JP2008141693A - Content reproducing apparatus and content reproduction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display caption text long when fast reproduction of content including caption data is performed. <P>SOLUTION: A content reproducing apparatus is equipped with: a caption data processing section (40) for extracting caption text and display time information thereof from caption data; a time information processing section (50) for calculating a display starting time and a display ending time of the caption text on the basis of the display time information; and a display control section (70) for displaying the caption text on a predetermined area of a display device after display of caption text is instructed to be started and until the display is instructed to be ended. In such a case, when the fast reproduction of the content is performed, the time information processing section (50) instructs the display control section (70) to start displaying the caption text earlier than the calculated display starting time or to stop displaying the caption text later than the calculated display ending time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multimedia content playback apparatus provided from digital terrestrial broadcasting or the like, in which video, audio, subtitles, metadata, and the like are multiplexed, and in particular, digest playback that enables an overview of the content to be viewed in a short time. The present invention relates to a content reproduction apparatus having a function.

  Along with the increase in capacity of hard disk drives (HDDs), a large amount of content can be stored in content playback devices such as DVD recorders with built-in HDDs and PCs with a television broadcast receiving function in general homes. However, since the time during which the user can view the content is limited, a new problem has arisen in that the user cannot view all of the recorded content. Thus, for example, when a one-hour content can be viewed in about 15 minutes, a digest reproduction function is being installed in the content reproduction apparatus. As a digest reproduction method, there are a method that reproduces only a scene without sound (for example, see Patent Document 1), a method that reproduces only an I picture of a scene in which captions are displayed (for example, see Patent Document 2), and the like. Are known.

In the method of extracting and playing back an important scene, the accuracy of the digest generated greatly depends on the scene extraction algorithm and the type of content, and in some cases, the scene that the user thinks important may be cut. In addition, the method of reproducing only unimportant scenes at a high speed has a problem that it is difficult to see the contents because the reproduction speed is frequently switched. On the other hand, if the entire content is uniformly reproduced at high speed, it becomes easy to view and the content can be viewed in a short time without dropping important scenes. However, since audio is generally not reproduced at high-speed reproduction of 2 times or more, the user has to grasp the outline of the content only from the video reproduced at high speed.
Japanese Patent Laid-Open No. 2001-45408 Japanese Patent Laid-Open No. 2002-344871

  In recent years, terrestrial television broadcasting has been digitized, and various data such as subtitle text in addition to video data and audio data have been multiplexed into multimedia content. In such multimedia contents, it is considered that information transmitted by voice can be visually grasped by subtitle text, so that the outline of the contents can be grasped relatively easily only from the video reproduced at high speed.

  Thus, the problem is that the display time of subtitle text is shortened by high-speed playback. FIG. 8 shows how the display time of subtitle text changes according to the playback speed. For content that includes three scenes and five subtitle texts in 120 seconds, the content is normally played back in 120 seconds, 60 seconds at double speed, and 30 seconds at quad speed. Even if the content is played back at high speed, the subtitle text is displayed in synchronization with the video signal. Therefore, for example, the display time of subtitle 1 is normally 10 seconds, but is 5 seconds at 2 × speed and 2.5 seconds at 4 × speed. That is, when the content is played back at a high speed of N times, the actual display time of the caption text is 1 / N. In particular, when the high-speed playback is performed, the display time of the subtitle text becomes extremely short, so that it is difficult for the user to read the subtitle text, and the outline of the content may not be understood.

  In view of the above problems, an object of the present invention is to display a caption text for a long time when content including caption data is played back at high speed.

  Means taken by the present invention in order to solve the above problems is based on the display time information, the caption data processing unit for extracting the caption text and the display time information from the caption data, as a device for reproducing the content including the caption data. The time information processing unit for calculating the display start time and the display end time of the subtitle text, and the subtitle text is displayed in a predetermined area on the display device from the start of display of the subtitle text until the display end is instructed A display control unit is provided. Here, the time information processing unit instructs the display control unit to start displaying the subtitle text earlier than the calculated display start time or the calculated display end time when the content is played back at high speed. It shall be instructed to end the display of subtitle text later. Further, as a method of reproducing content including subtitle data, a step of extracting subtitle text and display time information thereof from the subtitle data, a step of calculating display start time and display end time of the subtitle text based on the display time information, A subtitle text is displayed earlier than the calculated display start time or the subtitle text being displayed is deleted later than the calculated display end time when the content is played back at high speed. . According to this, when the content is played back at high speed, the display start time of the subtitle text may be increased because the display start time of the subtitle text is earlier than the expected time or the display end is later than the expected time. it can.

