# Patent

## Title
Detecting and processing corrupted video recordings

## Abstract

Embodiments of the invention include a method that comprises receiving a request to record television content on a specified channel for a specified period of time. The method can also include tuning to the specified channel at the specified time, and recording the specified content. The method can also include determining that one or more segments of the television content is corrupted. The method can also include presenting a notification indicating that some of the television content is corrupted, retuning to the specified channel made by the request, and acquiring uncorrupted television content for use in replacing the one or more segments of corrupted television content.

## Background
RELATED MATTERS
This application is related to U.S. patent application Ser. No. 11/875,313 filed Oct. 19, 2007.
TECHNICAL FIELD
Embodiments of the invention(s) generally relate to the field of correcting corruption in recorded content, and particularly relates to methods of detecting, correcting, and notifying a user of corrupted recordings, such as those commonly occurring due to inclement weather or power outages.
BACKGROUND
A digital video recorder (DVR) (a.k.a. personal video recorder or PVR) is a device that records audio and video content in a digital format to a disk drive or other medium. DVRs include stand-alone set-top boxes and software for personal computers, where the software enables content capture and playback to and from disk. DVRs often provide several enhancements to similar devices such as VCRs, including convenient “time shifting”. Additionally, some DVRs provide desirable features, such as pausing live TV, instant replay of interesting scenes, chasing playback, and skipping advertising. Most DVRs use MPEG format for encoding analog video signals.
DVRs can record corrupted content for a variety of reasons. For example, inclement weather can cause poor reception of satellite television broadcasts. As a result, DVRs may record corrupted or poor quality content. DVRs that are not connected to satellite dishes can experience other problems, such as power outages, poor signal quality, etc.
SUMMARY
Embodiments of the invention include a method that comprises recording broadcasted television content. The method can also determine if one or more segments of the content is corrupted. The method can also present a notification if the content is corrupted, where the notification can include indicia such as a pop-up window, an icon or symbol in a program guide screen or program recorded content screen, and/or an indicator on the DVR unit. The method can also acquire uncorrupted content to replace one or more segments of the corrupted content.



DESCRIPTION OF THE DRAWINGS
The present embodiments may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
FIG. 1 depicts a block diagram illustrating the configuration of die content delivery system with a content provider serving as a provider of uncorrupted content in an embodiment of the invention.
FIG. 2 depicts a block diagram illustrating the configuration of the content delivery system with a satellite serving as a provider of uncorrupted content in an embodiment of the invention.
FIG. 3 depicts a flowchart illustrating the operation of the DVR unit according to some embodiments of the invention.
FIG. 4 illustrates an example of different types of user notification methods, according to an embodiment of the invention.
FIG. 5 illustrates an example of the user demarcation method of detecting corruption in recorded content in an embodiment of the invention.
FIG. 6 depicts a flowchart illustrating the operation of the content provider providing, via the web, corrected content to the DVR unit containing corrupted content, according to an embodiment of the invention.
FIG. 7 depicts a flowchart illustrating the operations for retuning a satellite dish, according to some embodiments of the invention.
FIG. 8 depicts a flowchart illustrating the operations for reprogramming a satellite dish, according to some embodiments of the invention.



