System and method for displaying and editing digitally sampled

System and method for displaying and editing digitally sampled

US 20140304598A1

(19) United States

(12) Patent Application Publication (10) Pub. No.: US 2014/0304598 A1

Robinson (43) Pub. Date: Oct. 9, 2014

Publication Classi?cation

DATA (51) Int. Cl.

G06F 3/16

(52) us, C1,

(2006.01)

(71) Applicant: CHANNEL D CORPORATION,

Trenton, NJ (US)

(72) Inventor: Robert S. Robinson, Trenton, NJ (US)

USPC ........................................................ .. 715/716

(21) App1.No.: 14/309,257 (57) ABSTRACT

(22) Filed: Jun. 19, 2014

Related U.S.Application Data

A method and system including segmenting digital samples

related to input audio data into arc segments representing

(63) Continuation of application No. 11/759,068, ?led on outpln audlo M?" The are segments are arranged. to form

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(60) Provisional application No. 60/811,249, ?led on Jun.

6, 2006. be marked based on a command received from a user via an interaction With the record image.

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US 2014/0304598 A1 Oct. 9, 2014

DATA

CROSS REFERENCE TO RELATED

APPLICATIONS

[0001] This application is a continuation of US. patent application Ser. No. 11/759,068, ?led Jun. 6, 2007, which in turn claims the bene?t of US. Provisional Application Ser.

No. 60/811,249, ?led on Jun. 6, 2006. The entire disclosures ofU.S. patent application Ser. No. 11/759,068 and US. Pro visional Application Ser. No. 60/81 1,249 are hereby incorpo rated by reference herein.

FIELD OF THE INVENTION

[0002] The present invention relates generally to a method and system for transforming sampled data into a visual rep resentation with which a user may interact. In particular, this invention relates to the transformation of audio data into a realistic visual depiction of a mechanical recording (e.g., a conventional vinyl record). The present invention relates to a method of emulating the traditional playback experience of the pre-digital-audio era by simulating the tactile interaction with vinyl records which were originally used as a recording and 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.

BACKGROUND OF THE INVENTION

[0003] In the playback of digitally recorded audio, if done in conjunction with a visual display, such as a computer monitor, 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 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).

[0004] On the technical side, provision is usually made for

manually 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 display, such as regions of low signal amplitude, andusing 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

cally obscured by nearby audio having higher amplitudes.

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.

[0005] An additional drawback arises when editing audio not sourced from a quiet digital recording, such as when transcribing an actual analog vinyl record. Here, the ampli tude 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 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, when viewed as the waveform.

[0006] 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 interact with the visual representation in the form of a conventional ‘vinyl’ record and record playback apparatus

(i.e., a record player) to perform a number of tasks, including playback, editing, content management, and error/ defect detection.

[0007] The current invention provides an alternative means of display of information about the audio. Speci?cally, the invention describes the generation of an image of an analog format vinyl record disc, used as an interactive, virtual object.

This avoids many limitations of the current art, as well as more closely and favorably linking the technical and enter tainment (such as the rotation of the image on the computer

display during playback, or applying other visual effects)

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 ally. This enhances anticipation and enjoyment of the music.

[0008] Instead of representing the audio as a traditional type of rectilinear waveform display, a spiral radial paradigm, or a plurality of arcs, is used that permits ?nding features of interest in the recording with greater precision than conven tional methods, while providing an easily manipulated over view of the entire audio recording.

[0009] According to an embodiment of the present inven

tion, the plurality of digital samples are segmented into

groups, or arc segments. The digital samples of each arc segment are analyzed 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 audio parameter (e.g., modulation). The visual identi?er, as used herein, may include, but is not lim ited to, a color, hue, shade, other visual characteristic which may be used to represent the parameter value. This provides a user with a visual representation in the change of the param eter in the different arc segments.Advantageously, changes in the value of the parameter in one arc segment as compared to another, as illustrated by the different visual identi?ers, may be used to communicate to the user relevant information about the audio content. By comparing the visual identi?ers of the arc segments, the user can ‘see’ changes in the audio

parameter.

[0010] 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 dis played as an overlay or color shading of the vinyl image. Also, displayed in the circular format, periodic features in the recording are emphasized, and defects such as scratches (in

US 2014/0304598 Al Oct. 9, 2014 the case of recordings transcribed from vinyl records) used to facilitate the calibration of the true playback speed.

[0011] According to an embodiment of the present inven tion, the system and method convert discretely sampled data into a display that emulates the vinyl record format. Then, the familiar toneann/stylus/vinyl record metaphor can be used for the ?rst time as a tool for editing and playing back digital audio ?les.

