JP6677482B2 - Hierarchical encoding device and transmission device - Google Patents

Description

  The present invention relates to a hierarchical encoding apparatus, and more particularly to an apparatus for compression-encoding a video with a plurality of types of spatial resolutions or a plurality of types of image quality according to a transmission band. The present invention also relates to a transmission device provided with the hierarchical coding device.

  In recent years, development and application in the broadcasting field of ultra-high-definition video having a horizontal 7680 × vertical 4320 (8K × 4K, so-called 8K) or horizontal 3840 × vertical 2160 (4K × 2K, so-called 4K) pixel count has been advanced. . In addition, services using satellite waves and networks of ultra-high-definition video have been sequentially started. On the other hand, the study of ultra-high-definition video transmission in terrestrial broadcasting, which plays an important role in broadcasting services, is starting to be started. However, in the case of terrestrial broadcasting, the bandwidth per channel is fixed. Not only is it difficult to increase, but also many channels are already used in the current HDTV (High Definition Television) broadcasting service, and it is difficult to start a new service.

  FIG. 12 is a conceptual diagram of a transmission system currently used for terrestrial waves. A system includes a transmitting device having one antenna for transmitting a single-polarized (for example, horizontally polarized) radio wave and a receiving device having one antenna for receiving the same single-polarized (for example, horizontal polarized) radio wave. This is called an SISO (Single Input Single Output) method. On the transmitting side, the video signal X is subjected to necessary compression encoding and modulation by the modulator 11, and is transmitted as a horizontally polarized radio wave from the horizontally polarized transmission antenna 12. On the receiving side, the radio wave (compressed signal) transmitted as the horizontally polarized wave is received by the horizontally polarized wave receiving antenna 22 and demodulated and decoded by the demodulator 21 to reproduce the video signal X. You.

  In the current SISO system, the transmission capacity can be increased to some extent by improving the modulation system, and a 4K × 2K high-definition image can be transmitted with high image quality. High definition images cannot be transmitted.

  In such a situation, a MIMO (Multi Input Multi Output) system utilizing a plurality of antennas has attracted attention as a terrestrial transmission system. The MIMO scheme is a scheme in which a signal is transmitted from a transmitting side using a plurality of antennas, and a signal is also received on a receiving side using a plurality of antennas, and the transmission capacity can be greatly increased. In particular, the polarization MIMO system that uses the plane of polarization of radio waves to transmit and receive horizontally polarized radio waves and vertically polarized radio waves at the same frequency with different antennas must expand the transmission capacity to twice that of the SISO system. Is possible, and is expected as a transmission system capable of transmitting 8K × 4K ultra-high-definition video with high image quality (Non-Patent Document 1).

  FIG. 13 is a conceptual diagram of the polarization MIMO method. On the transmitting side, the video signal X is subjected to necessary compression encoding and modulation by the modulator 11, and is transmitted as a horizontally polarized radio wave from the horizontally polarized transmission antenna 12. The video signal X 'undergoes necessary compression encoding and modulation by the modulator 13, and is transmitted from the vertically polarized wave transmitting antenna 14 as vertically polarized radio waves. The receiving device 20 includes equipment capable of receiving both horizontal polarization and vertical polarization. That is, a radio wave (compressed signal) transmitted as a horizontally polarized wave is received by a horizontally polarized wave receiving antenna 22, demodulated and decoded by a demodulator 21, and a video signal X is reproduced. The radio wave (compressed signal) transmitted as a vertically polarized wave is received by the wave receiving antenna 24, demodulated and decoded by the demodulator 23, and the video signal X 'is reproduced. The video signal X and the video signal X ′ can be combined to generate one ultra-high-definition image (for example, a high-quality 8K × 4K high-definition video).

  On the other hand, there is a hierarchical (or scalable) coding method as a method of compressing and coding a video which is indispensable for transmission of an ultra-high definition video (Non-Patent Document 2). Hierarchical encoding is such that when a part of one compressed stream is extracted, a low-resolution video, a low-quality video, or a low-frame-rate video is reproduced. When the entire stream is received, a high-resolution or high-quality video is reproduced. Alternatively, it is a system that can reproduce a video with a high frame rate. This hierarchical coding method is expected to be used in the future as a coding method that can flexibly cope with the difference in signal processing capability of each receiving device.

Takuya Shitomi, "Transmission Characteristics of Polarized MIMO-Super Multi-Valued OFDM in Multipath Environment", NHK Giken R & D, November 2012, No. 136, p. 24-32 Shinya Kadono, "Keywords you should know Hierarchical Coding (Scalable Coding)", Journal of the Institute of Image Information and Television Engineers, 2007, Vol. 61, no. 4, p. 459-461

  As described above, by introducing the polarization MIMO system, it is possible to realize a broadcasting system for transmitting 8K × 4K ultra-high-definition video with high image quality. However, in order to introduce the polarization MIMO system, a conventional receiving apparatus that supports signals of a single polarization (for example, horizontal polarization) is required on the receiving side (that is, the viewer side). In order to cope with the two polarizations, it is necessary to change the receiving equipment such as an antenna. Even if the service using the broadcasting waves of the two polarizations is started, it takes time for the new receiving equipment to be widely used. Therefore, it is required to gradually shift and spread from the current SISO transmission / reception system using only one polarization. In other words, it is necessary that a receiving device that supports a transmission service of a broadcasting service at a certain stage can receive a signal even when a transmission system of a broadcasting service at the next stage is introduced. The next stage here means that the resolution of the video is refined or the image quality is improved by increasing the transmittable bit rate.