DESCRIPTION OF EMBODIMENT(S)
The description that follows includes exemplary systems, methods, techniques, instruction sequences and computer program products that embody techniques of the present invention. However, it is understood that the described invention may be practiced without these specific details. In other instances, well-known instruction instances, protocols, structures and techniques have not been shown in detail in order not to obfuscate the description.
FIG. 1 illustrates a content delivery system 100, according to some embodiments of the invention. The content delivery system includes a DVR unit 101, display device 112 (e.g., television), network 109, content provider 110, and content replacement service 112. The content provider 110 can provide television content via a cable television infrastructure (e.g., optical fiber, coaxial cables, ect.) or other infrastructures, such as digital subscriber lines (DSL). In FIG. 1, the DVR unit 101 includes a storage device 102, content corruption detection unit 104, user notification unit 106, and content corruption correction unit 108, all of which are connected via a bus 103. Although FIG. 1 shows the DVR's components connected via a bus 103, the components can be connected using other technologies (e.g., software interfaces). The storage device 102 includes uncorrupted content 111 and corrupted content 105.
Although not shown in FIG. 1, the DVR unit 101 includes components for recording and presenting content (e.g., video decoding logic, read/write logic, video tuner(s), etc.) Furthermore, any of the components shown herein can include hardware, firmware, and/or machine-readable data storage media including instructions for performing the operations described herein. Machine-readable data storage media includes any mechanism that stores information in a form readable by a machine (e.g., a wagering game machine, computer, etc.). For example, tangible machine-readable data storage media includes read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory machines.
In some embodiments of the invention, the content corruption detection unit 104 utilizes a variety of methods to detect corrupted content in the storage device 102. These methods can include reduced signal strength detection, power outage detection, digital block detection, and user demarcation. Furthermore, in some embodiments, the user notification unit 106 can notify the user that a recording is corrupted upon detection by the content corruption detection unit 104. Example notifications can include an indicator on the DVR unit itself indicating that a recording includes corrupted content, a graphical user interface indicating that one or more recordings are corrupted, and modified icons that indicate corrupted content has been recorded. A network 109 connects the DVR unit 101 to the content provider 110 and content replacement service 112.
FIG. 2 illustrates another content delivery system 200, according to some embodiments of the invention. The content delivery system 200 includes a DVR unit 201, display device 218, network 209, content replacement service 210, and satellite dish 216. In FIG. 2, the DVR unit 201 includes a storage device 202 that includes uncorrupted content 211 and corrupted content 205. The DVR unit 201 also includes a content corruption detection unit 204, user notification unit 206, and content corruption correction unit 208, all of which are connected via a bus 203. Although FIG. 1 shows the DVR's components connected via a bus 103, the components can be connected using other technologies (e.g., software interfaces). Also, the DVR unit 101 can include components (not shown) for recording and presenting content (e.g., video decoding logic, read/write logic, video tuner(s), etc.).
In some embodiments of the invention, the content corruption detection unit 204 can utilize a variety of methods to detect the corrupted content 205 in the storage device 202. The corrupted content 205 can include “dead” (unviewable) content. The DVR unit 201 may record unviewable content by can errantly recording from a channel that is not carrying content supplied by the content provider 110. When presented, the dead content may cause the display device 112 to show a blank screen, monochromatic screen, or white noise. The corruption detection unit's methods for detecting corrupted content can include pixel monitoring, white noise detection, and digital block detection. Furthermore, in some embodiments, the user notification unit 206 can notify the user that a recording is corrupted upon detection by the content corruption detection unit 204. Example notifications include indicia appearing on the DVR unit itself, icons appearing in graphical user interfaces, pop-up windows appearing in graphical user interfaces, etc.
The DVR unit 201 also includes a transmission unit 212 that can send wireless signals 214 (e.g., infrared (IR) signals, radio frequency (RF) signals, etc.) to reprogram a satellite dish 216. In the embodiment in FIG. 2, the transmission unit 212 includes a wire through which it transmits the wireless signals. A network 209 connects the DVR unit 201 to a content replacement service 210
System Operations
This section describes operations performed by some embodiments of the systems described above. In certain embodiments, the operations can be performed by executing instructions residing on machine-readable content (e.g., software), while in other embodiments, the operations can be performed by a combination of software, hardware, and/or other logic (e.g., firmware). In some embodiments, the operations can be performed in series, while in other embodiments, one or more of the operations can be performed in parallel. Moreover, some embodiments can perform less than all the operations shown in the Figures.
FIG. 3 is a flow diagram illustrating operations of a DVR unit, according to some embodiments of the invention. In FIG. 3, the flow 300 begins at block 302, where the DVR unit 101 detects corrupted content in the storage device 102. The flow continues at block 304. At block 304, the content corruption detection unit 104 identifies the corrupted content segment.
The methods of detecting and identifying can include one or more of the following:

    
    
