Method and apparatus for store and replay functions in a digital radio broadcasting receiver
View Patent ↗A method includes: receiving a plurality of audio frames, assembling groups of the audio frames into logical recording units, storing a plurality of the logical recording units, retrieving the stored logical recording units, and decoding the retrieved logical recording units. An apparatus that performs the method is also provided.
1. A method comprising:
receiving an input signal including compressed audio protocol data units;
storing core components of the input signal in a first buffer;
storing enhanced components of the input signal in a second buffer;
aligning core and enhanced packets retrieved from the first and second buffers; and
if a store function is enabled, retrieving a plurality of audio frames from the core and enhanced packets;
assembling groups of the audio frames into logical recording units, each including a header and a program specific data packet;
storing a plurality of the logical recording units; and
if a playback function is enabled, retrieving a file of the stored logical recording units; and
decoding the retrieved logical recording units to produce an output signal.
2. The method of claim 1 , further comprising:
encrypting the logical recording units prior to the storing step,
wherein the logical recording units are encrypted using a radio identification tag which identifies a particular receiver.
3. The method of claim 2 , further comprising:
decrypting the logical recording units; and
decoding the decrypted logical recording units.
4. The method of claim 1 , wherein the audio frames comprise:
a core packet length field;
an enhanced packet length field;
a core packet field; and
an enhanced packet field.
5. The method of claim 1 , wherein the logical recording unit header includes:
a logical recording unit marker field;
a logical recording unit length field;
a logical recording unit number field;
a packets/logical recording unit field;
a codec mode field;
a number of streams field;
an audio level field;
an audio processing field;
an encryption type field; and
a program specific data length field.
6. The method of claim 3 , further comprising:
storing the decrypted logical recording units in a playback buffer.
7. The method of claim 1 , further comprising:
calculating a signal quality of the audio frames.
8. The method of claim 1 , wherein each logical recording unit includes five audio frames.
9. An apparatus comprising:
a radio receiver implemented using hardware including an input for receiving an input signal including compressed audio protocol data units;
a first buffer for storing core components of the input signal;
a second buffer for storing enhanced components of the input signal;
a processor for aligning core and enhanced packets retrieved from the first and second buffers; and if a store function is enabled, retrieving a plurality of audio frames from the core and enhanced packets, and assembling groups of the audio frames into logical recording units, each including a header and a program specific data packet; and
a host system for storing a plurality of the logical recording units;
wherein if a playback function is enabled, the processor retrieves a file of the logical recording units, and decodes the retrieved logical recording units to produce an output signal.
10. The apparatus of claim 9 , wherein the processor encrypts the logical recording units for delivery to the host, and decrypts the logical recording retrieved from the host.
11. The apparatus of claim 10 , wherein the processor decodes the decrypted logical recording units and uses the decoded logical recording units to produce an output.
12. The apparatus of claim 9 , wherein the audio frames comprise:
a core packet length field;
an enhanced packet length field;
a core packet field; and
an enhanced packet field.
13. The apparatus of claim 9 , wherein the logical recording unit header includes:
a logical recording unit marker field;
a logical recording unit length field;
a logical recording unit number field;
a packets/logical recording unit field;
a codec mode field;
a number of streams field;
an audio level field;
an audio processing field;
an encryption type field; and
a program specific data length field.
14. The apparatus of claim 11 , wherein the processor stores the decrypted logical recording units in a playback buffer.
15. The apparatus of claim 9 , wherein the processor calculates a signal quality of the audio frames.
16. The apparatus of claim 9 , wherein each logical recording unit includes five audio frames.