Patent Description:
The high dynamic range (HDR) has been drawing attention as a scheme covering a luminance range with an increased maximum luminance value in order to represent bright light such as mirror-reflected light that cannot be represented using current TV signals, with brightness closer to the actual brightness while maintaining dark grayscale values of existing video. Specifically, the scheme covering the luminance range supported by the existing TV signals is called the standard dynamic range (SDR) and has the maximum luminance value of <NUM> nits. In contrast, the HDR is expected to have an increased maximum luminance value of at least <NUM> nits.

<CIT> relates to decoding image data, converting the luminance dynamic range according to the display characteristics of a display device and displaying the converted image.

<CIT> relates to luminance level mapping, wherein a prescribed mapping curve is applied to input video data having a first level range to obtain transmission video data having a narrower, second level range.

In transmission or reception of video signals supporting a plurality of luminance dynamic ranges as described above, it is desired that a reception apparatus be capable of displaying more appropriate video.

The scope of protection of the present invention is as defined in the appended claims, which eminently cover the Embodiment <NUM> presented in this specification. Any other embodiment not falling within such scope should be construed as examples which do not describe parts of the invention.

According to, for example, a video coding standard known as ITU-T H. <NUM> | ISO/IEC <NUM>-<NUM> HEVC, the optical-electro transfer function (OETF) or electro-optical transfer function (EOTF) of a video signal is notified of using a syntax known as transfer characteristics in video usability information (VUI) included in a sequence parameter set (SPS). Use of the transfer characteristics in the SPS enables notification of switching of transfer characteristics (transfer function) at frame accuracy. A video reception apparatus determines a method of controlling a video display, based on the transfer characteristics.

According to the MPEG-<NUM> transport stream (TS) standard, which is used for transmitting a video signal and an audio signal in a multiplexed manner as in the case of TV broadcast etc., there is a known method of including, in a descriptor of program-specific information (PSI), a parameter included in the aforementioned SPS and information related to the parameter, and transmitting information related to an operation of the video reception apparatus in an upper layer. By using the descriptor of the PSI for the transfer characteristics as well, the video reception apparatus can more easily determine a method of controlling the video display. Since the PSI is generally Amended description for entry into European phase replacing the originally filed description inserted into a multiplexed stream at a constant cycle, the PSI is not synchronized with frames of a video signal. Note that according to the MPEG-H MPEG media transport (MMT) standard, a structure similar to the PSI is defined as MMT-SI.

The transfer characteristics are defined by, for example, ITU-R BT. <NUM> (hereinafter, BT. <NUM>), ARIB STD-B67 (hereinafter, STD-B67), and SMPTE ST2084 (hereinafter, ST2084). STD-B67 and ST2084 can handle a video signal having a luminance ten to a hundred times as high as the conventional BT. <NUM>, known as the high dynamic range (HDR). In contrast to the HDR, the dynamic range of the conventional BT. <NUM> etc., is called the standard dynamic range (SDR).

The TV broadcast compatible with the HDR may include both HDR programs and commercials and SDR programs and commercials. Accordingly, the video reception apparatus needs to operate while switching the control on the display, depending on whether the program/commercial is the HDR or the SDR.

A video reception method according to an aspect of the present disclosure is a video reception method performed by a video reception apparatus including a display. The video reception method includes: receiving a reception signal including video data and transfer characteristics information, the transfer characteristics information being information for specifying, at frame accuracy, a transfer function corresponding to a luminance dynamic range of the video data; and displaying the video data while controlling a luminance dynamic range of the display at frame accuracy according to the Amended description for entry into European phase replacing the originally filed description transfer characteristics information.

This makes it possible to control the luminance dynamic range of the display at frame accuracy, and thus more appropriate video can be displayed.

For example, the video reception method may further include: demultiplexing the reception signal multiplexed from a video signal and an audio signal; and obtaining the video data and the transfer characteristics information by decoding the video signal obtained by the demultiplexing.

For example, the transfer characteristics information may be included in control information that is included in the video signal, the control information being provided on a sequence-by-sequence basis.

For example, the transfer characteristics information may be information for specifying, at frame accuracy, a first transfer function corresponding to a first luminance dynamic range or a second transfer function corresponding to a second luminance dynamic range wider than the first luminance dynamic range. In the displaying of the video data, the luminance dynamic range of the display may be switched between the first luminance dynamic range and the second luminance dynamic range.

For example, the video reception method may further include: determining whether the video data is correctly obtained in the receiving of the reception signal. In the displaying of the video data, the first luminance dynamic range may be set as the luminance dynamic range of the display when it is determined that the video data is not correctly obtained. Amended description for entry into European phase replacing the originally filed description.

