WO2016063474A1

WO2016063474A1 - Reproduction device, display device, and transmission method

Info

Publication number: WO2016063474A1
Application number: PCT/JP2015/005102
Authority: WO
Inventors: 小塚　雅之; 直司臼木; 歳朗西尾; 西　孝啓; 遠間　正真
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-10-21
Filing date: 2015-10-08
Publication date: 2016-04-28

Abstract

A display device according to an embodiment of the present disclosure is a Blu-ray device connected to a TV by HDMI, and comprises a processing unit that: (i) acquires, from the TV via the HDMI, EDID including, in a CEA Data Block, identification information indicating whether or not the TV can display a video in which the dynamic range of luminance is in a high dynamic range (HDR) which is wider than the standard dynamic range (SDR); (ii) determines the dynamic range of an output video signal in accordance with the identification information included in the acquired EDID; and (iii) transmits, to the TV via the HDMI, an InfoFrame including metadata according to the determined dynamic range.

Description

REPRODUCTION DEVICE, DISPLAY DEVICE, AND TRANSMISSION METHOD

This disclosure relates to a playback device, a display device, and a transmission method.

Conventionally, an image signal processing apparatus for improving the displayable luminance level has been disclosed (see, for example, Patent Document 1).

JP 2008-167418 A

A playback device according to an aspect of the present disclosure is a playback device connected to a display device via HDMI (registered trademark, the same applies hereinafter), and (i) a dynamic range of luminance is wider than a standard dynamic range (SDR) EDID including identification information indicating whether the display device can display high dynamic range (HDR) video in CEA Data Block is acquired from the display device via the HDMI, and (ii) the acquired EDID Determining the dynamic range of the video signal to be output according to the identification information included in (iii), and transmitting the InfoFrame including metadata corresponding to the determined dynamic range to the display device via the HDMI. A processing unit is provided.

A display device according to an aspect of the present disclosure is a display device connected to a playback device by HDMI, and (i) a high dynamic range (HDR) in which a dynamic range of luminance is wider than a standard dynamic range (SDR). ) Is transmitted to the playback device via the HDMI, and (ii) the identification included in the transmitted EDID. A processing unit is provided for acquiring InfoFrame including metadata corresponding to a dynamic range of an output video signal determined according to information from the playback device via the HDMI.

These general comprehensive or specific modes may be realized by a transmission method, a system, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM. The present invention may be realized by any combination of computer programs or recording media.

FIG. 1 is a diagram for explaining the evolution of video technology. FIG. 2 is a diagram showing a relationship between a flow for producing a master for home entertainment of SDR and HDR, a distribution medium, and a display device. FIG. 3 is a diagram for explaining the relationship between EDID (EXTENDED DISPLAY IDENTIFICATION DATA) and InfoFrame on HDMI. FIG. 4 is a diagram for explaining an example of HDR-related metadata stored in EDID. FIG. 5 is a diagram for explaining an example of HDR-related metadata stored in the InfoFrame. FIG. 6 is a diagram illustrating an example of a specific structure of the InfoFrame. FIG. 7 is a diagram for explaining a usage example of static metadata. FIG. 8 is a diagram for explaining an outline of processing performed by a Blu-ray (registered trademark, hereinafter the same) device. FIG. 9 is a diagram for explaining a new transmission method of a video signal from the playback device to the display device. FIG. 10 is a diagram showing a configuration of an HDR system capable of selecting a plurality of EOTFs. FIG. 11 is a diagram for explaining another example of the outline of the processing performed by the Blu-ray device. FIG. 12 is a diagram for explaining a new transmission method of a video signal from a playback device to a display device when a hybrid stream is further recorded on a Blu-ray Disc. FIG. 13 is a diagram for explaining the outline of the hybrid type OETF and the hybrid type EOTF. FIG. 14 is a diagram for comparing each OETF. FIG. 15 is an enlarged view of the dark area (low luminance area) in FIG. FIG. 16A is a diagram for describing a case where an HDR stream whose luminance value is quantized using PQ OETF is transmitted / distributed to HDRTV and SDRTV. FIG. 16B is a diagram for explaining a case where an HDR stream whose luminance value is quantized using hybrid OETF is transmitted / distributed to HDRTV and SDRTV. FIG. 17 is a diagram for explaining processing according to a flag that permits output to SDRTV. FIG. 18 shows a case where the video signal from the playback device to the display device when the hybrid stream is further recorded on the Blu-ray Disc and the SDRTV output permission flag is included in the static metadata. It is a figure for demonstrating a new transmission method. FIG. 19 is a diagram for explaining a transmission method when a warning message is included in a Blu-ray Disc including an HDR stream in cases 1 to 3 illustrated in FIG.

