JP2008011371A - Playback apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more efficient viewing and listening environment when a quick viewing mode for reproducing recorded contents in a time shorter than normal reproduction is executed. <P>SOLUTION: Time table data is generated by referring to metadata included in digital data. The reproduction speed is controlled according to the time table data. In this case, the time table data are generated so that the reproduction speed may change gradually with respect to the target scene. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus and method for controlling the playback speed of recorded or stored content. More particularly, the present invention relates to an apparatus and method for controlling playback speed using metadata accompanying digital television broadcasting.

  Conventionally, a broadcast program has been recorded and viewed. In particular, in recent years, with the increase in capacity of hard disk drives, time-difference playback in which a large amount of video recording and viewing at a time different from the broadcast time is generally performed.

  Furthermore, “server-type broadcasting” specified in ARIB_STD-B38 will be operated from 2006. In the server type broadcasting, TYPE1 and TYPE2 are defined. In particular, TYPE 2 is premised on content accumulation.

  Under such circumstances, users have come to desire to view a lot of content in a short time.

  In contrast, a 1.5x playback function has been devised and commercialized.

  However, in the conventional 1.5x playback, the main scenes and scenes that the user wants to see have been fast-forwarded. For this reason, the user has had to repeat the remote control operation in order to see the desired scene.

  Several techniques have been devised to avoid these problems.

  Patent Document 1 discloses a method for controlling the playback speed according to data attributes. This is an effective method for multimedia contents in which text and video data are mixed.

  Patent Document 2 discloses a method of measuring the audio volume of recorded content and controlling the playback speed according to the audio volume. This makes it possible to control the playback speed regardless of the content attributes.

  Patent Document 3 discloses a method for controlling a playback speed by detecting a keyword specific to a program using a voice recognition technique. This makes it easy to narrow down the target scene.

  Patent Document 4 discloses a control method in which a keyword and a playback speed are associated with each other using metadata accompanying digital television broadcasting. This makes it possible to set the target scene in detail.

In particular, server-based broadcasting has clearer operational rules for metadata than conventional digital broadcasting, making it easier to create applications using metadata.
JP 07-181936 JP 08-084319 JP2002-133837 JP2005-244404

  However, in the conventional playback speed control method, since the playback speed is determined in accordance with the detected key, the playback speed suddenly increases or decreases at the transition of the scene. This gave viewers a sense of discomfort and discomfort.

  Time table data is generated with reference to metadata included in the digital data, and playback speed control is performed according to the time table data. At this time, the time table data is generated so that the reproduction speed is changed stepwise for the target scene.

  By automatically changing the playback speed such that the key scene is normally played back and the unnecessary scene is fast-forwarded according to the keyword specified by the user and the digest information of the metadata, it is possible to view efficiently in a short time.

  In particular, it is possible to switch the playback speed without giving the user a sense of incongruity by changing the normal playback and fast-forward switching units in stages.

  Two best modes for carrying out the present invention will be described below.

<First embodiment>
One embodiment of the present invention is shown in FIG.

  101 is an antenna, 102 is a recording / playback device according to the present invention, 103 is a tuner, 104 is a decoder, 105 is a hard disk recording device (HDD), 106 is an MD acquisition device, 107 is an SD extraction device, 108 is a TTD generation device, 109 is A reproduction speed control device, 110 is a CPU, 111 is a remote controller, 112 is a light receiving unit, and 113 is a remote control unit.

  The antenna 101 receives a television broadcast and inputs it to the recording / playback apparatus 102.

  The recording / playback apparatus 102 receives an instruction from the user, for example, from the remote control 111, and performs recording and playback operations for the received television broadcast. An image reproduced by the recording / reproducing apparatus 102 is displayed on a display device (not shown).

  The instruction signal transmitted from the remote controller 111 is received by the light receiving unit 112 provided in the recording / playback apparatus 102 and is passed to the remote control unit 113. The remote control control unit 113 decodes instruction information from the remote control 111 and transmits it to the CPU 110.

  Inside the recording / playback apparatus 102, the received television broadcast is received by the tuner 103, and channel selection is performed in accordance with an instruction from the CPU 110.

  The selected data is decoded by the decoder 104 and recorded in the HDD 105. The metadata portion of the data decoded by the decoder 104 is sent to the MD acquisition device 106.

  The metadata sent to the MD acquisition device 106 is sequentially sent to the SD extraction device 107 to extract necessary segment data. Which data is to be extracted is instructed from the TTD generator 108.

  The segment data extracted by the SD extraction device 107 is sent to the TTD generation device 108.

  The TTD generator 108 generates time table data based on the segment data in accordance with an instruction from the CPU 110. The generated time table data is sent to the playback speed control device 109.

  The playback speed control device 109 controls the playback speed of the HDD 105 according to the time table data with the instruction of the CPU 110 as a trigger.

