Machine-readable media, methods, apparatus and system for caption detection are described. In some embodiments, a plurality of text boxes may be detected from a plurality of frames. A first percentage of the plurality of text boxes whose locations on the plurality of frames fall into a location range may be obtained. A second percentage of the plurality of text boxes whose sizes fall into a size range may be obtained. Then, it may be determined if the first percentage and the location range are acceptable and if the second percentage and the size range are acceptable.