(Knowledge that became the basis of this disclosure)
The inventor has found that the following problems occur with respect to the image signal processing apparatus described in the “Background Art” section.

Conventionally, when a reproduction signal obtained by reproducing (decoding) a video stream is transmitted from a Blu-ray device to a display device such as a TV, the transmission is performed by HDMI (registered trademark). However, the playback signal output from the playback device is a video stream (hereinafter referred to as “HDR stream”) corresponding to HDR (High Dynamic Range) or a video stream (hereinafter referred to as “SDR”) corresponding to SDR (Standard Dynamic Range). A plurality of types of streams may be output (refer to the description using FIG. 1 described later). For this reason, it is necessary to realize a mechanism for storing a plurality of types of metadata when such a reproduction signal is transmitted using HDMI. Regarding a mechanism for storing such a plurality of types of metadata, It has not been considered in the past.

In other words, the present inventor examined the following improvement measures in order to solve the above-mentioned problems.

A playback device according to an aspect of the present disclosure is a playback device connected to a display device by HDMI, and (i) has a high dynamic range (HDR) in which the dynamic range of luminance is wider than the standard dynamic range (SDR). EDID including identification information indicating whether or not the display device can display a video in CEA Data Block is acquired from the display device via the HDMI, and (ii) the identification information included in the acquired EDID Accordingly, a processing unit is provided that determines a dynamic range of the video signal to be output, and (iii) transmits InfoFrame including metadata corresponding to the determined dynamic range to the display device via the HDMI.

According to this, a plurality of types of metadata can be stored by a storage method compatible with HDMI transmission and output to the display device. For this reason, it is possible to easily output an appropriate video to the display device.

In addition, for example, the InfoFrame may include the identification information indicating whether static metadata is stored, and the static metadata when the identification information indicates that the static metadata is stored. Data may be stored.

A transmission method according to an aspect of the present disclosure is a transmission method performed between a playback device and a display device that are connected to each other via HDMI, and has a luminance dynamic range wider than a standard dynamic range (SDR). An EDID including identification information indicating whether or not the display device can display high dynamic range (HDR) video in the CEA Data Block is acquired from the display device via the HDMI, and is included in the acquired EDID. The dynamic range of the video signal to be output is determined according to the identification information, and InfoFrame including metadata corresponding to the determined dynamic range is transmitted to the display device via the HDMI.

Note that these general comprehensive or specific modes may be realized by a recording medium such as a device, a system, an integrated circuit, a computer program, or a computer-readable CD-ROM. The device, system, integrated circuit, computer You may implement | achieve with arbitrary combinations of a program or a recording medium.

Note that each of the embodiments described below shows a specific example of the present disclosure. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment 1)
[background]
First, the transition of video technology will be described with reference to FIG. FIG. 1 is a diagram for explaining the evolution of video technology.

Up to now, the main focus has been on increasing the number of display pixels to improve the image quality. From the definition of Standard Definition (SD) 720 x 480 pixels to the high definition (HD) 1920 x 1080 pixels, so-called 2K. Video is prevalent.

In recent years, the introduction of so-called 4K video with 3840 × 1920 pixels of Ultra High Definition (UHD) or 4096 × 1920 pixels of 4K has been started with the aim of achieving higher image quality.

In addition to increasing the resolution of images by introducing 4K, it is being studied to increase the image quality by expanding the dynamic range, expanding the color gamut, or adding or improving the frame rate.

Among them, the dynamic range is the maximum brightness to express bright light such as specular reflection light that cannot be expressed by the current TV signal with more realistic brightness while maintaining the dark gradation in the conventional video. HDR (High Dynamic Range) is attracting attention as a method corresponding to a luminance range in which the value is expanded. Specifically, the method of the luminance range supported by conventional TV signals is called SDR (Standard Dynamic Range), and the maximum luminance value was 100 nits, whereas in HDR the maximum is 1000 nits or more. It is assumed that the luminance value is enlarged. Standardization of HDR is underway in SMPTE (Society of Motion Picture & Television Engineers) and ITU-R (International Telecommunications Union Radiocommunications Sector).

As a specific application destination of HDR, it is assumed that it is used in broadcasting, package media (Blu-ray (registered trademark) Disc, etc.), Internet distribution, etc., like HD and UHD.