        Reduced Signal Method—The reduced signal strength detection method marks the recording as corrupted if the signal strength decreases below a threshold while recording. The start of reduced signal strength and duration of lowered signal strength can be stored to identify the corrupted content segment.
        Content Provider Method—Using the content provider notification method, a content provider 110 can detect potentially corrupted recordings through customer complaints or automated systems that analyze region specific weather data. If the content provider 110 detects conditions sufficient to cause corrupted recordings, the provider may notify the DVR unit 101 that content recorded during a particular time window may be damaged. The corruption detection unit 108 can store an indication of the time window.
        Power Outage Detection Method—A power outage for a DVR during a recording results in corrupted media wherein the recording is missing the segments from when the power outage occurred until the DVR was restarted and capable of recording again. In the power outage detection method, the content corruption detection unit 104 detects a power outage by comparing the DVRs recording list against the last known time the system was functional before the most recent startup. The duration of the corruption is determined by the time period between the DVRs last known functional time prior to restart and the time when the DVR resumed recording.
        User Demarcation Method—In the user demarcation method, the content corruption detection unit 104 detects a corrupted content segment by allowing a user to identify corrupt content through a user interface. The user interface can include pop-up menus and other graphics that allow users to identify start and end points of in a segment of recorded content. The start and end points demarcate the corrupted content.
        Mismatch Checksum Detection Method—In the mismatch checksum detection method, the DVR's content corruption detection unit 101 can calculate a checksum as content is recorded. The DVR unit's checksum is compared to a checksum given by the content provider 110. If the checksums do not match, the recording is corrupted. If a checksum error occurs, the content corruption detection unit 104 and content provider 110 may perform a rolling checksum to detect which parts of the recording are corrupted. The start and duration for the corruption consist of the area of the recording with disparate rolling checksum values. In situations where the mismatch checksum method is inadequate due to an analog television broadcast that gives an imprecise measurement of signal, the content corruption detection unit 104 can compare the recorded length of the show with the published length, which would be further broken up into show lengths and commercial lengths. If there is corruption to a non-critical part of the recording (e.g. a commercial or intermittent black space), the content corruption detection unit 104 can decide whether the recording is acceptable. If a critical portion of the show is not matching the proper length, the content corruption detection unit 104 can replace the corrupted segment.
        Silent and White Noise Method—In the silent and white noise detection method, the content corruption detection unit 104 measures the silence resulting from signal loss for an extended time period or the presence of white noise as indications of corrupted content.
    
    


