Method and device for outputting audio linked with video screen zoom
Disclosed are method and device for outputting audio linked with a video screen zoom. The method of the present invention comprises the steps of: receiving an audio signal linked with a video and generating a decoded audio signal and object metadata; linking with an execution of a video screen zoom so as to change respective object gain values for objects which are present in a zoom area; and rendering the decoded audio signal by using the changed object gain values. In addition, the method for outputting audio, of the present invention, further comprises a step for changing a channel signal-specific gain value which is linked with the video screen zoom. An audio can be linked, through the method and device for outputting audio, according to an embodiment of the present invention, in accordance with the video screen zoom such that the audio which is more realistic can be provided.
1. A method of outputting an audio by an apparatus, the method comprising:
generating a decoded audio signal and an object metadata by receiving an audio signal linked to a video;
changing an object gain value for each object existing in a zoom area in association with a video screen zoom execution based on a first control flag information indicating whether the object gain is changed, a new object gain value calculated only if a change of the object gain value is allowed by the first control flag information, wherein the changing of the object gain value includes:
obtaining a zoom ratio from a zoom area size with respect to a size of an entire video screen; and
calculating each object gain value in consideration of the obtained zoom ratio and a relative position of each object in the zoom area; and
rendering the decoded audio signal based on the changed object gain value.
2. The method of claim 1 , further comprising changing a gain value of each audio channel after the rendering.
3. The method of claim 2 , further comprising receiving a second control flag information indicating whether a channel gain value is changed, wherein the changing the gain value of the audio channel calculates a new channel gain value only if a change of each audio channel gain value is allowed by the second control flag information.
4. The method of claim 3 , the changing the channel gain value, comprising:
determining a channel nearest to the zoom area;
determining a distance ratio between the determined channel nearest to the zoom area and a remaining channel; and
calculating each channel gain value in consideration of the distance ratio per channel.
5. The method of claim 1 , further comprising a binaural rendering step based on a Binaural Room Impulse Response (BRIR) to output the rendered audio signal as a 2-channel surround audio.
6. An apparatus for outputting an audio linked to a video screen zoom, the apparatus comprising:
an audio decoder to generate a decoded audio signal and an object metadata by receiving an audio signal linked to a video;
a metadata processor to change an object gain value for each object existing in a zoom area in association with a video screen zoom execution based on a first control flag information indicating whether the object gain is changed, a new object gain value calculated only if a change of the object gain value is allowed by the first control flag information wherein the metadata processor is further configured to obtain a zoom ratio from a zoom area size with respect to a size of an entire video screen and calculate each object gain value in consideration of the obtained zoom ratio and a relative position of each object in the zoom area; and
a renderer to render the decoded audio signal based on the changed object gain value.
7. The apparatus of claim 6 , wherein the renderer is configured to change a gain value of each audio channel after the rendering.
8. The apparatus of claim 7 , wherein the metadata processor is configured to receive a second control flag information indicating whether a channel gain value is changed and wherein the renderer is configured to calculate a new channel gain value only if a change of each audio channel gain value is allowed by the second control flag information.
9. The apparatus of claim 8 , wherein the renderer is configured to determine a channel nearest to the zoom area, determine a distance ratio between the determined channel nearest to the zoom area and a remaining channel, and calculate each channel gain value in consideration of the distance ratio per channel.
10. The apparatus of claim 6 , further comprising a binaural renderer to use a Binaural Room Impulse Response (BRIR) to output the rendered audio signal as a 2-channel surround audio.