# C Packet APIs

**Detailed Description**

This section contains C Packet APIs related to Cellular-V2X packet analysis operation.

- *group* Telematics\_cv2x\_c\_packet

    - Provide utilities and structures for CV2X packet analysis.

Defines

- META\_DATA\_MASK\_SFN

    - meata data validity mask of each received packet, used by [rx\_packet\_meta\_data\_t](https://docs.qualcomm.com/doc/80-PF458-2/topic/struct_a00335.html#a00335)

- META\_DATA\_MASK\_SUB\_CHANNEL\_INDEX

    - 

- META\_DATA\_MASK\_SUB\_CHANNEL\_NUM

    - 

- META\_DATA\_MASK\_PRX\_RSSI

    - 

- META\_DATA\_MASK\_DRX\_RSSI

    - 

- META\_DATA\_MASK\_L2\_DEST

    - 

- META\_DATA\_MASK\_SCI\_FORMAT1

    - 

- META\_DATA\_MASK\_DELAY\_ESTI

    -

Functions

- [v2x\_status\_enum\_type](https://docs.qualcomm.com/doc/80-PF458-2/topic/c_apis_common.html#_CPPv420v2x_status_enum_type) v2x\_parse\_rx\_meta\_data(const uint8\_t \*payload, uint32\_t length, [rx\_packet\_meta\_data\_t](https://docs.qualcomm.com/doc/80-PF458-2/topic/packet.html#_CPPv421rx_packet_meta_data_t) \*meta\_data, size\_t \*num, size\_t \*meta\_data\_len)

    - Parse the received packet’s meta data from the payload

- **Associated data types**
    - [rx\_packet\_meta\_data\_t](https://docs.qualcomm.com/doc/80-PF458-2/topic/struct_a00335.html#a00335)

- **Detailed description**
    - This function extracts the received packet’s meta data from the payload, there maybe several meta data reports in the received payload.

- 
    - Otherwise:

- [V2X\_STATUS\_FAIL](https://docs.qualcomm.com/doc/80-PF458-2/topic/enum_a00065_1ga49d62bdeb1801fa5715ad5fe72f9427d.html#a00065_1gga49d62bdeb1801fa5715ad5fe72f9427da3858c725ee54429d49ea708f6d86e150) — Other failure.

- Parameters:

    - - **payload** – **[in]** Pointer to the received message which may contains the meta data reports
- **length** – **[in]** Length of the received message in byte
- **meta\_data** – **[out]** Pointer to the meta data structure array
- **num** – **[inout]** array size of meta\_data as input, be assigned to the number of meta data reports parsed out. The caller can use this value to index the array meta\_data.
- **meta\_data\_len** – **[out]** length of the meta data in byte parsed out from the payload

- Returns:

    - [V2X\_STATUS\_SUCCESS](https://docs.qualcomm.com/doc/80-PF458-2/topic/enum_a00065_1ga49d62bdeb1801fa5715ad5fe72f9427d.html#a00065_1gga49d62bdeb1801fa5715ad5fe72f9427dad6de32b5dffe2d50d735121355f2cfc6).

- struct rx\_packet\_meta\_data\_t

    - Contains the detailed meta data report of a packet received.

Public Members

- uint32\_t validity

    - Validity of the meta data

- uint16\_t sfn

    - System Frame Number \* 10 + subframe number

- uint8\_t sub\_channel\_index

    - The subchannel used for transmission

- uint8\_t sub\_channel\_num

    - Number of subchannels in the Rx pool

- int8\_t prx\_rssi

    - RSSI of primary receive signal, in dBm

- int8\_t drx\_rssi

    - RSSI of diversity receive signal, in dBm

- uint32\_t l2\_destination\_id

    - L2 destination ID

- uint32\_t sci\_format1\_info

    - SCI format1, 3GPP TS 36.213 section 14.1

- int32\_t delay\_estimation

    - Packet delay estimation, in Ts (1/(15000 \* 2048) seconds)

Last Published: Jun 24, 2026

[Previous Topic
C Config APIs](https://docs.qualcomm.com/bundle/publicresource/80-PF458-2/topics/config.md) [Next Topic
C++](https://docs.qualcomm.com/bundle/publicresource/80-PF458-2/topics/cpp_apis.md)