  Therefore, an object of the present invention made in view of the above-described problems is to provide a receiving apparatus corresponding to a certain stage of the transmission system and a receiving apparatus corresponding to the next stage of the transmission system at the time of transition of the transmission system. It is an object of the present invention to provide a hierarchical encoding device suitable for a signal transmission system capable of receiving signals.

  Another object of the present invention is to provide a transmission device capable of transmitting a compressed signal capable of reproducing an appropriate video corresponding to a reception device when a transmission system is shifted.

In order to solve the above-described problem, a hierarchical encoding device according to the present invention includes a first transmission signal transmitted by a first polarization radio wave and a second transmission signal transmitted by a second polarization radio wave. In the hierarchical encoding apparatus for transmitting a high-resolution video, the first transmission signal is used as video encoded data of a base layer, and the second transmission signal is defined as having a resolution corresponding to the video of the base layer. A first layer encoding device that encodes and transmits a high-level image as a plurality of layers and encodes and transmits the image in a plurality of layers; and the second transmission signal, wherein the first transmission signal is video encoded data of a base layer. And a second layer encoding device that encodes and transmits the image in a plurality of layers by encoding an image in which the image with improved image quality at the same resolution as the image of the base layer is encoded. Hierarchical encoding device and the second hierarchical encoding device And selectively switched, the switching selection by the evaluation measure of the image quality, and selects the hierarchical encoding apparatus quality of decoded video to generate a high video coding data.

The transmission apparatus according to the present invention includes the above-described hierarchical encoding apparatus, transmits the first transmission signal of a radio wave of the first polarization, the second transmission signal of the second polarization It is characterized by transmission by radio waves.

  According to the present invention, in response to the gradual transition of the transmission system from the SISO system to the SISOx2 system and further to the polarization MIMO system, the receiving apparatus corresponding to the transmission system of a certain stage broadcast service is transmitted to the next stage. A signal transmission system capable of receiving signals can also be configured in the broadcasting service transmission system. In addition, image quality, resolution, and the like can be improved with the expansion of the transmission method, and smooth transition of the transmission method can be promoted.

FIG. 3 is a conceptual diagram of the SISOx2 system at the time of transition of the transmission system. FIG. 3 is a diagram illustrating an encoding method for transmitting a high-quality image in the SISO method. FIG. 3 is a diagram illustrating an encoding method for transmitting a high-resolution image in the SISO method. FIG. 3 is a diagram illustrating an encoding method for transmitting a high-quality image by hierarchical encoding in the SISOx2 method. FIG. 3 is a diagram illustrating an encoding method for transmitting a high-resolution image by hierarchical encoding in the SISOx2 method. FIG. 2 is a diagram illustrating an encoding method for transmitting a high-quality image by hierarchical encoding in a polarization MIMO method. FIG. 2 is a diagram illustrating an encoding method for transmitting a high-resolution image by hierarchical encoding in a polarization MIMO method. FIG. 1 is a block diagram of a hierarchical encoding device that implements a high-quality image encoding process of the present invention. It is a block diagram of the hierarchical decoding device which implements the decoding process of a high quality image. FIG. 1 is a block diagram of a hierarchical encoding device that implements a high-resolution image encoding process according to the present invention. It is a block diagram of the hierarchical decoding device which implements the decoding process of a high-resolution image. It is a conceptual diagram of SISO system. It is a conceptual diagram of a polarization MIMO system.

  Hereinafter, embodiments of the present invention will be described.

(Embodiment)
FIG. 1 is a conceptual diagram of a transmission system assumed to be adopted in the present invention during the transition from the SISO system to the polarization MIMO system. The transmission system in FIG. 1 is a system in which a horizontally polarized radio wave is transmitted with high power and a vertically polarized radio wave is separately transmitted with low power similarly to the SISO system. This method will be referred to as the SISOx2 method.

  On the transmission side, the video signal X (transmission capacity x) is subjected to necessary compression encoding and modulation by the modulator 11, and a horizontal polarization (first polarization) of a certain frequency is transmitted from a horizontal polarization transmission antenna 12. Is transmitted as radio waves. This horizontal polarization is the same as in the SISO system. Further, on the transmission side, the video signal Y (transmission capacity y) is subjected to necessary compression encoding and modulation by the modulator 13, and is transmitted from the vertical polarization transmission antenna 14 to the vertical polarization (second polarization) of the same frequency. Wave). Here, the transmission capacity y is, for example, about half of the transmission capacity x.