The flow continues at block 306, where the DVR unit's notification unit 106 presents a notification about the corrupted content. For example, the notification unit 106 can notify users about corrupted content via pop-up screens, indicators on the DVR unit itself, and/or icons in the recorded content list (e.g., see FIG. 4). Once the user is notified of the corrupted content, the DVR unit 101 can choose whether to download the corrected content segment of the corrupted content recording (see block 307).
If the DVR unit 101 chooses to download the corrected content segment of the corrupted content recording, the flow continues at block 308. At block 308, the corrected content segment may be downloaded from a web enabled content repository via a web service, according to some embodiments of the invention. In some embodiments, the content corruption correction unit 108 can alter the recording by replacing corrupted segments with the downloaded segments. In other embodiments, the content corruption correction unit 108 can store the corrupted content and location of downloaded content segments as metadata and playback the downloaded content segments at the times described in the metadata. Therefore, the system 300 can seamlessly replace corrupted content segments with downloaded segments. From block 308, the flow ends.
If the DVR unit 101 chooses not to download the corrected content segment of the corrupted recording, the flow continues at block 310. At block 310 the DVR unit 101 schedules a recording of a rebroadcast of the original content. For example, since west coast broadcasts run hour(s) behind those in the east, the corrupt segment can be recorded during the west coast showing of the originally recorded content. Alternatively, the DVR unit 101 can analyze a content guide to discover if and when the content is being rebroadcasted and automatically record during that rebroadcast. Some embodiments may replace the entire recording, while others may opt to only rerecord the sections damaged in the original recording. From block 310, the flow ends.
FIG. 4 illustrates how a user notification unit can notify users of corrupted recordings, according to some embodiments of the invention. In FIG. 4, the user notification unit 402 can notify users of corrupted recorded content via an indicator 404 on the DVR unit 406, pop-up screen 408 on the television (e.g., television screen, computer monitor, etc.), and/or icons in the recorded content list 410. For example, if the user notification unit 402 detects corrupted content, the user notification unit 402 can activate the indicator 404 on the DVR unit 406. In some embodiments the indicator 404 can flash, stay continuously lit, change color, etc. to alert users that some recorded content is corrupted. The user notification unit 402 can also notify users about corrupted content in other ways. For example, the user notification unit 402 can present a pop-up screen 408 that includes a message indicating what content is corrupted. The user notification unit 402 can present the pop-up screen 408 in concert with other information, such as program guides, listings of recorded content, etc. Additionally, the user notification unit 402 can present icons, text, or other indicia indicating that some recorded content is corrupted. For example, the user notification unit 402 can insert an indicator 410 in a listing of recorded shows, where the indicator 402 indicates that a particular show includes corrupted content. The indicator 402 can include text, graphics, symbols, etc. In some embodiments, the user notification unit 402 notifies users of corrupted content using sound, such as beeps, recorded messages, etc.
FIG. 5 illustrates how users can identify segments of corrupted content through a graphical user interface, according to some embodiments of the invention. In this method for identifying corrupted content (a.k.a. the user demarcation method), the content corruption detection unit 502 can receive user input indicating what content is corrupted. In some embodiments, the content corruption detection unit 502 presents a graphical user interface 504 in which users can demarcate corrupted content. For example, the graphical user interface 504 can include a “strip” 510 representing the recorded content. The content corruption detection unit 502 enables users to mark points (506 & 508) on die strip 510. Content between the points (506 & 508) is corrupted. Users can identify corrupted content via a remote control or other suitable input devices. After the DVR unit's content corruption detection unit 502 identifies corrupted content, the DVR unit's content corruption correction unit can replace the corrupted content with uncorrupted content (see also discussion of FIG. 3).
FIG. 6 is a flow diagram illustrating how a content provider provides, via the web, corrected content to the DVR unit containing corrupted content. The flow 600 will be described with respect to FIG. 1. In FIG. 6, flow 600 begins at block 602 where the content replacement service 112 receives, via the web, a request from the DVR unit 101 for a content segment. The request can identify a corrupted content segment by serial number, time stamps, a title and scene number, etc. The flow continues at block 604, where the content replacement service 112 authenticates the DVR unit 101. For example, the content provider can verify passwords, digital certificates, or other authentication credentials. Furthermore, the content provider may verify that the DVR unit 101 has subscribed for the content that it needs (e.g., if the request is for content of a premium channel, the requester must be subscribed to the premium channel). If the content replacement service 112 authenticates the DVR unit 101, the flow continues at block 608. Otherwise, the flow ends.
At block 608, the content replacement service 112 determines the requested content segment needed by the DVR unit 101. For example, the content provider 101 fetches the content segment from a local or remote content repository. The flow continues at block 610, where the content provider transmits the corrected content segment to the DVR unit 101. This transmission can be done over the world wide web, internet, telephony, satellite, and/or other suitable communication facilities. From block 610, the flow ends.
As noted above, a DVR unit can receive content from a satellite dish. In such embodiments, the DVR unit can tune the satellite dish to a particular channel by sending wireless signals (see FIG. 2). However, sometimes the wireless signals are errantly sent or errantly received. As a result, the satellite dish may tune to an incorrect channel. The incorrect channel may include “dead content” or undesired content (e.g., the wrong television show). This discussion continues with a description of embodiments in which a DVR unit can detect and recover from a situation in which it has recorded content from an incorrect channel.