  Preferably, the time information processing unit instructs the display start time of the caption text at the calculated display start time when the video data is played back at a high speed N times, and the difference between the calculated display start time and the display end time It is assumed that the display of the subtitle text is instructed after elapse of a time equivalent to N times or more. According to this, the display time of the subtitle text at the time of high speed reproduction is ensured at least longer than the display time at the time of standard reproduction.

  Preferably, the time information processing unit instructs the display stop of the preceding subtitle text and the display start of the subsequent subtitle text at the same timing for two consecutive subtitle texts extracted by the subtitle data processing unit. And According to this, the display time of the preceding subtitle text can be maximized without overlapping two consecutive subtitle texts.

  More preferably, the time information processing unit instructs the display start of the subsequent caption text at the calculated display start time. According to this, since the subtitle text display start is performed at the expected display start time, the synchronism between the scene change and the subtitle display is kept good.

  Preferably, the display control unit is instructed to start display of the subsequent subtitle text before the display end of the previous subtitle text is instructed for the two subtitle texts continuously extracted by the subtitle data processing unit. When this happens, the subsequent subtitle text is displayed in a different area from the predetermined area. According to this, when the display time of two subtitle texts overlaps, these two subtitle texts can be displayed separately without overlapping.

  More preferably, the display control unit displays the second subtitle text when the first subtitle text is displayed in another area for the first and second subtitle texts extracted by the subtitle data processing unit. When the start is instructed, the first subtitle text is displayed in a predetermined area, and the second subtitle text is displayed in another area. According to this, since the first subtitle text is scrolled at the timing of displaying the second subtitle text, the time relationship between the subtitle texts can be clarified.

  As described above, according to the present invention, it is possible to display caption text for a long time when content including caption data is played back at high speed. As a result, the visibility of the caption text is improved when the entire content is uniformly played back at high speed, so that the user can easily grasp the outline of the content.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of a content reproduction apparatus according to the present invention. The content reproduction apparatus includes a demax unit 10, a video data processing unit 20, an audio data processing unit 30, a caption data processing unit 40, a time information processing unit 50, a recording unit 60, a display control unit 70, and a reproduction control unit 80. Yes.

  The demax unit 10 performs demax processing on the input multimedia stream and separates various packets. FIG. 2 schematically shows a multimedia stream. In the multimedia stream 100, a video packet 101, an audio packet 102, a caption packet 103, time information 104, and the like are multiplexed. The video packet 101 includes a header 111 and compressed video data 112. The voice packet 102 includes a header 111 and compressed voice data 115. The caption packet 103 includes a header 111, caption text display time information 113, and caption text data 114. The time information 104 is used as a reference time for displaying video, audio, and subtitles.

  The video data processing unit 20 receives the video data from the demux unit 10 and decodes it to generate a video signal. The audio data processing unit 30 receives audio data from the demax unit 10 and decodes it to generate an audio signal. The subtitle data processing unit 40 receives subtitle data from the demax unit 10 and extracts subtitle text and display time information from the subtitle data.

  The time information processing unit 50 receives time information from the demux unit 10 and manages a reference time for content reproduction based on the time information. The time information processing unit 50 receives the caption display time information extracted by the caption data processing unit 40, and calculates the display start time and display end time of the caption text based on the caption display time information. Then, based on the calculated time, the display control unit 70 is instructed to start and end the display of the caption text.

  The recording unit 60 is calculated by the video signal generated by the video data processing unit 20, the audio signal generated by the audio data processing unit 30, the subtitle text extracted by the subtitle data processing unit 40, and the time information processing unit 50. The time information of the system and the time information related to the caption display are recorded in the storage areas 60a, 60b, 60c and 60d, respectively.

  The display control unit 70 overlays the subtitle text extracted by the subtitle data processing unit 40 on the video signal generated by the video data processing unit 20 so that the subtitle text is displayed in a predetermined area of a display device (not shown). Generate a video signal. The time information processing unit 50 instructs the display start and the display end of the caption text.

  When playing back the content recorded in the recording unit 60, the playback control unit 80 appropriately reads video data, audio data, subtitle data, and time information from the recording unit 60, and reads the various types of read data into the video data processing unit 20, audio. The data is supplied to the data processing unit 30, the caption data processing unit 40, and the time information processing unit 50. During reproduction, the recording unit 60 does not record signals output from the above units.

