Systems and methods are provided for generating a viewport for display. A user preference for a character and/or a genre of a scene in a spherical media content item is determined, wherein the spherical media content item comprises a plurality of tiles. A tile of the plurality of tiles is identified based on the determined user preference. A viewport to be generated for display at a computing device is predicted, based on the identified tile. A first tile to be transmitted to a computing device at a first resolution is identified, based on the predicted viewport to be generated for display. The tile is transmitted, to the computing device, at the first resolution.

The disclosed computer-implemented method may include generating a table for a plurality of encodings of media files stored in at least one data center, the generating including determining a benefit to cost ratio for each encoding listed in the table based on one or more criteria associated with the respective encoding, and assigning a priority to each of the encodings in the table based on the benefit to cost ratio, determining whether a soft quota for an amount of memory for storage of the media files has been exceeded, and in response to determining that a soft quota for an amount of memory for storage of the media files has been exceeded, performing a data storage reduction process based on the priority associated with each of the encodings in the table. Various other methods, systems, and computer-readable media are also disclosed.

The disclosed computer-implemented method may include generating a table for a plurality of encodings of media files stored in at least one data center, the generating including determining a benefit to cost ratio for each encoding listed in the table based on one or more criteria associated with the respective encoding, and assigning a priority to each of the encodings in the table based on the benefit to cost ratio, determining whether a soft quota for an amount of memory for storage of the media files has been exceeded, and in response to determining that a soft quota for an amount of memory for storage of the media files has been exceeded, performing a data storage reduction process based on the priority associated with each of the encodings in the table. Various other methods, systems, and computer-readable media are also disclosed.

In a method for image transmitting executed in a transmitting device, three data transmitting channels are established, the three data transmitting channels are a first channel, a second channel and a third channel. An image of a video is obtained, and the image is divided into a region of interest and a background region. A first data of the region of interest and a second data of the background region are obtained, and the first data is encoded through fountain coding to obtain a third data. The first data, the second data, and the third data are respectively transmitted through the first channel, the second channel, and the third channel to a receiving device. A network condition is received, and whether the network condition matches a preset condition is determined. When the network condition matches the preset condition, the first data is compensated according to a first preset algorithm.

In a method for image transmitting executed in a transmitting device, three data transmitting channels are established, the three data transmitting channels are a first channel, a second channel and a third channel. An image of a video is obtained, and the image is divided into a region of interest and a background region. A first data of the region of interest and a second data of the background region are obtained, and the first data is encoded through fountain coding to obtain a third data. The first data, the second data, and the third data are respectively transmitted through the first channel, the second channel, and the third channel to a receiving device. A network condition is received, and whether the network condition matches a preset condition is determined. When the network condition matches the preset condition, the first data is compensated according to a first preset algorithm.

Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of video processing includes performing a conversion between a video and a bitstream of the video, wherein the bitstream includes network abstraction layer (NAL) units for multiple video layers according to a rule; wherein the rule defines a sub-bitstream extraction process by which NAL units are removed from the bitstream to generate an output bitstream, and wherein the rule specifies to remove all supplemental enhancement information (SEI) NAL units that contain a non-scalable-nested SEI message with a particular payload type, responsive to a list of NAL unit header layer identifier values in an output layer set (OLS) with a target OLS index not including all values of NAL unit header layer identifiers in all video coding layer (VCL) NAL units in the bitstream that is input to the sub-bitstream extraction process.

Methods and apparatus for collecting user feedback information from viewers of content are described. Feedback information is received from viewers of content. The feedback indicates, based on head tracking information in some embodiments, where users are looking in a simulated environment during different times of a content presentation, e.g., different frame times. The feedback information is used to prioritize different portions of an environment represented by the captured image content. Resolution allocation is performed based on the feedback information and the content re-encoded based on the resolution allocation. The resolution allocation may and normally does change as the priority of different portions of the environment change.

Methods and apparatus for collecting user feedback information from viewers of content are described. Feedback information is received from viewers of content. The feedback indicates, based on head tracking information in some embodiments, where users are looking in a simulated environment during different times of a content presentation, e.g., different frame times. The feedback information is used to prioritize different portions of an environment represented by the captured image content. Resolution allocation is performed based on the feedback information and the content re-encoded based on the resolution allocation. The resolution allocation may and normally does change as the priority of different portions of the environment change.

An example device for retrieving media data includes a memory configured to store media data; and one or more processors implemented in circuitry and configured to: determine that a manifest file for a presentation of the media data includes data specifying a period of time of the presentation for which media data is not available but for which a segment timeline can be extended; retrieve a first set of segments of the presentation including media data having presentation times prior to the period of time; retrieve a second set of segments of the presentation including media data having presentation times after the period of time; in response to the determination that the manifest file includes the data specifying the period of time: omit retrieval of media data having presentation times during the period of time; and extend the segment timeline according to the determination.

An example device for retrieving media data includes a memory configured to store media data; and one or more processors implemented in circuitry and configured to: determine that a manifest file for a presentation of the media data includes data specifying a period of time of the presentation for which media data is not available but for which a segment timeline can be extended; retrieve a first set of segments of the presentation including media data having presentation times prior to the period of time; retrieve a second set of segments of the presentation including media data having presentation times after the period of time; in response to the determination that the manifest file includes the data specifying the period of time: omit retrieval of media data having presentation times during the period of time; and extend the segment timeline according to the determination.