  Here, the instruction from the CPU 110 represents a case where the user has set the “quick mode” from the remote controller 111. Normal “fast forward playback” is not limited to this because it is not necessary to refer to timetable data.

  In addition, the above-mentioned “Quick Look Mode” is a mode in which the user plays back and watches a recorded program in a time shorter than the normal playback time. By referring to the timetable data, the scene is played at a normal speed and is redundant. A scene is a viewing mode that automatically fast forwards.

  FIG. 2 shows the concept of time table data generation.

  The metadata that accompanies digital broadcasting is usually described in XML. Particularly in server type broadcasting, it is specified that detailed metadata is described for each time.

  From this metadata, segment data necessary for playback speed control is extracted. The segment data represents individual information such as a time stamp, digest data, and keywords.

  A playback speed is calculated based on the segment data, and time table data is generated. The time table data is data describing the reproduction time and the reproduction speed at that time in association with each other.

  Details of the time table data generation method will be described later.

  FIG. 3 is a graph showing an example of reproduction speed control.

  The vertical axis of the line graph represents the playback speed (Play_Back_Speed = Pbs), and the horizontal axis represents time.

  Pbs on the vertical axis is represented by H (High) and L (Low). H is the maximum playback speed of the quick-view mode preset by the user. About 1.5 to 2 times the normal playback speed is set. L represents the normal reproduction speed.

  The time on the horizontal axis represents the time from the start of playback when the recorded content is played back at the normal speed. This time is associated with a metadata time stamp.

  Described in the lower part of the line graph is a correspondence table of time table data (TTD). Here, an example is shown in which the playback speed adjustment is performed based on the digest information of the metadata.

  Here, the TTD parts are named as a quick reference part, a front adjustment part, a digest part, and a rear adjustment part, and the calculation method of Pbs in each part is described. T in the calculation formula represents the time on the time axis of the line graph.

  In this example, the digest information of the metadata is extracted, the reproduction is performed at the normal speed in the digest portion, and the fast-forward reproduction is performed in the other portions.

  In the quick-view part, playback is performed at the maximum playback speed in the fast-view mode preset by the user. That is, the reproduction is performed by the following equation regardless of the time t.

Pbs = H
In the pre-adjusting unit, the adjustment coefficient a is calculated by the following equation based on the adjustment time set in advance by the user.

a = (L−H) / (Adjustment time)
FIG. 3 shows an example in which the pre-adjustment time is set to 15 (minutes). From the adjustment time 15 (minutes) and the digest unit start time 25 (minutes), the adjustment unit start time 10 (minutes) is calculated as 25−15 = 10.

  Therefore, the reproduction speed Pbs in the pre-adjusting unit can be obtained by a function of the following equation that changes with time t.

Pbs = a (t−10) + H
Since the digest part is set to be played back at a normal speed, it is played back according to the following equation regardless of the time t.

Pbs = L
In the post-adjustment unit, the adjustment coefficient b is calculated by the following equation based on the adjustment time set in advance by the user.

b = (HL) / (adjustment time)
FIG. 3 shows an example in which the post-adjustment time is set to 10 (minutes). From the adjustment time 10 (minutes) and the digest unit end time 35 (minutes), the adjustment unit end time 45 (minutes) is calculated as 35 + 10 = 45.

  Therefore, the reproduction speed Pbs in the post-adjustment unit can be obtained by a function of the following equation that changes with time t.

Pbs = b (t−35) + L
In the above example, the adjustment coefficient is automatically determined by the user setting the adjustment time. Conversely, the adjustment time is automatically determined by the user setting the adjustment coefficient. May be.

  Further, the sampling number for setting the playback speed on the time axis is determined by the performance of the HDD and playback speed control device, and is not limited by the present invention.

  FIG. 4 is a flowchart showing an example of a method for generating time table data.

  First, metadata is acquired from the received digital broadcast (S401).

  Next, it is confirmed whether or not a keyword for the quick-view mode is set by the user (S402).

  If no keyword is set, segment data related to digest information is extracted from the metadata (S403).

  If a keyword is set, segment data relating to the keyword is extracted from the metadata (S404).

  Next, the maximum playback speed setting value (S405) and the adjustment time setting value (S406) in the quick-view mode are referred to.

  An adjustment time is calculated from these set values (S407), and time table data in which playback speed calculation formulas are arranged in time series from the calculated adjustment time is generated (S408).

  FIG. 5 is a flowchart illustrating the quick-view mode operation.

  When the user gives an instruction to start the quick-view mode from the remote controller or the like, the quick-view mode is started (S501).

  Next, the reproduction time of the content at that time is acquired (S502). This playback time represents the count time from the beginning of the content when played back at normal speed. That is, the count time and the metadata time stamp have a one-to-one correspondence.

  Next, a speed calculation formula at each timing of the time table data is acquired (S503).

  Next, the playback speed is calculated from the current speed calculation formula and the count time (S504).