  On the receiving side, a receiving device that receives only horizontal polarization receives a radio wave (compressed signal) transmitted as a horizontal polarization by a horizontal polarization receiving antenna 22 and demodulates the signal, similarly to the conventional SISO system. The demodulator 21 decodes and decodes the video signal X. Note that the vertical polarization is a radio wave of the same frequency but weak power, and therefore does not significantly affect the reception of the existing horizontal polarization.

  Also, in the receiving apparatus 20 having a new receiving facility capable of receiving both horizontal and vertical polarizations, the radio wave (compressed signal) transmitted as horizontal polarization by the antenna 22 for horizontal polarization reception is received, and the demodulator 21 The video signal X is reproduced by demodulation and decoding, and the radio wave (compressed signal) transmitted as the vertically polarized wave by the vertically polarized wave receiving antenna 24 is received. The decoding is performed to reproduce the video signal Y. That is, the receiving device 20 can additionally receive the video signal Y (transmission capacity y) due to vertical polarization, and the transmission capacity is expanded. The video signal X and the video signal Y can be combined to form one ultra-high definition image.

  As described above, in the SISOx2 system, the receiving device capable of receiving only horizontally polarized radio waves and the receiving device 20 capable of receiving both horizontal and vertical polarized waves can coexist. Thereafter, after the receiving equipment (receiving device 20) capable of receiving both horizontal and vertical polarizations has sufficiently spread, it is possible to shift to the polarization MIMO system of FIG. 13 in which both horizontal and vertical polarizations are transmitted with the same power. .

  When shifting to the polarization MIMO system, both horizontal and vertical polarizations can be received, but SISOx2, which can receive only a part of a vertically polarized radio signal (a signal corresponding to the video signal Y). If there is a receiver corresponding to the system, it is necessary to further design a signal transmission system in a transition stage in which the receiver compatible with the SISOx2 system and the receiver compatible with the polarization MIMO system can coexist. it can.

  According to the present invention, it is possible to increase the image quality and the definition in a stepwise manner by using a video compression encoding method corresponding to each of the SISO, SISOx2, and polarization MIMO transmission methods. Then, in order to cope with the stepwise change of the transmission method, hierarchical coding is applied as a video coding method. In the following description, specific transmission capacity (bit rate) and resolution (size) of a video image are exemplified for explanation, but the present invention is not limited thereto.

  FIG. 2 is a diagram conceptually illustrating an encoding method for transmitting a high-quality image based on the SISO method. Assuming that the transmission capacity of the SISO system is about 30 Mbps, MPEG-H HEVC / H. By applying the latest compression technology such as H.265 (Moving Picture Experts Group-High Efficiency Video Coding / H.265), it is possible to compress and encode a video of about 4K × 2K to high quality and transmit it. Such a transmission method giving priority to high image quality is hereinafter referred to as “A pattern”. A 4K × 2K video signal is encoded by an encoder 31, transmitted by a transmission path (transmission capacity 30 Mbps), and decoded by a decoder 41 to obtain a 4K × 2K high image quality. A decoded video signal is obtained.

  FIG. 3 is a diagram conceptually illustrating an encoding method for transmitting a high-resolution image based on the SISO method. Assuming that the transmission capacity of the SISO system is about 30 Mbps, it is possible to compress and encode a video of about 6K × 3K (5760 × 3240) with medium image quality and transmit it by a compression technique. Such a transmission method giving priority to high resolution is hereinafter referred to as a “B pattern”. A 6K × 3K video signal is encoded by the encoder 31, transmitted by a transmission path (transmission capacity 30 Mbps), and decoded by the decoder 41, whereby a 6K × 3K medium-quality video decoded signal is obtained. can get. Here, "medium image quality" and "high image quality" mean the degree of noise on an image, and do not mean the number of bright and dark bits of a pixel. Here, 6K × 3K is the resolution (format size) of the video signal to be transmitted, and does not necessarily mean the resolution of the display screen (monitor) on the receiving side. The display device on the receiving side can display the image after converting it into an appropriate resolution (for example, expanding to 8K × 4K) based on the decoded video signal.

  FIG. 4 is a diagram conceptually illustrating an encoding method for transmitting a high-quality image by hierarchical encoding on the premise of the SISOx2 method. In the SISOx2 system, about 13 Mbps can be additionally transmitted as the transmission capacity y by using vertical polarization. Therefore, in a receiving device capable of receiving both polarized waves, 30 Mbps + 13 Mbps = 43 Mbps, so that a video of about 6K × 3K can be compressed and encoded with high image quality and transmitted.

  In FIG. 4, the original 6K × 3K video signal is reduced to a 4K × 2K video signal, which is encoded by the encoder 31 to be a compressed encoded signal having a transmission capacity of 30 Mbps. This compression-encoded signal becomes basic hierarchical data for hierarchical encoding. This compression-encoded signal is transmitted, for example, as horizontally polarized radio waves, and is decoded by the decoder 41 to become a 4K × 2K high-quality video decoded signal (A pattern).

