1. A computer-implemented method for transcoding a tile based video bitstream, the method comprising: receiving a picture of an input video bitstream at a first parser processor, the picture comprising a plurality of coding blocks partitioned into a plurality of tiles, each tile comprising tile rows of coding blocks; parsing, performed by the first parser processor, the plurality of coding blocks of the picture in a tile scan order to produce a plurality of subsets of entropy coding state data, each subset of entropy coding state data associated with a corresponding tile row of coding blocks of each tile; generating, performed by the first parser processor, a list of identified coding blocks in the tile scan order based on the parsing of the plurality of coding blocks, wherein the list of identified coding blocks includes a plurality of identifiers, each identifier associated with a corresponding first coding block of each tile row of coding blocks of each tile, each identifier indicating a position of the corresponding first coding block in the input video bitstream; storing, performed by the first parser processor, the plurality of subsets of entropy coding state data and the list of identified coding blocks in a data repository coupled to the first parser processor and to a second parser processor, wherein each identifier of the list of identified coding blocks is associated with a corresponding subset of entropy coding state data; receiving the picture of the input video bitstream at the second parser processor; parsing, performed by the second parser processor, the same plurality of coding blocks of the picture in a raster scan order by using the list of identified coding blocks and the plurality of subsets of entropy coding state data stored in the data repository to produce a first portion of a parsed video bitstream, wherein the parsing the same plurality of coding blocks comprises: sorting, performed by the second parser processor, the list of identified coding blocks into the raster scan order, wherein a sequence of tile rows in the raster scan order corresponds to a full row of coding blocks that spans the picture, and for each tile row in the full row of coding blocks that spans the picture: identifying a present identifier from the sorted list of identified coding blocks that corresponds to a present position in the input video bitstream, restoring a selected subset of entropy coding state data that corresponds to the present identifier, and decoding syntax elements of a set of coding blocks that correspond to a present tile row using the selected subset of entropy coding state data.
1. A computer-implemented method for transcoding a tile based video bitstream, the method comprising: receiving a picture of an input video bitstream at a first parser processor, the picture comprising a plurality of coding blocks partitioned into a plurality of tiles, each tile comprising tile rows of coding blocks; parsing, performed by the first parser processor, the plurality of coding blocks of the picture in a tile scan order to produce a plurality of subsets of entropy coding state data, each subset of entropy coding state data associated with a corresponding tile row of coding blocks of each tile; generating, performed by the first parser processor, a list of identified coding blocks in the tile scan order based on the parsing of the plurality of coding blocks, wherein the list of identified coding blocks includes a plurality of identifiers, each identifier associated with a corresponding first coding block of each tile row of coding blocks of each tile, each identifier indicating a position of the corresponding first coding block in the input video bitstream; storing, performed by the first parser processor, the plurality of subsets of entropy coding state data and the list of identified coding blocks in a data repository coupled to the first parser processor and to a second parser processor, wherein each identifier of the list of identified coding blocks is associated with a corresponding subset of entropy coding state data; receiving the picture of the input video bitstream at the second parser processor; parsing, performed by the second parser processor, the same plurality of coding blocks of the picture in a raster scan order by using the list of identified coding blocks and the plurality of subsets of entropy coding state data stored in the data repository to produce a first portion of a parsed video bitstream, wherein the parsing the same plurality of coding blocks comprises: sorting, performed by the second parser processor, the list of identified coding blocks into the raster scan order, wherein a sequence of tile rows in the raster scan order corresponds to a full row of coding blocks that spans the picture, and for each tile row in the full row of coding blocks that spans the picture: identifying a present identifier from the sorted list of identified coding blocks that corresponds to a present position in the input video bitstream, restoring a selected subset of entropy coding state data that corresponds to the present identifier, and decoding syntax elements of a set of coding blocks that correspond to a present tile row using the selected subset of entropy coding state data. 13. The method of claim 1 , wherein the first parser processor stores each subset of entropy coding state data at a start of a corresponding tile row before any bin has been decoded.