FIG. 7 illustrates operations for retuning a satellite dish, according to some embodiments of the invention. The flow 700 will be described with respect to FIG. 2. In FIG. 7, the flow 700 begins at block 702, where the DVR unit 201 receives a request to record a specified channel for a specified period of time. In some embodiments, the DVR unit 201 receives the request when a user selects a show from a menu of shows that are available for recording. The flow continues at block 704, where at the specified time, the DVR unit 201 tunes the satellite dish 216 to the specified channel. The flow then continues to block 706.
At block 706, the DVR unit 201 receives and records content from the satellite dish 216. The flow continues at block 707.
At block 707, the DVR unit 201 determines whether there is corruption in the recorded content. The DVR unit 201 can detect corruption in the content by monitoring pixels in the content. When monitoring pixels in the content, the DVR unit's content corruption detection unit 204 can check for changes in the pixels over a certain period of time. If the pixels do not change (or if changes are below a threshold), the content is corrupted. The content may be corrupted because the DVR unit 201 incorrectly tuned the satellite dish 216 to a channel that does not include broadcast content (at block 704). That is, although a user programmed the DVR unit 201 to tune the satellite dish 216 to a particular channel, the satellite dish 216 did not tune to that channel. Instead, the satellite dish 216 tuned to a different channel (e.g., because of errant wireless signals, etc.). Alternatively, the content may be corrupted for other reasons, such as poor signal quality, low signal strength, etc. In some embodiments, the DVR unit 201 can detect corruption in the content using any of the methods described above. If the DVR unit 201 detects corruption in the content, the flow continues at block 708. Otherwise, the flow continues at block 709.
At block 708, the DVR unit 201 retunes the satellite dish 216 to the channel specified in the request (see block 702). The DVR unit 201 can retune the satellite dish 216 by transmitting wireless signals (e.g., infrared signals, radiofrequency signals, etc.) that cause the satellite dish 216 to tune to the originally desired channel. In some embodiments, the satellite dish 216 will not retune to a channel upon receiving only a channel signal (e.g., a wireless signal indicating a channel, such as channel 105). Instead, in some embodiments, the satellite dish 216 needs both a channel signal and a key sequence signal (these signals can be combined into a single signal). The DVR unit 201 typically generates these signals after detecting certain key presses on its remote control or other input device. For example, the DVR unit 201 may generate a key sequence signal after detecting remote control key presses [right arrow][select] and channel signals after detecting remote control key presses [1][0][5]. The satellite dish 216 may require the key sequence to ensure that users go through certain menus when tuning to different channels. When retuning the satellite dish 216 at block 708, some embodiments of the DVR unit 201 can generate the key sequence signal and a channel signal without receiving remote control input (i.e., automatically). As a result, in some embodiments, the DVR unit 201 retunes the satellite dish 216 to the specified channel by sending a wireless signal including the needed key sequence and channel. The flow continues at block 710.
At block 709, if the recording time period is not complete, the flow will return to block 706. If the recording time period is complete, the flow continues at block 710.
At block 710, the DVR unit 201 determines whether there is any content missing from the complete recording. If no content is missing, the flow ends. If content is missing, the flow continues at block 711. At block 711, the DVR unit 201 chooses whether to download content to replace the corrupted content segment. If the DVR unit 201 downloads content, the flow continues at block 714. Otherwise, the flow continues at block 712.
At block 712, the DVR unit 201 downloads content to replace the corrupted content. The DVR unit 201 can download from the content from a web enabled content repository via a web service, according to some embodiments of the invention (e.g., the content replacement service 210). In some embodiments, the DVR's content corruption correction unit 208 can alter the corrupted content by replacing corrupted segments with the downloaded segments. In other embodiments, the content corruption correction unit 208 can create metadata indicating when, during playback, to present the downloaded content segments. Therefore, the system 700 can seamlessly correct corrupted content using the downloaded content. From block 710, the flow ends.
At block 714, the DVR unit 201 schedules a recording of a rebroadcast of the original content. For example, since west coast broadcasts run hour(s) behind those in the east, the corrupt segment can be recorded during the west coast showing of the originally recorded content. Alternatively, the DVR unit 101 can analyze a content guide to discover if and when the content is being rebroadcasted and automatically record during that rebroadcast. Some embodiments may replace the entire recording, while others may opt to only rerecord the sections damaged in the original recording. From block 712, the flow ends.
FIG. 8 illustrates operations for reprogramming a satellite dish, according to some embodiments of the invention. In FIG. 8, the flow 800 begins at block 802, where the satellite dish 216 receives a sequence of signals (e.g., infrared signals, radio frequency signals, etc.) to reprogram it to the desired channel. In some embodiments, the DVR unit 201 transmits IR signals via the wire 212, as shown in FIG. 2. The flow then continues to block 804.
At block 804, the satellite dish 216 reprograms to the channel indicated in the signals. The flow then continues to block 806, where the satellite dish 216 transmits content from the channel to the DVR 201. From block 806, the flow ends.
Other Embodiments
While the invention(s) is (are) described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the invention(s) is not limited to them. In general, the techniques described herein may be implemented with facilities consistent with any hardware system or hardware systems. Many variations, modifications, additions, and improvements are possible.
Plural instances may be provided for components, operations or structures described herein as a single instance. Finally, boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of the invention(s). In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the invention(s).

