Apparatus, a method and a computer program for video coding and decoding

An apparatus comprising at least one processor and at least one non-transitory memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

• encode video media content into at least a first representation and a second representation, wherein:
• the first representation comprises a switchable inter-coded picture, wherein the switchable inter-coded picture comprises a first characteristic that no pictures preceding the switchable inter-coded picture in decoding order are used as reference pictures for non-switchable pictures following the switchable inter-coded picture in decoding order;
• and
• the second representation comprises one or more decoder reset pictures aligned with switchable inter-coded pictures of the first representation,
• wherein a frame rate of the second representation is smaller than or equal to a frame rate of the first representation and resolutions of the first and the second representations are equal or substantially equal,
• wherein the first representation and the second representation are encoded to enable decoding of a decoder reset picture of the second representation, followed by decoding of pictures of the first representation that are subsequent to a switchable inter-coded picture of the first representation that corresponds to the decoder reset picture, without the corresponding switchable inter-coded picture having been decoded.

A method comprising:

• receiving at least one bitstream corresponding to a first representation of encoded video media content, the first representation comprising a switchable inter-coded picture, wherein the switchable inter-coded picture comprises a first characteristic that no pictures preceding the switchable inter-coded picture in decoding order are used as reference pictures for non-switchable pictures following the switchable inter-coded picture in decoding order;
• receiving, from or along the at least one bitstream, an indication about suitability of switching between the first representation and a second representation of the encoded video media content in decoding, wherein the second representation comprises one or more decoder reset pictures aligned with switchable inter-coded pictures of the first representation, wherein a frame rate of the second representation is smaller than or equal to a frame rate of the first representation and resolutions of the first and the second representations are equal or substantially equal;
• receiving at least one decoder reset picture of the second representation;
• and
• decoding the at least one decoder reset picture of the second representation, followed by decoding of pictures of the first representation that are subsequent to a switchable inter-coded picture of the first representation that corresponds to the at least one decoder reset picture, without the corresponding switchable inter-coded picture having been decoded.

An apparatus comprising at least one processor and at least one non-transitory memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

• receive at least one bitstream corresponding to a first representation of encoded video media content, the first representation comprising a switchable inter-coded picture, wherein the switchable inter-coded picture comprises a first characteristic that no pictures preceding the switchable inter-coded picture in decoding order are used as reference pictures for non-switchable pictures following the switchable inter-coded picture in decoding order;
• receive, from or along the at least one bitstream, an indication about suitability of switching between the first representation and a second representation of the encoded video media content in decoding, wherein the second representation comprises one or more decoder reset pictures aligned with switchable inter-coded pictures of the first representation, wherein a frame rate of the second representation is smaller than or equal to a frame rate of the first representation and resolutions of the first and the second representations are equal or substantially equal;
• receive at least one decoder reset picture of the second representation;
• and
• decode at least one decoder reset picture of the second representation, followed by decoding of pictures of the first representation that are subsequent to a switchable inter-coded picture of the first representation that corresponds to the at least one decoder reset picture, without the corresponding switchable inter-coded picture having been decoded.

A computer program product comprises at least one non-transitory computer-readable storage medium having computer executable program code instructions stored therein, the computer executable program code instructions comprising program code instructions configured, upon execution, to:

• receive at least one bitstream corresponding to a first representation of encoded video media content, the first representation comprising a switchable inter-coded picture, wherein the switchable inter-coded picture comprises a first characteristic that no pictures preceding the switchable inter-coded picture in decoding order are used as reference pictures for non-switchable pictures following the switchable inter-coded picture in decoding order;
• receive, from or along the at least one bitstream, an indication about suitability of switching between the first representation and a second representation of the encoded video media content in decoding, wherein the second representation comprises one or more decoder reset pictures aligned with switchable inter-coded pictures of the first representation, wherein the frame rate of the second representation is smaller than or equal to a frame rate of the first representation and resolutions of the first and the second representation are equal or substantially equal;
• receive at least one decoder reset picture of the second representation;
• and
• decode the at least one decoder reset picture of the second representation, followed by decoding of pictures of the first representation that are subsequent to a switchable inter-coded picture of the first representation that corresponds to the at least one decoder reset picture, without the corresponding switchable inter-coded picture having been decoded.