JSON Configuration Guide#

Media Transport Library sample app can use JSON file to configure sessions. This documentation explains how to write the JSON files.

Examples#

Example tx_1v_1a_1anc.json file, find more examples config files in example config directory.

{
    "interfaces": [
        {
            "name": "0000:af:01.0",
            "ip": "192.168.30.10"
        }
    ],
    "tx_sessions": [
        {
            "dip": [
                "239.1.1.1",
            ],
            "interface": [
                0,
            ],
            "st20p": [
                {
                    "replicas": 1,
                    "start_port": 20000,
                    "payload_type": 112,
                    "width": 1920,
                    "height": 1080,
                    "fps": "p59",
                    "device": "AUTO",
                    "input_format": "YUV422PLANAR10LE",
                    "transport_format": "YUV_422_10bit",
                    "st20p_url": "./yuv422p10le_1080p.yuv"
                }
            ],
            "st30p": [
                {
                    "replicas": 1,
                    "start_port": 30000,
                    "payload_type": 111,
                    "audio_format": "PCM24",
                    "audio_channel": ["U02"],
                    "audio_sampling": "96kHz",
                    "audio_ptime": "1",
                    "audio_url": "./test.pcm"
                }
            ],
            "ancillary": [
                {
                    "replicas": 1,
                    "start_port": 40000,
                    "payload_type": 113,
                    "type": "frame",
                    "ancillary_format": "closed_caption",
                    "ancillary_url": "./test.txt",
                    "ancillary_fps": "p59"
                }
            ],
            "fastmetadata": [
                {
                    "replicas": 1,
                    "start_port": 40000,
                    "payload_type": 115,
                    "type": "frame",
                    "fastmetadata_data_item_type": 123456,
                    "fastmetadata_k_bit": 1,
                    "fastmetadata_url": "./test.txt",
                    "fastmetadata_fps": "p59"
                }
            ]
        }
    ]
}

Schema#

Interfaces#

List all interfaces that can be used by app

name (string): PF/VF pci name, for example: 0000:86:00.0

proto (string): "static", "dhcp" interface network protocol, if DHCP is used, below IPs will be ignored

ip (string): interface assigned IP

netmask (string): interface netmask(optional), for example: 255.255.254.0

gateway (string): interface gateway(optional), for example: 172.16.10.1, use “route -n” to check the gateway address before binding port to DPDK PMD.

tx_queues_cnt (int): the number of tx queues(optional). Default it will calculated based on the sessions number in this configuration.

rx_queues_cnt (int): the number of tx queues(optional). Default it will calculated based on the sessions number in this configuration.

Session group contains a group of sessions which use some common settings, there can be 0 or multiple video/audio/ancillary sessions in one group, and there can be 0 or multiple tx/rx session groups in the following parts in case you have multiple destination IP. See tx_multi_dest and rx_multi_dest for multiple destination reference.

TX Sessions (array of tx session groups)#

Common settings for following sessions in the group:

dip (array-string): destination IP address, at least 1 primary IP, the second is redundant IP

interfaces (array-int): interfaces/ports used by the sessions, at least 1 primary interface, the second is redundant interface

video (array of video sessions)#

Items in each element of the “video” array

replicas (int): 1~max_num the number of session copies

type (string): "frame", "rtp", "slice" app->lib data type

pacing (string): "narrow", "wide", "linear" pacing type

packing (string): "BPM", "GPM", "GPM_SL" packing mode, default is “BPM” mode (1260 bytes in payload)

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

video_format (string): "i1080p59", "i1080p50", "i1080p29", "i720p59", "i720p50", "i720p29", "i2160p59", "i2160p50", "i2160p29" video format

pg_format (string): "YUV_422_10bit", "YUV_422_12bit", "YUV_444_10bit", "YUV_444_12bit", "RGB_10bit", "RGB_12bit" pixel group format

video_url (string): video source

display (bool): true, false display video frames with SDL, only works with YUV 422 10bit and 8bit stream

audio (array of audio sessions)#

Items in each element of the “audio” array

replicas (int): 1~max_num the number of session copies

type (string): "frame", "rtp" app->lib data type

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

audio_format (string): "PCM8", "PCM16", "PCM24" audio format

audio_channel (array-string): "M", "DM", "ST", "LtRt", "51", "71", "222", "SGRP", "U01...U64" audio channel-order(a listing of these channel grouping symbols), the library only cares the total number of channels

audio_sampling (string): "48kHz", "96kHz" audio sample rate

audio_ptime (string): "1", "0.12", "0.25", "0.33", "4" audio packet time, AES67(st30) supported: 1ms, 4ms, 125us(0.12), 250us(0.25) and 333us(0.33), AM824(st31) supported: 1ms