[0012] For example, inter-track silences are rendered as plainly visible areas of low modulation, appearing as discrete

circular bands, rather than being compressed visually and

obscured by adjacent high amplitude areas of the audio sig nal. This provides a visually informative cue or track mark starting location (i.e., a starting boundary of the track). The

vinyl record image waveform display format further expands this metaphor, because by manipulation of the computer input

device, such as a mouse, the playback position can be manu

ally ?ne tuned by “grabbing” and “spinning” the vinyl disk,

while simultaneously listening to a looped playback of a fraction of a second’s worth of audio.

[0013] After navigating to a speci?c place of interest in the audio recording with the aid of the vinyl image, which is a primary advantage compared to an overview type rectilinear waveform 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

avoiding the tedious task of having to scroll slowly through

the recording using only a zoomed in rectilinear display.

[0014] Setting track marks (i.e., the boundaries of the track) interactively using both the waveform and audible feedback eliminates the possibility of inadvertently placing a track mark before the actual fade-out or after an actual fade-in. The present invention allows a user to intuitive grab and spin the

“platter” to re?ne and accelerate the editing process.

[0015] The general familiarity of the public with such

records and their associated playback equipment is an advan tage, as most persons already possess an intuitive grasp of the concept of the vinyl LP disc. For users lacking familiarity with analog turntables and vinyl records, these elements present an attractive aspect of the design, given the current resurgence of interest in this recording and playback medium. tion of waveform data is used to assist in locating features of interest in the sampled data ?le;

[0022] FIG. 5 illustrates an use of an embodiment of the present invention to locate track boundaries in an analog

music recording;

[0023] FIGS. 6A, 6B, 7A and 7B illustrate an exemplary process for calibration of the time base of a data sample using physical, periodic defects present in the source material, according to an embodiment of the present invention;

[0024] 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

[0025] FIG. 9 illustrates an exemplary process for generat ing a platter image, according to an embodiment of the present invention.

[0026] It is to be understood that the attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.

DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention relates to a method and sys tem for generating a visual representation of input audio data received from a source, wherein in the visual representation emulates a conventional vinyl record. The input audio data 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

ity of digital samples, according to any suitable method

known in the art. Alternatively, the input audio data may be in

digital format and comprise a plurality of digital samples,

and, thus, no conversion is required.

[0028] The plurality of digital samples (either as received

from the 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 into a series of arcs, the series of arcs emulating a

record image.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be more readily under stood from the detailed description of exemplary embodi ments presented below considered in conjunction with the attached drawings, of which:

[0017] 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 inven

tion;

[0018] FIG. 2A illustrates exemplary components of the data display, according to an acoustic-model data rendering embodiment of the present invention;

[0019] FIG. 2B illustrates an exemplary components of a data display, according to a physical-model rendering embodiment of the present invention;

[0020] FIGS. 3A and 3B show modi?ed data renderings using subsets of the data shown in FIGS. 2A and 2B; embodiment of the present invention wherein a radial depic representation of the input audio, herein referred to as the

“record image”. The record image comprises a plurality of arcs, arranged to emulate a conventional “vinyl record.”

[0030] Embodiments of the present invention are described below in detail with reference to FIGS. 1-9. FIG. 1 illustrates an exemplary record image generated according to the present invention. Advantageously, a user may interact with the record image much in the way one interacts with a con ventional vinyl record to perform a number of functions, as described in detail below.

[0031] The digital samples of the input data are processed

(as 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, denoted by progress animation arrow 4, as the image data is progressively calculated and overlaid on the platter substrate

3.

US 2014/0304598 A1 Oct. 9, 2014

[0032] Portions of the digital samples with large amounts of modulation, as assessed by the analysis algorithm, are displayed as image highlights 1, while low levels of signal modulation 2 are represented as unchanged, or nearly so, compared to the substrate data display area 3.

[0033] The platter substrate 3 may be displayed as dark gray or black color, or as a solid, bright color. The platter substrate 3 may also be patterned for aesthetic, ornamental purposes, such as with a design, photographic image, or other illustration. 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 aesthetic enhancement of the display, in conjunction with 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 represented as gradations of gray tones or as false color shading. A combination of the two may be used to convey additional 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.

[0034] Other aspects of the data display, which is con?g ured to emulate a familiar object, an audio recording playback turntable, include a label area 7 for various information, a

radial spindle 6, tone arm 5, playback cartridge 9, playback

stylus 8, cueing emulation button 10 and lead-in area 11.

According to a preferred embodiment of the present inven tion, a linear-style carriage-type tone arm is shown; but other aesthetic variations may include pivoted straight or curved of the simpler computation of data offsets during emulated cueing operations, as described in detail below.

[0035] 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 functional aesthetic construction, are intended to emulate components, features and aspects of a traditional audio ana

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 interest in this recording and playback medium, even among the demographic born after the onset of the mainstream appli

cation of digital sound recording.