## Claims

1. A method of recording content by a digital video recorder (DVR), the method comprising:
the DVR receiving a request to record television content on a specified channel at a specified time;
the DVR tuning to the specified channel at the specified time;
the DVR recording some of the television content;
the DVR determining that one or more segments of the television content is corrupted by analyzing the one or more segments of the television content using stagnant pixel analysis;
the DVR presenting a notification indicating that some of the television content is corrupted;
the DVR retuning to the specified channel; and
after the retuning, the DVR recording more of the television content to acquire uncorrupted content from a rebroadcast of the television content for use in replacing the one or more segments of corrupted television content.

2. The method of claim 1, wherein the DVR retuning to the specified channel includes transmitting a signal including a key sequence and the specified channel to another device.

3. The method of claim 1, wherein the DVR receiving a request to record television content on a specified channel at a specified time includes the DVR receiving a user selection of the television content from a menu of television content available for recording.

4. The method of claim 1, wherein the notification includes one or more indicia selected from the group consisting of a pop-up window, an icon in a program guide screen, an icon in a recorded content screen, and an indicator on a digital video recorder.

5. The method of claim 1, further comprising the DVR determining that the television content will be rebroadcast, and wherein the DVR retuning is performed responsive to determining that the television content will be rebroadcast.

6. A media content delivery system comprising:
a DVR unit configured to record a first content, to detect corruption in the first content by analyzing the first content using stagnant pixel analysis, the DVR unit further configured to transmit wireless signals specifying a key sequence and a channel to cause a satellite dish to retune to the specified channel, and
a satellite dish configured to receive the wireless signals from the DVR unit and to retune to the specified channel according to the key sequence and the channel, the satellite dish also configured to receive and provide to the DVR unit, a second content to replace a corrupted portion of the first content from a rebroadcast of the first content contained in the second content.

7. The media content delivery system of claim 5, wherein the DVR unit further comprises a user notification unit configured to present notifications about the corruption in the first content.

8. The media content delivery system of claim 7, wherein the notifications include one or more selected from the group consisting of a pop-up screen indicating that the first content is corrupted, an icon in a recorded content interface, an indicator on the DVR unit, and a message describing the corruption and time.

9. The media content delivery system of claim 6, wherein the DVR unit further comprises a media corruption correction unit configured to create metadata to indicate when to present the second content.

10. An apparatus comprising:
a bus;
a machine-readable tangible storage device connected to the bus;
machine-readable program instructions, stored on the machine-readable tangible storage device, to receive a request to record television content on a specified channel for a specified period of time;
machine-readable program instructions, stored on the machine-readable tangible storage device, to determine that one or more segments of the television content is corrupted by analyzing the one or more segments of the television content using stagnant pixel analysis;
machine-readable program instructions, stored on the machine-readable tangible storage device, to present a notification that the one or more segments of the television content is corrupted, wherein the machine-readable program instructions to present the notification present indicia indicating that the one or more segments of the television content is corrupted; and
machine-readable program instructions, stored on the machine-readable tangible storage device, to retune to the specified channel;
machine-readable program instructions, stored on the machine-readable tangible storage device, to, after retuning to the specified channel, record more of the television content to acquire uncorrupted content from a re-broadcast of the television content for use in replacing the one or more segments of corrupted television content.

11. The apparatus of claim 10, further comprising:
machine-readable program instructions, stored on the machine-readable tangible storage device, to present indicia that include one of more selected from the group consisting of a pop-up window, an icon in a program guide screen, an icon in a recorded content screen, and an indicator on a digital video recorder.

12. A machine-readable tangible storage device having machine-readable program instructions stored thereon, said machine-readable program instructions being configured to be executed by a digital video recorder (DVR) to implement a method of recording video content by the DVR, the method comprising:
the DVR receiving a request to record television content on a specified channel at a specified time;
the DVR tuning to the specified channel at the specified time;
the DVR recording some of the television content;
the DVR determining that one or more segments of the television content is corrupted by analyzing the one or more segments of the television content using stagnant pixel analysis;
the DVR presenting a notification indicating that some of the television content is corrupted;
the DVR retuning to the specified channel, the retuning including transmitting a signal indicating the specified channel and a key sequence; and
the DVR recording more of the television content to acquire uncorrupted content from a rebroadcast of the television content for use in replacing the one or more segments of corrupted television content.

13. The machine-readable tangible storage device of claim 12, wherein the DVR receiving a request to record television content on a specified channel at a specified time includes the DVR receiving a user selection of the television content from a menu of television content available for recording.