System and method for displaying and editing digitally sampled

System and method for displaying and editing digitally sampled
US008793580B2
(12) United States Patent
(10) Patent N0.:
(45) Date of Patent:
Robinson
(54)
5,204,969 A
5,227,892 A
5,467,288 A
SYSTEM AND METHOD FOR DISPLAYING
AND EDITING DIGITALLY SAMPLED AUDIO
DATA
US 8,793,580 B2
Jul. 29, 2014
4/1993 Capps et al.
7/1993 Lince
11/1995 Fasciano et al.
(Continued)
(75) Inventor: Robert S. Robinson, Trenton, NJ (US)
(73) Assignee: Channel D Corporation, Trenton, NJ
(Us)
(*)
Notice:
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.C. 154(b) by 1592 days.
Filed:
EP
WO
1258879
9103053
11/2002
3/1991
OTHER PUBLICATIONS
Howarth, Jamie, et al “Correction of Wow and Flutter Effects in
Analog Tape Transfers,” Audio Engineering Society Convention
Paper, 117th Convention, pp. 1-6 (Oct. 2004).
(21) App1.No.: 11/759,068
(22)
FOREIGN PATENT DOCUMENTS
(Continued)
Jun. 6, 2007
Primary Examiner * Boris Pesin
(65)
Prior Publication Data
US 2008/0074486 A1
Assistant Examiner * Matthew E11
(74) Attorney, Agent, or Firm * Lowenstein Sandler LLP
Mar. 27, 2008
Related US. Application Data
(60)
Provisional application No. 60/811,249, ?led on Jun.
6, 2006.
(51)
Int. Cl.
data recordings are digitally sampled, segmented, and ren
(58)
(2006.01)
(2006.01)
(2006.01)
dered into a plurality of arc segments. A value of one or more
audio data parameters are determined for each arc segment. A
US. Cl.
CPC . GIIB 33/10 (2013.01); GIIB 3/00 (2013.01)
USPC
........................................................ ..
715/716
Field of Classi?cation Search
USPC
and transforming the digital samples into a user-controllable
visual representation for computer-based data interpretation
and editing. A plurality of synchronized streams of sampled
G06F 3/00
GIIB 3/00
GIIB 33/10
(52)
(57)
ABSTRACT
A method and system for receiving audio data, converting the
audio data into discretely sampled data, such as digital audio,
........................................................ .. 715/716
See application ?le for complete search history.
(56)
References Cited
U.S. PATENT DOCUMENTS
2,033,479 A *
5,047,999 A *
3/1936
Murphy .......................... .. 369/6
9/1991
van derMeulen ....... .. 369/30.17
visual indication of the parameter value, such as a color, hue,
or shade, is determined for each arc segment. The plurality of
arc segments are arranged into a plurality of arcs, and the
plurality of arcs are arranged as a smooth, continuous radial
spiral, or arcs, using graduated grays or colors to denote
waveform characteristics to form a realistic visual depiction
of a mechanical recording emulating a conventional “vinyl”
record. A user may interact with the record image, using a
locator cursor, to control and edit the audio data. In addition,
recording defects or other features may be highlighted on the
surface of the image as color keyed or iconic overlays, to
assist in the editing process.
22 Claims, 9 Drawing Sheets
US 8,793,580 B2
Page 2
(56)
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6’897’868 B2 *
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Parker, Conrad, “Sweep: Audio Editing, Scrubbing and Latency
Visualisation,” PP~ 1-6~
Plangent Process Software, “Frequently Asked Questions,” pp. 1-4.
Van Aeken, Francis, “Jackson DJ Software Powered by Musical
Metadata,” pp, 1-5,
Francis Van Aeken, “Jackson: DJ Software Powered by Musical
Metadata,”Van Aeken Software bvba (2005).
Conrad Parker, “Sweep: Audio Editing, Scrubbing and Latency
Visualisation” Linux 2003 Conference and Tutorials (Jul 31-Aug
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3 2003
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Johnston ....................... .. 700/94
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’
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_
_
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Milne et al. .............. .. 707/500.1
* cited by examiner
'
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US 8,793,580 B2
1
2
SYSTEM AND METHOD FOR DISPLAYING
AND EDITING DIGITALLY SAMPLED AUDIO
DATA
points or boundaries of the track) based only on the appear
ance of the waveform. For instance, a gradual song fade-out
or fade in can be heard quite noticeably even in the presence
of vinyl background noise, which may obscure the music,
CROSS REFERENCE TO RELATED
APPLICATION
when viewed as the waveform.
Accordingly, there is a need in the art for a method and
system for generating an intuitive and user-friendly visual
representation of discretely sampled data, wherein a user may
This application claims the bene?t of US. Provisional
Application Ser. No. 60/811,249 ?led on Jun. 6, 2006. The
entire disclosure of US. Provisional Application Ser. No.
interact with the visual representation in the form of a con
ventional ‘vinyl’ record and record playback apparatus (i.e., a
record player) to perform a number of tasks, including play
back, editing, content management, and error/defect detec
60/811,249 is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to a method and
system for transforming sampled data into a visual represen
tation with which a user may interact. In particular, this inven
tion relates to the transformation of audio data into a realistic
visual depiction of a mechanical recording (e.g., a conven
tional vinyl record). The present invention relates to a method
tion.
SUMMARY OF THE INVENTION
The current invention provides an alternative means of
display of information about the audio. Speci?cally, the
20
invention describes the generation of an image of an analog
format vinyl record disc, used as an interactive, virtual object.
of emulating the traditional playback experience of the pre
digital-audio era by simulating the tactile interaction with
This avoids many limitations of the current art, as well as
vinyl records which were originally used as a recording and
more closely and favorably linking the technical and enter
tainment (such as the rotation of the image on the computer
playback medium. The emulation of the visual properties of
the vinyl record format facilitates the display and editing of
the content of, for example, audio recordings.
25
characteristics of the display. A side bene?t to the platter
image, when playing back music in a way that emulates the
“album” format, is that an estimate of the remaining duration
of the current track, and subsequent tracks can be made visu
BACKGROUND OF THE INVENTION
In the playback of digitally recorded audio, if done in
30
conjunction with a visual display, such as a computer moni
35
ear amplitude versus time waveform display. The reasons for
providing the display can vary between the need for showing
technical information regarding the audio and to provide an
entertaining visual display (by viewing the audio waveform
or frequency spectrum information, for example).
40
plurality of arcs, is used that permits ?nding features of inter
est in the recording with greater precision than conventional
methods, while providing an easily manipulated overview of
the entire audio recording.
According to an embodiment of the present invention, the
plurality of digital samples are segmented into groups, or arc
segments. The digital samples of each arc segment are ana
lyzed to determine a value of at least one audio parameter for
the arc segment. Next, each arc segment is displayed with a
visual identi?er which represents the value of the at least on
On the technical side, provision is usually made for manu
ally altering the location of the playback position, such as
using a cursor indicator on the display, controllable via input
from a mouse. This is usually required for editing of the audio
data, such as dividing a long recording into individual tracks.
The editing is facilitated by observing visual cues in the
ally. This enhances anticipation and enjoyment of the music.