audio_url (string): audio source

ancillary (array of ancillary sessions)#

Items in each element of the “ancillary” array

replicas (int): 1~max_num the number of session copies

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

ancillary_format (string): "closed_caption" ancillary format

ancillary_url (string): ancillary source

ancillary_fps (string): "p59", "p50", "p29" ancillary fps which should be aligned to video

fast metadata (array of fast metadata sessions)#

Items in each element of the “fastmetadata” array

replicas (int): 1~max_num the number of session copies

type (string): "frame", "rtp" app->lib data type

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

fastmetadata_data_item_type (int): 0~4194303 (0x - 0x3fffff) 22 bits data item type

fastmetadata_k_bit (int): 0~1 1 bit K-bit value

fastmetadata_url (string): fast metadata source

fastmetadata_fps (string): "p59", "p50", "p29" fast metadata fps which should be aligned to video

RX Sessions (array of rx session groups)#

Common settings for following sessions in the group:

ip (array-string): the transmitter’s IP or the multicast group IP, at least 1 primary IP, the second is redundant IP

mcast_src_ip (array-string): the source IP filter for multicast(optional), assume primary and redundant sessions use different multicast group, if one of the source filter set, another is allowed to be set as 0.0.0.0(any source)

interfaces (array-int): interfaces/ports used by the sessions, at least 1 primary interface, the second is redundant interface

video (array of video sessions) for RX#

Items in each element of the “video” array

replicas (int): 1~max_num the number of session copies

type (string): "frame", "rtp", "slice" lib->app data type

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

video_format (string): "i1080p59", "i1080p50", "i1080p29", "i720p59", "i720p50", "i720p29", "i2160p59", "i2160p50", "i2160p29" video format

pg_format (string): "YUV_422_10bit", "YUV_422_12bit", "YUV_444_10bit", "YUV_444_12bit", "RGB_10bit", "RGB_12bit" pixel group format

user_pg_format (string): "YUV_422_8bit" user required pixel group format

display (bool): true, false display video frames with SDL, only works with YUV 422 10bit and 8bit stream

audio (array of audio sessions) for RX#

Items in each element of the “audio” array

replicas (int): 1~max_num th number of session copies

type (string): "frame", "rtp" lib->app data type

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

audio_format (string): "PCM8", "PCM16", "PCM24" audio format

audio_sampling (string): "48kHz", "96kHz" audio sample rate

audio_ptime (string): "1", "0.12", "0.25", "0.33", "4" audio packet time, AES67(st30) supported: 1ms, 4ms, 125us(0.12), 250us(0.25) and 333us(0.33), AM824(st31) supported: 1ms

audio_url (string): audio reference file

ancillary (array of ancillary sessions) for RX#

Items in each element of the “ancillary” array

replicas (int): 1~max_num the number of session copies

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

fast metadata (array of fast metadata sessions) for RX#

Items in each element of the “fastmetadata” array

replicas (int): 1~max_num the number of session copies

start_port (int): 0~65535 start udp port for copies of sessions

payload_type (int): 0~127 7 bits payload type define in RFC3550

fastmetadata_data_item_type (int): 0~4194303 (0x - 0x3fffff) 22 bits data item type - reference value (for testing the flow) - Optional setting

fastmetadata_k_bit (int): 0~1 1 bit K-bit value - reference value (for testing the flow) - Optional setting

fastmetadata_url (string): fast metadata reference file (for testing the flow) - Optional setting

Others#

shared_tx_queues (bool): If enable the shared tx queues or not, (optional). The queue number is limited for NIC, to support sessions more than queue number, enable this option to share queue resource between sessions.

shared_rx_queues (bool): If enable the shared rx queues or not, (optional). The queue number is limited for NIC, to support sessions more than queue number, enable this option to share queue resource between sessions.

tx_no_chain (bool): If disable the tx chain support or not, (optional). Tx chain is for zero copy support for audio and video transmitters with two different memory pool for header and payload. Use can enable this option to use copy mode to reduce the mempool usage, usually for audio sessions number max than 128.

sch_session_quota (int): The quota unit in 1080p59 yuv422_10bit for one single scheduler(core), (optional). Default it will use the quota define in the lib.

rss_mode (string): "none", "l3_l4", "l3" (optional). Default it will be detected by lib.

log_file (string): set log file for mtl log. If you’re initiating multiple RxTxApp processes simultaneously, please ensure each process has a unique filename path. Default the log is writing to stderr.

JSON Configuration Guide

Contents

JSON Configuration Guide#

Examples#

Schema#

Interfaces#

TX Sessions (array of tx session groups)#

video (array of video sessions)#

audio (array of audio sessions)#

ancillary (array of ancillary sessions)#

fast metadata (array of fast metadata sessions)#

RX Sessions (array of rx session groups)#

video (array of video sessions) for RX#

audio (array of audio sessions) for RX#

ancillary (array of ancillary sessions) for RX#

fast metadata (array of fast metadata sessions) for RX#

Others#