmitting a first data stream carrying the particular
video from the video server to reception equipment at the
viewer's location; receiving, by the video server, a scanning request
including control data indicative of the viewer's
selection of a scanning speed from a selectable range of
scanning speeds faster than a normal playout speed; identifying based at least in part on the control data
and a number of storage devices included in the mass
storage media, particular frames of the video to be
retrieved from the mass storage media; and transmitting, to the viewers location, a second data
stream including the particular frames instead of the
frames that would have been transmitted had the video
continued at the normal playout speed.
Claim 2
Dependent Claim
54 words
The method of Claim 1 wherein the frames are identified
and encoded intra (I) frames, predictive frames and
interpolated frames and stored in the mass storage media
as units of retrieval each of the units of retrieval
comprising consecutive ones of the frames beginning with
an I frame and ending before another I frame.
Claim 3
Dependent Claim
60 words
The method of Claim 1 wherein mass storage media is a disk
array, the particular frames are also identified as a
function of a number of disks in the array, the frames of
the video are distributed among a plurality of disks in
the disk array and wherein a plurality of the frames are
retrieved from the disks in parallel.
Claim 4
Dependent Claim
47 words
The method of Claim 1 wherein the storage media is an
array of disks and comprising the further step of
distributing the frames among the disks in the array as a
function of a number of disks in the array and at least
one predetermined scanning rate.
Claim 5
Dependent Claim
62 words
The method of Claim 1 wherein mass storage media is a disk
array, and wherein the frames of the video are distributed
among a plurality of disks in the disk array and such that
the particular frames are distributed evenly among the
disks and wherein the total number of frames retrieved is
the same as for transmission of the first data stream.
Claim 6
Dependent Claim
34 words
The method of Claim 3 wherein the frames are stored as
segments on the media and wherein each of the segments
comprises a sequence of consecutive frames which can be
decoded as a unit.
Claim 7
Dependent Claim
190 words
A video-on-demand system, comprising: a user station having a video decoder, a control
interface for receiving scan speed control commands from
a user and a first network interface for receiving video
data from the video server and for communicating the scan
speed control commands to the video server; said scan
speed control commands being indicative of the viewer's
selection of a scanning speed from a selectable range of
scanning speeds faster than a normal playout speed; a video server having a mass storage media, a second
network interface for sending the video data to the user
station and for receiving the control commands from the
user station; and processing logic at least in part
responsive to the control commands and a number of
storage devices included in the mass storage media for
identifying particular frames of a video to be retrieved
from the mass storage media and provided to the user
station, said particular frames being provided instead of
the frames that would have been provided had the video
continued at the normal playout speed; and a communication network, coupled to the first network
interface and the second network interface.
Claim 8
Dependent Claim
39 words
The video-on-demand system of Claim 7 wherein the frames
are stored as segments on the media and wherein each of
the segments comprises a sequence of consecutive frames
which can be decoded as a unit by the user station.
Claim 9
Dependent Claim
141 words
A video server, comprising: a mass storage media for storing a plurality of videos; a network interface for sending video data to a user, for
receiving a request for performance of one of the videos
and scan speed control commands from the user, said scan
speed control commands being indicative of the viewer's
selection of a scanning speed from a selectable range of
scanning speeds faster than a normal playout speed; and processing logic at least in part responsive to the
control commands and a number of storage devices included
in the mass storage media for identifying particular
frames of the one of the videos to be retrieved from the
mass storage media and provided to the user, said
particular frames being provided instead of the frames
that would have been provided had the video continued at
the normal playout speed.
Claim 10
Dependent Claim
62 words
The video server of Claim 9 wherein the frames of the one
of the videos are identified and encoded as intra (I)
frames, predictive frames and interpolated frames and
stored in the mass storage media as units of retrieval
each of the units of retrieval comprising consecutive ones
of the frames beginning with an I frame and ending before
another I frame.
Claim 11
Dependent Claim
61 words
The video server of Claim 9 wherein mass storage media is
a disk array, the particular frames are also identified as
a function of a number of disks in the array, the frames
of the video are distributed among a plurality of disks in
the disk array and wherein a plurality of the frames are
retrieved from the disks in parallel.
Claim 12
Dependent Claim
51 words
The video server of Claim 9 wherein the storage media is
an array of disks and wherein the frames a distributed
among the disks in the array as a function of a number of
disks in the array and at least one predetermined scanning
speed other than a normal playout speed.
Claim 13
Dependent Claim
54 words
The video server of Claim 9 wherein the mass storage media
is a disk array, and wherein the frames of the video are
distributed evenly among disks in the disk array such that
the number of frames retrieved during scanning is the same
as for transmission of a video stream at normal playout
speed.
Claim 14
Dependent Claim
39 words
The video server of Claim 9 wherein the frames are stored
as segments on the media and wherein each of the segments
comprises a sequence of consecutive frames which can be
decoded as a unit by a user station.
Claim 15
Dependent Claim
57 words
The video server of claim 11, further comprising
retrieval means for retrieving the particular frames of
the one of the movies from the disks in parallel groups
of the frames, wherein the number of frames retrieved in
parallel from the disks during scanning is the same as
for transmission of a video stream at normal playout
speed.
References Cited (Backward Citations)
No citation records indexed.
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