Instead of representing the audio as a traditional type of
rectilinear waveform display, a spiral radial paradigm, or a
tor, it is customary to provide some type of display that shows
information regarding the audio amplitude and time offset
(relative to the beginning or end of the recording) at the
playback position. Typically, this takes the form of a rectilin
display during playback, or applying other visual effects)
45
audio parameter (e.g., modulation). The visual identi?er, as
used herein, may include, but is not limited to, a color, hue,
shade, other visual characteristic which may be used to rep
display, such as regions of low signal amplitude, and using
resent the parameter value. This provides a user with a visual
these regions as tentative locations for establishing track divi
sions. One drawback to this approach is that in the display of
the overall waveform of a recording, the track separation
locations cannot be resolved visually, because they are typi
representation in the change of the parameter in the different
arc segments. Advantageously, changes in the value of the
50
parameter in one arc segment as compared to another, as
illustrated by the different visual identi?ers, may be used to
cally obscured by nearby audio having higher amplitudes.
communicate to the user relevant information about the audio
This is usually addressed by “zooming in” on a smaller por
tion of the waveform, permitting the visualization of the
lower amplitude audio at track boundaries. However, since
the zoomed waveform only comprises a subset of the entire
audio recording, a tedious scrolling operation may be
required to reliably ?nd all track boundaries.
An additional drawback arises when editing audio not
sourced from a quiet digital recording, such as when tran
content. By comparing the visual identi?ers of the arc seg
ments, the user can ‘see’ changes in the audio parameter.
55
The simulation goes beyond a cosmetic, stylized rendition
of the appearance of a vinyl record, because the appearance of
the groove modulations re?ects the actual audio content of the
recording, or possibly other parameters derived from the
audio information, which also can be displayed as an overlay
60
or color shading of the vinyl image. Also, displayed in the
circular format, periodic features in the recording are empha
scribing an actual analog vinyl record. Here, the amplitude at
track boundaries doesn’t drop to zero (digital silence);
instead, a residual background noise (such as turntable low
frequency noise, commonly known as “rumble”) is imposed
on the quiet parts of the audio. Digital silence doesn’t exist in
analog transcriptions of vinyl records, so it’s impossible to
establish accurate track mark points (i.e., the start and end
65
sized, and defects such as scratches (in the case of recordings
transcribed from vinyl records) used to facilitate the calibra
tion of the true playback speed.
According to an embodiment of the present invention, the
system and method convert discretely sampled data into a
display that emulates the vinyl record format. Then, the famil
US 8,793,580 B2
4
3
iar tonearm/stylus/vinyl record metaphor can be used for the
?rst time as a tool for editing and playing back digital audio
?les.
For example, inter-track silences are rendered as plainly
visible areas of low modulation, appearing as discrete circular
FIG. 8 illustrates a comparison of the performance of
exemplary approaches for locating physical defects during a
calibration process, according to an embodiment of the
present, invention; and
FIG. 9 illustrates an exemplary process for generating a
bands, rather than being compressed visually and obscured by
platter image, according to an embodiment of the present
adjacent high amplitude areas of the audio signal. This pro
invention.
It is to be understood that the attached drawings are for
purposes of illustrating the concepts of the invention and may
vides a visually informative cue or track mark starting loca
tion (i.e., a starting boundary of the track). The vinyl record
image waveform display format further expands this meta
not be to scale.
phor, because by manipulation of the computer input device,
DETAILED DESCRIPTION OF THE INVENTION
such as a mouse, the playback position can be manually ?ne
tuned by “grabbing” and “spinning” the vinyl disk, while
The present invention relates to a method and system for
simultaneously listening to a loopedplayback; of a fraction of
a second’s worth of audio.
generating a visual representation of input audio data
After navigating to a speci?c place of interest in the audio
recording with the aid of the vinyl image, which is a primary
received from a source, wherein in the visual representation
emulates a conventional vinyl record. The input audio data
advantage compared to an overview type rectilinear wave
form display, the process also may be enhanced at this stage
by viewing a highly magni?ed or zoomed version of the
waveform, as a visual overlay, in the familiar rectilinear for
mat. In this way, the two methods of displaying the recording
are complementary and reinforce each other’s utility, while
may be in either analog or digital format. If the input data is in
analog format, the analog data is ?rst converted into a plural
avoiding the tedious task of having to scroll slowly through
the recording using only a zoomed in rectilinear display.
Setting track marks (i.e., the boundaries of the track) inter
actively using both the waveform and audible feedback elimi
nates the possibility of inadvertently placing a track mark
20
digital format and comprise a plurality of digital samples,
and, thus, no conversion is required.
The plurality of digital samples (either as received from the
25
before the actual fade-out or after an actual fade-in. The
present invention allows a user to intuitive grab and spin the
30
source or as converted) are then segmented into a plurality of
arc segments. Next, for each arc segment, the value of at least
one audio parameter is determined. The arc segment is then
rendered and displayed with a visual identi?er which visually
represents the value of the at least on audio parameter. The
visual identi?er may be a color, shade, hue or other visual
expression of the value. By presenting each arc segment with
a visual identi?er representation of the value of the selected
audio parameter, the changes in the parameter may be seen
when viewing the plurality of arc segments when arranged
“platter” to re?ne and accelerate the editing process.
The general familiarity of the public with such records and
their associated playback equipment is an advantage, as most
persons already possess an intuitive grasp of the concept of
the vinyl LP disc. For users lacking familiarity with analog
ity of digital samples, according to any suitable method
known in the art. Alternatively, the input audio data may be in
35
into a series of arcs, the series of arcs emulating a record
turntables and vinyl records, these elements present an attrac
tive aspect of the design, given the current resurgence of
image.
interest in this recording and playback medium.
resentation of the input audio, herein referred to as the “record
A plurality of the arcs are combined to form a visual rep
image”. The record image comprises a plurality of arcs,
BRIEF DESCRIPTION OF THE DRAWINGS
40
The present invention will be more readily understood
from the detailed description of exemplary embodiments pre
sented below considered in conjunction with the attached
drawings, of which:
FIG. 1 is a diagram of an exemplary data display including
characteristics of a conventional record playback apparatus,
according to an embodiment of the present invention;
FIG. 2A illustrates exemplary components of the data dis
play, according to an acoustic-model data rendering embodi
ment of the present invention;
FIG. 2B illustrates an exemplary components of a data
exemplary record image generated according to the present
45
invention. Advantageously, a user may interact with the
record image much in the way one interacts with a conven
tional vinyl record to perform a number of functions, as
described in detail below.
The digital samples of the input data are processed (as
50
described below with reference to FIGS. 2A and 2B) and
converted to the radial representation, or plurality of arc seg
ments making up the larger arcs of the record image. This may
be accompanied by visual feedback of the ongoing process,
display, according to a physical-model rendering embodi
ment of the present invention;
FIGS. 3A and 3B show modi?ed data renderings using
subsets of the data shown in FIGS. 2A and 2B;
arranged to emulate a conventional “vinyl recor .”
Embodiments of the present invention are described below
in detail with reference to FIGS. 1-9. FIG. 1 illustrates an
denoted by progress animation arrow 4, as the image data, is
progressively calculated and overlaid on the platter substrate
55
3.
Portions of the digital samples with large amounts of
modulation, as assessed by the analysis algorithm, are dis
FIGS. 4A and 4B illustrate a process according to an
played as image highlights 1, while low levels of signal
embodiment of the present invention wherein a radial depic
tion of waveform data is used to assist in locating features of
invention to locate track boundaries in an analog music
modulation 2 are represented as unchanged, or nearly so,
compared to the substrate data display area 3.