[0036] The brightness or color of the image is calculated at a 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 at a point lying somewhere on the substrate.

[0037] The image construction may commence at any loca tion on the substrate, or even at the innermost radius of the substrate. However, in accordance with the aesthetics of the emulation of the familiar analog disc playback paradigm, a starting location is chosen a small distance inset from the outer simulated edge of the substrate, commonly known as the inner radius also is reserved for a legend, printed descrip tion or decorative image or design, the label area 7.

[0038] The label area 7 may have a radius between 5 per cent 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 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 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 con struction of single-track 12, 10 or 7 inch physical format emulation, for a somewhat diminished image data display capacity, and may be useful in certain other contexts. radius of the label area may be reserved for the lead-out area, again for aesthetic compliance and conformity with the

physical playback medium being emulated.

[0040] 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 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 tive radius is calculated for each pixel of the image. The radius need not have a whole-number value, because modern com

puter graphic imaging programs and routines are con?gured

to alias intermediate, ?oating-point representations, thus pro

viding increased realism of the spiral image drawing.

[0041] 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 (bright ness or color) of this pixel (or arc segment) is determined by the analysis model, as explained below. In the case of emu lating an analog playback disc, the next pixel, arc segment 5, is applied counterclockwise from the ?rst pixel (because an 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 tion). The starting radius 6 of the next arc segment (or pixel)

5 depends on the circumference and radius of the spiral arc being considered at that point.

[0042] According to an embodiment of the present inven tion, the unit of length of the arc segment is expressed in degrees. The arc length (in degrees) is determined by the desired quality of the ?nal image, balanced against the com putational time required. For example, if a ?xed arc length of

1 degree is selected, the radius of the arc also must be con

tinuously decreased by ((2 pi)/360) pixels for each segment to

continue to maintain a spiral appearance.

[0043] According to an embodiment of the present inven tion, each radius step employs a ?xed-radius, circular arc; each revolution of the generated image consists of concentric, discrete, 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 employs variable-radius, noncircular, spiral arcs to construct the record image.

US 2014/0304598 A1 Oct. 9, 2014

[0044] The arc length also affects the way the input data is analyzed. 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

Fs the digital signal sample rate.

[0045] For example, given a sample rate of 44.1 kHZ and a disc rotational rate of 33 1/3 revolutions per minute, each digi tal sample occupies an arc angle of (360 degrees/revolution)

*((33+1/3 revolutions)/60 seconds)/ (44100.0 samples/sec

ond):0.004535 degrees per digital sample.

[0046] Given the above parameters, the arc segment length must therefore be constrained to multiples of 0.004535 degrees.At an arc spiral radius of 800 pixels, this corresponds to an arc segment circumference (length) of 0.06332 pixels per data sample.

[0047] 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.

[0048] According to an embodiment of the present inven tion, a minimum arc length of 1 pixel is considered. In the above example, a minimum arc segment length of 1 pixel correspond to 1/0.06332 or 15.79 data samples. Since an

integer number of samples is required, this ?gure is back

calculated using a minimum value of 16 samples per analysis sample, giving a segment length of 16/15.79 or 1.013 pixels.

[0049] 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 must be increased). This causes discrete changes to the arc segment lengths, that were found to be unnotice able. ture. 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 slightly larger and a following segment having

slightly smaller radii, respectively. The granularity caused by

this method is practically invisible. This technique was used to generate the images included in the Figures.

[0051] One additional step was performed to reduce the prominence 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 ?rst-order In?nite Impulse Response (IIR) ?lter func tion,

h0:h1 Equation 2: where h1 is the highlighting parameter applied to the current

segment;

h0 is the highlighting parameter applied to the previous seg ment; and c1 is the ?lter coe?icient.

[0052] According to a preferred embodiment of the present invention, c1 has a value between 1.0 (no ?ltering) and 0.01

(signi?cant ?ltering), with a value of 0.9 determined to be optimum. After calculating h1, its value is substituted for h0

which then becomes the previous segment’s highlighting

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.

[0053] In practice, the tradeoff between drawing many small arc segments and computational ef?ciency dictates that arc segment lengths of greater than one pixel (including more data 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

aliasing and transparency of the line segments, provided by

the host computer’s built-in graphics routines, may be 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 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 pixel (including more data samples per arc segment) and arc line 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.

[0054] For large data sets the number of samples per arc segment 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 taining a reasonable computational rate. For example, gener

ating a complete, high quality spiral image “platter” from 30

minutes of sampled digital audio on a currently shipping consumer-level computer workstation takes approximately

30 seconds.

