In this paper, error-resilient video coding schemes based on data-embedding techniques are proposed for the H.263+ codec. Data embedding, popularly applied to secret hiding and digital watermarking, is now used to convey error recovery information to the decoder via a covert channel, without causing significant increase in transmission bitrate. Our embedded information provides implicit macroblock (MB) delimiters for resynchronization in presence of channel errors. In this way, the decoder is capable of isolating erroneous MBs with the extracted information. A set of variational schemes is proposed, extensively analyzed, and compared to the competitive counterparts (e.g., the original H.263+ TMN8 and its synchronization-enhanced version) at the same bitrate. Experimental results show that our data embedding process decreases the average peak signal-to-noise ratio (PSNR) in error-free conditions by 0.3 dB (light data embedding) to 1.8 dB (heavy data embedding), but it is capable of achieving a significant PSNR improvement up to 2 and 9.5 dB when the bit error rate is 10-5 and 10-3, respectively. We also provide suggestions of how to adaptively apply the proposed schemes for different channel error conditions and different video contents.