  On the transmitting side, the 30 Mbps compressed and coded signal is converted into a 4K × 2K video decoded signal by the decoder 41, and this video decoded signal is expanded to a 6K × 3K video signal, and the input signal of the encoder 32 is input. And The encoder 32 uses the decoded video signal from the decoder 41 as a prediction reference image (base hierarchical image), hierarchically encodes the original 6K × 3K video signal, and transmits the first hierarchical data having a transmission capacity of 13 Mbps. Generate The first hierarchical data is transmitted as vertically polarized radio waves, and is hierarchically decoded by the decoder 42 together with a video decoded signal decoded from the basic hierarchical data to generate a 6K × 3K high-quality video decoded signal. Can be.

  In FIG. 4, a part 50 of the encoding system including the encoder 31 and the decoder 41 is the same as that in FIG. 2, and can be received by the SISO system. Therefore, the SISOx2 system shown in FIG. 4 can be said to be a system in which a transmission line of 13 Mbps is newly added to the transmission line configuration of the SISO system of FIG. 2, and can coexist with the SISO system.

  FIG. 4 is a diagram for explaining the relationship between hierarchical encoding and decoding. In FIG. 4, the decoders 41 and 42 not only represent decoding units of the receiving device but also decoding units of the transmitting device. You may. Similarly, in FIGS. 5 to 7, a decoder does not simply mean a receiving device, but also means a decoding unit in a transmitting device.

  FIG. 5 is a diagram conceptually illustrating an encoding method for transmitting a high-resolution image by hierarchical encoding on the premise of the SISOx2 method. In FIG. 5, the original video signal of 6K × 3K is encoded by the encoder 31 to be a compressed encoded signal having a transmission capacity of 30 Mbps. This compression-encoded signal becomes basic hierarchical data for hierarchical encoding. This compression-coded signal is transmitted, for example, as horizontally polarized radio waves, and is decoded by the decoder 41 to be a 6K × 3K medium-quality video decoded signal (B pattern).

  On the transmitting side, the 30 Mbps compressed and coded signal is converted into a 6K × 3K video decoded signal by the decoder 41, and this video decoded signal is used as an input signal of the encoder 32. The encoder 32 uses the decoded video signal from the decoder 41 as a prediction reference image (base hierarchical image), hierarchically encodes the original 6K × 3K video signal, and transmits the first hierarchical data having a transmission capacity of 13 Mbps. Generate The first hierarchical data is transmitted by vertically polarized radio waves, and is hierarchically decoded by the decoder 42 together with a video decoded signal decoded from the basic hierarchical data, thereby generating a 6K × 3K high-quality video decoded signal.

  In FIG. 5, a part 50 of the encoding system including the encoder 31 and the decoder 41 is the same as that of FIG. 3, and can be received by the SISO system. Therefore, the SISOx2 system shown in FIG. 5 can be said to be a system in which a transmission line of 13 Mbps is newly added to the transmission line configuration of the SISO system of FIG. 3, and can coexist with the SISO system.

  Note that the hierarchical encoding function used in the SISOx2 scheme of FIGS. 4 and 5 has no restriction on the encoding scheme of a low bit rate or a low-resolution video, which is a basic layer. For example, HEVC / H. When using the H.265 system, the base layer is AVC / H. Conventional methods such as H.264 and MPEG-2 may be used.

  FIG. 6 is a diagram conceptually illustrating a coding method for transmitting a high-quality image by hierarchical coding on the premise of the polarization MIMO method. In the polarization MIMO system, a transmission signal of about 30 Mbps can be transmitted with the vertical polarization as the same power output as the horizontal polarization. Therefore, in a receiving apparatus capable of receiving both polarized waves, the transmission rate is 60 Mbps, so that 8K × 4K video can be compressed and encoded with high image quality and transmitted. Note that, in the polarization MIMO system, the horizontal polarization is output in the same manner as the SISO system, but the vertical polarization is transmitted at the same frequency as the horizontal polarization and with the same power as the horizontal polarization. Affects polarization reception. Therefore, it is difficult to receive only horizontally polarized waves with the conventional SISO receiving equipment, and it is desirable to introduce the SISO receiving equipment after at least all of the SISO x2 receiving equipment has been shifted to the SISOx2.