[0055] 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 the art will appreciate that alternative models similar to the ones described in detail herein may be used to create a record image where areas of differing signal characteristics can be differentiated upon visual inspection of the image. The visual representation may be based on one or more of the following 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 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 to generate a visual representation of any suitable signal parameter, for the purposes of illustration, the exemplary 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.

[0056] FIG. 2A shows a record image producing according to an exemplary model according to an embodiment of the present invention, herein referred to as the “Acoustic” model.

US 2014/0304598 A1 Oct. 9, 2014

According to this embodiment, the Acoustic model calculates the RMS amplitude of the sum of the synchronized (in time) input signal channels, for the number of samples per arc segment, as described in detail above. The input signal typi cally comprises two channels (stereo), in the case of an audio music recording. However, any number of channels, includ ing additional channels, may be included in the analysis. The

highlighting amount (i.e., the pixel brightness) applied is

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 the substrate were so imprinted.

[0057] According to an embodiment of the present inven tion, the opacity of the arc drawing may be varied depending on the 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 dark blue, the highlights appear bluish white, and the areas of 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 100 percent. Alternatively, the opacity of the overlaid arc drawing may be maintained at a ?xed value between 5 and 100 percent. At 100 percent opacity, the appearance of the image would depend solely on the arc drawing and would not be affected by any coloration or patterning in the substrate.

[0058] FIGS. 2A and 2B illustrate an exemplary embodi ment 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 12. Iconic markers indicated by 13 and 36 highlight regions of interest, and are superimposed on the image. Here, the markers are con?gured to indicate putative transients in the data 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 described in detail below. Markers also can be displayed as a circular highlight, as 42.

[0059] The lead-in area as explained above is indicated by

14. In a preferred embodiment of the present invention, addi tional parameters are adjustable; a proportional slide control tion 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 amplitude metering 28 and monitoring volume adjustment

29. Controls 30, 31, and 32 affect the operational mode of the

preferred embodiment of the present invention; namely, play back, editing or archiving (recording) mode, respectively.

[0060] In accordance with the tumtable/platter paradigm, the offset 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

“offset” refers to the position in number of digital samples

from the beginning of the recording of digitally sampled input

data. For an audio recording, this could be represented either 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 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 represents the mean amplitude value of the signal over one circular arc (one revolution) at the radius on the platter image corresponding to the radial position on the ribbon. Its purpose is to provide an additional visual aid to locating areas of low 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.

[0061] The stylus radial offset from rest position at the lead-in area (data offset time coordinate 0) and angular posi tion of the platter are used to back-calculate using an inverse of the image generation algorithm to generate an accurate offset into the digital source data ?le used to generate the

image. For example, given a manually chosen stylus position,

the offset into the data is simply the fraction of the total radial displacement 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 data offset is calculated by the rotational rate represented by

the platter image times 1/360 times the manually changed angle

of the platter. set 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 generat ing the image is suf?cient to ensure pixel-accurate correspon dence between 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 necessarily 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.

[0063] The angular position of the platter is controlled by

clicking and spinning the platter, in emulation of the familiar feedback cue for the user. One having ordinary skill in the art will appreciate that any suitable pointer icon may be used in the present invention. The platter-spinning paradigm and its applications to examining and editing the data are explained below, in conjunction with FIGS. 4 and 5.

[0064] Optionally, based on the type of input data, addi tional features may be added to the record image. For example, for a digital music recording, the record image may include information display on the label area 34, including plus spaces for 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 with reference to FIGS. 6 and 7. The additional information 43 may include the date of the record ing of the digitally sampled music or data ?le.

[0065] The rendering model used (i.e., the Acoustic or the

Physical model) is indicated by 46 and 47 on the label data area, according to an embodiment of the present invention.

US 2014/0304598 A1 Oct. 9, 2014

The Physical rendering model generates a somewhat different image (shown in FIG. 2B), than theAcoustic model (shown in

FIG. 2A). The overall difference between the images gener ated by the two models are not limited to contrast and/or brightness differences in the generated highlighting. This is 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 example of the kind of differences in the image appearance which result from the choice of the Acoustic or Physical model. Other differences in the models may be found in comparing the images of FIGS. 2A and 2B.

[0066] 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 undu lations on the disc causes a greater physical undulation to appear when the stereo channels have a reverse polarity rela tionship. Therefore, to emulate the physical appearance of the

disc, the Physical model subtracts the corresponding digital

samples of the stereo channels before calculating the RMS

amplitude value. In practice, visual comparison of actual, physical platter recordings to the emulated images usually

yields the most realistic representation when the Physical model is used.

[0067] Other models could be constructed, such as using

Peak 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.