  Next, details of a subtitle text display start and display end instruction by the time information processing unit 50 will be described. FIG. 3 shows how the content is displayed during standard reproduction. For convenience, drawing of the audio signal is omitted. In the example of FIG. 3, three video scenes are displayed in 120 seconds from the standard time 9:10:00 to 9:13:00, and five subtitles are synchronized with the video signal at the timing of a scene change or the like. Is displayed. For example, subtitle 1 is displayed only for 20 seconds from the reference time 9:10:00 to 9:10:20.

On the other hand, FIG. 4 shows a state of display of the content when the content playback apparatus performs double speed playback. In the double speed playback mode, the playback control unit 80 receives video data, audio data, subtitle data, and time information (system time information, subtitle display start time, and subtitle display end time) from the recording unit 60 according to the double speed playback speed. Is read. As a result, the reference time at the time of double-speed reproduction advances at twice the normal speed, and the video signal and the audio signal are reproduced at a speed twice the normal speed. Here, the subtitle text is displayed according to the following conditions.
(1) ts [i] = Ts [i]
(2) te [i] = Ts [i] + N × ΔT [i] = Ts [i] + N × (Te [i] −Ts [i])
However, ts is a time for instructing display start, Ts is a display start time calculated based on display time information in caption data, te is a time for instructing display end, and Te is based on display time information in caption data. The display end time calculated in this way, N is the playback speed, and i is the identifier (integer) of the caption text. For example, for subtitle 1 (i = 1)
ts [1] = Ts [1] = 9: 10: 00 te [1] = Ts [1] + 2 × ΔT [1] = Ts [1] + 2 × 20 = 9: 10: 40, 9 o'clock It is displayed for 40 seconds from 10:00 to 9:10:40. This is 20 seconds in terms of real time. In this way, by controlling the subtitle display according to the conditions (1) and (2) during high-speed playback, the subtitle text can be displayed for the same period as during standard playback while being synchronized with the video scene. Thereby, the visibility of captions during high-speed playback can be improved.

If the display time of subtitle text is extended during high-speed playback, the display times of multiple subtitle texts may overlap. For example, in the example of FIG. 4, the display times of subtitle 2 and subtitle 3 partially overlap (the hatched portion of FIG. 4). FIG. 5 shows a state where two subtitle texts are overlapped and displayed on the display device (subtitle display area 200). Such overlapping of subtitle text is considered to occur more frequently as the playback speed increases. Therefore, the following condition may be adopted instead of condition (2).
(2-1) te [i] = Ts [i] + N × ΔT [i] = Ts [i] + N × (Te [i] −Ts [i]) {Ts [i] + N × ΔT [i] < For ts [i + 1]}
(2-2) te [i] = Ts [i + 1] {when Ts [i] + N × ΔT [i]> ts [i + 1]}
That is, for the two subtitle texts extracted successively by the subtitle data processing unit 40, the display subtitle text with the display end time (Ts [i] + N × ΔT [i]) according to the condition (2) of the preceding subtitle text follows. Is later than the display start time (Ts [i + 1]), that is, if the display times of the two subtitle texts overlap, the display start time (Ts [ i + 1]) is instructed to end the display of the preceding subtitle text (condition (2-2)). If the display times of the two subtitle texts do not overlap, the display end time of the preceding subtitle text is calculated according to the condition (2-1). As a result, as shown in FIG. 6, the display end time of subtitle 2 is 9:11:20 which is the same as the display start time of subtitle 3, and the display time of subtitle 2 and subtitle 3 shown in FIG. Is resolved. In this case, the display time of the subtitle 2 is 15 seconds in terms of real time, which is shorter than 20 seconds at the time of standard reproduction, but the subtitle text is longer than the conventional high speed reproduction while avoiding the overlap of the subtitle text. Can be displayed.

  As another means for avoiding the overlap of the caption text, the caption text may be displayed in a plurality of caption display areas in the display device. FIG. 7 shows a state in which subtitle 2 and subtitle 3 are displayed in each of the two subtitle display areas of the display device. In this case, the display control unit 70 controls caption display in the caption display areas 200a and 200b on the display device, and displays the preceding caption text in the area 200a and the subsequent caption text in the area 200b. Thereby, it is possible to display the subtitle text for a longer period than in the conventional high-speed playback while avoiding the overlap of the subtitle text.

  When the subtitle text is displayed in the area 200b shown in FIG. 7 and when the display start of the subsequent subtitle text is instructed, the subtitle text displayed in the area 200b is scrolled to the area 200a and the subsequent subtitle text is displayed. The subtitle text may be displayed in the area 200b. The display scroll control is performed by the display control unit 70. In this way, by scrolling the already displayed subtitle text at the timing of displaying the subsequent subtitle text, the time relationship between the subtitle texts can be clarified, and the user can easily understand the outline of the content.

