CN114205027A - Dual-mode FM-CDR emergency broadcast message receiving method without clearing buffer area - Google Patents

Abstract

The invention relates to a dual-mode FM-CDR emergency broadcast message receiving method without a buffer area, which comprises a first CDR tuning demodulation module, a first CDR transmission stream buffer area, a detection module, a second CDR tuning demodulation module, a second CDR transmission stream buffer area and a main control module, wherein FM-CDR signals are circularly received, an emergency broadcast index table in a corresponding CDR transmission stream is detected, if overtime occurs, the detection is finished once, and when the index table is analyzed and an information target area in the index table is matched with a local machine, the FM-CDR emergency broadcast message is received; specifically, the waiting period T3 detects the emergency broadcast index table in the first CDR transmission stream buffer again, and the waiting period T4 receives the emergency broadcast index table and the content table in the second CDR transmission stream buffer again. The invention realizes the judgment of whether FM-CDR emergency broadcast messages sent to the local computer exist or not and receives the FM-CDR emergency broadcast messages, and prevents the data distortion of CDR transmission streams.

Description

Dual-mode FM-CDR emergency broadcast message receiving method without clearing buffer area

Technical Field

The invention belongs to the technical field of emergency broadcasting, and particularly relates to a dual-mode FM-CDR emergency broadcast message receiving method without a buffer area.

Background

The emergency broadcast system consists of an emergency broadcast platform, an adapter, a transmission coverage system and an emergency broadcast terminal, wherein the emergency broadcast platform transmits emergency broadcast messages to the emergency broadcast terminal for playing through the adapter and the transmission coverage system. The emergency broadcast message includes an emergency broadcast instruction and emergency broadcast content. Emergency broadcast content is message incidental content (text, audio-video) or parameters specifying a broadcast television program.

When a sudden disaster is faced, the government can timely convey politics, release authority information, guide social public opinion and actively assist in disaster relief by using the emergency broadcasting system. The emergency broadcast can reach the emergency broadcast terminal singly or in a relay mode through a plurality of transmission coverage networks. Current broadcast television transmission coverage includes digital frequency modulation (FM-CDR). The national specification for FM-CDR includes "part 1 of FM-band digital audio broadcasting: digital broadcast channel frame structure, channel coding and modulation, part 2 of fm band digital audio broadcasting: multiplexing ], and the like.

The FM-CDR emergency broadcast message is an emergency broadcast message sent by an FM-CDR transmission and transmission system. How to receive FM-CDR emergency broadcast messages by emergency broadcast terminals and adapters is a technical problem to be solved.

Disclosure of Invention

The technical problem to be solved by the invention is how to receive FM-CDR emergency broadcast messages and transmit the emergency broadcast messages from an FM-CDR transmission coverage system to an emergency broadcast terminal and an adapter.

The technical scheme of the invention is as follows.

Receiving method of dual-mode FM-CDR emergency broadcast message without buffer cleaning, N FM-CDR frequencies are possible to receive FM-CDR emergency broadcast message, and FM-CDR emergency broadcast message is in CDR data packet with PID = = PID _ sel, characterized in that, the N FM-CDR frequency values are included in frequency array F [ N ], and FM-CDR signals of all frequencies in F [ N ] are circularly detected, wherein, one detection process includes the following steps, the current detection frequency is known as frequency F [ i ]:

step 1, a detection module sets the receiving frequency of a first CDR tuning demodulation module as a current detection frequency;

step 2, the first CDR tuning demodulation module performs tuning demodulation on the FM-CDR signal according to the receiving frequency to obtain a CDR transmission stream, and a first CDR transmission stream buffer area is placed;

step 3, waiting for a time period T3, so that the CDR transmission stream with the new frequency is fully written into the first CDR transmission stream buffer area without specially clearing the old data in the first CDR transmission stream buffer area;

step 4, filtering out a data packet corresponding to the emergency broadcast message in the CDR transport stream from the first CDR transport stream buffer area according to PID = = PID _ sel;

step 5, in time period T, the detection module retrieves and extracts the emergency broadcast index table from the data packet, if overtime, the detection of the receiving frequency is ended, and step 7 is executed;

step 6, if the message target area in the emergency broadcast index table is matched with the local machine, setting the current receiving frequency as the frequency F [ i ], and executing a response process;

and 7, the detection module changes the current detection frequency to F [ j ], wherein j = i +1, and j =0 if j = = array length.

The one-time response process comprises the following steps:

step a, setting the receiving frequency of a second CDR tuning demodulation module as the current receiving frequency, and tuning and demodulating the FM-CDR signal by the second CDR tuning demodulation module according to the receiving frequency to obtain a CDR transmission stream and put a second CDR transmission stream buffer area;

b, waiting for a time period T4 to ensure that the CDR transmission stream with the new frequency is fully written into the second CDR transmission stream buffer area without specially clearing the old data in the second CDR transmission stream buffer area;

c, filtering a data packet corresponding to the emergency broadcast message in the CDR transport stream from the second CDR transport stream buffer area according to PID = = PID _ sel;

and d, the main control module extracts the emergency broadcast index table and the emergency broadcast content table from the data packet to further obtain the CDR emergency broadcast message.