The platter substrate 3 may be displayed as dark gray or
black color, or as a solid, bright color. The platter substrate 3
recording;
may also be patterned for aesthetic, ornamental purposes,
interest in the sampled data ?le;
60
FIG. 5 illustrates an use of an embodiment of the present
FIGS. 6A, 6B, 7A and 7B illustrate an exemplary process
for calibration of the time base of a data sample using physi
cal, periodic defects present in the source material, according
to an embodiment, of the present invention;
65
such as with a design, photographic image, or other illustra
tion. The highlights may be drawn with a variable opacity
from 0 to 100 percent, with a 100 percent value obscuring the
image of the substrate. Low levels of opacity may be used for
US 8,793,580 B2
5
6
aesthetic enhancement of the display, in conjunction with
for aesthetic compliance and conformity with the physical
playback medium being emulated.
different substrate colors or visual patterns. The highlighting
in areas with high waveform modulation, and substrate
prominence in areas of low modulation may be inverted,
providing a negative shaded image. The modulation may be
As shown schematically in FIG. 9, beginning at the lead-in
area 7, the image data information is applied to the blank
platter substrate 3. Each pixel in the image is treated as a
sub-segment of a larger arc, and has a variable, diminishing
(in the case of image data application begun at the lead-in
represented as gradations of gray tones or as false-color shad
ing. A combination of the two may be used to convey addi
tional information in the data display. For example, color
shading might be used to indicate differences in relative
amplitude or phase between a plurality of channels.
Other aspects of the data display, which is con?gured to
area) radius. The sub-segment is herein referred to as an arc
segment. As such, according to an embodiment, of the present
invention, each pixel equates to one arc segment. As the
image data is applied, the arc radius is diminished. The effec
emulate a familiar object, an audio recording playback tum
tive radius is calculated for each pixel of the image. The radius
table, include a label area 7 for various information, a radial
need not have a whole-number value, because modern com
spindle 6, tone arm 5, playback cartridge 9, playback stylus 8,
puter graphic imaging programs and routines are con?gured
to alias intermediate, ?oating-point representations, thus pro
cueing emulation button 10 and lead-in area 11. According to
a preferred embodiment of the present invention, a linear
style carriage-type tone arm is shown; but other aesthetic
variations may include pivoted straight or curved tone arms.
A linear design is illustrated in the ?gures because of the
viding increased realism of the spiral image drawing.
operations, as described in detail below.
For example, as shown in FIG. 9, given a substrate 1 with
radius 2 of 820 pixels, and a lead-in radius 3 of 800 pixels, the
?rst pixel applied is considered to be part of an arc segment 4
having a radius of 800 pixels. The shading (brightness or
One having ordinary skill in the art will appreciate that
features 5, 6, 7, 8, 9, 10, 11 are optional, and may or may not
be included in the data display. These features, used here as a
analysis model, as explained below. In the case of emulating
an analog playback disc, the next pixel, arc segment 5, is
simpler computation of data offsets during emulated cueing
functional aesthetic construction, are intended to emulate
components, features and aspects of a traditional audio ana
20
color) of this pixel (or arc segment) is determined by the
25
log disc recording playback system (turntable). Embodi
ments of the present invention incorporate these elements to
leverage the user’s likely familiarity and comfort level with
this particular object (i.e., the turntable). For users lacking
familiarity with analog turntables, these elements present an
attractive aspect of the design, given the current resurgence of
30
35
The brightness or color of the image is calculated at a
40
The image construed on may commence at any location on
the substrate, or even at the innermost radius of the substrate.
45
location is chosen a small distance inset from the outer simu
to maintain a spiral appearance.
According to an embodiment of the present invention, each
radius step employs a ?xed-radius, circular arc; each revolu
non-interconnected circles. This design allows the inclusion
of many of the desirable characteristics of the record image,
according to an embodiment of the present invention. A pre
able-radius, noncircular, spiral arcs to construct the record
image.
50
The label area 7 may have a radius between 5 percent and
90 percent of the substrate radius, although the optimum
value would be in conformance with the physical medium
emulated, such as, for example, a 7 inch diameter 33 or 45
55
The arc length also affects the way the input data is ana
lyzed. The input data is segmented into an integer number of
digital samples per arc segment. The optimum arc length for
emulation of an analog playback disc is determined by the
disc emulation model rotational rate, in conjunction with the
sample rate of the digital input data. This arc length is deter
mined by the following relation:
where s is the angular rotational rate of the disc, and
60
Fs the digital signal sample rate.
For example, given a sample rate of 44.1 kHZ and a disc
rotational rate of 331/3 revolutions per minute, each digital
sample occupies an arc angle of (360 degrees/revolution)*
somewhat diminished image data display capacity, and may
be useful in certain other contexts.
A small band of the substrate adjacent to the outside radius
of the label area may be reserved for the lead-out area, again
the ?nal image, balanced against the computational time
ferred embodiment, of the present invention employs vari
lated edge of the substrate, commonly known as the lead-in
RPM, physical recording disc; a 10 inch 33, 45 or 78 RPM
physical recording disc; or a 12 inch 33 or 45 RPM physical
recording disc. For purposes of illustration of an embodiment
of the present invention, a 12-inch 33 RPM LP format with
multiple individual music tracks is shown, with a label radius
approximately 20 percent of the substrate radius. This is
somewhat less than normally used with a physical analog
disc. The present invention also lends itself to construction of
single-track 12, 10 or 7 inch physical format emulation, for a
According to an embodiment of the present invention, the
unit of length of the arc segment is expressed in degrees. The
arc length (in degrees) is determined by the desired quality of
tion of the generated image consists of concentric, discrete,
However, in accordance with the aesthetics of the emulation
area 11. A portion of the image display area near the inner
radius also is reserved for a legend, printed description or
decorative image or design, the label area 7.
5 depends on the circumference and radius of the spiral arc
decreased by ((2 pi)/360) pixels for each segment to continue
at a point lying somewhere on the substrate.
of the familiar analog disc playback paradigm, a starting
tion). The starting radius 6 of the next arc segment (or pixel)
required. For example, if a ?xed arc length of 1 degree is
selected, the radius of the arc also must be continuously
plurality of points. The practical limit of the number of points
or pixels in the image is determined by the speed of the host
computer and the resolution of the display device. Regardless
of the resolution chosen, the image construction commences
analog disc normally is spun in a clockwise fashion, so
increasing time coordinate is in the counterclockwise direc
tion; the image data could also be applied in a clockwise
direction in an alternative embodiment of the present inven
being considered at that point.
interest in this recording and playback medium, even among
the demographic born after the onset of the mainstream appli
cation of digital sound recording.
applied counterclockwise from the ?rst, pixel (because an
65
((33+1/3 revolutions)/ 60 seconds)/(44100.0
second):0.004535 degrees per digital sample.
samples/
Given the above parameters, the arc segment length must
therefore be constrained to multiples of 0.004535 degrees. At
US 8,793,580 B2
7
8
an arc spiral radius of 800 pixels, this corresponds to an arc
the art will appreciate that, in practice, the tradeoff between
drawing many small arc segments and computational ef?
ciency dictates that arc segment lengths of greater than one
segment circumference (length) of 0.06332 pixels per data
sample.
One having ordinary skill in the art will appreciate that the
input data could be progressively resampled to any practically
attainable sample rate, generating the optimum number of
sampled points for a given arc segment length.
pixel (including more data samples per arc segment) and arc
Sine widths greater than one pixel be used. As such, according
to an embodiment of the present invention, a typical arc line
width of square root (2) pixels is used.