This makes it possible to inhibit excessively bright video from being displayed when an error occurs.

For example, in the determining, whether an intra coded frame is correctly decoded may be determined.

A video transmission method according to an aspect of the present disclosure includes: generating a transmission signal including video data and transfer characteristics information, the transfer characteristics information being information for specifying, at frame accuracy, a transfer function corresponding to a luminance dynamic range of the video data; and transmitting the transmission signal.

With this, the video reception apparatus that receives the signal generated using the video transmission method can control the luminance dynamic range of the display at frame accuracy, and thus can display more appropriate video.

For example, the generating of the transmission signal may include: generating a video signal by coding the video data and the transfer characteristics information; and generating the transmission signal by multiplexing the video signal generated and an audio signal.

For example, the transfer characteristics information may be included in control information that is included in the video signal, the control information being provided on a sequence-by-sequence basis. Amended description for entry into European phase replacing the originally filed description.

For example, the transfer characteristics information may be information for specifying, at frame accuracy, a first transfer function corresponding to a first luminance dynamic range or a second transfer function corresponding to a second luminance dynamic range wider than the first luminance dynamic range.

A video reception apparatus according to an aspect of the present disclosure is a video reception apparatus including: a receiver that receives a reception signal including video data and transfer characteristics information, the transfer characteristics information being information for specifying, at frame accuracy, a transfer function corresponding to a luminance dynamic range of the video data; and a display that displays the video data while controlling a luminance dynamic range of the display at frame accuracy according to the transfer characteristics information.

With this, the video reception apparatus can control the luminance dynamic range of the display at frame accuracy, and thus can display more appropriate video.

A video transmission apparatus according to an aspect of the present disclosure is a video transmission apparatus including: a generator that generates a transmission signal including video data and transfer characteristics information, the transfer characteristics information being information for specifying, at frame accuracy, a transfer function corresponding to a luminance dynamic range of the video data; and a transmitter that transmits the transmission signal.

With this, the video reception apparatus that receives the signal generated by the video transmission apparatus can control the luminance dynamic range of the display at frame accuracy, and thus can display more appropriate video.

Hereinafter, embodiments will be specifically described with reference to the drawings.

Note that each of the embodiments described below illustrates a specific example of the present disclosure. The numerical values, shapes, materials, structural elements, the arrangement and connection of the structural elements, steps, the processing order of the steps, etc., illustrated in the embodiments below are mere examples, and are therefore not intended to limit the present disclosure. Furthermore, among the structural elements in the following embodiments, structural elements not recited in any one of the independent claims representing the most generic concepts are described as arbitrary structural elements.

A video reception apparatus according to the present embodiment, not covered by the appended claims, controls a luminance dynamic range of a display at frame accuracy, using transfer characteristics information indicating transfer characteristics at frame accuracy. By doing so, the video reception apparatus can display more appropriate video.

First, a configuration of the video reception apparatus according to the Amended description for entry into European phase replacing the originally filed description present embodiment will be described. <FIG> is a block diagram of video reception apparatus <NUM> according to the present embodiment. Video reception apparatus <NUM> is a TV, for example, and receives reception signal <NUM> transmitted via broadcast waves and displays video based on reception signal <NUM> received. Video reception apparatus <NUM> includes receiver <NUM>, demultiplexer <NUM>, video decoder <NUM>, display controller <NUM>, and display <NUM>.

Receiver <NUM> receives reception signal <NUM>. Reception signal <NUM> is a system stream multiplexed from a video signal and an audio signal.

Demultiplexer <NUM> generates video signal <NUM> that is a video stream, by demultiplexing (system decoding) reception signal <NUM>. Furthermore, demultiplexer <NUM> outputs, as first transfer characteristics information <NUM>, transfer characteristics obtained from, for example, a descriptor included in reception signal <NUM>. That is to say, first transfer characteristics information <NUM> is included in a multiplexing layer.

Video decoder <NUM> generates video data <NUM> by decoding video signal <NUM>. Furthermore, video decoder <NUM> outputs, as second transfer characteristics information <NUM>, transfer characteristics obtained from the SPS. That is to say, second transfer characteristics information <NUM> is included in a video coding layer.