Preferably, the core of the first CDR tuning demodulation module and the second CDR tuning demodulation module is a hail Hi5216 chip.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the frequency in the receiving frequency array F [ n ], the FM-CDR signals are circularly received, CDR transmission stream data are detected, and when an emergency broadcast index table is obtained through analysis and a message target area in the emergency broadcast index table is matched with the local machine, the FM-CDR emergency broadcast messages sent to the local machine are judged. This enables how to find FM-CDR emergency broadcast messages addressed to the local machine in at least 1 frequency.

2. The FM-CDR emergency broadcast message receiving is realized by a first CDR tuning demodulation module, a first CDR transmission stream buffer area, a detection module, a second CDR tuning demodulation module, a second CDR transmission stream buffer area and a main control module.

3. The first CDR tuning demodulation module, the first CDR transmission stream buffer area and the detection module are used for detecting whether the FM-CDR emergency broadcast message exists or not, the second CDR tuning demodulation module, the second CDR transmission stream buffer area and the main control module are used for receiving the FM-CDR emergency broadcast message, and the FM-CDR emergency broadcast message and the main control module are carried out simultaneously, so that the FM-CDR emergency broadcast message is detected uninterruptedly and received without omission.

4. Waiting for a time period T3 to allow the CDR transport stream of the new frequency to be written into the first CDR transport stream buffer with sufficient overlap without having to specifically clear the first CDR transport stream buffer of old data. This prevents the detection module from detecting the emergency broadcast index table of the CDR transport stream data of the new frequency, i.e., from detecting distortion, because the CDR transport stream data of the new frequency is less time-consuming to cover the CDR transport stream data of the old frequency.

5. Waiting for a time period T4 to allow the CDR transport stream of the new frequency to be written into the second CDR transport stream buffer with sufficient overlap without having to specifically clear the second CDR transport stream buffer of old data. This prevents the master control module from receiving the emergency broadcast index table and the emergency broadcast content table of the CDR transport stream data of the new frequency, that is, from receiving distortion, because the CDR transport stream data of the new frequency is not as long as the CDR transport stream data of the old frequency is covered.

Drawings

Fig. 1 is a block diagram of the structure of the embodiment of the present invention.

FIG. 2 is a flowchart of a method of a detection process according to an embodiment of the present invention.

Fig. 3 is a flow chart of a method of a response procedure according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings and examples.

As shown in fig. 1-3, a dual-mode FM-CDR emergency broadcast message receiving method without a buffer, where there are N FM-CDR frequencies that can receive FM-CDR emergency broadcast messages, and the FM-CDR emergency broadcast messages are in a CDR packet with PID = = PID _ sel, wherein the N FM-CDR frequency values are included in a frequency array F [ N ], and FM-CDR signals of all frequencies in the F [ N ] are cyclically detected, wherein a detection process includes the following steps, and the currently detected frequency is known as a frequency F [ i ]:

step 1, a detection module sets the receiving frequency of a first CDR tuning demodulation module as a current detection frequency;

step 2, the first CDR tuning demodulation module performs tuning demodulation on the FM-CDR signal according to the receiving frequency to obtain a CDR transmission stream, and a first CDR transmission stream buffer area is placed;

step 3, waiting for a time period T3, so that the CDR transmission stream with the new frequency is fully written into the first CDR transmission stream buffer area without specially clearing the old data in the first CDR transmission stream buffer area;

step 4, filtering out a data packet corresponding to the emergency broadcast message in the CDR transport stream from the first CDR transport stream buffer area according to PID = = PID _ sel;

step 5, in time period T, the detection module retrieves and extracts the emergency broadcast index table from the data packet, if overtime, the detection of the receiving frequency is ended, and step 7 is executed;

step 6, if the message target area in the emergency broadcast index table is matched with the local machine, setting the current receiving frequency as the frequency F [ i ], and executing a response process;

and 7, the detection module changes the current detection frequency to F [ j ], wherein j = i +1, and j =0 if j = = array length.

The one-time response process comprises the following steps:

step a, setting the receiving frequency of a second CDR tuning demodulation module as the current receiving frequency, and tuning and demodulating the FM-CDR signal by the second CDR tuning demodulation module according to the receiving frequency to obtain a CDR transmission stream and put a second CDR transmission stream buffer area;

b, waiting for a time period T4 to ensure that the CDR transmission stream with the new frequency is fully written into the second CDR transmission stream buffer area without specially clearing the old data in the second CDR transmission stream buffer area;

c, filtering a data packet corresponding to the emergency broadcast message in the CDR transport stream from the second CDR transport stream buffer area according to PID = = PID _ sel;

and d, the main control module extracts the emergency broadcast index table and the emergency broadcast content table from the data packet to further obtain the CDR emergency broadcast message.