[0068] 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 transcription of two sides recorded from a vinyl analog music disc, Creedence Clearwater Revival’s “Cosmo’s Fac tory,” Mobile Fidelity catalog number MFSL-l -037. An accurate emulation of the original physical platter would consist of only one side of the music disc. In the Edit mode of the 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 established, as are the individual track or song locations/ 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 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.

[0069] The manufacture of analog music discs sometimes employs a technique known to practitioners in the art as

“vari-pitch,” which adjusts the inter-groove spacing (pitch) of

the disc. This prevents areas of large modulation from causing the cutter head, used to generate the master stamper disc, from crossing into a previously cut groove, ruining the stamper.

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 ally increases the duration of audio that can be placed on a disc, compared to using a ?xed inter-groove spacing dictated by the maximum modulation level of the recording.

[0070] According to an embodiment of the present inven tion, the 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 corresponding physical media (if transcribed digitally

from an analog disc) illustrate the differences that exist ther ebetween. However, there are a plurality of different results possible when mastering the physical recorded disc, as dic tated by the judgment of the mastering engineer. Because of

this uncontrollable variable, the platter image generated by

the method an system of the present invention resemble, but not necessarily 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 tech

niques in the invention.

[0071] The models used to generate the platter image use

nearly un?ltered digitized input data, which, when obtained from samples of analog music discs, has already been equal

ized to compensate for the emphasis scheme used for play

back of analog disc recordings. Here, nearly un?ltered indi

cates that 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 emphasis curve, well-known to practitioners of the art, accentuates high frequencies while attenuating low frequencies; the corner frequency between the two regions

being approximately 1 kHz. The corresponding playback

equalization is the inverse of the curve used in the disc manu facturing process. The de-emphasis applied at playback to

high frequencies minimizes the in?uence of high frequency

noise generated during the playback process. The low fre quency emphasis compensates for the low frequency roll-off applied to the sound recording during cutting of the disc, to limit the mechanical excursion of the disc cutter, which is 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 left emphasized, which produces a sat

isfactory result. Changes in appearance of the platter image

naturally would result from different ?ltering schemes. How ever, the choice of a particular ?ltering scheme is not funda

mentally required by the present invention.

[0072] 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 digi tized information from side 2. FIG. 3 indicates the Play mode

58 of a preferred embodiment of the present invention, after generating the individual disc side images. The Play mode loads in the disc side images and adjusts the sensitivity of the

stylus positioning (time coordinate) accordingly. The image

segment 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

US 2014/0304598 A1 Oct. 9, 2014

of the platter image data, 54, 55, 56, 57 also is updated

accordingly for side 1 in FIG. 3B and side 2 as shown in FIG.

3A.

[0073] FIG. 4 illustrates the use of the platter cueing para digm to adjust the offset of the waveform inspector. FIG. 4A shows an offset into the original ?le, obtained by clicking and sliding the cartridge and stylus 62 to the desired offset. The mouse is positioned above the image of the platter, and pro vides feedback to the user by clenching the hand cursor when the mouse is clicked. At this stage, the preferred embodiment of the present invention reveals a waveform display, indicat ing the source waveform represented by the platter image at the offset of the stylus position. Here, the offset has been adjusted to place the stylus over an iconic overlay 62 that indicated a waveform amplitude maximum; in this case, caused by a physical defect (pop) on the analog source disc.

The corresponding time offset in the source data is indicated by display 60. The waveform 63 is comprised of left channel

64, right channel 66 and 67, and their normalized sum 65.

[0074] In FIG. 4B, the mouse has been dragged, from former position 70 to new position 71, in the direction illus trated by arrow 72, rotating the platter image clockwise about the center 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.

[0075] FIG. 5 illustrates using the platterparadigm to deter mine and set audio recording track boundaries. This may be

accomplished 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.

[0076] In FIG. 5, the stylus is positioned in the platter lead-in area, just prior to the start of the music information.

The waveform inspector display is split into two portions. The left half, 76 is the waveform at a time offset prior to the stylus position. The right half, 77, depicts the waveform at a time offset following the stylus position. The ?ducial mark 83 indicates the waveform at exactly the stylus position.

[0077] Each half of the waveform display is independently normalized for amplitude. The waveform halves depicted in

76 and 77 are halves of a contiguous waveform; the apparent discontinuity is caused by differences in scaling applied to the display. The waveform immediately to the right of 83 appears smaller because its scaling is in?uenced by the onset of the music waveform at 78.

[0078] As the mouse is clicked and dragged on the platter image surface, the waveform in the display 84 scrolls hori zontally and is rescaled in two halves about the ?ducial point

83. (The waveform depicted comes from the same source used to generate all other Figures.)

[0079] The turntable platter paradigm becomes extremely

useful in setting a track mark point, especially when dealing with data sampled from an analog source. In contrast to data originating from a digital recording, analog data often is accompanied by various forms of background noise. Unfor tunately, because of the masking effects of the noise, it’s not always possible to accurately determine the beginning or end of an audio track based solely on the appearance of the wave form. 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.

