Quantum parameter control and the method thereof
An electronic device is provided. The electronic device includes a memory and a processor operatively connected to the memory, wherein the processor may obtain a maximum allowable bit rate of the electronic device, determine a maximum quantization value for encoding an image composed of at least one frame, obtain a first bitrate by encoding a first frame set of the image with a quantization value equal to or less than the maximum quantization value, increase the maximum quantization value in response to the obtained first bitrate exceeding the maximum allowable bitrate, decrease the maximum quantization value in response to the obtained first bitrate being less than or equal to the maximum allowable bitrate, obtain a second bitrate by encoding a second frame set subsequent to the first frame set of the image based on the increased or decreased maximum quantization value, increase the maximum quantization value in response to the obtained second bitrate exceeding the maximum allowable bitrate, and decrease the maximum quantization value in response to the obtained second bitrate being less than or equal to the maximum allowable bitrate.
1. An electronic device comprising:
a memory; and
a processor operatively connected to the memory,
wherein the processor is configured to:
obtain a maximum allowable bitrate of the electronic device,
determine a maximum quantization value for encoding a video composed of a plurality of frames,
obtain a first bitrate by encoding a first frame set of the video with a quantization value equal to or less than the maximum quantization value,
increase the maximum quantization value in response to the obtained first bitrate exceeding the maximum allowable bitrate,
decrease the maximum quantization value in response to the obtained first bitrate being less than or equal to the maximum allowable bitrate,
obtain a second bitrate by encoding a second frame set subsequent to the first frame set of the video, based on the increased or decreased maximum quantization value,
increase the maximum quantization value in response to the obtained second bitrate exceeding the maximum allowable bitrate,
decrease the maximum quantization value in response to the obtained second bitrate being less than or equal to the maximum allowable bitrate,
determine a first resource level of the first frame set based on the first bitrate,
determine a second resource level of the second frame set based on the second bitrate, and
store the second resource level in a header of video data when the second resource level is higher than the first resource level, and
wherein a resource level is required to reproduce the video in a playback device.
2. The electronic device of claim 1 ,
wherein the plurality of frames of the video comprises at least one macroblock, and
wherein the processor is further configured to determine a quantization value for each macroblock.
3. The electronic device of claim 1 , wherein the processor is further configured to:
determine at least one region of interest in the first frame set of the video,
determine a maximum quantization value of the at least one region of interest, and
determine a quantization value that does not exceed the maximum quantization value of the at least one region of interest, based on the first bitrate.
4. The electronic device of claim 3 , wherein the processor is further configured to:
determine a first region of interest and a second region of interest from a first frame in the first frame set,
determine priorities of the first region of interest and the second region of interest,
assign a value smaller than a second maximum quantization value for the second region of interest to a first maximum quantization value for the first region of interest when a priority of the first region of interest is higher than a priority of the second region of interest, and
assign a value greater than the second maximum quantization value to the first maximum quantization value when the priority of the second region of interest is higher than the priority of the first region of interest.
5. The electronic device of claim 4 , wherein the processor is further configured to:
determine whether to reset a region of interest in a second frame subsequent to a first frame,
reset a priority among the at least one region of interest when resetting the at least one region of interest, and
reset the maximum quantization value based on the priority.
6. The electronic device of claim 3 , wherein the processor is further configured to:
compare, when determining the at least one region of interest, an initially assigned maximum quantization value with the maximum quantization value of the at least one region of interest in a current frame, and
increase the maximum quantization value of the current frame when the maximum quantization value of the current frame is smaller than the maximum quantization value initially assigned.
7. The electronic device of claim 1 , wherein the processor is further configured to:
obtain frame information comprising information on at least one of brightness, sensitivity, noise, and motion of the video, and
determine a quantization value based on the frame information.
8. The electronic device of claim 1 , wherein the processor is further configured to:
determine a search range to refer to at least one previous frame in a current frame; and
determine a lower quantization value as a number of previous frames of at least one previous searched increases.
9. A method of encoding with adjusting a maximum quantization value, the method comprising:
obtaining a maximum allowable bitrate of an electronic device;
determining a maximum quantization value of a video composed of a plurality of frames;
obtaining a first bitrate by encoding a first frame set of the video with a quantization value equal to or less than the maximum quantization value;
increasing the maximum quantization value in response to the obtained first bitrate exceeding the maximum allowable bitrate;
decreasing the maximum quantization value in response to the obtained first bitrate being less than or equal to the maximum allowable bitrate;
obtaining a second bitrate by encoding a second frame set subsequent to the first frame set of the video, based on the increased or decreased maximum quantization value;
increasing the maximum quantization value in response to the obtained second bitrate exceeding the maximum allowable bitrate;
decreasing the maximum quantization value in response to the obtained second bitrate being less than or equal to the maximum allowable bitrate;
determining a first resource level of the first frame set based on the first bitrate;
determining a second resource level of the second frame set based on the second bitrate; and
storing the second resource level in a header of video data when the second resource level is higher than the first resource level,
wherein a resource level is required to reproduce the video in a playback device.
10. The method of claim 9 ,
wherein a frame of the video comprises at least one macroblock, and
wherein the encoding of the video further comprises determining a quantization value for each macroblock.
11. The method of claim 9 , wherein the encoding of the video further comprises:
determining at least one region of interest in the first frame set of the video;
determining a maximum quantization value of the at least one region of interest; and
determining a quantization value that does not exceed the maximum quantization value of the at least one region of interest based on the first bitrate.
12. The method of claim 11 , wherein the determining of the maximum quantization value of the at least one region of interest further comprises:
determining a first region of interest and a second region of interest from the first frame in the first frame set;
determining priorities of the first region of interest and the second region of interest;
assigning a value smaller than a second maximum quantization value for the second region of interest to a first maximum quantization value for the first region of interest when a priority of the first region of interest is higher than a priority of the second region of interest; and
assigning a value greater than the second maximum quantization value to the first maximum quantization value when the priority of the second region of interest is higher than the priority of the first region of interest.
13. The method of claim 9 , wherein the increasing or decreasing of the maximum quantization value further comprises:
comparing when determining at least one region of interest, an initially assigned maximum quantization value, with the maximum quantization value of the at least one region of interest in a current frame; and
increasing the maximum quantization value of the current frame when the maximum quantization value of the current frame is smaller than the maximum quantization value initially assigned.
14. The method of claim 9 , wherein the encoding of the video further comprises:
obtaining frame information comprising information on at least one of brightness, sensitivity, noise, and motion of the video; and
determining a quantization value based on the frame information.
15. The method of claim 10 , wherein, when the maximum quantization value is not set in an uninterested region, increasing the quantization value of the uninterested region to a hardware maximum.
16. The method of claim 15 , further comprising compressing data of a corresponding macroblock based on a quantization value set in the macroblock,
wherein the quantization value is proportional to an amount of data to be compressed.
17. The method of claim 16 , further comprising setting a quantization value of a macroblock corresponding to at least one region of interest among the macroblocks to be lower than the quantization value of the macroblock of the uninterested region.