In the following, in a video corresponding to HDR, the luminance of the video is composed of luminance values in the HDR luminance range, and a luminance signal obtained by quantizing the luminance value of the video is referred to as an HDR signal. . In a video corresponding to SDR, the luminance of the video is composed of luminance values in the luminance range of SDR, and a luminance signal obtained by quantizing the luminance value of the video is called an SDR signal.

[Relationship between master, distribution method, and display device when introducing HDR]
FIG. 2 is a diagram showing a relationship between a flow for producing a master for home entertainment of SDR and HDR, a distribution medium, and a display device.

The HDR concept has been proposed and its effectiveness at the HDR concept level has been confirmed. Moreover, the first implementation method of HDR is proposed. However, a large amount of HDR content was created using this method, and the first implementation method was not verified. For this reason, when the production of HDR content becomes full-scale in the future, the current HDR master method may change.

[Relationship between EDID and InfoFrame]
FIG. 3 is a diagram for explaining the relationship between EDID (EXTENDED DISPLAY IDENTIFICATION DATA) and InfoFrame on HDMI.

(1. EDID)
EDID is for transmitting display capability information indicating a video format that can be displayed by a Sync device (display device) such as the TV 200 conforming to (compatible with) HDMI to a Source device (playback device) such as the Blu-ray device 100. ROM data. The EDID is data composed of usually 256 bytes. Specifically, the EDID indicates the video timing that can be displayed such as the manufacturer name, the year of manufacture, etc. (1080i / 60, 720p / 60, 480p, etc. that can be displayed), presence of DeepColor support, and presence of 3D support Information (display capability information). In the present embodiment, the EDID further includes information (display capability information) indicating whether or not HDR (required HDR, option 1 HDR, and option 2 HDR) is supported.

The Blu-ray device 100 can automatically select and output a playback signal that can be displayed on the TV by acquiring the EDID of the TV via HDMI.

(2. InfoFrame)
The InfoFrame is a packet describing the attributes of the reproduction signal being output by the Blu-ray device 100, and is data transmitted during the blanking period of the TV 200. Specifically, InfoFrame is AVI_InfoFrame (Video timing, RGB / YCbCr, colorimetry information, etc.), Audio InfoFrame (including Audio information), Vendor Specific InfoFrame (IEEE encoded V1 defined VID information 24V). .4b includes data such as 3D information).

From the above, the Blu-ray device 100 has (i) a display capability indicating whether or not the TV 200 can display a video with a high dynamic range (HDR) whose luminance dynamic range is wider than the standard dynamic range (SDR). EDID including information (identification information) in CEA Data Block is acquired from the display device via HDMI, and (ii) the video signal to be output according to display capability information (identification information) included in the acquired EDID A processing unit that determines a dynamic range and (iii) transmits InfoFrame including metadata according to the determined dynamic range to the TV 200 via HDMI.

Also, the TV 200 transmits (i) EDID including display capability information in the CEA Data Block indicating whether or not the TV 200 can display an image having a dynamic luminance range of HDR to the Blu-ray device 100 via HDMI. And (ii) obtaining InfoFrame including metadata corresponding to the dynamic range of the output video signal determined according to the display capability information included in the transmitted EDID from the Blu-ray device 100 via HDMI. And a processing unit.

[Definition of HDMI data structure]
An area for storing attribute information of video data output from the source device in HDMI or an area for storing information indicating the playback capability of the sink device is secured, and an area for storing HDR-related metadata is secured. Stores metadata.

(1. Display device (EDID))
FIG. 4 is a diagram for explaining an example of HDR-related metadata stored in EDID.

As shown in FIG. 4, an area for storing HDR-related metadata is secured in a data block (CEA Data Block) that stores information defined by “CEA” of “CEA Extension for HDR” of block 1. In the area, HDR-related metadata (for example, 4 bytes) is stored.

(2. Blu-ray device)
FIG. 5 is a diagram for explaining an example of HDR-related metadata stored in the InfoFrame. FIG. 6 is a diagram illustrating an example of a specific structure of the InfoFrame.

The Blu-ray device transmits InfoFrame (IF) to the display device as HDR-related metadata. The InfoFrame includes a sequence number area and a data area.

The “sequence number” is identification information indicating whether static metadata is defined, mandatory dynamic metadata is defined, or option 1 or option 2 dynamic metadata is defined. That is, a plurality of types of IF packets can be defined using the sequence number field.