Second transfer characteristics information <NUM> is information for specifying a transfer function (OETF or EOTF) at frame accuracy supporting a luminance dynamic range of video data <NUM>. For example, second transfer characteristics information <NUM> is information for specifying, at frame accuracy, Amended description for entry into European phase replacing the originally filed description a first transfer function corresponding to a first luminance dynamic range (SDR) or a second transfer function corresponding to a second luminance dynamic range (HDR) wider than the first luminance dynamic range. That is to say, second transfer characteristics information <NUM> indicates whether video data <NUM> is SDR video data or HDR video data. Moreover, when there is more than one method for the HDR, second transfer characteristics information <NUM> may indicate the method of the HDR. That is to say, second transfer characteristics information <NUM> indicates the luminance dynamic range of video data <NUM>. For example, second transfer characteristics information <NUM> indicates one of a plurality of predetermined luminance dynamic ranges.

The SPS is control information included in video signal <NUM>. Here, the control information is provided on a sequence-by-sequence basis (on a plurality of frames-by-a plurality of frames basis).

Display controller <NUM> generates control information <NUM> for controlling display <NUM>, according to first transfer characteristics information <NUM> and second transfer characteristics information <NUM>.

Display <NUM> displays video data <NUM> while controlling the luminance dynamic range at frame accuracy according to control information <NUM> (that is, first transfer characteristics information <NUM> and second transfer characteristics information <NUM>). Display <NUM> includes video characteristics converter <NUM> and display device <NUM>.

Video characteristics converter <NUM> generates input signal <NUM> by converting video data <NUM> according to control information <NUM>. Specifically, Amended description for entry into European phase replacing the originally filed description video characteristics converter <NUM> converts video data <NUM> into input signal <NUM> using a transfer function indicated in first transfer characteristics information <NUM> or second transfer characteristics information <NUM>.

Display device <NUM> is, for example, a liquid crystal panel, and changes the luminance dynamic range of video displayed, according to control information <NUM>. For example, when display device <NUM> is a liquid crystal panel, display device <NUM> changes the maximum luminance of a backlight.

Next, an operation of video reception apparatus <NUM> will be described. Note that although <FIG> illustrates a configuration in which both first transfer characteristics information <NUM> and second transfer characteristics information <NUM> are used, it is only necessary that at least second transfer characteristics information <NUM> is used. Hereinafter, control performed using second transfer characteristics information <NUM> will be described in detail.

<FIG> is a flow chart of display control processing performed by display controller <NUM>. Note that the processing illustrated in <FIG> is performed on a frame-by-frame basis or every time second transfer characteristics information <NUM> is changed.

First, display controller <NUM> determines which one of the SDR and the HDR is indicated by second transfer characteristics information <NUM> (S101).

When the HDR is indicated by second transfer characteristics information <NUM> (YES in S101), display controller <NUM> outputs control information <NUM> for HDR display (S102). With this, display <NUM> displays video Amended description for entry into European phase replacing the originally filed description in a luminance dynamic range corresponding to the HDR.

On the other hand, when the SDR is indicated by second transfer characteristics information <NUM> (NO in S101), display controller <NUM> outputs control information <NUM> for SDR display (S103). With this, display <NUM> displays video in a luminance dynamic range corresponding to the SDR.

In such a manner, by switching control information <NUM> according to second transfer characteristics information <NUM> notified of at frame accuracy, it is possible to synchronize the switching of the transfer characteristics and the control on display <NUM>.

Note that when there are a plurality of HDR methods (for example, STD-B67 and ST2084), control information <NUM> for HDR display may include identification information identifying an HDR method. This allows display <NUM> to display video in a luminance dynamic range of the corresponding method.

<FIG> is a flow chart of video reception processing performed by video reception apparatus <NUM>. First, receiver <NUM> receives reception signal <NUM> (S111). Next, demultiplexer <NUM> generates video signal <NUM> by demultiplexing reception signal <NUM> (S112). Next, video decoder <NUM> generates video data <NUM> and obtains second transfer characteristics information <NUM> by decoding video signal <NUM> (S113).

Next, display controller <NUM> controls the luminance dynamic range of display <NUM> according to second transfer characteristics information <NUM>. Amended description for entry into European phase replacing the originally filed description Specifically, display controller <NUM> determines, for each frame, at frame accuracy, whether the frame is an HDR frame or an SDR frame, based on second transfer characteristics information <NUM> (S114). When the frame is an HDR frame (YES in S114), display <NUM> displays video in the luminance dynamic range of the HDR (S115). When the frame is an SDR frame (NO in S114), display <NUM> displays video in the luminance dynamic range of the SDR (S116).

<FIG> illustrates switching from an SDR program to an HDR program. <FIG> illustrates switching from an HDR program to an SDR program. As illustrated in <FIG> and <FIG>, the above processing enables appropriate switching between the SDR and the HDR at frame accuracy.