  As described above, according to the present embodiment, it is possible to ensure a sufficiently long display time for caption text when the entire content is reproduced at high speed. As a result, the user can grasp the entire content in a short time.

  Regardless of the conditions (1) and (2), the display start of the caption text may be instructed earlier than the intended time (Ts). For example, in the example of FIG. 4, the display start time of subtitle 2 may be 9:10:40 which is the display end time of subtitle 1. In this case, although the subtitle text is displayed before the video scene, the synchronism between the scene change and the subtitle display is somewhat deteriorated, but the display time of the subtitle text can be secured sufficiently long. Furthermore, it is possible to eliminate the overlap of a plurality of subtitle texts.

  Also, the display time of subtitle text during high-speed playback is not necessarily the same as the display time during standard playback. For example, in the example of FIG. 4, the display end time of subtitle 1 may be 9:10:50, which is the display start time of subtitle 2, or 9:10:30. In the former case, the display time of subtitle 1 is 25 seconds in terms of real time, and in the latter case, it is 15 seconds. In any case, the display time of the subtitle text can be secured longer by instructing the display end of the subtitle text later than the expected time (Te).

  The content playback apparatus according to the present invention can display caption text for a long time when content including caption data is played back at high speed, and is thus useful as a video recorder for recording and playing back multimedia content such as terrestrial digital broadcasting. .

It is a block diagram of the content reproduction apparatus which concerns on this invention. It is a schematic diagram of a multimedia stream. It is a figure which shows the mode of the display of the content at the time of standard reproduction | regeneration. It is a figure which shows the mode of the display of a content when it reproduces at 2 speed with the content reproduction apparatus which concerns on this invention. It is a figure showing the example of a screen display when a some subtitle text overlaps. It is a figure which shows the mode of the display of the content from which the overlap of the some subtitle text was eliminated. It is a figure which shows the example of a screen display from which the overlap of the some subtitle text was eliminated. It is a figure showing a mode that the display time of a caption changes according to reproduction speed.

Explanation of symbols

40 subtitle data processing unit 50 time information processing unit 70 display control unit

Claims (7)

An apparatus for playing back content including subtitle data,
A caption data processing unit that extracts caption text and display time information thereof from the caption data;
A time information processing unit for calculating a display start time and a display end time of the subtitle text based on the display time information;
A display control unit that displays the subtitle text in a predetermined area in a display device from the start of display of the subtitle text until the end of display is instructed;
The time information processing unit instructs the display control unit to start displaying the caption text earlier than the calculated display start time when the content is played back at high speed, or the calculated display end An apparatus for instructing the end of display of the subtitle text later than time. The content playback apparatus according to claim 1,
The time information processing unit instructs the display start of the caption text at the calculated display start time when the video data is played back at high speed N times, and the calculated display start time and display end time A content playback apparatus that instructs to end display of the subtitle text after elapse of a time equivalent to N times or more of the difference between the subtitle texts. The content playback apparatus according to claim 1,
The time information processing unit instructs to stop the display of the preceding subtitle text and to start the display of the subsequent subtitle text at the same timing for two consecutive subtitle texts extracted by the subtitle data processing unit. Content playback apparatus. The content playback apparatus according to claim 3,
The time information processing unit instructs the display start of the subsequent subtitle text at the calculated display start time. The content playback apparatus according to claim 1,
When the display control unit is instructed to start display of the subsequent subtitle text before the display end of the previous subtitle text is instructed for the two subtitle texts continuously extracted by the subtitle data processing unit, The content reproduction apparatus, wherein the subsequent subtitle text is displayed in an area different from the predetermined area. The content playback apparatus according to claim 5, wherein
The display control unit is configured to display the second subtitle text when the first subtitle text is displayed in the different area with respect to the first and second subtitle text extracted by the subtitle data processing unit. The content playback apparatus, wherein when the display start is instructed, the first subtitle text is displayed in the predetermined area, and the second subtitle text is displayed in the other area. A method for playing back content including subtitle data,
Extracting subtitle text and its display time information from the subtitle data;
Calculating a display start time and a display end time of the caption text based on the display time information;
A step of displaying the subtitle text earlier than the calculated display start time or erasing the subtitle text being displayed later than the calculated display end time when the content is played back at a high speed. A content reproduction method characterized by the above.

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