For large data sets the number of samples per arc segment,
According to an embodiment of the present invention, a
minimum arc length of 1 pixel is considered. In the above
example, a minimum arc segment length of 1 pixel corre
spond to 1/0.06332 or 15.79 data samples. Since an integer
can be increased and/or the arc line width decreased. These
parameters are adjustable at the discretion of the user, to
provide the most aesthetically pleasing image, while main
number of samples is required, this ?gure is back-calculated
using a minimum value of 1.6 samples per analysis sample,
taining a reasonable computational rate. For example, gener
giving a segment length of 16/15.79 or 1.013 pixels.
minutes of sampled digital audio on a currently shipping
consumer-level computer workstation takes approximately
ating a complete, high quality spiral image “platter” from 30
Therefore, the arc segment length is predetermined by the
sample rate of the input data. As the spiral radius decreases,
the arc segment length, in pixels, also decreases, in proportion
to the radius. Therefore, to maintain the minimum design
constraint of 1 pixel of arc length, the number of samples per
segment must be gradually increased (because the arc angle
30 seconds.
According to embodiments of the present invention, two
primary signal analysis models may be used to emulate the
appearance of the record image. One having ordinary skill in
20
image where areas of differing signal characteristics can be
differentiated upon visual inspection of the image. The visual
A computational shortcut may be taken at this juncture. Arc
segments with lengths greater than one pixel may be applied
that have a ?xed radius within the segment. These ?xed radius
segments are then joined to a previous segment having a
representation may be based on one or more of the following
25
slightly larger and a following segment having slightly
smaller radii, respectively. The granularity caused by this
30
per minute value; results of signal convolution showing
coherence with a comparison signal; and other known signal
characteristics. Although one having ordinary skill in the art
will appreciate that the present invention may be con?gured
35
parameter, for the purposes of illustration, the exemplary
40
embodiments described herein related to the present inven
tion are described with reference to signal characteristics/
parameters described herein as the level of amplitude of
modulation.
FIG. 2A shows a record image producing according to an
One additional step was performed to reduce the promi
nence of the locations where arcs are joined. The Root Mean
Square (RMS) values (explained below) obtained are slightly
low-pass ?ltered, so that the change in highlighting from one
segment to the next is less abrupt. The ?ltering is a simple
to generate a visual representation of any suitable signal
?rst-order In?nite Impulse Response (IIR) ?lter function,
h0:h1
Equation 2
exemplary signal characteristics, including, but not limited to
the interchannel or single channel phase or amplitude (modu
lation level); frequency balance; signal amplitude at a par
ticular or range of frequencies; total harmonic or intermodu
lation distortion over a range of or at a single frequency; beats
method is practically invisible. This technique was used to
generate the images included in the Figures.
the art will appreciate that alternative models similar to the
ones described in detail herein may be used to create a record
must be increased). This causes discrete changes to the arc
segment lengths, that were found to be unnoticeable.
where h1 is the highlighting parameter applied to the current
exemplary model according to an embodiment of the present
segment;
invention, herein referred to as the “Acoustic” model. Accord
h0 is the highlighting parameter applied to the previous seg
ment; and
ing to this embodiment, the Acoustic model calculates the
c1 is the ?lter coef?cient.
According to a preferred embodiment of the present inven
45
as described in detail above. The input signal typically com
prises two channels (stereo), in the case of an audio music
tion, c1 has a value between 1.0 (no ?ltering) and 0.01 (sig
ni?cant ?ltering), with a value of 0.9 determined to be opti
mum. After calculating h1, its value is substituted for h0
which then becomes the previous segment’s highlighting
50
55
60
calculated highlight level. For example, at high levels of
modulation, the opacity may be increased to approximately
90 percent, and reduced proportionate to the modulation level
to a minimum of approximately 30 percent at locations of low
or zero modulation. Thus, if the substrate blank; color is a
aliasing and transparency of the line segments, provided by
the host computer’s built-in graphics routines, may be
dark; blue, the highlights appearbluish white, and the areas of
adjusted to cover gaps in between adjacent arcs at different
radii. According to a preferred embodiment of the present
invention, the arc segment length may correspond to the
drawn width of the arc segment. One having ordinary skill in
the substrate were so imprinted.
According to an embodiment of the present invention, the
opacity of the arc drawing may be varied depending on the
samples per arc segment) and arc line widths greater than one
pixel be used. According to an embodiment of the present
invention, a typical arc line width of square root (2) pixels is
used, and a radius step of 1.0 pixel per revolution. Line
recording. However, any number of channels, including addi
tional channels, may be included in the analysis. The high
lighting amount (i.e., the pixel brightness) applied is propor
tional to the computed RMS value for the data sample. At
lower amounts of highlighting, the opacity of the arc drawing
may be reduced proportionately, to allow the color of the
substrate to show, or a decorative design to show through, if
value for the next iteration of the arc rendering. Note that such
highlight smoothing is not a requirement for the present
invention, but may optionally be applied to improve the
appearance of the record image.
In practice, the tradeoff between drawing many small arc
segments and computational ef?ciency dictates that, arc seg
ment lengths of greater than one pixel (including more data
RMS amplitude of the sum of the synchronized (in time) input
signal channels, for the number of samples per arc segment,
65
low modulation bluish black (black being the arc color used
for areas of low modulation). The preferred variable opacity
used is between approximately 5 and 1.00 percent. Altema
tively, the opacity of the overlaid arc drawing may be main
US 8,793,580 B2
9
10
tained at a ?xed value between 5 and 100 percent. At 100
data offset is calculated by the rotational rate represented by
percent opacity, the appearance of the image would depend
the platter image times 1/360 times the manually changed angle
of the platter.
solely on the arc drawing and would not be affected by any
coloration or patterning in the substrate.
FIGS. 2A and 2B illustrate an exemplary embodiment of
the present invention. As shown in FIGS. 2A and 2B, portions
of the data with low signal modulation appear as a dark band
11 in the image. Areas with moderate or high modulation
become highlighted according to the level of modulation, as
An alternate method of determining an accurate offset into
the source ?le may be accomplished by saving a lookup table
with an offset corresponding to each rendered image point, or
a lookup table for each image radius, and the data offset
calculated based on the sample offset for a given offset angle
from the lookup value. The precision in generating the image
is suf?cient to ensure pixel-accurate correspondence between
12. Iconic markers indicated by 13 and 36 highlight regions of
interest, and are superimposed on the image. Here, the mark
ers are con?gured to indicate putative transients in the data,
the image and the corresponding original sampled data. In the
case of a more complicated “vari-pitch” image generation
method mentioned below, the arc radius would not necessar
caused by defects (pops) in the source (digitally sampled
from an actual analog record platter). The algorithmic method
for pop detection in conjunction with the data display is
ily decrease in a simple linear fashion during the generation of
the image, and an alternate method, such as a look-up table,
may be used to correlate the stylus position and data offset.
described in detail below. Markers also can be displayed as a
The angular position of the platter is controlled by clicking
circular highlight, as 42.
The lead-in area as explained above is indicated by 14. In a
and spinning the platter, in emulation of the familiar turntable
preferred embodiment of the present invention, additional
20
paradigm. A “hand” cursor 33 is used to provide a feedback
cue for the user. One having ordinary skill in the art will
parameters are adjustable; a proportional slide control for
appreciate that any suitable pointer icon may be used in the
make-up gain 15. A Repeat parameter 16 used in conjunction
present invention. The platter-spinning paradigm and its
applications to examining and editing the data are explained
with an Editing feature and settings con?gured with controls
18, 19, 20 is detailed below. “Stylus cueing” for the emulated
turntable is provided by control 17; playback signal ampli
25
tude metering 28 and monitoring volume adjustment 29. Con
trols 30, 31, and 32 affect the operational mode of the pre
ferred embodiment of the present invention; namely,
mation display on the label area 34, including artist name 37,
title of recording 38, track names and times 41, plus spaces for
playback, editing or archiving (recording) mode, respec
tively.