Specifically, as shown in FIG. 5A, in the case of sequence number = 0 packet, it is shown that static metadata is defined in InfoFrame. That is, the first IF packet (SN = 0) is used for static metadata.

In addition, as shown in FIGS. 5B to 5D, in the case of a packet with sequence number = 1 to 100, essential dynamic metadata, option 1 and option 2 dynamic metadata are defined. It shows that. These dynamic metadata are used in HDMI 2.1. By using IF packets (SN ≧ 1), essential dynamic metadata and two optional dynamic metadata can be defined.

As shown in FIG. 6, by using a sequence number (Seq_number) field, the length of the payload can be extended to 26 × 255 bytes. Further, the IF having Seq_number = 0x00 includes the minimum necessary information of HDR. Further, when a plurality of sequence numbers are transmitted in the frame period, the Seq_numbers must be arranged in descending order so that the IF having Seq_number = 0x00 is the last.

[Example of using static metadata]
FIG. 7 is a diagram for explaining a usage example of static metadata.

Static metadata includes the following information, for example. Specifically, the static metadata includes the color space information of the master display, the type of EOTF (PQ, BBC4, BBC8, etc.), Content Peak Luminance (maximum value of luminance value in the content), Maximum Average Luminance (content Information indicating the average value of the luminance values in the image). Here, EOTF of PQ is standardized as ST2084 of SMPTE.

Here, if the HDR content stored in the content distribution means such as Blu-ray Disc or OTT contains a very bright scene, it is inappropriate to alert the viewer in advance. It is necessary not to watch HDR content.

In the static metadata, if the value of Maximum Average Luminance of the content exceeds 350 nits, for example, it can be seen that the video includes a very bright scene. For this reason, when it is determined that the video includes a very bright scene, a video for alerting the viewer is generated and displayed on the Blu-ray device side or the TV side. Can do.

Also, in order to avoid instructing the display of the caution message on both the Blu-ray device and the TV, a flag for determining the presence or absence of the caution message display function may be described in the EDID of the TV. If this flag is present in the EDID of the TV, the Blu-ray device controls the viewer to stop displaying the caution message, thereby displaying the caution message on both the Blu-ray device and the TV. You can avoid giving instructions.

[Outline of processing in playback device]
As described above, in order to support the display of various BDs of 2K_SDR compatible TV and 4K_SDR compatible TV, conversion from HDR to SDR and down conversion from 4K to 2K are required. It is also necessary to satisfy the requirements of HDMI and HDCP. Therefore, the new Blu-ray device 100 (playback apparatus) performs the following processing. FIG. 8 is a diagram for explaining an overview of processing performed by the Blu-ray device. Hereinafter, (a) to (d) of FIG. 8 will be described.

(A) The Blu-ray device 100 converts a 4K_HDR video signal (HDR stream) into a 4K_SDR video signal, and converts the 4K_SDR video signal to HDMI2. Transmit to 4K_SDR compatible TV using x and HDCP2.2. Note that HDMI2. x indicates a version of HDMI 2.0 or later corresponding to HDR static metadata.

(B) The Blu-ray device 100 converts a 2K_HDR video signal into a 2K_SDR video signal, and transmits the 2K_SDR video signal to a 2K_SDR compatible TV or 4K_SDR compatible TV using at least HDMI 1.4 and HDCP 1.4. .

(C) The Blu-ray device 100 converts the 4K_HDR video signal into a 4K_SDR video signal, and down-converts the 4K_SDR video signal into a 2K_SDR video signal. The Blu-ray device 100 transmits a 2K_SDR video signal to a 2K_SDR-compatible TV using at least HDMI 1.4 and HDCP 1.4.

(D) The Blu-ray device 100 converts the 4K_SDR video signal into a 2K_SDR video signal, and transmits the 2K_SDR video signal to the 2K_SDR-compatible TV using at least HDMI 1.4 and HDCP 1.4.

In order to support the current HDTV (HDMI 1.4 & HDCP 1.4), it is necessary to add a new transmission method for permitting the above cases (b), (c) and (d). As a new transmission method, for example, cases 1 to 4 can be considered as shown in FIG. FIG. 9 is a diagram for explaining a new transmission method of a video signal from the playback device to the display device.

