Parallel parsing in a video decoder

A method of decoding an encoded video bitstream, said method comprising the steps of:

• parsing said encoded video bitstream using a first parsing unit and a second parsing unit, each parsing unit independently deriving a full set of parsing state information from said encoded video bitstream on which subsequent parsing of said encoded video bitstream at least partially depends and to identify macroblock information for decoding,
• wherein said encoded video bitstream comprises frame header information and macroblock information, said frame header information defining a sequence of frames and each frame being composed of macroblocks represented by said macroblock information,
• wherein said parsing step comprises parsing said frame header information in both said first parsing unit and said second parsing unit such that each derives and maintains said full set of parsing state information for said encoded video bitstream;
• and
• allocating each frame of macroblock information to one of said first parsing unit and said second parsing unit, wherein said first parsing unit and said second parsing unit each parse said macroblock information, skipping macroblock information allocated to the other parsing unit.

A video decoder configured to decode an encoded video bitstream, said video decoder comprising:

• first parsing means and second parsing means, said first parsing means and said second parsing means for independently parsing said encoded video bitstream to derive a full set of parsing state information therefrom on which subsequent parsing of said encoded video bitstream at least partially depends and to identify macroblock information for decoding;
• and
• control means for controlling operation of said first parsing means and said second parsing means,
• wherein said encoded video bitstream comprises frame header information and macroblock information, said frame header information defines a sequence of frames and each frame is composed of macroblocks represented by said macroblock information, said control means configured to allocate each frame of macroblock information to one of said first parsing means and said second parsing means,
• wherein said first parsing means and said second parsing means are configured to both parse said frame header information to thereby each derive and maintain said full set of parsing state information for said encoded video bitstream, and
• wherein said first parsing means and said second parsing means are each configured to parse said macroblock information, skipping macroblock information allocated to the other parsing means.