Method and device for transmitting and receiving broadcast signal
The present invention relates to a device and a method for transmitting and receiving a broadcast signal comprising a subtitling service. Provided in one embodiment of the present invention is a method for transmitting a broadcast signal, the method comprising the steps of: generating a broadcast signal comprising video data and subtitle data; and transmitting the generated broadcast signal. According to the embodiment of the present invention, a transport stream providing a digital broadcast subtitling service using an XML subtitle may be transmitted.
1. A method of transmitting a broadcast signal, the method comprising:
encoding video data having one of Standard Definition (SD) resolution, High Definition (HD) resolution, or Ultra High Definition (UHD) resolution;
generating Extensible Markup Language (XML)-based subtitle data,
wherein the XML-based subtitle data include subtitle text and subtitle metadata,
wherein the subtitle metadata include base dynamic range information and supplementary dynamic range information of the subtitle text to modify a luminance of the subtitle text by performing dynamic range mapping when the luminance of the subtitle text is different from a luminance supported by a displaying device that displays the subtitle text, and
wherein the subtitle metadata further include base Electro Optical Transfer Function (EOTF) information and supplementary EOTF information that are used for luminance linearization prior to the dynamin range mapping;
multiplexing the video data and the XML-based subtitle data; and
transmitting a broadcast signal including the multiplexed data.
2. The method according to claim 1 , wherein the supplementary dynamic range information includes contrast ratio information for identifying a ratio of maximum luminance to minimum luminance.
3. The method according to claim 1 , wherein the subtitle metadata further include information on a wide color gamut a for a high-quality broadcast.
4. The method according to claim 1 , wherein the subtitle metadata further include information on a color gamut of the subtitle text and a bit depth of the ssubtitle text.
5. The method according to claim 1 , wherein the subtitle metadata includes base information and supplementary information on a color gamut of the subtitle text and a bit depth of the subtitle text.
6. A method of receiving a broadcast signal, the method comprising:
receiving the broadcast signal including video data and Extensible Markup Language (XML)-based subtitle data, the video data having one of Standard Definition (SD) resolution, High Definition (HD) resolution, or Ultra High Definition (UHD) resolution, wherein the XML-based subtitle data include subtitle text and subtitle metadata and wherein the subtitle metadata include base dynamic range information and supplementary dynamic range information of the subtitle text;
demultiplexing the video data and the XML-based subtitle data from the broadcast signal;
decoding the video data;
modifying a luminance of the subtitle text by performing dynamic range mapping based on the subtitle metadata when the luminance of the subtitle text is different from a luminance supported by a displaying device that displays the subtitle text; and
displaying the decoded video data and the subtitle text having the modified luminance,
wherein the subtitle metadata further include base Electro Optical Transfer Function (EOTF) information and supplementary EOTF information that are used for luminance linearization prior to the dynamin range mapping.
7. The method according to claim 6 , wherein the supplementary dynamic range information includes contrast ratio information for identifying a ratio of maximum luminance to minimum luminance.
8. The method according to claim 6 , wherein the subtitle metadata further include information on a wide color gamut for a high-quality broadcast.
9. The method according to claim 6 , wherein the subtitle metadata further include information on a color gamut of the subtitle text and a bit depth of the subtitle text.
10. The method according to claim 6 , wherein the subtitle metadata further include base information and supplementary information on a color gamut of the subtitle text and a bit depth of the subtitle text.
11. A transmission device for transmitting a broadcast signal, the transmission device comprising:
an encoder to code video data having one of Standard Definition (SD) resolution, High Definition (HD) resolution, or Ultra High Definition (UHD) resolution;
a multiplexer to multiplex the video data and Extensible Markup Language (XML)-based subtitle data,
wherein the XML-based subtitle data include subtitle text and subtitle metadata,
wherein the subtitle metadata include base dynamic range information and supplementary dynamic range information of the subtitle text to modify a luminance of the subtitle text by performing dynamic range mapping when the luminance of the subtitle text is different from a luminance supported by a displaying device that displays the subtitle text, and
wherein the subtitle metadata further include base Electro Optical Transfer Function (EOTF) information and supplementary EOTF information that are used for luminance linearization prior to the dynamin range mapping; and
a transmitter to transmit a broadcast signal including the multiplexed data.
12. The transmission device according to claim 11 , wherein the supplementary dynamic range information includes contrast ratio information for identifying a ratio of maximum luminance to minimum luminance.
13. A reception device for receiving a broadcast signal, the reception device comprising:
a receiver to receive the broadcast signal including video data and Extensible Markup Language (XML)-based subtitle data, the video data having one of Standard Definition (SD) resolution, High Definition (HD) resolution, or Ultra High Definition (UHD) resolution, wherein the XML-based subtitle data include subtitle text and subtitle metadata and wherein the subtitle metadata include base dynamic range information and supplementary dynamic range information of the subtitle text;
a demultiplexer to demultiplex the video data and the XML-based subtitle data from the broadcast signal; and
a decoder to decode the video data; and
a processor to modify a luminance of the subtitle text by performing dynamic range mapping based on the subtitle metadata when the luminance of the subtitle text is different from a luminance supported by a displaying device that displays the subtitle text,
wherein the displaying device displays the decoded video data and the subtitle text having the modified luminance and
wherein the subtitle metadata further include base Electro Optical Transfer Function (EOTF) information and supplementary EOTF information that are used for luminance linearization prior to the dynamin range mapping.
14. The reception device according to claim 13 , wherein the subtitle metadata includes base information and supplementary information on a color gamut of the subtitle text and a bit depth of the subtitle text.