(Case 1) A video signal down-converted from UHD to HD and converted from HDR to SDR can be transmitted as a HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 2) The video signal converted from HDR to SDR can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 3) The video signal down-converted from UHD (SDR) to HD can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 4) HD / SDR HEVC 10-bit (bt.2020 & bt.709) video signal (protected by AACS2.0) is used as an HD video signal in a display device such as a TV compatible with HDCP 1.4 or later. Can be transmitted.

If the above cases 1 to 4 do not apply, these video signals must be transmitted to a display device such as a TV compatible with HDCP 2.2 or later, and are regarded as HDCP type 1 content.

FIG. 10 is a diagram showing a configuration of an HDR system capable of selecting a plurality of EOTFs.

Blu-ray devices and HDR-compatible TVs determine whether the content included in the Blu-ray Disc is SDR, HDR (PQ), or HDR (BBC) content, and according to the determined dynamic range Change the behavior.

For example, when a Blu-ray device outputs a playback signal to a TV capable of HDR display (that is, connected by HDMI), it outputs the playback signal as it is. When the connected TV is SDRTV (TV that does not support HDR video display and also supports SDR video display), the Blu-ray device can only change from HDR to SDR when the content is HDR (PQ). The playback signal obtained by performing conversion to (automatically or manually selecting the maximum brightness after conversion) is output to SDRTV, and if the content is other than HDR (PQ), the playback signal is not converted. Output to SDRTV as it is.

When converting from HDR to SDR, if the Blu-ray device acquires attribute information (display capability information) indicating the type of video that can be displayed by the SDRTV connected to the Blu-ray device, It is converted into a playback signal that can be displayed by SDRTV according to the attribute information. If the type of video that can be displayed on the TV is not known, the type of conversion (HDR effect, weak / medium / strong, etc.) may be changed according to user designation. That is, when the maximum brightness of SDRTV is high, the HDR effect may be strengthened for conversion. If the maximum luminance is low, the displayed image becomes dark when the maximum brightness is increased, and the HDR effect cannot be enjoyed. Therefore, it is important for the user to appropriately specify the conversion intensity.

Also, the TV performs display after mapping the brightness value of the content and the display brightness of the panel (HDR Color Mapping) according to the input playback signal of the content.

FIG. 11 is a diagram for explaining another example of the outline of the processing performed by the Blu-ray device. FIG. 11 is a diagram for explaining a case where a hybrid stream is included in the type of video stream recorded in the Blu-ray Disc in the configuration of FIG.

A video stream obtained by quantization using a hybrid type OETF (for example, BBC OETF), which is one of HDR types, is a hybrid type video stream that can maintain compatibility with SDRTV. For this reason, compatibility with the existing TV can be maintained by treating the same as the SDR signal.

As shown in FIG. 11, when a hybrid stream is recorded on a Blu-ray Disc, cases 1 to 6 are conceivable as a new transmission method, for example, as shown in FIG. FIG. 12 is a diagram for explaining a new transmission method of a video signal from a playback device to a display device when a hybrid stream is further recorded on a Blu-ray Disc.

(Case 1) A UHD / HDR (PQ) video signal down-converted from UHD to HD and converted from HDR to SDR is a display device such as a TV that supports HDCP 1.4 or later as an HD video signal. Can be transmitted.

(Case 2) A video signal down-converted from UHD / HDR (hybrid EOTF) (bt.2020 and bt.709) to HD is displayed as an HD video signal on a TV or the like that supports HDCP 1.4 or later. Can be transmitted to the device.

(Case 3) The video signal down-converted from UHD (bt.2020 and bt.709) to HD can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 4) An HD / HDR (PQ) video signal converted from HDR to SDR can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 5) The video signal of HD / HDR (hybrid EOTF) (bt.2020 and bt.709) can be transmitted to a display device such as a TV compatible with HDCP1.4 or later.

(Case 6) An HD / SDR HEVC 10-bit (bt.2020 & bt.709) video signal can be transmitted to a display device such as a TV compatible with HDCP 1.4 or later.

If the above cases 1 to 6 do not apply, these video signals need to be transmitted to a display device such as a TV compatible with HDCP 2.2 or later, and are regarded as HDCP type 1 contents.

Thus, content distribution means such as Blu-ray Disc and OTT store video streams of HDR content having different EOTFs, and one video stream is a hybrid stream compatible with SDR. In this case, interoperability with SDRTV can be improved by performing HDCP processing similar to SDR content.

Next, an outline of the hybrid EOTF will be described with reference to FIGS. 13 to 16B.