[0080] The track mark-in, or start point of the track, may be

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.

When a satisfactory mark-in has been established, it may be

?nalized, in the preferred embodiment of the present inven tion, and displayed accordingly in list 82.

[0081] 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 posi

tion, 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.

[0082] FIGS. 6 and 7 depict using defects in the recorded material to calibrate the proper playback speed. A primary source of 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 determine the rotation rate. The line frequency of utility power is subject to variation, which affect the rota tional speed accuracy. Mechanical tolerances in the turntable components can also affect the rotational speed. Finally, play back 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 embodiment of the present invention, these in?uences are lumped together and considered to be due to

turntable absolute speed inaccuracy.

[0083] In the case of sound data sourced from an analog

recording platter, surface noise caused by physical damage to

the disc surface, due to normal wear and tear, tend to accrue.

Some of this noise may be caused by scratches or physical contamination 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 periodicity of such pops in two adjacent grooves is approximately equal to the reciprocal of the disc rotational deviation from this value would re?ect an error in the tum table playback rotation rate.

[0084] The measured deviation can be used to recalibrate the image generation to increase the realism of the platter image simulation, and also for correcting the time base (abso

lute pitch) of the digitized recording via resampling. Tech

niques for resampling digital audio to arbitrary values for pitch modi?cation are well-known to practitioners of the art.

The calibration procedure described below is valuable for

determining the degree of pitch correction required.

[0085] In FIG. 6 a sorted list 89 and 99 of the amplitude maxima in the digitally sampled ?le is presented. Two adja

US 2014/0304598 A1 Oct. 9, 2014 cent entries 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 33 1/3 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, there fore the percent relative error between choosing among these two measurements for calibration is 100*(1.78923—1.

78838)/1.78838 or less than 0.05 percent.)

[0086] In FIG. 6A the stylus is positioned at the ?rst maxima at time offset 26: 10.90964 seconds. The maxima also is indicated iconically on the platter image 91. By rotating the platter, the offset may be ?ne-tuned to coincide with the peak

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

FIG. 8 at offsets 3310988402 (123) and 3310809557 (124) pop defects were located. The time offset between these defects is 1.78845 seconds. Comparing this to the defects used for the above calibration example, 26: 10.90964 (90) and

26: 12.69802 (100) which are separated by 1.78838, the 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 differ ence. 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.

[0091] FIG. 7B is a more detailed view of the result of the calibration 109, where the overlap of the iconic representa tions of peak maxima demonstrate that the calibration suc cessfully corrects the effective rotational rate.

[0092] FIG. 7A shows the offset of the maximum iconically represented as 110 with time offset indicated 115. The next revolution (arrow 114 indicates the direction of rotation) of the platter image brings maximum 111 into view, at time offset 116. Maximum 110 is offset because of rotational rate is displayed 94. The selection of the peak maximum may be done manually or automatically.

[0087] 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 waveform maxima position 104 performed manu ally, if necessary. 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 positioned (102) directly under the stylus. If the rotation

rate of the turntable were exactly 331/3 RPM, the iconic over lays 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 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 con?rms the calibration and regenerates the platter image, basing the platter revolution on a period of 1.78838 instead of

1.8000 seconds.

[0088] The resultant platter image shows that the iconic overlays 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; however, overlays 112. 111' and 110" directly corre

[0089] This calibration procedure could conceivably be applied at different regions of the recording, in case the abso lute rotational error varies throughout the recording process, and presuming that other surface defects exist at advanta geous locations on the recording. However, it’s unlikely that properly cared-for analog discs will have a large number of

physically suitable defects; therefore, this technique is prima

rily intended as a means of a single-point rotational rate calibration 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 short-term variation in absolute rotational rate error can be neglected.

[0090] For example, another suitable pop defect was located on this recording with the aid of automated tools. In 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 tration 109 at time offset 118. The latter time offset is the same as time offset 117 because maximum 112 was used as the point of reference for the rotational rate correction.

[0093] According to an embodiment of the present inven tion, tools for transcribing audio disc recordings to a digital format, includes tools for locating physical “pop” defects on

the discs by analyZing the digitally sampled audio. This facili

tates the calibration procedure described above.

[0094] Three separate algorithms were considered for

“pop” detection. In FIG. 8, analysis results using the three algorithms 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

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

uses the maximum slew rate of the left or right signal chan nels. Of the 22 candidates displayed in the list 121, only one

(122) was an actual pop event. The other candidates were comprised of valid musical information.

