| 摘要 |
<p>The present invention relates to adaptive time-shifting of audio frames (Fa) in encoded audio signal relative to video frames (F v) in encoded video signal, which together form an audio/video message steam such that the corresponding decoded audio and video signals are aligned in time within the maximum degree of deviation. The invention accomplishes this alignment by determining a desired delay of the encoded audio signal for the decoded signals to meet deviation requirement. The desired (Dd) delay is then converted into a frame delay number (nD), which is calculated as one of the two neighbouring integers to a ratio between the desired delay (Dd) and an interval (Ta) at which the audio frames (Fa) are received. A number of audio frames (Fa) equal to the frame delay number (nD) are alternately stored into respective read out from FIFO-buffers (309; 310) such that sufficiently delayed audio frames (Fa) are delivered to an audio decoding unit (313). After signal decoding (313; 315) synchronised audio and video information can thus be presented via a loudspeaker (314) and a video monitor (316) respectively.</p> |
