Generating adaptive digital video encodings based on downscaling distortion of digital video content

Abstract

Methods, systems, and non-transitory computer readable storage media are disclosed for two-phase encoding a digital video based on downsampling distortion of the digital video and a constant rate factor transition threshold. For example, the disclosed system can determine a downsampling distortion indicating a measure of distortion resulting from downsampling an input digital video. The disclosed systems can utilize the downsampling distortion to determine a constant rate factor transition threshold for selecting sets of encoding parameters. For example, the disclosed systems can select a first set of encoding parameters below the constant rate factor transition threshold and a second set of encoding parameters at or above the constant rate factor transition threshold. Additionally, the disclosed systems can generate first and second sets of digital video encodings of the input digital video by utilizing the first and second sets of encoding parameters, respectively.

What is claimed is: 
     
         1 . A method comprising:
 determining a constant rate factor transition threshold for a plurality of frames of a digital video based on downsampling distortion, wherein the constant rate factor transition threshold defines a point to transition between holding resolution constant and holding constant rate factor constant;   transcoding frames for constant rate factors below the constant rate factor transition threshold to a fixed resolution; and   transcoding frames for constant rate factors at or above the constant rate factor transition threshold to a fixed constant rate factor.   
     
     
         2 . The method of  claim 1 , further comprising determining the downsampling distortion by:
 generating one or more downsampled frames by downsampling one or more frames of the digital video; and   determining the downsampling distortion from the one or more downsampled frames.   
     
     
         3 . The method of  claim 1 , further comprising determining the constant rate factor transition threshold by fitting the downsampling distortion to a distortion-threshold curve. 
     
     
         4 . The method of  claim 1 , wherein transcoding the frames for the constant rate factors below the constant rate factor transition threshold comprises:
 transcoding a first frame using the fixed resolution and a first constant rate factor below the constant rate factor transition threshold; and   transcoding a second frame using the fixed resolution and a second constant rate factor below the constant rate factor transition threshold and above the first constant rate factor.   
     
     
         5 . The method of  claim 1 , wherein transcoding the frames for the constant rate factors at or above the constant rate factor transition threshold to the fixed constant rate factor comprises:
 transcoding a third frame using the fixed constant rate factor and a first resolution; and   transcoding a fourth frame using the fixed constant rate factor and a second resolution below the first resolution.   
     
     
         6 . The method of  claim 1 , wherein transcoding the frames for the constant rate factors at or above the constant rate factor transition threshold comprises:
 determining network connection speeds for a plurality of client devices; and   selecting the frames for the constant rate factors below the constant rate factor transition threshold and the frames for the constant rate factors at or above the constant rate factor transition threshold based on the network connection speeds.   
     
     
         7 . The method of  claim 1 , further comprising:
 determining network connection speeds for a client device; and   transcoding the frames for the constant rate factors below the constant rate factor transition threshold for the client device based on the network connection speeds for the client device.   
     
     
         8 . The method of  claim 7 , further comprising:
 determining additional network connection speeds for the client device; and   transcoding the frames for the constant rate factors at or above the constant rate factor transition threshold for the client device based on the additional network connection speeds being lower than the network connection speeds.   
     
     
         9 . A system comprising:
 at least one processor; and   a non-transitory computer readable storage medium comprising instructions that, when executed by the at least one processor, cause the system to:   determine a constant rate factor transition threshold for a plurality of frames of a digital video based on downsampling distortion, wherein the constant rate factor transition threshold defines a point to transition between holding resolution constant and holding constant rate factor constant;   transcode frames for constant rate factors below the constant rate factor transition threshold to a fixed resolution; and   transcode frames for constant rate factors at or above the constant rate factor transition threshold to a fixed constant rate factor.   
     
     
         10 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to:
 generate one or more downsampled frames by downsampling one or more frames of the digital video; and   determine the downsampling distortion from the one or more downsampled frames.   
     
     
         11 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to determine the constant rate factor transition threshold by fitting the downsampling distortion to a distortion-threshold curve. 
     
     
         12 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to transcode the frames for the constant rate factors below the constant rate factor transition threshold by:
 transcoding a first frame using the fixed resolution and a first constant rate factor below the constant rate factor transition threshold; and   transcoding a second frame using the fixed resolution and a second constant rate factor below the constant rate factor transition threshold and above the first constant rate factor.   
     
     
         13 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to transcode the frames for the constant rate factors at or above the constant rate factor transition threshold to the fixed constant rate factor by:
 transcoding a third frame using the fixed constant rate factor and a first resolution; and   transcoding a fourth frame using the fixed constant rate factor and a second resolution below the first resolution.   
     
     
         14 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to transcode the frames for the constant rate factors at or above the constant rate factor transition threshold by:
 determining network connection speeds for a plurality of client devices; and   selecting the frames for the constant rate factors below the constant rate factor transition threshold and the frames for the constant rate factors at or above the constant rate factor transition threshold based on the network connection speeds.   
     
     
         15 . The system of  claim 9 , further comprising instructions that, when executed by the at least one processor, cause the system to:
 determine network connection speeds for a client device;   transcode the frames for the constant rate factors below the constant rate factor transition threshold for the client device based on the network connection speeds for the client device;   determine additional network connection speeds for the client device; and   transcode the frames for the constant rate factors at or above the constant rate factor transition threshold for the client device based on the additional network connection speeds being lower than the network connection speeds.   
     
     
         16 . A non-transitory computer readable storage medium comprising instructions that, when executed by at least one processor, cause the at least one processor to:
 determine a constant rate factor transition threshold for a plurality of frames of a digital video based on downsampling distortion, wherein the constant rate factor transition threshold defines a point to transition between holding resolution constant and holding constant rate factor constant;   transcode frames for constant rate factors below the constant rate factor transition threshold to a fixed resolution; and   transcode frames for constant rate factors at or above the constant rate factor transition threshold to a fixed constant rate factor.   
     
     
         17 . The non-transitory computer readable storage medium of  claim 16 , further comprising instructions that, when executed by the at least one processor, cause the at least one processor to:
 generate one or more downsampled frames by downsampling one or more frames of the digital video; and   determine the downsampling distortion from the one or more downsampled frames.   
     
     
         18 . The non-transitory computer readable storage medium of  claim 16 , further comprising instructions that, when executed by the at least one processor, cause the at least one processor to transcode the frames for the constant rate factors below the constant rate factor transition threshold by:
 transcoding a first frame using the fixed resolution and a first constant rate factor below the constant rate factor transition threshold; and   transcoding a second frame using the fixed resolution and a second constant rate factor below the constant rate factor transition threshold and above the first constant rate factor.   
     
     
         19 . The non-transitory computer readable storage medium of  claim 16 , further comprising instructions that, when executed by the at least one processor, cause the at least one processor to transcode the frames for the constant rate factors at or above the constant rate factor transition threshold to the fixed constant rate factor by:
 transcoding a third frame using the fixed constant rate factor and a first resolution; and   transcoding a fourth frame using the fixed constant rate factor and a second resolution below the first resolution.   
     
     
         20 . The non-transitory computer readable storage medium of  claim 16 , further comprising instructions that, when executed by the at least one processor, cause the at least one processor to transcode the frames for the constant rate factors at or above the constant rate factor transition threshold by:
 determining network connection speeds for a plurality of client devices; and   selecting the frames for the constant rate factors below the constant rate factor transition threshold and the frames for the constant rate factors at or above the constant rate factor transition threshold based on the network connection speeds.