Preferably, the core of the first CDR tuning demodulation module and the second CDR tuning demodulation module is a hail Hi5216 chip.

The beneficial effects are that:

1. according to the frequency in the receiving frequency array F [ n ], the FM-CDR signals are circularly received, CDR transmission stream data are detected, and when an emergency broadcast index table is obtained through analysis and a message target area in the emergency broadcast index table is matched with the local machine, the FM-CDR emergency broadcast messages sent to the local machine are judged. This enables how to find FM-CDR emergency broadcast messages addressed to the local machine in at least 1 frequency.

2. The FM-CDR emergency broadcast message receiving is realized by a first CDR tuning demodulation module, a first CDR transmission stream buffer area, a detection module, a second CDR tuning demodulation module, a second CDR transmission stream buffer area and a main control module.

3. The first CDR tuning demodulation module, the first CDR transmission stream buffer area and the detection module are used for detecting whether the FM-CDR emergency broadcast message exists or not, the second CDR tuning demodulation module, the second CDR transmission stream buffer area and the main control module are used for receiving the FM-CDR emergency broadcast message, and the FM-CDR emergency broadcast message and the main control module are carried out simultaneously, so that the FM-CDR emergency broadcast message is detected uninterruptedly and received without omission.

4. Waiting for a time period T3 to allow the CDR transport stream of the new frequency to be written into the first CDR transport stream buffer with sufficient overlap without having to specifically clear the first CDR transport stream buffer of old data. This prevents the detection module from detecting the emergency broadcast index table of the CDR transport stream data of the new frequency, i.e., from detecting distortion, because the CDR transport stream data of the new frequency is less time-consuming to cover the CDR transport stream data of the old frequency.

5. Waiting for a time period T4 to allow the CDR transport stream of the new frequency to be written into the second CDR transport stream buffer with sufficient overlap without having to specifically clear the second CDR transport stream buffer of old data. This prevents the master control module from receiving the emergency broadcast index table and the emergency broadcast content table of the CDR transport stream data of the new frequency, that is, from receiving distortion, because the CDR transport stream data of the new frequency is not as long as the CDR transport stream data of the old frequency is covered.

The present invention has been described in terms of embodiments, and it will be appreciated that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope and spirit of the principles of this disclosure. More specifically, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, other uses will also be apparent to those skilled in the art.

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Claims (2)

1. Receiving method of dual-mode FM-CDR emergency broadcast message without buffer cleaning, N FM-CDR frequencies are possible to receive FM-CDR emergency broadcast message, and FM-CDR emergency broadcast message is in CDR data packet with PID = = PID _ sel, characterized in that, the N FM-CDR frequency values are included in frequency array F [ N ], and FM-CDR signals of all frequencies in F [ N ] are circularly detected, wherein, one detection process includes the following steps, the current detection frequency is known as frequency F [ i ]:

step 1, a detection module sets the receiving frequency of a first CDR tuning demodulation module as a current detection frequency;

step 2, the first CDR tuning demodulation module performs tuning demodulation on the FM-CDR signal according to the receiving frequency to obtain a CDR transmission stream, and a first CDR transmission stream buffer area is placed;

step 3, waiting for a time period T3, so that the CDR transmission stream with the new frequency is fully written into the first CDR transmission stream buffer area without specially clearing the old data in the first CDR transmission stream buffer area;

step 4, filtering out a data packet corresponding to the emergency broadcast message in the CDR transport stream from the first CDR transport stream buffer area according to PID = = PID _ sel;

step 5, in time period T, the detection module retrieves and extracts the emergency broadcast index table from the data packet, if overtime, the detection of the receiving frequency is ended, and step 7 is executed;

step 6, if the message target area in the emergency broadcast index table is matched with the local machine, setting the current receiving frequency as the frequency F [ i ], and executing a response process;

step 7, the detection module changes the current detection frequency to F [ j ], wherein j = i +1, and j =0 if j = = array length;

the one-time response process comprises the following steps:

step a, setting the receiving frequency of a second CDR tuning demodulation module as the current receiving frequency, and tuning and demodulating the FM-CDR signal by the second CDR tuning demodulation module according to the receiving frequency to obtain a CDR transmission stream and put a second CDR transmission stream buffer area;

b, waiting for a time period T4 to ensure that the CDR transmission stream with the new frequency is fully written into the second CDR transmission stream buffer area without specially clearing the old data in the second CDR transmission stream buffer area;

c, filtering a data packet corresponding to the emergency broadcast message in the CDR transport stream from the second CDR transport stream buffer area according to PID = = PID _ sel;

and d, the main control module extracts the emergency broadcast index table and the emergency broadcast content table from the data packet to further obtain the CDR emergency broadcast message.

2. The unbuffered dual mode FM-CDR emergency broadcast message receiving method of claim 1, wherein a core of the first CDR tuning demodulation module and the second CDR tuning demodulation module is a hail Hi5216 chip.

Images