FIG. 13 is a diagram for explaining the outline of the hybrid type OETF and the hybrid type EOTF. FIG. 14 is a diagram for comparing each OETF. FIG. 15 is an enlarged view of the dark area (low luminance area) in FIG.

First, EOTF will be described. EOTF is generally called a gamma curve, shows the correspondence between luminance values and code values, and quantizes the luminance values and converts them into code values. That is, EOTF is relationship information indicating the correspondence between the luminance value and the plurality of code values. For example, when a luminance value of a video corresponding to SDR is expressed by a 10-bit gradation code value, the luminance value in a luminance range up to 100 nit is quantized and mapped to 1024 integer values from 0 to 1023. Is done. That is, by performing quantization based on EOTF, the luminance value in the luminance range up to 100 nit (the luminance value of the video corresponding to SDR) is converted into an SDR signal that is a 10-bit code value. In EOTF corresponding to HDR (hereinafter referred to as “HDR EOTF”), it is possible to express a luminance value higher than that of EOTF corresponding to SDR (hereinafter referred to as “SDR EOTF”). For example, in FIG. 13, the maximum luminance value (peak luminance) is 1000 nits. That is, the HDR luminance range includes the entire SDR luminance range, and the HDR peak luminance is larger than the SDR peak luminance. The HDR luminance range is a luminance range in which the maximum value is expanded from, for example, 100 nit, which is the maximum value of the SDR luminance range, to 1000 nit. The HDR signal is also expressed with, for example, a 10-bit gradation.

OETF is an inverse function of EOTF. In other words, if the opposite relationship of EOTF is used, OETF is used. Therefore, in the following, the luminance value of the video is quantized using EOTF in the same meaning as the luminance value of the video using OETF. It is also said to quantize the value.

The video after grading is quantized by the OETF shown in FIG. 13A, and a code value corresponding to the luminance value of the image is determined. Image coding or the like is performed based on this code value, and an elementary stream is generated. Further, at the time of reproduction, the luminance value for each pixel is restored by performing inverse quantization on the decoding result of the elementary stream based on the EOTF shown in FIG. In the case of FIG. 13, BT. It is quantized by using 1886 OETF, and BT. The luminance value is restored by using 1886 EOTF. The HDR stream is quantized by using a hybrid OETF, and the HDR stream is reproduced by using a hybrid EOTF to restore the luminance value. In the case of FIG. 13, the hybrid type OETF and the hybrid type EOTF are used for the generation and reproduction of the HDR stream, respectively, but the PQ OETF and the PQ EOTF may be used.

Hybrid EOTF is, for example, HDR EOTF compatible with SDRTV proposed by ITU-R by BBC (British Broadcasting Corporation). HDR EOTF compatible with SDRTV means that when displayed on HDRTV (TV compatible with HDR video display), the luminance value of the video in the HDR luminance range can be restored and displayed on SDRTV Is an EOTF that can restore the luminance value of the video in the luminance range of the SDR.

Specifically, in the hybrid OETF that is an inverse function of the hybrid EOTF, the dark area (low luminance area) is BT. It is quantized with the same characteristics as 1886, and the high-intensity part (region) is quantized with a coarse quantization step size. In SDRTV, a high code value is set to BT. Inverse quantization as a code value of 1886. That is, when the hybrid HDR stream is displayed in SDRTV, the high luminance region is automatically remapped to the luminance range of the SDR signal.

As shown in FIG. 13, the hybrid type OETF has a BT. BT. In a dark area (low luminance area) having a luminance value smaller than 50 nits. It has the same curve as 1886 OETF (SDR OETF). That is, the hybrid type OETF and the SDR OETF have substantially the same relationship between the luminance value and the code value in the dark area. For example, the hybrid type OETF is represented by the following formula 1. This is described, for example, in the following document “White paper of BBC's EOTF (http://www.bbc.co.uk/rd/publications/whitepaper 283)”.

It should be noted that Equation 1 shows that BT. It shows that the relational expression is the same as 1886 OETF.

Here, referring to FIGS. 14 and 15, the PQ OETF and the hybrid OETF are compared. 14 and 15 show BT. As SDR OETF. O886 of 1886 is represented by a solid line, and as a hybrid type OETF, Lmax4 of BETF OETF is represented by a one-dot chain line, Lmax8 of BETF OETF is represented by a long broken line, and OQ of PQ is represented by a short broken line. Note that Lmax4 and Lmax8 of the OBC of the BBC are curves having different peak luminance from each other, and BT. It has the same curve as the 1886 OETF.