30
“offset” refers to the position in number of digital samples
with reference to FIGS. 6 and 7. The additional information
43 may include the date of the recording of the digitally
35
cal model) is indicated by 46 and 47 on the label data area,
according to an embodiment of the present invention. The
data. For an audio recording, this could be represented either
Physical rendering model generates a somewhat different
40
image (shown in FIG. 2B), than theAcoustic model (shown in
FIG. 2A). The overall difference between the images gener
data offset time coordinate in minutes and seconds is indi
cated by time display 27. To assist in locating a low-modula
tion area, a ribbon display 26 representing the integrated
highlighting at each discrete radius is provided. According to
an embodiment of the present invention, the ribbon display
sampled music or data ?le.
The rendering model used (i.e., the Acoustic or the Physi
from the beginning of the recording of digitally sampled input
by the sample number or by a temporal value (time coordi
nate) in seconds. The exact sample position is indicated by
stylus 23; sighting aids are provided as marks 22 and 24. The
additional data 35 and 43. The additional information 35 may
include the calibrated platter rotational rate/pitch adjustment,
the application of which is described in greater detail below
In accordance with the tumtable/platter paradigm, the off
set into the digitally sampled input data can be adjusted by
moving the emulated cartridge 21 attached to the emulated
tone arm 25. As known in the art and used herein, the term
below, in conjunction with FIGS. 4 and 5.
Optionally, based on the type of input data, additional
features may be added to the record image. For example, for
a digital music recording, the record image may include infor
ated by the two models are not limited to contrast and/or
brightness differences in the generated highlighting. This is
45
illustrated by the arc highlight indicated by 48 in the Acoustic
model and 49 in the Physical model. The prominent highlight
48, at the same radial offset indicated by 49, illustrates an
represents the mean amplitude value of the signal over one
example of the kind of differences in the image appearance
circular arc (one revolution) at the radius on the platter image
corresponding to the radial position on the ribbon. Its purpose
which result from the choice of the Acoustic or Physical
model. Other differences in the models may be found in
is to provide an additional visual aid to locating areas of low
50
comparing the images of FIGS. 2A and 2B.
The Physical model is designed to more closely emulate
the physical appearance of an analog recorded disc. The
translation of an electronic signal to the physical undulations
55
when the stereo channels have a reverse polarity relationship.
or high modulation, for manually adjusting the playback or
editing location with the emulated stylus/cartridge. Although
the ribbon is con?gured here to show the signal amplitude/
modulation level, it alternatively may be con?gured to dis
play other suitable signal parameters.
on the disc causes a greater physical undulation to appear
The stylus radial offset from rest position at the lead-in area
Therefore, to emulate the physical appearance of the disc, the
(data offset time coordinate 0) and angular position of the
Physical model subtracts the corresponding digital samples
platter are used to back-calculate using an inverse of the
of the stereo channels before calculating the RMS amplitude
image generation algorithm to generate an accurate offset into
the digital source data ?le used to generate the image. For
value. In practice, visual comparison of actual, physical plat
60
example, given a manually chosen stylus position, the offset
into the data is simply the fraction of the total radial displace
Other models could be constructed, such as using Peak
ment from the lead-in area to the start of the lead-out area,
because each revolution of the platter represents the same
amount (time coordinate) of data (at constant rotational
velocity). When spinning the platter manually, such as when
editing the sampled data, as described below, any additional
ter recordings to the emulated images usually yields the most
realistic representation when the Physical model is used.
65
waveform values to generate highlighting information, for
example. However, in the preferred embodiment of the
present invention, the best results in generating interesting,
informative and aesthetically pleasing images were obtained
with the two models described herein.
US 8,793,580 B2
11
12
ner frequency between the two regions being approximately 1
kHz. The corresponding playback equalization is the inverse
An additional aspect of FIGS. 2A and 2B is that the entire
sampled data ?le was used to generate the platter image. Here,
the sampled ?le was a continuously recorded digital tran
scription of two sides recorded from a vinyl analog music
of the curve used in the disc manufacturing process. The
de-emphasis applied at playback to high frequencies mini
mizes the in?uence of high frequency noise generated during
the playback process. The low frequency emphasis compen
disc, Creedence Clearwater Revival’s “Cosmo’s Factory,”
Mobile Fidelity catalog number MFSL-l-037. An accurate
emulation of the original physical platter would consist of
sates for the low frequency roll-off applied to the sound
only one side of the music disc. In the Edit mode of the
recording during cutting of the disc, to limit the mechanical
preferred embodiment of the present invention, the full-?le
platter image assists in selecting the individual track mark
locations. For example, using the track editing features of an
embodiment of the invention, described below, the locations
in the digitally sampled recording corresponding to Side 1
and Side 2 of the original, physical vinyl based recording are
excursion of the disc cutter, which is greatest at low frequen
cies. A strict recreation of the physical characteristics of the
disc would apply the exact RIAA emphasis/de-emphasis
curve. Both platter generation models used in the present
invention use a hybrid approach that only attenuates the low
frequencies below 100 Hz, with a single-pole roll-off similar
to the RIAA equalization scheme. The high frequencies are
established, as are the individual track or song locations/
left emphasized, which produces a satisfactory result.
Changes in appearance of the platter image naturally would
offsets, by visually locating areas of low modulation on the
platter image, and manually positioning the stylus 23 at each
of these locations, in turn, and noting the corresponding sty
lus positions. In practice, the stylus position coordinates
would be noted and saved by the software application hosting
20
the invention, at the command of the user. This process is
further explained below in the description of FIGS. 4 and 5,
and in greater detail below. After assignment has been com
pleted, the individual emulated disc side platter images are
then generated from the corresponding subsets of the ?le.
The manufacture of analog music discs sometimes
result from different ?ltering schemes. However, the choice
of a particular ?ltering scheme is not fundamentally required
by the present invention.
In FIG. 2B, the segment indicated by the double arrow 50
represents the digital samples from side 1 of the sampled
music disc; the double arrow of 51 represents digitized infor
mation front side 2 FIG. 3 indicates the Play mode 58 of a
employs a technique known to practitioners in the art as
preferred embodiment of the present invention, after gener
ating the individual disc side images. The Play mode loads in
the disc side images and adjusts the sensitivity of the stylus
“vari-pitch,” which adjusts the inter-groove spacing (pitch) of
positioning (time coordinate) accordingly. The image seg
the disc. This prevents areas of large modulation from causing
the cutter head, used to generate the master stamper disc, front
crossing into a previously cut groove, ruining the stamper.
25
30
the platter image data, 54, 55, 56, 57 also is updated accord
The inter-groove spacing also may be controlled manually at
the discretion of the mastering engineer. Normally, inter
groove spacing is smaller on quiet areas of the disc and larger
on loud areas of the disc, particularly those with high ampli
tude low-frequency program content. This technique gener
ment 50 of FIG. 2B corresponds to the image segment 52 of
FIG. 3B. The image segment 51 of FIG. 2B corresponds to the
image segment 53 of FIG. 3A. The label information area of
ingly for side 1 in FIG. 3B and side 2 as shown in FIG. 3A.
