A frame structure is provided for streaming A/V data providing improved protecting and opportunities for concealing errors. The frame structure includes a header block and a plurality of sub-blocks. Each of the sub-blocks includes digitally encoded audio/video data corresponding to predetermined consecutive periods of the A/V signal. The sub-blocks are generally of variable length. For the header block and each of the sub-blocks a respective associated error protecting code is present in the frame for protecting the associated block during transmission. The header block also includes a location information field that provides information on the location of at least one of the sub-blocks in the frame.