  In FIG. 6, by using the hierarchical encoding function on the SISOx2 system of FIG. 4, it is possible to encode an 8K × 4K video signal while maintaining compatibility with the SISOx2 system receiving equipment. First, the original 8K × 4K video signal is reduced to a 6K × 3K video signal, and this signal is further reduced to a 4K × 2K video signal, which is encoded by the encoder 31 and is compressed at a transmission capacity of 30 Mbps. It is an encoded signal. This compression-encoded signal becomes basic hierarchical data for hierarchical encoding, and is transmitted as horizontally polarized radio waves. The 30 Mbps compressed and coded signal is converted into a 4K × 2K video decoded signal by the decoder 41, and the decoded video signal is expanded into a 6K × 3K video signal to be used as an input signal of the encoder 32. The encoder 32 uses the decoded video signal from the decoder 41 as a prediction reference image (base hierarchical image), hierarchically encodes the original 6K × 3K video signal, and transmits the first hierarchical data having a transmission capacity of 13 Mbps. Generate The first hierarchical data is hierarchically decoded by the decoder 42 together with a video decoded signal decoded from the basic hierarchical data, and a 6K × 3K high quality video decoded signal is generated (A pattern). The 6K × 3K decoded video signal is expanded to an 8K × 4K video signal and used as an input signal of the encoder 33. The encoder 33 uses the decoded video signal from the decoder 42 as a prediction reference image (first hierarchical image), hierarchically encodes the original 8K × 4K video signal, and transmits the second hierarchical image having a transmission capacity of 17 Mbps. Generate data. The second layer data is transmitted together with the first layer data by vertically polarized radio waves, and is hierarchically decoded by the decoder 43 together with a video decoded signal decoded from the first layer data to obtain a high-quality 8K × 4K image. A decoded signal can be generated.

  In FIG. 6, a part 51 of the coding system including the encoders 31 and 32 and the decoders 41 and 42 is the same as that in FIG. 4, and can be received by a receiving apparatus that supports only the SISOx2 system. Therefore, the polarization MIMO system shown in FIG. 6 can be said to be a system in which a transmission line of 17 Mbps is newly added to the transmission line configuration of the SISOx2 system of FIG. 4, and can coexist with the SISOx2 system.

  FIG. 7 is a diagram conceptually illustrating an encoding method for transmitting a high-resolution image by hierarchical encoding on the premise of the polarization MIMO method. In FIG. 7, by using the hierarchical encoding function on the SISOx2 system of FIG. 5, it is possible to encode an 8K × 4K video signal while maintaining compatibility with the SISOx2 system receiving equipment. First, an original 8K × 4K video signal is encoded by the encoder 31 to be a compressed encoded signal having a transmission capacity of 30 Mbps. This compression-encoded signal becomes basic hierarchical data for hierarchical encoding, and is transmitted as horizontally polarized radio waves. The 30 Mbps compressed and coded signal is converted into a 8K × 4K low-quality video decoded signal by the decoder 41, and the decoded video signal is used as an input signal of the encoder 32. The encoder 32 uses the decoded video signal from the decoder 41 as a prediction reference image (basic hierarchical image), hierarchically encodes the original 8K × 4K video signal, and transmits the first hierarchical data having a transmission capacity of 13 Mbps. Generate The first hierarchical data is hierarchically decoded by the decoder 42 together with a video decoded signal decoded from the basic hierarchical data, and generates a video decoded signal of medium quality of 8K × 4K (B pattern). An 8K × 4K medium-quality video decoded signal is an input signal of the encoder 33. The encoder 33 uses the decoded video signal from the decoder 42 as a prediction reference image (first hierarchical image), hierarchically encodes the original 8K × 4K video signal, and transmits the second hierarchical image having a transmission capacity of 17 Mbps. Generate data. The second layer data is transmitted together with the first layer data by vertically polarized radio waves, and is hierarchically decoded by the decoder 43 together with a video decoded signal decoded from the first layer data to obtain a high-quality 8K × 4K image. A decoded signal can be generated.

  In FIG. 7, a part 51 of the encoding system including the encoders 31 and 32 and the decoders 41 and 42 has the same configuration as that of FIG. 5, and can be received by a receiving apparatus that supports only the SISOx2 system. Therefore, the polarization MIMO scheme shown in FIG. 7 can coexist with the SISOx2 scheme.

  In FIG. 7, it has been described that image processing of 8K × 4K (medium image quality) is possible with the SISOx2 method. However, as shown in FIG. 5, the SISOx2 method assumes processing of 6K × 3K (high image quality). In this case, an 8K × 4K video signal, which is an input signal, is compressed into a 6K × 3K video signal, input to the SISOx2 format part 51 (encoders 31 and 32), and processed in the block 51. After the end, the 6K × 3K (high image quality) decoded video signal hierarchically decoded by the decoder 42 can be enlarged to an 8K × 4K video signal to be used as an input signal of the encoder 33. In this case, the polarization MIMO system can be said to be a system in which a 17 Mbps transmission line is newly added to the transmission line configuration of the SISOx2 system of FIG. 5, and can coexist completely with the SISOx2 system of FIG.

  As described above, by applying hierarchical coding to the gradual change of the transmission method, it is possible to maintain the compatibility with the service of the existing transmission method in the process of dissemination of the receiving equipment, that is, to use the existing receiving device New services can be provided as they are.

  Until now, a plurality of services (pattern A and pattern B) that are possible new services within the above-described framework have been described separately. However, one transmitting apparatus is provided with a hierarchical coding apparatus for both services, and is switched. Can be possible.