[0095] Noticing that the transient waveforms in FIG. 6A showed that the relative signal polarity during the pop event was inverted at the peak of the pop, another algorithm that measured the difference between channels was used. In list

120, 13 of 22 candidates highlighted (130) were veri?ed as being caused by physical defects in the analog disc. The other pop event, 129 was the stylus lift mentioned above. This event also has characteristics in common with pop defects, namely

the large amplitude inverted polarity difference between

channels.

[0096] While this invention has been described in terms of several preferred embodiments, there are alterations, permu tations, and equivalents, which fall within the scope of this invention. Although the image display has been described in

US 2014/0304598 A1 Oct. 9, 2014 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 suitable example of this sort of data. Presuming an average heart rate 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 rotational rate at 2 Hz, 120 heartbeat events would be displayed per revolution. Each platter could show recording. A steady heart rate would be re?ected by events aligned along well de?ned radii, similar to the example for the calibrated disc rotational rate above. Any variations in rate would be 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 would be much more dif?cult over the time frame envisioned here.

[0097] It should also be noted that there are many alterna tive ways of implementing the methods and apparatuses of the present invention. For example, the virtual tone arm could be represented 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 cylinder with the data image applied to the inner or outer surface, with the time dependent axis parallel to the axis of

symmetry of the cylinder.

[0098] The methods and apparatuses of the present inven tion may be used to generate an emulated platter image from the contents of a digital recording that is intended to be mastered to a Compact Disc or Digital Versatile (Video) Disc.

For ornamental or marketing purposes, the emulated platter image may be impressed on the surface of the Disc, or used in the packaging or marketing materials of the Disc, providing a design that has added appeal because it would indicate the actual characteristics of the information contained on the

Disc.

[0099] According to an embodiment of the present inven tion, the methods and systems may be used to convert dis cretely sampled audio data, such as music into the circular 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 associated playback equipment is an advantage, as most persons already possess an intuitive grasp of the concept of the vinyl LP disc. Further, the simulation goes beyond a purely cosmetic, stylized rendition of the appearance of a vinyl record, because the appearance of the groove modula tions re?ects the actual audio content of the recording.

[0100] 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

format era.

[0101] The method and system convert the discretely sampled data into a display that emulates the vinyl record format, or record image. The record image may optionally comprise features of a conventional vinyl record and record player, such as, for example, a tonearm/which may be used as a way to edit and play back digital audio ?les. Areas of low modulation between tracks are easily selected by dropping the tonearm “stylus” on the “vinyl” surface. The track begin

ning/ end is then precisely located by “grabbing” and rotating the platter image.

[0102] An exemplary mode of operation is described in detail below. First, an audio ?le consisting of a single or multiple tracks is opened with the application software con

?gured 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 other digital source.

[0103] Next, the present invention automatically analyzes

the audio data and generates a realistic, accurate image of a of this step of the operation is shown in FIGS. 1 and 2. The 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

Physical rendering options, depending on the rendering intent

or personal preference. The user also may specify the platter rendering format, corresponding to those typically encoun

tered, such as, for example, RPM (331/3, 16, 45, 78, etc.) and image size (e.g., 7", 10", 12"). If digitally transcribing an

analog music disc, the selected format may be the same as the format of the source medium.

[0104] The user may also specify that an image be super imposed on the substrate, and the music “grooves” drawn over the image with varying degrees of transparency. The image may be a digital photograph, drawing or an abstract

design, for example.

[0105] If the audio recording is sourced from an analog LP of a recording originally released as a vinyl LP, the platter image created according to the present invention may consist of a single “side” comprised of all the tracks.

[0106] Next, the tonearm/ stylus assembly is used to assign track mark points. The user may assign a track mark for each 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 side 2. As an alternative, the user could assign marks and titles to all individual tracks.

[0107] The procedure for setting the track marks is described in detail above with reference to FIG. 5. As described above, after moving the tonearm/ stylus to a blank modulation groove, the record is “spun” and the audio wave form displayed. The operation mode selected is indicated in

?eld 81 on FIG. 5, for mark-IN. When the central part of the quiet area of the groove is located, the cueing button 17 (FIG.

2A), is engaged. The portion of the waveform displayed on the screen to the left of the mark-in location is repeated in a 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 the mark-in location were moved to past the beginning of the audio, a small snippet of the audio may be heard. The rotation of the platter while listening to the loop and watching the waveform provides the user with interactive feedback. This permits rapidly selecting the mark-in location. The mark-in location then is con?rmed.

US 2014/0304598 A1 Oct. 9, 2014

[0108] Next, the track (or album side) mark-out optionally

is 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, a snippet of the lead-out of the audio is heard.

[0109] This editing procedure is invaluable when used in

conjunction with making high-quality, accurate transcrip

tions of music recordings from a vinyl to a digital format.