35
FIG. 4 illustrates the use of the platter cueing paradigm to
adjust the offset of the waveform inspector. FIG. 4A shows an
offset into the original ?le, obtained by clicking and sliding
ally increases the duration of audio that can be placed on a
the cartridge and stylus 62 to the desired offset. The mouse is
disc, compared to using a ?xed inter-groove spacing dictated
by the maximum modulation level of the recording.
positioned above the image of the platter, and provides feed
According to an embodiment of the present invention, the
back to the user by clenching the hand cursor when the mouse
40
is clicked. At this stage, the preferred embodiment of the
present invention reveals a waveform display, indicating the
source waveform represented by the platter image at the offset
of the stylus position. Here, the offset has been adjusted to
45
waveform amplitude maximum; in this case, caused by a
method and system employ a ?xed inter-groove spacing.
Consequently, visual comparison of platter images created by
the systems and methods of the present invention and corre
sponding physical media (if transcribed digitally from an
analog disc) illustrate the differences that exist therebetween.
place the stylus over an iconic overlay 62 that indicated a
However, there are a plurality of different results possible
physical defect (pop) on the analog source disc. The corre
when mastering the physical recorded disc, as dictated by the
judgment of the mastering engineer. Because of this uncon
sponding time offset in the source data is indicated by display
60. The waveform 63 is comprised of left channel 64, right
trollable variable, the platter image generated by the method
an system of the present invention resemble, but not neces
50
sarily appear identical, to a physically manufactured product
made using the same audio data. While it would increase the
complexity of the platter image generation model used by the
present invention, it would be feasible to apply similar vari
pitch or adjustable inter-groove spacing techniques in the
55
invention.
The models used to generate the platter image use nearly
untiltered digitized input data, which, when obtained from
samples of analog music discs, has already been equalized to
compensate for the emphasis scheme used for playback of
analog disc recordings. Here, nearly un?ltered indicates that
position 70 to new position 71, in the direction, illustrated by
arrow 72, rotating the platter image clockwise about the cen
ter spindle, and incrementing the offset into the data ?le. This
is indicated by an increase of approximately 10 milliseconds
in the offset time indicator 69, the change in position of
waveform maxima icon 74, and translation of the peak 68
from waveform 63 by distance 73 in the waveform display.
FIG. 5 illustrates using the platter paradigm to determine
and set audio recording track boundaries. This may be accom
60
the input data samples are ?ltered to less than the usual extent
dictated by the pre-emphasis signal ?ltering that’s normally
applied during the manufacture (during the mastering stage)
of vinyl records. For example, the RIAA equalization empha
channel 66 and 67, and their normalized sum 65.
In FIG. 4B, the mouse has been dragged, from former
plished visually using only the waveform inspector 84, or
visually and audibly with the inspector in conjunction with
listening to a de?ned, continuously looped portion of the
audio ?le of interest.
65
In FIG. 5, the stylus is positioned in the platter lead-in area,
just prior to the start of the music information. The waveform
sis curve, well-known to practitioners of the art, accentuates
inspector display is split into two portions. The left half, 76 is
high frequencies while attenuating low frequencies; the cor
the waveform at a time offset prior to the stylus position. The
US 8,793,580 B2
13
14
right half, 77, depicts the waveform at a time offset following
the stylus position. The ?ducial mark 83 indicates the wave
embodiment of the present invention, these in?uences are
lumped together and considered to be due to turntable abso
form at exactly the stylus position.
lute speed inaccuracy.
Each half of the waveform display is independently nor
malized for amplitude. The waveform halves depicted in 76
and 77 are halves of a contiguous waveform; the apparent
platter, surface noise caused by physical damage to the disc
In the case of sound data sourced from an analog recording
surface, due to normal wear and tear, tend to accrue. Some of
discontinuity is caused by differences in scaling applied to the
display. The waveform immediately to the right of 83 appears
this noise may be caused by scratches or physical contami
nation involving adjacent grooves on the analog disc. The
noise is easily identi?able by its sound as an audible “pop” or
as a prominent transient in the waveform display. The peri
odicity of such pops in two adjacent grooves is approximately
equal to the reciprocal of the disc rotational rate. For a 331/3
RPM disc, this would be 1.800 seconds. Any deviation from
smaller because its scaling is in?uenced by the onset of the
music waveform at 78.
As the mouse is clicked and dragged on the platter image
surface, the waveform in the display 84 scrolls horizontally
and is rescaled in two halves about the ?ducial point 83. (The
this value would re?ect an error in the turntable playback
rotation rate.
The measured deviation can be used to recalibrate the
waveform depicted comes from the same source used to gen
erate all other Figures.)
The turntable platter paradigm becomes extremely useful
in setting a track mark point, especially when dealing with
image generation to increase the realism of the platter image
simulation, and also for correcting the time base (absolute
data sampled from an analog source. In contrast to data origi
nating from a digital recording, analog data often is accom
20
pitch) of the digitized recording via resampling. Techniques
panied by various forms of background noise. Unfortunately,
for resampling digital audio to arbitrary values for pitch
because of the masking effects of the noise, it’s not always
modi?cation are well-known to practitioners of the art. The
possible to accurately determine the beginning or end of an
audio track based solely on the appearance of the waveform.
mining the degree of pitch correction required.
In the preferred embodiment of the present invention, the
Mark-In mode selected by pressing control 81 causes the
audible playback and continuous looping of the waveform
from the edge of the frame 85 to the ?ducial 83, the portion of
the frame denoted by 76. The duration of the loop is set by the
Repeat interval control 16 in FIG. 2A, here 100 milliseconds.
The track mark-in, or start point of the track, may be
calibration procedure described below is valuable for deter
25
30
precisely determined by gently rotating the platter, which sets
the precise stylus offset, while listening to the playback. The
platter is rotated until any audible lead-in to the music wave
form 78 is absent. The auto-normalization of the lead-in
waveform also applies to the audible data as well as the
waveform inspector. This ampli?es the quiet prior to the
music introduction, ensuring that any musical information, is
included within the track mark-in, even if masked by noise,
and the nonmusical portion of the recording is excluded.
In FIG. 6 a sorted list 89 and 99 of the amplitude maxima
in the digitally sampled ?le is presented. Two adjacent entries
35
in the list at time offsets 26:10.90964 (90) and 26: 12.69802
(100) are separated by 1.78838 seconds. This is close to the
putative turntable rotation period (for a 331/3 RPM 12" LP
record) of 1.8000 seconds per revolution, and the maxima do
indeed correspond to a “pop” or defect on the surface of the
source analog disc recording. (There is an additional maxima,
at 26:09.12041 seconds that is indicated on the platter image
iconic overlay 92; but the calibration example below focuses
on the other two maxima. The time delta between maxima 91
and 92 is 1.78923 seconds, therefore the percent relative error
between choosing among these two measurements for cali
bration is 100*(1.78923—1.78838)/1.78838 or less than 0.05
40
percent.)
