1. A media decoding method based on cloud computing, comprising: extracting representing features from a media code stream to be decoded; searching in the cloud for a media object which has similar representing features with the media code stream to be decoded by using a feature matching method and the representing features extracted; filling, replacing and improving parts or segments of the media code stream to be decoded with whole or parts of the media object found; wherein the representing features are local features; searching in the cloud for a media object which has similar representing features with the media code stream to be decoded by using a feature matching method and the representing features extracted comprises: comparing the local features with local features of a candidate media object in the cloud to obtain a local feature pair; calculating geometric distributions of the local features corresponding to the local feature pair respectively in the media code stream and the candidate media object; determining whether the geometric distributions of the local features corresponding to the local feature pair in the media code stream, respectively in the media code and the candidate media object, are consistent; considering the candidate media object as the media object which has similar representing features with the media code stream to be decoded, if the two geometric distributions are consistent.