  The selection (switching) of the two types described above (A pattern and B pattern) can be determined as follows.

  As a policy for selecting a pattern, an A-pattern is used to obtain high image quality while minimizing deterioration caused by compression encoding, and a B-pattern is used to increase image resolution.

The criterion of which method (pattern) is selected is determined using an evaluation scale indicating image quality. For example, MSE (Mean Squared Error) (or PSNR (Peak Signal-to-Noise Ratio)) or SSIM (Structural SIMilarity) which is compared with the original image is used. In the transition stage, the scale of the image (low-resolution or low-quality image) obtained by using the receiving device of one stage (existing equipment) is E _M , and the scale of the image obtained by using the receiving device of the next stage is E _M. The scale of a high-resolution and high-quality image is E _H , and the overall scale D is the following equation (1), which is a linear sum of these.

D = E _M + αE _H ―――――― (1)

  That is, it is defined as a scale such that the larger the D, the higher the image quality. Here, α is a coefficient. By adjusting α, a balance between low resolution and high resolution can be achieved. In the early stage of dissemination, α is made small (for example, smaller than 1) because low-resolution images by receiving devices of existing facilities are emphasized, and α is increased in the latter stage of dissemination because importance is placed on high-resolution images by new receiving facilities. (For example, 1 or more).

Note that E _M and E _H are calculated based on the difference from the original image. Therefore, in the case of the A-pattern low-resolution video, since the resolution of the original image and the resolution of the encoded image are different, the difference between the enlarged image of the decoded image and the original image is calculated.

  The D value of the image of the A pattern is compared with the D value of the image of the B pattern, and the service with the higher D value is provided.

  It should be noted that the pattern can be switched on a frame basis, but it is not realistic. Therefore, the D value is calculated for each scene or each program (an average of a plurality of frames may be selected). Therefore, the service can be automatically switched on the transmitting side according to the D value.

  FIG. 8 is a block diagram of a hierarchical encoding device that realizes the encoding process (A pattern) shown in FIG. This example is an apparatus that transmits a video signal of 8K × 4K at a total of 60 Mbps using transmission signals of both polarizations by the polarization MIMO method. In order to maintain compatibility with the existing system SISOx2, a hierarchical coding system is used. Furthermore, in order to make the SISOx2 system compatible with the previous SISO system, a multi-stage hierarchical coding system is used.

  The hierarchical encoding device includes a low-resolution encoding unit 63, a low-resolution decoding unit 64, an enlargement processing unit 65, a medium-resolution encoding unit 66, a medium-resolution decoding unit 67, an enlargement processing unit 68, a high-resolution And an encoding unit 69.

  The 8K × 4K video signal is horizontally and vertically reduced to ／ by the reduction processing section 61, and is converted into a 6K × 3K video signal. A filter is usually applied to the reduction processing, but the type of the filter is not limited here. Subsequently, the 6K × 3K video signal is reduced in horizontal and vertical to ／ by the reduction processing section 62, and is converted into a 4K × 2K video signal. A filter is usually applied to the reduction processing, but the type of the filter is not limited here. The reduction processing units 61 and 62 may constitute a part of the hierarchical coding device, but may perform processing separately from the hierarchical coding device.

  The low-resolution encoder 63 compresses and encodes the 4K × 2K video signal at an appropriate bit rate to generate a 4K × 2K compressed signal. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used. The bit rate is, for example, 30 Mbps, and a 4K × 2K video signal can be compression-coded while maintaining high image quality.

  The compression-encoded signal is multiplexed with an audio signal or the like, and is transmitted alone when a SISO service exists. Alternatively, in the case of the SISOx2 system or the polarization MIMO system, the data is transmitted as basic layer data of the layer coding system.

  The low resolution decoding unit 64 decodes the compressed signal by a decoding method corresponding to the compression coding method of the low resolution coding unit 63, and generates a 4K × 2K video decoded signal. The enlargement processing unit 65 enlarges the 4K × 2K video decoded signal in the horizontal and vertical directions to 3/2, respectively, and converts it into a 6K × 3K video signal. Normally, a filter and a super-resolution process are applied to the enlargement process, but the type of the process is not limited here.

  The medium resolution hierarchical encoding unit 66 encodes a 6K × 3K video signal reduced from an 8K × 4K video signal, and generates a 6K × 3K compressed signal. Here, since a hierarchical encoding method is used, encoding is performed using a 6K × 3K video signal enlarged from a 4K × 2K video decoded signal as a prediction reference image. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used.

  The compression-encoded signal is multiplexed with an audio signal or the like, and is transmitted alone when the SISOx2 service is present, and is decoded on the decoding side together with the SISO 4K × 2K video signal. Alternatively, in the case of the polarization MIMO system, the data is transmitted as the first layer data of the layer coding method.