  Next, playback speed control is performed by setting the calculated playback speed in the HDD (S505).

  Subsequently, the process returns to S502, and the above operation is repeated until the quick-look mode is canceled.

<Second embodiment>
In the first embodiment, the reproduction speed control in the adjustment unit is expressed using a linear linear function, but the second embodiment shows an example in which curve control is performed using a trigonometric function.

  FIG. 6 is a graph showing an example of reproduction speed control.

  The vertical axis of the curve graph represents the playback speed (Play_Back_Speed = Pbs), and the horizontal axis represents time.

  Pbs on the vertical axis is represented by H (High) and L (Low). H is the maximum playback speed in the quick-view mode preset by the user. About 1.5 to 2 times the normal playback speed is set. L represents the normal reproduction speed.

  The time on the horizontal axis represents the time from the start of playback when the recorded content is played back at the normal speed. This time is associated with a metadata time stamp.

  Described in the lower part of the line graph is a correspondence table of time table data (TTD). Here, an example is shown in which the playback speed adjustment is performed based on the digest information of the metadata.

  Here, the TTD parts are named as a quick reference part, a front adjustment part, a digest part, and a rear adjustment part, and the calculation method of Pbs in each part is described. T in the calculation formula represents the time on the time axis of the line graph.

  In this example, the digest information of the metadata is extracted, the reproduction is performed at the normal speed in the digest portion, and the fast-forward reproduction is performed in the other portions.

  In the quick-view part, playback is performed at the maximum playback speed in the fast-view mode preset by the user. That is, the reproduction is performed by the following equation regardless of the time t.

Pbs = H
In the pre-adjusting unit, the adjustment coefficient a is calculated by the following equation based on the adjustment time set in advance by the user.

a = π / (2 * (adjustment time))
FIG. 6 shows an example in which the pre-adjustment time is set to 15 (minutes). From the adjustment time 15 (minutes) and the digest unit start time 25 (minutes), the adjustment unit start time 10 (minutes) is calculated as 25−15 = 10.

  Therefore, the reproduction speed Pbs in the pre-adjusting unit can be obtained by a function of the following equation that changes with time t.

Pbs = (HL) * cos (a (t-10)) + L
Since the digest part is set to be played back at a normal speed, it is played back according to the following equation regardless of the time t.

Pbs = L
In the post-adjustment unit, the adjustment coefficient b is calculated by the following equation based on the adjustment time set in advance by the user.

b = π / (2 * (adjustment time))
FIG. 6 shows an example in which the post-adjustment time is set to 10 (minutes). From the adjustment time 10 (minutes) and the digest unit end time 35 (minutes), the adjustment unit end time 45 (minutes) is calculated as 35 + 10 = 45.

  Therefore, the reproduction speed Pbs in the post-adjustment unit can be obtained by a function of the following equation that changes with time t.

      Pbs = (HL) * sin (b (t-10)) + L

  In a digital broadcast receiving apparatus having a recording function, particularly a recording / reproducing apparatus compatible with server-type broadcasting, it is highly likely to be used when trying to realize the quick-view mode.

The block diagram which shows the structural example of this invention. The conceptual diagram of timetable data generation. The figure which showed the example of the reproduction speed control in a 1st Example. The flowchart of time table data generation. The flowchart of quick-view mode operation | movement. The figure which showed the example of the reproduction speed control in 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Antenna 102 Recording / reproducing apparatus 103 Tuner 104 Decoder 105 Hard disk recording device 106 Metadata acquisition apparatus 107 Segment data extraction apparatus 108 Timetable data generation apparatus 109 Playback speed control apparatus 110 CPU
111 Remote controller 112 Light receiving unit 113 Remote control unit

Claims (5)

In a recording / playback apparatus having a quick-view mode for receiving a digital broadcast and recording it in a recording apparatus, and playing back the recorded content in a time shorter than the normal speed playback time,
A metadata acquisition device for acquiring metadata during digital broadcasting;
A segment data extraction device for extracting segment data in metadata;
A time table data generating device for generating time table data in which a reproduction speed is associated with a time;
A playback speed control device for controlling playback speed of the recording device;
And a playback speed control according to the time table data.   The time table data changes the playback speed between the normal playback unit and the fast-forward unit in a stepwise manner, a normal playback unit that plays back the target scene at a normal speed, a fast-forward unit that plays back at a preset fast-forward speed, The recording / playback apparatus according to claim 1, further comprising an adjustment unit.   3. The recording / reproducing apparatus according to claim 2, wherein the start and end times of the adjusting unit described in the time table data are calculated when the time table data is generated.   4. The recording / reproducing apparatus according to claim 2, wherein the reproduction speed of the adjusting unit described in the time table data is expressed by a linear function with respect to the reproduction time.   4. The recording / reproducing apparatus according to claim 2, wherein the reproduction speed of the adjusting unit described in the time table data is represented by a trigonometric function with respect to the reproduction time.

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