As shown in FIG. 14, when the peak luminance is 1000 to 1200 nits, the PQ OETF cannot use an area having a code value (CV (Code Value)) of 750 or more. However, the BBC OETF can use all code values for both Lmax4 and Lmax8. That is, the hybrid type OETF can realize better image quality in the luminance range of 0 to 1000 nits.

In addition, as shown in FIG. The 1886 OETF and the BBC OETF Lmax4 and Lmax8 have almost the same code value. That is, the hybrid OETF can maintain the image quality in the low luminance region even when the SDRTV is used.

FIG. 16A is a diagram for explaining a case where an HDR stream whose luminance value is quantized using PQ OETF is transmitted / distributed to HDRTV and SDRTV. FIG. 16B is a diagram for explaining a case where an HDR stream whose luminance value is quantized using hybrid OETF is transmitted / distributed to HDRTV and SDRTV.

As shown in FIG. 16A, when the PQ OETF is used to generate the HDR stream, the user can select the SDR disc or the HDR disc according to the type of TV (that is, SDRTV or HDRTV) during BD playback. Must be selected. On the other hand, as shown in FIG. 16B, when the hybrid type OETF is used to generate the HDR stream, the user does not need to know the type of TV (that is, SDRTV or HDRTV), and is simply a hybrid type. An HDR disk on which an HDR stream (hybrid stream) generated by OETF is recorded may be used for reproduction.

Similarly, in a so-called OTT service that distributes video streams over the Internet, distributing a hybrid stream quantized using a hybrid OETF can avoid user confusion.

FIG. 17 is a diagram for explaining processing according to a flag that permits output to SDRTV.

The static metadata of HDR content stored in Blu-ray Disc, etc. has an SDRTV output permission flag (legacy HDTV (HDCP1.4) output permission flag) as the type of EOTF (PQ, BBC4, BBC8, etc.). It may be included. Thus, by including the SDRTV output permission flag in the static metadata, the content provider can specify the output method to the SDRTV 200a. As shown in FIG. 17, when the SDRTV output permission flag indicates permission, the Blu-ray device 100 can also output an HDR signal to the SDRTV 200a (HDCP1.4 legacy TV). When the SDRTV output permission flag indicates non-permission, the Blu-ray device 100 converts the SDR signal into an SDR signal and transmits the SDR signal to the SDRTV 200a.

As shown in FIG. 11, when a hybrid stream is recorded on a Blu-ray Disc and the SRDTV output permission flag is included in the static metadata as shown in FIG. For example, cases 1 to 6 are conceivable as shown in FIG. FIG. 18 shows a case where the video signal from the playback device to the display device when the hybrid stream is further recorded on the Blu-ray Disc and the SDRTV output permission flag is included in the static metadata. It is a figure for demonstrating a new transmission method.

(Case 1) A UHD / HDR (Flag = OFF) video signal down-converted from UHD to HD and converted from HDR to SDR is an HD video signal such as a TV compatible with HDCP 1.4 or later. It can be transmitted to the display device.

(Case 2) The video signal down-converted from UHD / HDR (Flag = ON) (bt.2020 and bt.709) to HD is a display device such as a TV that supports HDCP1.4 or later as an HD video signal. Can be transmitted.

(Case 4) An HD / HDR (Flag = OFF) video signal converted from HDR to SDR can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later.

(Case 5) The video signal of HD / HDR (Flag = ON) (bt.2020 and bt.709) can be transmitted to a display device such as a TV compatible with HDCP1.4 or later.

As described above, the static metadata includes the SDRTV output permission flag, so that the content provider can specify the output method to SDRTV. When the SDRTV output permission flag indicates that the output to SDRTV is permitted, the HDR signal can be sent to the legacy TV of HDCP1.4. After conversion, it can be transmitted to SDRTV.

(Requests from content creators)
The PQ EOTF HDR content in Blu-ray Disc must be transmitted as it is to a TV capable of HDR display (PQ EOTF display is possible). This means that a PTV EOTF displayable HDRTV user must see the PQ EOTF HDR content on the user's HDRTV.

Specifically, cases 1 to 4 can be considered as shown below.

(Case 1) When transmitting to HDRTV (TV capable of displaying both PQ EOTF and hybrid EOTF) The Blu-ray device must transmit the PQ HDR content in the Blu-ray disc to the HDRTV as it is. Also, a Blu-ray device must not convert PQ HDR content into hybrid type HDR content or SDR content before transmitting PQ HDR content to HDRTV.