When a satisfactory mark-in has been established, it may be
In FIG. 6A the stylus is positioned at the ?rst maxima at
time offset 26:10.90964 seconds. The maxima also is indi
?nalized, in the preferred embodiment of the present inven
tion, and displayed accordingly in list 82.
platter, the offset may be ?ne-tuned to coincide with the peak
A similar procedure is used to establish the end point of the
track, also referred to as the track mark-out position, except
that the mark-out mode 88 is selected, and the looping mode
of the inspector display is reversed. Instead of looping the
portion of the waveform prior to the cursor position, 76, the
part of the waveform looped during playback is that after the
cursor position, between ?ducial 83 and edge of the looping
frame 86. In a similar fashion to that described above, the
platter is rotated until musical information at the lead-out of
the song is absent. This is ?nalized and used as the Mark-Out
as depicted 87.
FIGS. 6 and 7 depict using defects in the recorded material
to calibrate the proper playback speed. A primary source of
cated iconically on the platter image 91. By rotating the
45
be chosen. The sum of the waveforms of the two channels also
50
determine the rotation rate. The line frequency of utility
power is subject to variation, which affect the rotational speed
accuracy. Mechanical tolerances in the turntable components
can also affect the rotational speed. Finally, playback speed
inaccuracy can arise in the case of sampled digital audio if the
sample clock rates of the recording and playback devices are
different, again due to component tolerances. According to an
is displayed 94. The selection of the peak maximum may be
done manually or automatically.
In a preferred embodiment of the present invention, the
selection of the ?rst calibration offset is con?rmed by clicking
button 96. The time offset is echoed in the text display 97. The
next maxima 99 is selected in the list and ?ne tuning of
55
waveform maxima position 104 performed manually, if nec
essary. The iconic representation 91 of the ?rst maxima at
time offset 26:10.90964 (89) has rotated clockwise to 91' and
the second maxima at time offset 26:12.69802 now is posi
error in transcription of analog disc recordings is the quality
of the speed accuracy of the turntable. Many mid-priced
“audiophile” turntables rely on an AC synchronous motor to
maximum 95 (right channel) or 93 (left channel). Generally,
the channel with the transient having the most consistently
prominent waveform shape among the two time offsets would
60
tioned (102) directly under the stylus. If the rotation rate of the
turntable were exactly 331/3 RPM, the iconic overlays 92,
91/91' and 102 would be positioned on adjacent arcs of the
platter image, instead of being offset circumferentially from
each other. The offset occurs on the image because of the
turntable rotational velocity error. Con?rmation of the second
65
calibration mark is con?rmed by pressing button 106, and the
corresponding time offset 107 and calculated actual rota
tional rate 108 are echoed on the display. Pressing button 101
US 8,793,580 B2
15
16
con?rms the calibration and regenerates the platter image,
bly by playback). (Event 125 was generated by lifting the
physical playback stylus from the disc, understandably gen
erating a large amplitude transient.) The second algorithm
basing the platter revolution on a period of 1.78838 instead of
1.8000 seconds.
The resultant platter image show’s that the iconic overlays
uses the maximum slew rate of the left or right signal chan
nels. Of the 22 candidates displayed in the list 121, only one
indicating the peak maxima are now adjacent, as shown in
FIG. 7B (109), which focuses on the iconic overlay detail.
FIGS. 7A and 7B are described more thoroughly below, how
(122) was an actual pop event. The other candidates were
comprised of valid musical information.
Noticing that the transient waveforms in FIG. 6A showed
that the relative signal polarity during the pop event was
ever, overlays 112. 111' and 110" directly correspond to 92,
91/91' and 102, respectively, in FIGS. 6A and 6B.
This calibration procedure could conceivably be applied at
inverted at the peak of the pop, another algorithm that mea
sured the difference between channels was used. In list 120,
13 of 22 candidates highlighted (130) were veri?ed as being
different regions of the recording, in case the absolute rota
tional error varies throughout the recording process, and pre
suming that other surface defects exist at advantageous loca
caused by physical defects in the analog disc. The other pop
tions on the recording. However, it’s unlikely that properly
cared-for analog discs will have a large number of physically
event, 129 was the stylus lift mentioned above. This event also
has characteristics in common with pop defects, namely the
suitable defects; therefore, this technique is primarily
large amplitude inverted polarity difference between chan
intended as a means of a single-point rotational rate calibra
nels.
While this invention has been described in terms of several
tion that’ s applied uniformly for the duration of the recording.
It is possible that over a time period of typically 30 minutes,
representing the duration of a single side of an analog disc, the
preferred embodiments, there are alterations, permutations,
20
short-term variation in absolute rotational rate error can be
neglected.
For example, another suitable pop defect was located on
this recording with the aid of automated tools. In FIG. 8 at
offsets 33:09.88402 (123) and 33:08.09557 (124) pop defects
25
and equivalents, which fall within the scope of this invention.
Although the image display has been described in terms of
generating emulated images of analog audio discs, any data
possessing an innate periodicity lends itself to this type of
display. The effective rotational period of the display could be
adapted to suit the periodicity of the available data. A record
were located. The time offset between these defects is
ing of an electrocardiogram of a human or animal is a suitable
1.78845 seconds. Comparing this to the defects used for the
example of this sort of data. Presuming an average heart rate
above calibration example, 26: 10.90964 (90) and
26:12.69802 (100) which are separated by 1.78838, the
for a particular patient of 60 HZ, with a primary periodicity of
roughly 1 HZ, a long time record of events could be displayed
on the virtual platter surface. By setting the virtual display
resultant percentage difference in rotational error between
using these two measurements for calibration is 100*
(1.78845—1.78838)/1.78838) or less than 0.004 percent dif
ference. While it’s possible that the close agreement is fortu
itous, more likely it indicates that the variation in turntable
rotational velocity accuracy is probably small over the time
needed to digitally record and transcribe an analog audio disc.
30
rotational rate at 2 HZ, 120 heartbeat events would be dis
played per revolution. Each platter could show the equivalent
of 30 minutes or more of the electrocardiogram recording. A
steady heart rate would be re?ected by events aligned along
35
immediately apparent upon visual examination of the platter
image. In contrast, discerning ?uctuations in data periodicity
by the visual examination of a linear, orthogonal x-y plot
FIG. 7B is a more detailed view of the result of the cali
bration 109, where the overlap of the iconic representations of
peak maxima demonstrate that the calibration successfully
corrects the effective rotational rate.
well de?ned radii, similar to the example for the calibrated
disc rotational rate above. Any variations in rate would be
40
FIG. 7A shows the offset of the maximum iconically rep
would be much more dif?cult over the time frame envisioned
resented as 110 with time offset indicated 115. The next
here.
It should also be noted that there are many alternative ways
revolution (arrow 114 indicates the direction of rotation) of
the platter image brings maximum 111 into view, at time
invention. For example, the virtual tone arm could be repre
offset 116. Maximum 110 is offset because of rotational rate
error to 110' relative to 111. A subsequent clockwise rotation
of implementing the methods and apparatuses of the present
45
of the platter image brings maximum 112 into view at time
offset 117. The previous maxima also are visible at 110' and
111'. Applying the calibration corrects the platter image for
rotational rate error bringing the maxima into adjacent regis
50
as time offset 117 because maximum 112 was used as the
point of reference for the rotational rate correction.
According to an embodiment of the present invention, tools
55
rithms are sorted in tables according to the strength of the
measured parameter. Two obvious methods consider the
amplitude or slew rate of the signals as the pop detection
parameter. The ?rst algorithm uses the maximum amplitude
of the left or right signal channels. Of the 22 candidates
displayed in the list 119, three (126, 127, 128) were physical
pop events (con?rmed by examining the waveform and audi
mental or marketing purposes, the emulated platter image
may be impressed on the surface of the Disc, or used in the
by analyZing the digitally sampled audio. This facilitates the
calibration procedure described above.