  The medium resolution decoding unit 67 decodes the compressed signal by a decoding method corresponding to the compression coding method of the medium resolution hierarchical coding unit 66 (hierarchical decoding with reference to the 6K × 3K video signal obtained by the enlargement processing unit 65). , 6K × 3K video decoded signals. The enlargement processing section 68 enlarges the 6K × 3K video decoded signal in the horizontal and vertical directions to 4/3, and converts it into an 8K × 4K video signal. Normally, a filter and a super-resolution process are applied to the enlargement process, but the type of the process is not limited here.

  The high-resolution hierarchical encoding unit 69 encodes an 8K × 4K video signal and generates an 8K × 4K compressed signal. Here, since a hierarchical encoding method is used, encoding is performed using an 8K × 4K video signal enlarged from a 6K × 3K video decoded signal as a prediction reference image. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used.

  The compression-coded signal is multiplexed with a voice signal or the like and transmitted as a polarization MIMO service. Here, it is transmitted as the second layer data of the layer coding method.

  FIG. 9 is a block diagram of a decoding device (hierarchical decoding device) corresponding to the hierarchical encoding device in FIG. The decoding device includes a low-resolution decoding unit 71, an enlargement processing unit 72, a medium-resolution decoding unit 73, an enlargement processing unit 74, and a high-resolution decoding unit 75.

  The low-resolution decoding unit 71 decodes the 4K × 2K compressed signal by a decoding method corresponding to the compression encoding method of the low-resolution encoding unit 63 in the encoding device, and generates a 4K × 2K video decoded signal. The enlargement processing section 72 enlarges the 4K × 2K video decoded signal in the horizontal and vertical directions to 3/2, respectively, and converts it into a 6K × 3K video signal. Normally, a filter and a super-resolution process are applied to the enlargement process, but the type of the process is not limited here.

  The medium resolution decoding unit 73 decodes the 6K × 3K compressed signal by hierarchical decoding with reference to the 6K × 3K video signal obtained by the enlargement processing unit 72, and generates a 6K × 3K decoded video signal. The enlargement processing unit 74 enlarges the 6K × 3K video decoded signal in the horizontal and vertical directions to 4/3, and converts the signal into an 8K × 4K video signal. Normally, a filter and a super-resolution process are applied to the enlargement process, but the type of the process is not limited here.

  The high-resolution decoding unit 75 decodes the 8K × 4K compressed signal by hierarchical decoding with reference to the 8K × 4K video signal obtained by the enlargement processing unit 74, and generates an 8K × 4K video decoded signal. In this manner, a video decoded signal having an appropriate resolution for each layer can be decoded with high image quality.

  FIG. 10 is a block diagram of a hierarchical encoding device that realizes the encoding process (B pattern) shown in FIG.

  This example is an apparatus that transmits a video signal of 8K × 4K at a total of 60 Mbps using transmission signals of both polarizations by the polarization MIMO method. In order to maintain compatibility with the existing system SISOx2, a hierarchical coding system is used. Furthermore, in order to make the SISOx2 system compatible with the previous SISO system, a multi-stage hierarchical coding system is used, and an 8K × 4K video signal is compression-coded at each image quality in each layer.

  The hierarchical coding device includes a low-quality coding unit 81, a low-quality decoding unit 82, a medium-quality coding unit 83, a medium-quality decoding unit 84, and a high-quality coding unit 85. The 8K × 4K video signal is directly input to each encoding unit.

  The low-quality image coding unit 81 compression-codes an 8K × 4K video signal at an appropriate bit rate (for example, 30 Mbps) to generate an 8K × 4K (low-quality) compressed signal. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used.

  The compression-encoded signal is multiplexed with an audio signal or the like, and is transmitted alone when a SISO service exists. Alternatively, in the case of the SISOx2 system or the polarization MIMO system, the data is transmitted as basic layer data of the layer coding system.

  The low image quality decoding unit 82 decodes the compressed signal by a decoding method corresponding to the compression coding method of the low image quality coding unit 81, and generates an 8K × 4K (low image quality) video decoded signal.

  The middle image quality layer coding unit 83 codes the 8K × 4K video signal and generates an 8K × 4K (medium image quality) compressed signal. Here, since the hierarchical coding method is used, the decoding is performed using the 8K × 4K (low image quality) video decoded signal obtained by the low image quality decoding unit 82 as a prediction reference image. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used.

  The compression-encoded signal is multiplexed with an audio signal or the like, and transmitted alone when the SISOx2 service is present, and is decoded on the decoding side together with the SISO 8K × 4K video signal. Alternatively, in the case of the polarization MIMO system, the data is transmitted as the first layer data of the layer coding method.

  The medium quality decoding unit 84 decodes the compressed signal by a decoding method (hierarchical decoding with reference to an 8K × 4K (low quality) video decoding signal) corresponding to the compression coding method of the medium quality hierarchical coding unit 83, and Generate a 4K (medium quality) video decoded signal.