Hereinafter, video transmission apparatus <NUM> that generates transmission signal <NUM> corresponding to aforementioned reception signal <NUM> will be described. <FIG> is a block diagram of video transmission apparatus <NUM> according to the present embodiment. Video transmission apparatus <NUM> illustrated in <FIG> includes generator <NUM> and transmitter <NUM>.

Generator <NUM> generates transmission signal <NUM> including video data and second transfer characteristics information that is information for specifying, at frame accuracy, a transfer function corresponding to the luminance dynamic range of the video data. Generator <NUM> includes video coder <NUM> and multiplexer <NUM>.

<FIG> is a flow chart of video transmission processing performed by video transmission apparatus <NUM>. First, video coder <NUM> generates video Amended description for entry into European phase replacing the originally filed description signal <NUM> by coding video data and second transfer characteristics information (S201). The second transfer characteristics information corresponds to second transfer characteristics information <NUM> described above, and is information for specifying, at frame accuracy, the first transfer function corresponding to the first luminance dynamic range (for example, the SDR) or the second transfer function corresponding to the second luminance dynamic range (for example, the HDR) wider than the first luminance dynamic range. The second transfer characteristics information is stored in the SPS included in video signal <NUM>.

Next, multiplexer <NUM> generates transmission signal <NUM> by multiplexing coded video signal <NUM> and an audio signal (S202). Next, transmitter <NUM> transmits transmission signal <NUM> generated (S203).

With the above processing, video transmission apparatus <NUM> generates transmission signal <NUM> including the second transfer characteristics information for specifying a transfer function at frame accuracy. With this, the video reception apparatus that receives transmission signal <NUM> can control the luminance dynamic range of the display at frame accuracy, and thus can display more appropriate video.

With the TV broadcast, an error may occur due to the radio wave condition of terrestrial waves, a satellite, etc. <FIG> illustrates the case of a reception error caused by radio disturbance, for example. <FIG> illustrates the case where, when switching from the SDR to the HDR, radio disturbance or the like occurs after the video reception apparatus obtains second transfer characteristics information <NUM> included in the SPS, and, as a result, a loss of a Amended description for entry into European phase replacing the originally filed description video stream occurs, causing inability to obtain the initial frame of the HDR program. In this case, video decoder <NUM> continues to display an immediately preceding frame for error concealment. In other words, the frame of the SDR program is repeatedly displayed.

In this case, a subsequent frame refers to this frame, and thus abnormal video mixed with video of a past program is displayed as subsequent video.

Moreover, immediately after the switching from the SDR to the HDR, the luminance dynamic range of the display is set to the HDR, causing the frame of the SDR program to be displayed in the luminance dynamic range of the HDR. This results in a problem of displaying video having a luminance higher than intended.

The present embodiment describes a video reception apparatus that addresses this problem. <FIG> is a block diagram of video reception apparatus 100A according to the present embodiment. Video reception apparatus 100A illustrated in <FIG> includes, in addition to the elements included in video reception apparatus <NUM> illustrated in <FIG>, abnormality detector <NUM> and message superimposer <NUM> included in display 105A. Moreover, display controller 104A has an additional function.

Abnormality detector <NUM> determines whether video data <NUM> (video signal <NUM>) is correctly obtained. Specifically, abnormality detector <NUM> detects a packet loss based on the sequence number of each packet, and obtains the starting position of frame data by analyzing the payload of each packet, so as to Amended description for entry into European phase replacing the originally filed description determine whether all the frame data is obtained (normal) or only a part of the frame data is obtained (abnormal). Furthermore, abnormality detector <NUM> outputs abnormality notifying information <NUM> indicating the determination result to display controller 104A. That is to say, display controller 104A is notified that an abnormal condition has occurred, or is notified of information for specifying an abnormal frame.

Display controller 104A generates control information <NUM> and message <NUM> according to abnormality notifying information <NUM> in addition to first transfer characteristics information <NUM> and second transfer characteristics information <NUM>. Specifically, when there is an abnormality, display controller 104A generates message <NUM> indicating that there is an abnormality, and generates control information <NUM> for SDR display.

Message superimposer <NUM> generates input signal <NUM> by superimposing message <NUM> on video data (input signal <NUM>) according to control information <NUM> and message <NUM>, and outputs generated input signal <NUM> to display device <NUM>. With this, a message such as "Error has occurred" is displayed on display device <NUM>, notifying the viewer that it is not a failure of the apparatus.

<FIG> is a flow chart of display control processing performed by display controller 104A. First, display controller 104A determines whether second transfer characteristics information <NUM> is updated (S121). When second transfer characteristics information <NUM> is updated (YES in S121), display controller 104A starts determination regarding the switching of the display control. Amended description for entry into European phase replacing the originally filed description.

