Abstract: A method of testing audio/video synchronization comprising calculating a frequency of a device used to encode a digital stream based on program clock references calculating first time differences between audio decoding time stamps and actual audio decoding times; calculating second time differences between audio presentation time stamps and actual audio presentation times; calculating third time differences between video decoding time stamps and 4 actual video decoding times; and calculating fourth time differences between video presentation time stamps and actual video presentation times.

Abstract: A receiver for receiving an MPEG encrypted transport stream and outputting audio and video signals comprising: a decryptor adapted to receive and decrypt the encrypted transport stream; a de-multiplexer adapted to convert the decrypted transport stream to audio and video elementary streams and to change the values in presentation time stamp and decoding time stamp fields of each packet of the audio and elementary streams to match the time of a receiver record clock; a storage sub-system adapted to store the audio and the video elementary streams and to change the values in the presentation time stamp and decoding time stamp fields of each header of the audio and video elementary streams to compensate for the amount of time the audio and video elementary streams are stored; and audio and video decoders to decode the audio and video elementary streams respectively.

Abstract: A tuning module in a multi-tuner receiver stores channel parameters for tuning of channels within a channel list. Channels are tuned sequentially by the tuning module in response to channel advance (up/down) signals. Such signals may be provided by a central processor/controller. If a channel advance signal would cause the tuning module to advance past the beginning or end of the channel list, the module generates a list complete signal. The processor/controller may react accordingly. For example, the central processor/controller may disable a currently active tuning module and enable another tuning module/tuner in response to the list complete signal.

Abstract: A method of testing audio/video synchronization comprising calculating a frequency of a device used to encode a digital stream based on program clock references calculating first time differences between audio decoding time stamps and actual audio decoding times; calculating second time differences between audio presentation time stamps and actual audio presentation times; calculating third time differences between video decoding time stamps and 4 actual video decoding times; and calculating fourth time differences between video presentation time stamps and actual video presentation times.

Abstract: A receiver for receiving an MPEG encrypted transport stream and outputting audio and video signals comprising: a decryptor adapted to receive and decrypt the encrypted transport stream; a de-multiplexer adapted to convert the decrypted transport stream to audio and video elementary streams and to change the values in presentation time stamp and decoding time stamp fields of each packet of the audio and elementary streams to match the time of a receiver record clock; a storage sub-system adapted to store the audio and the video elementary streams and to change the values in the presentation time stamp and decoding time stamp fields of each header of the audio and video elementary streams to compensate for the amount of time the audio and video elementary streams are stored; and audio and video decoders to decode the audio and video elementary streams respectively.

Abstract: An internal system time clock within an MPEG-2 decoder is synchronized in frequency and optionally in phase, but not in value, to program clock reference time stamps within a received MPEG-2 transport stream. A demultiplexer separating audio and video packets from the transport stream modifies the decoding and presentation time stamps within such packets by at least an offset between the program clock reference time stamp values and the internal system time clock time before forwarding the packets to the audio and video decoders. Discontinuities in the program clock reference time stamp sequence automatically result in a change in the offset, such that the internal system time clock continues to increase monotonically and decoding and presentation time stamps within the packets are not suddenly invalidated.