Three separate algorithms were considered for “pop”
detection. In FIG. 8, analysis results using the three algo
of the cylinder.
The methods and apparatuses of the present invention may
be used to generate an emulated platter image from the con
tents of a digital recording that is intended to be mastered to
a Compact Disc or Digital Versatile (Video) Disc. For oma
tration 109 at time offset 118. The latter time offset is the same
for transcribing audio disc recordings to a digital format,
includes tools for locating physical “pop” defects on the discs
sented as a linear carriage as depicted, or a pivoted linear or
curved virtual tone arm. The platter metaphor also could be
extended to other periodic implementations, such as a cylin
der with the data image applied to the inner or outer surface,
with the time dependent axis parallel to the axis of symmetry
packaging or marketing materials of the Disc, providing a
design that has added appeal because it would indicate the
60
65
actual characteristics of the information contained on the
Disc.
According to an embodiment of the present, invention, the
methods and systems may be used to convert discretely
sampled audio data, such as music into the circular display
format indicated by FIGS. 2 and 3. A display of data obtains
that emulates the appearance of a popular format for music
dissemination, the vinyl (or formerly shellac) record. The
general familiarity of the public with such records and their
US 8,793,580 B2
17
18
associated playback equipment is an advantage, as most per
sons already possess an intuitive grasp of the concept of the
played. The operation mode selected is indicated in ?eld 81
vinyl LP disc. Further, the simulation goes beyond a purely
cosmetic, stylized rendition of the appearance of a vinyl
of the groove is located, the cueing button 17 (FIG. 2A), is
engaged. The portion of the waveform displayed on the
on FIG. 5, for mark-IN. When the central part of the quiet area
screen to the left of the mark-in location is repeated in a
record, because the appearance of the groove modulations
re?ects the actual audio content of the recording.
looping fashion, and played back audibly over the computer’ s
speakers. The mark-in location may then be ?ne-tuned by
gently rotating the platter until only lead-in noise is audible. If
Selecting a track marking or cueing point by moving the
“tonearm” and spinning the disc was the intuitive means
employed by professional disc jockeys during the vinyl LP
the mark-in location were moved to past the beginning of the
audio, a small snippet of the audio may be heard. The rotation
format era.
The method and system convert the discretely sampled
of the platter while listening to the loop and watching the
data into a display that emulates the vinyl record format, or
waveform provides the user with interactive feedback. This
record image. The record image may optionally comprise
permits rapidly selecting the mark-in location. The mark-in
features of a conventional vinyl record and record player,
location then is con?rmed.
such as, for example, a tonearm/which may be used as a way
Next, the track (or album side) mark-out optionally is
to edit and play back digital audio ?les. Areas of low modu
lation between tracks are easily selected by dropping the
tonearm “stylus” on the “vinyl” surface. The track beginning/
selected. The procedure is similar to selecting the mark-in.
Mark-OUT button 88 is engaged. The stylus is positioned at
the end of the previous track (or album side). When the
mark-out location is successfully located, only the noise of
the lead-out of the previous track is heard. If the mark-out
location is adjusted to a location before the end of the audio,
end is then precisely located by “grabbing” and rotating the
platter image.
20
An exemplary mode of operation is described in detail
below. First, an audio ?le consisting of a single or multiple
a snippet of the lead-out of the audio is heard.
tracks is opened with the application software con?gured
This editing procedure is invaluable when used in conjunc
tion with making high-quality, accurate transcriptions of
according to the present invention. The source of the audio ?le
may be a transcription from a vinyl LP, a digital recording
from another source (such as a cassette tape or live concert
music recordings from a vinyl to a digital format. Compared
to music recordings sourced from digital master recordings,
recording), or a digital recording copied from a CD or other
digital source.
and distributed in a digital format, the modulation in between
tracks of a transcribed vinyl disk does not drop to silence,
25
Next, the present invention automatically analyzes the
audio data and generates a realistic, accurate image of a
30
single-track or multiple track vinyl record platter. An example
of this step of the operation is shown in FIGS. 1 and 2, The
ter, because one merely uses the waveform display to cut or
select the tracks at obvious, digitally “silen ” locations.
However, digital silence doesn’t exist in analog transcrip
user may specify the color of the ‘vinyl’ substrate, in the same
sense that commercially released records sometimes are
pressed on colored or clear vinyl for cosmetic or promotional
purposes. The user may also choose from the Acoustic or
because of record vinyl surface noise. When editing purely
digital recordings, locating track mark points is a trivial mat
35
tions of vinyl, so it’s impossible to establish accurate track
mark points based only on the appearance of the waveform.
For instance, a gradual song fade-out or fade-in may be heard
Physical rendering options, depending on the rendering intent
quite noticeably even in the presence of vinyl background
or personal preference. The user also may specify the platter
rendering format, corresponding to those typically encoun
noise, which may obscure the music, viewed as the wave
tered, such as, for example, RPM (331/3, 16, 45, 78, etc.) and
image size (e.g., 7", 10", 12"). If digitally transcribing an
form. However, setting track marks interactively using both
40
the waveform and audible feedback eliminates the possibility
of inadvertently placing a track mark before the actual fade
analog music disc, the selected format may be the same as the
out or after an actual fade-in. The ease of use of the visual
format of the source medium.
representation generated according to the present invention
The user may also specify that an image be superimposed
on the substrate, and the music “grooves” drawn over the
45
allows the user to intuitively grab and spin the “platter” to
further re?ne and accelerate the editing process.
image with varying degrees of transparency. The image may
The procedure of setting track, marks may be repeated for
be a digital photograph, drawing or an abstract design, for
each track. In the case of a multisided transcription of a vinyl
example.
record album, provision is made to specify the number of
If the audio recording is sourced from an analog LP con
sisting of multiple individual sides, or a CD transcription of a
sides that are present in the recording. When the lead-out
50
recording originally released as a vinyl LP, the platter image
mark of the last track on side one has been determined, the
label area is clicked. The software program con?gured to
created according to the present invention may consist of a
implement the present invention interprets this as moving to
single “side” comprised of all the tracks.
Next, the toneam1/ stylus assembly is used to assign track
the next side of the album. Track marks and song titles may
continued to be added. This is repeated until all album sides
are completed.
Either before or after establishing track markers, the user
mark points. The user may assign a track mark for each
individual track, or only marks to delineate the sides of the LP
record that is the source of the digital transcription. In the
second instance, a two-sided transcription of a vinyl LP may
be assigned four mark points. These mark points would cor
respond to the music lead-in of side 1, the music lead-out of
side 1, the music lead-in of side 2, and the music lead-out of
55
may optionally calibrate the accurate rotational velocity of
the platter image (and putative playback speed) of the vinyl
transcription. This calibration procedure depends on locating
60
side 2.As an alternative, the user could assign marks and titles
to all individual tracks.
aid in selecting suitable defects. For example, for a 33 1/3 RPM
vinyl LP, at least one pair of defects must be located that are
The procedure for setting the track marks is described in
detail above with reference to FIG. 5. As described above,
after moving the toneam1/ stylus to a blank modulation
groove, the record is “spun” and the audio waveform dis
physical defects in the audio recording caused by scratches or
blemishes on the source disc. According to an embodiment of
the present invention, one or more tools may be provided to
65
spaced approximately 1.8 seconds apart. The spacing
depends on the putative rotational rate (1 6, 33 1/3, 45, 78 RPM,
etc.) of the analog source disc.
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