First, display controller 104A determines whether video data is correctly obtained. Specifically, display controller 104A determines whether an intra coded frame is normally decoded, based on abnormality notifying information <NUM> (S122). When the intra coded frame is not normally decoded (NO in S122), display controller 104A outputs control information <NUM> for SDR display (S123). With this, display <NUM> displays video in a luminance dynamic range corresponding to the SDR. That is to say, when determining that the video data is not correctly obtained, display controller 104A sets the SDR (the first luminance dynamic range) as the luminance dynamic range of display <NUM>.

If an error occurs when switching from one luminance dynamic range to another, a frame displayed may include pixels of a frame displayed before the switch. In contrast, according to the present embodiment, in such a case, setting the display control for SDR display as the display control makes it possible to inhibit a frame of the SDR program from being displayed with the HDR high luminance settings.

When an intra coded frame that guarantees interrupt playback, such as IDR or CRA of HEVC, is normally decoded (YES in S122), the display control is switched in the same manner as in Embodiment <NUM>. That is to say, display controller 104A determines which one of the SDR and the HDR is indicated by updated second transfer characteristics information <NUM> (S124). When the HDR is indicated by second transfer characteristics information <NUM> (YES in S124), display controller 104A outputs control information <NUM> for HDR display (S125). On the other hand, when the SDR is indicated by second transfer characteristics information <NUM> (NO in S124), display controller 104A outputs Amended description for entry into European phase replacing the originally filed description control information <NUM> for SDR display (S126).

In such a manner, video reception apparatus 100A according to the present embodiment can inhibit excessively bright video from being displayed when an error occurs, by displaying video in the luminance dynamic range of the SDR when the error occurs.

Hereinbefore, the video reception apparatus and the video transmission apparatus according to embodiments of the present disclosure have been described; however, the present disclosure is not limited to these embodiments.

Moreover, each of processing members included in the video reception apparatus and the video transmission apparatus according to the above embodiments are typically implemented as LSI which is an integrated circuit. These may be implemented in a single chip individually, or in a single chip that includes some or all of them.

Moreover, the method of circuit integration is not limited to LSI. Integration may be implemented with a specialized circuit or a general purpose processor. It is also acceptable to use: a field programmable gate array (FPGA) that is programmable after the LSI is manufactured; and a reconfigurable processor that allows reconfiguration of the connections and settings of the inner circuit cells of the LSI circuit.

Further, in each embodiment described above, each structural element may be implemented by dedicated hardware or by execution of a software program appropriate for the structural element. Each structural element may also be implemented by reading and execution, by a program executing unit such as a central processing unit (CPU) or a processor, of a software program recorded on a recording medium such as a hard disk or semiconductor memory.

Furthermore, the present disclosure is implemented as a video reception method performed by a video reception apparatus, and may be implemented as a video transmission method performed by a video transmission apparatus.

The division of the functional blocks in the block diagrams is a mere example. A plurality of functional blocks may be implemented as one functional block, or one functional block may be divided into a plurality of blocks, or a part of the functions may be transferred to another functional block. Moreover, the functions of a plurality of functional blocks having similar functions may be performed by single hardware or software in parallel or by time division.

Furthermore, since the processing order of the steps in each flow chart is one example given for specifically describing the present disclosure, other processing orders may be adopted. In addition, a part of the steps may be performed simultaneously (in parallel) with another step.

Claim 1:
A video reception method performed by a video reception apparatus (<NUM>) including a display (<NUM>), the video reception method comprising:
receiving (S111) a reception signal including video data and transfer characteristics information;
displaying (S115, S116) the video data while controlling a luminance dynamic range of the display (<NUM>);
the transfer characteristics information being information for specifying, at frame accuracy, a first transfer function being an EOTF or an OETF and corresponding to a first luminance dynamic range of the video data or a second transfer function being an EOTF or an OETF and corresponding to a second luminance dynamic range wider than the first luminance dynamic range; and
the video data being displayed while controlling the luminance dynamic range of the display (<NUM>) on a frame-by-frame basis using the transfer function indicated in the transfer characteristics information, wherein
the luminance dynamic range of the display (<NUM>) is switched between the first luminance dynamic range and the second luminance dynamic range, based on the transfer characteristics information;
characterized by
determining whether an intra coded frame is correctly decoded,
wherein, in the displaying of the video data, the first luminance dynamic range is set as the luminance dynamic range of the display (<NUM>) when it is determined that the intra coded frame is not correctly decoded.