(Case 2) When transmitting to HDRTV (TV capable of displaying only PQ EOTF) The Blu-ray device must transmit the PQ HDR content in the Blu-ray disc to HDRTV as it is. A Blu-ray device must not convert PQ HDR content into SDR content before transmitting PQ HDR content to HDRTV.

(Case 3) When transmitting to SDRTV (PQ non-EOTF compatible TV) Blu-ray devices must not transmit PQ HDR content on a Blu-ray disc to HDRTV as it is. The Blu-ray device must convert the PQ HDR content into SDR content using its own HDR-to-SDR conversion function, and transmit the SDR content obtained by the conversion to SDRTV.

(Case 4) When transmitting to SDRTV (TV capable of displaying only hybrid type EOTF) The Blu-ray device must transmit the PQ HDR content in the Blu-ray disc to the HDRTV as it is. A Blu-ray device must not convert PQ HDR content into hybrid HDR content before transmitting PQ HDR content to HDRTV. The Blu-ray device must convert the PQ HDR content into SDR content using its own HDR-to-SDR conversion function, and transmit the SDR content obtained by the conversion to SDRTV.

(Playback device)
The playback device must support conversion from HDR to SDR.

Also, the playback device must provide PSR and BD-J system properties to indicate to the HDMV or Java (registered trademark, hereinafter the same) application whether or not the playback device is connected to the HDR display.

(content)
The content makes it possible to select a stream (HDR or SDR) suitable for playback.

Content will be able to provide messages if requested.

The content is when the playback device is connected to the SDR display, and when the HDR stream is played back, it is possible to indicate to the playback device whether the message has been provided.

FIG. 19 is a diagram for describing a transmission method when a warning message is included in a Blu-ray Disc including an HDR stream in cases 1 to 3 illustrated in FIG.

(Case 1) A video signal down-converted from UHD to HD and converted from HDR to SDR can be transmitted as a HD video signal to a display device such as a TV compatible with HDCP 1.4 or later. In this case, a warning message may be displayed on a TV compatible with HDCP 1.4 or later.

(Case 2) The video signal converted from HDR to SDR can be transmitted as an HD video signal to a display device such as a TV compatible with HDCP 1.4 or later. In this case, a warning message may be displayed on a TV compatible with HDCP 1.4 or later.

In each of the above embodiments, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

As described above, the display method and the display device according to one or more aspects of the present disclosure have been described based on the embodiments, but the present disclosure is not limited to the embodiments. Unless it deviates from the gist of the present disclosure, various modifications conceived by those skilled in the art have been made in this embodiment, and forms constructed by combining components in different embodiments, etc. It may be included within the scope of the embodiments.

The present disclosure is useful as a playback device that can easily output an appropriate video to a display device.

100 Blu-

ray equipment

200, 200a TV

Claims

A playback device connected to a display device via HDMI,
(I) EDID including identification information indicating whether or not the display device can display an image having a high dynamic range (HDR) whose luminance dynamic range is wider than a standard dynamic range (SDR), in the CEA Data Block, Acquired from the display device via HDMI,
(Ii) determining the dynamic range of the video signal to be output according to the identification information included in the acquired EDID;
(Iii) A playback device including a processing unit that transmits InfoFrame including metadata according to the determined dynamic range to the display device via the HDMI.
The InfoFrame stores identification information indicating whether static metadata is stored, and the static metadata when the identification information indicates that the static metadata is stored. The playback apparatus according to claim 1.
A display device connected to the playback device via HDMI,
(I) EDID including identification information indicating whether or not the display device can display an image having a high dynamic range (HDR) whose luminance dynamic range is wider than a standard dynamic range (SDR), in the CEA Data Block, Sent to the playback device via HDMI,
(Ii) A processing unit that acquires, from the playback device via the HDMI, an InfoFrame that is determined according to the identification information included in the transmitted EDID and includes metadata according to a dynamic range of an output video signal A display device comprising:
A transmission method performed between a playback device and a display device connected to each other via HDMI,
Through the HDMI, the EDID including identification information indicating whether or not the display device can display a video with a high dynamic range (HDR) whose luminance dynamic range is wider than the standard dynamic range (SDR). Obtained from the display device,
According to the identification information included in the acquired EDID, determine the dynamic range of the video signal to be output,
A transmission method of transmitting InfoFrame including metadata corresponding to the determined dynamic range to the display device via the HDMI.