Compared to music recordings sourced from digital master recordings, and distributed in a digital format, the modulation in between tracks of a transcribed vinyl disk does not drop to silence, because of record vinyl surface noise. When editing

purely digital recordings, locating track mark points is a

trivial matter, because one merely uses the waveform display to cut or select the tracks at obvious, digitally “silent” loca tions.

[0110] However, digital silence doesn’t exist in analog

transcriptions of vinyl, so it’s impossible to establish accurate track mark points based only on the appearance of the wave form. For instance, a gradual song fade-out or fade-in may be heard quite noticeably even in the presence of vinyl back ground noise, which may obscure the music, viewed as the

waveform. However, setting track marks interactively using

both the waveform and audible feedback eliminates the pos sibility of inadvertently placing a track mark before the actual fade-out or after an actual fade-in. The ease of use of the

visual representation generated according to the present

invention allows the user to intuitively grab and spin the

“platter” to further re?ne and accelerate the editing process.

[0111] The procedure of setting track marks may be repeated for each track. In the case of a multisided transcrip tion of a vinyl record album, provision is made to specify the number of sides that are present in the recording. When the lead-out mark of the last track on side one has been deter mined, the label area is clicked. The software program con

?gured to implement the present invention interprets this as moving to 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.

[0112] Either before or after establishing track markers, the user 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

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 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

spaced approximately 1.8 seconds apart. The spacing

depends on the putative rotational rate (16, 33 1/3, 45, 78 RPM, etc.) of the analog source disc.

[0113] According the present invention, the system

includes a Calibration mode, as illustrated in FIG. 6. In this example, the ?rst defect is selected and con?rmed by pressing button 96. The second defect is selected and con?rmed by pressing button 106. Both choices are then con?rmed by pressing button 101.

[0114] The ?nal platter images are then automatically gen erated. In the case of only setting four mark points (for a two-sided album), two sound ?les are optionally created, corresponding to the audio ?le segments bounded by the chosen mark points. Likewise, two new platter images are

generated, using only the portions of the sound ?le delineated

by the mark points. In the case of marking multiple tracks, the

recording may optionally be split into multiple sound ?les

corresponding to the individually marked tracks. These ?les or the ?les could be incorporated into digital music libraries, stored on a computer or other device, for playback with music library management software, such as, for example, iTunes

by Apple Computer, Inc. The platter images include informa

tion on the central label area, which may include a decorative design or image, in addition to track listing, track timings, artist, album title, side number, RPM and other information.

[0115] In the case of only marking the album side bound aries, the sound ?les generated would emulate the experience of playing back the music in discrete, side long sections, similar to playing LP records.According to an embodiment of the present invention, the host software is used to record vinyl transcriptions at sample rates (88.2, 96, 176.4, 192 kHz or other) and quantization resolutions (24, 32, 48, 64 bits or other) which signi?cantly exceed those commonly used for is possible for vinyl playback systems to exceed the band width of CD recordings. The bandwidth of LP cutter heads and high quality playback styli/cartridges can extend to 50 kHz or more. There is some evidence that the ultrasonic

information conveyed from vinyl playback helps to preserve

spatial and timing cues when listening to the recording. Fur ther, the audio transcribed from the vinyl can be recorded without applying the RIAA inverse equalization that is

required for accurate playback, merely by amplifying the

signal from the playback cartridge with a linear preampli?er.

(Proper passive resistive/capacitive loading of the cartridge

would need to be observed, of course). The high-sample-rate

audio ?le may be equalized later, in software, during play

back. This arrangement creates an archival copy of the infor mation on the audio LP disc. Even further, the edits made as described as above could serve as nondestructive markers that are used to coordinate the playback process. An additional

advantage is that digitally applied inverse equalization is

immune to errors arising from component (resistor, capacitor,

inductor) tolerances present in analog equalization networks.

[0116] In this vein, the turntable calibration may be used as a basis for precision resampling of the archived high-sample rate ?le to create a transcription to CD or DVD format that eliminates pitch errors caused by incorrect turntable rotation rate, and more faithfully represents the source material

(elimination of analog component errors in inverse equaliza tion).

[0117] The tape bias information may be preserved by the high sample rate used for archiving. This allows for the removal of the analog “wow” and “?utter” frequency modu lation distortion not only caused by the tape equipment used to record and manufacture the LP, but also to correct problems due to the short-term variations in speed of the vinyl playback

turntable, creating, in effect, a very high stability vinyl play

back system from a possibly marginal mechanical source.

[0118] After generating the ?nal platter images, provision

is made to display an album side image and play back the original or rendered audio ?les. The tonearm may be used in

initiating playback. The stylus may be dropped at the begin

ning of the platter image lead-in groove, or at a speci?c track

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