JP2004072217A5

JP2004072217A5 -

Info

Publication number: JP2004072217A5
Application number: JP2002225691A
Authority: JP
Filing date: 2002-08-02
Publication date: 2005-10-20

Claims

In the device that plays back the received data,
A buffer memory that sequentially stores the received data from the receiving means and sequentially reads out the oldest data in response to a read clock;
Unread data amount calculating means for calculating an unread data amount in the buffer memory;
Based on the output from the unread data amount calculation means, the output of the read clock is prohibited until the amount of unread data first reaches the predetermined amount, and after that, the output of the read clock is permitted and the buffer is output. Read control means for reading data from the memory;
Smoothing means for smoothing the output of the unread data amount calculating means temporally;
Clock frequency changing means for changing the frequency of the read clock based on the output from the smoothing means;
And a reproducing means for reproducing the data read from the buffer memory in synchronization with the read clock.

In an apparatus for receiving and reproducing data transmitted after being encoded and packetized ,
A buffer memory that sequentially stores the received data from the receiving means and sequentially reads out the oldest data in response to a read clock;
Unread data amount calculating means for calculating an unread data amount in the buffer memory;
Based on the output from the unread data amount calculation means, the output of the read clock is prohibited until the amount of unread data reaches the predetermined amount for the first time, and after that, the output of the read clock is permitted and the buffer is output. Read control means for reading data from the memory;
Smoothing means for smoothing the output of the unread data amount calculating means temporally;
Clock frequency changing means for changing the frequency of the read clock based on the output from the smoothing means;
And a reproducing means for reproducing the data read from the buffer memory in synchronization with the read clock.

The clock signal source for creating the read clock comprises a voltage controlled oscillator,
The unread data amount calculating means outputs a 1-bit flag signal indicating whether or not the unread data amount is a predetermined value or more, and the clock frequency changing means is based on the 1-bit flag signal output, 3. A data reproducing apparatus according to claim 1, wherein a voltage to be increased and a voltage to be decreased are switched and output to the smoothing means .

4. The data reproducing apparatus according to claim 3, wherein the predetermined value is half of the capacity of the buffer memory.

The clock frequency changing means is configured to increase the frequency and decrease the voltage until the unread data amount reaches a predetermined value from the start of data input to the buffer memory and reading is started. 5. The data reproducing apparatus according to claim 3, wherein an intermediate value is output.

The clock signal source for creating the read clock comprises a voltage controlled oscillator,
3. The data reproducing apparatus according to claim 1, wherein the clock frequency changing unit outputs an analog voltage corresponding to the output data of the unread data amount calculating unit.

7. The voltage controlled oscillator is set to a non-linear function in which a change in output frequency with respect to a change in input voltage is small near a center voltage and large at a peripheral voltage. A data reproducing apparatus according to claim 1.

The received data to be reproduced is video data and / or audio data, and is stored in the buffer memory except for components other than the video and / or audio components. Data playback device.

3. A data reproducing apparatus according to claim 1, wherein the received data to be reproduced is 1-bit audio data.

When received data from the receiving means is input, an identification number indicating the order of each packet attached in advance to packet data is identified, and if the identification number becomes discontinuous in the received packet sequence, it is lost 3. The data reproducing apparatus according to claim 2, further comprising a data compensating means for writing predetermined specific data in place of the packet into the buffer memory.

11. The data reproducing apparatus according to claim 10, wherein the specific data is data such that the level of the reproduction signal becomes a constant value or data that becomes zero level.