  The high-quality hierarchical encoding unit 85 encodes an 8K × 4K video signal and generates an 8K × 4K (high-quality) compressed signal. Here, since the hierarchical coding method is used, the decoding is performed using the 8K × 4K (medium image quality) video decoded signal obtained by the medium image quality decoding unit 84 as a prediction reference image. As encoding means, HEVC / H. An existing system such as H.265 can be used, and another system may be used.

  The compression-coded signal is multiplexed with a voice signal or the like and transmitted as a polarization MIMO service. Here, it is transmitted as the second layer data of the layer coding method.

  FIG. 11 is a block diagram of a decoding device (hierarchical decoding device) corresponding to the hierarchical encoding device in FIG. The decoding device includes a low image quality decoding unit 91, a medium image quality decoding unit 92, and a high image quality decoding unit 93.

  The low image quality decoding unit 91 decodes the 8K × 4K (low image quality) compressed signal by a decoding method corresponding to the compression encoding method of the low image quality encoding unit 81 in the encoding device, and outputs an 8K × 4K (low image quality) video. Generate a decoded signal.

  The medium-quality decoding unit 92 decodes the 8K × 4K (medium-quality) compressed signal by hierarchical decoding with reference to the 8K × 4K (low-quality) video decoded signal obtained by the low-quality decoding unit 91, and performs 8K × 4K ( Generates a (medium quality) video decoded signal.

  The high-quality decoding unit 93 decodes the 8K × 4K (high-quality) compressed signal by hierarchical decoding with reference to the 8K × 4K (medium-quality) video decoded signal obtained by the medium-quality decoding unit 92, and Generate a high quality) decoded video signal.

  As described above, a video decoded signal having an appropriate image quality for each layer can be decoded at a high resolution.

  It is to be noted that a layer coding apparatus including both the layer coding apparatus shown in FIG. 8 and the layer coding apparatus shown in FIG. 10 is configured, and for example, both apparatuses may be switched and selected based on the above-described image quality scale D. Good.

  Further, a transmission apparatus including at least one of the layer coding apparatus shown in FIG. 8 and the layer coding apparatus shown in FIG. 10 is formed, and the video coding data (FIG. 8 or a 8K × 4K (low image quality) compressed signal shown in FIG. 10 and transmitted by vertically polarized (second polarized) radio waves to the upper layer of the video encoded data (FIG. 8). A 6K × 3K compressed signal and an 8K × 4K compressed signal, or an 8K × 4K (medium image quality) compressed signal and an 8K × 4K (high image quality) compressed signal shown in FIG. 10 can be transmitted.

  According to this transmission device, a signal transmission system capable of receiving signals at the time of transition of the transmission system can be received by both the reception device corresponding to the transmission system of a certain stage and the reception device corresponding to the transmission system of the next stage. Can be.

  Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiment, and various modifications and changes can be made without departing from the scope of the claims. For example, a plurality of constituent blocks described in the embodiment can be combined into one, or one constituent block can be divided.

DESCRIPTION OF SYMBOLS 11 Modulator 12 Antenna for horizontal polarization transmission 13 Modulator 14 Antenna for vertical polarization transmission 20 Receiver 21 Demodulator 22 Antenna for horizontal polarization reception 23 Demodulator 24 Antennas 31-33 for vertical polarization reception Encoders 41 to 43 Decoders 61 and 62 Reduction processing unit 63 Low resolution encoding unit 64 Low resolution decoding unit 65 Enlargement processing unit 66 Medium resolution encoding unit 67 Medium resolution decoding unit 68 Enlargement processing unit 69 High resolution encoding unit 71 Low-resolution decoding unit 72 Enlargement processing unit 73 Medium-resolution decoding unit 74 Enlargement processing unit 75 High-resolution decoding unit 81 Low-quality coding unit 82 Low-quality decoding unit 83 Medium-quality coding unit 84 Medium-quality decoding unit 85 High-quality coding Section 91 low picture quality decoding section 92 medium picture quality decoding section 93 high picture quality decoding section

Claims (2)

A hierarchical encoding device for transmitting a high-resolution video using a first transmission signal transmitted by a first polarization radio wave and a second transmission signal transmitted by a second polarization radio wave ,
The first transmission signal is video encoded data of a base layer, the second transmission signal is an extended layer obtained by coding a video having a higher resolution than the video of the base layer, and the video is coded and transmitted in a plurality of layers. A first hierarchical encoding device that performs
The first transmission signal is encoded video data of a base layer, and the second transmission signal is an extended layer obtained by encoding a video image having the same resolution and improved image quality as the video image of the base layer. A second layer encoding device that encodes and transmits in layers.
Switching and selecting the first layer coding apparatus and the second layer coding apparatus,
The switching coding is characterized in that a hierarchical coding device that generates video coded data with high quality of a decoded video is selected based on an evaluation scale indicating a picture quality . A transmitting device comprising the hierarchical coding device according to claim 1 , wherein the transmitting device transmits the first transmission signal by the first polarized wave and transmits the second transmission signal by the second polarized wave. .