Random access at resync points of DASH segments

A device for retrieving media data, the device comprising:

• a memory configured to store media data of a media presentation;
• and
• one or more processors implemented in circuitry and configured to:
• retrieve a manifest file for a media presentation indicating, for a segment including media data of a representation of the media presentation, a maximum difference of index values of any two consecutive resync points in the segment, a minimum difference of the index values of any two consecutive resync points in the segment, and a bandwidth value for the representation;
• calculate a maximum byte difference value as a product of the maximum difference of index values and the bandwidth value;
• calculate a minimum byte difference value as a product of the minimum difference of index values and the bandwidth value;
• determine a byte location of a first resync point of the segment;
• determine a byte range for a second resync point of the segment such that the byte range has a starting byte equal to the minimum byte difference value plus the byte location and an ending byte value equal to the maximum byte difference value plus the byte location;
• retrieve the byte range of the segment;
• and
• parse media data of the byte range to identify the second resync point comprising a random access point (RAP) of the segment.

A computer-readable storage medium having stored thereon instructions that, when executed, cause a processor to:

• retrieve a manifest file for a media presentation indicating, for a segment including media data of a representation of the media presentation, a maximum difference of index values of any two consecutive resync points in the segment, a minimum difference of the index values of any two consecutive resync points in the segment, and a bandwidth value for the representation;
• calculate a maximum byte difference value as a product of the maximum difference of index values and the bandwidth value;
• calculate a minimum byte difference value as a product of the minimum difference of index values and the bandwidth value;
• determine a byte location of a first resync point of the segment;
• determine a byte range for a second resync point of the segment such that the byte range has a starting byte equal to the minimum byte difference value plus the byte location and an ending byte value equal to the maximum byte difference value plus the byte location;
• retrieve the byte range of the segment;
• and
• parse media data of the byte range to identify the second resync point comprising a random access point (RAP) of the segment.

A device for retrieving media data, the device comprising:

• means for retrieving a manifest file for a media presentation indicating, for a segment including media data of a representation of the media presentation, a maximum difference of index values of any two consecutive resync points in the segment, a minimum difference of the index values of any two consecutive resync points in the segment, and a bandwidth value for the representation;
• means for calculating a maximum byte difference value as a product of the maximum difference of index values and the bandwidth value;
• means for calculating a minimum byte difference value as a product of the minimum difference of index values and the bandwidth value;
• means for determining a byte location of a first resync point of the segment;
• means for determining a byte range for a second resync point of the segment such that the byte range has a starting byte equal to the minimum byte difference value plus the byte location and an ending byte value equal to the maximum byte difference value plus the byte location;
• means for retrieving the byte range of the segment;
• and
• means for parsing media data of the byte range to identify the second resync point comprising a random access point (RAP) of the segment.