Sample code for how to develop application#

1. Introduction#

The dir include the simple sample code for how to develop application quickly based on Media Transport Library.

2. Pipeline samples which based on get/put APIs#

tx_st20_pipeline_sample.c: A tx video(st2110-20) application based on pipeline interface, library will call the color format conversion in case the input format is not the one defined in RFC4175. Application can focus on the frame buffer producer.

./build/app/TxSt20PipelineSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_st20_pipeline_sample.c: A rx video(st2110-20) application based on pipeline interface, library will call the color format conversion in case the output format is not the one defined in RFC4175. Application can focus on the frame buffer consumer.

./build/app/RxSt20PipelineSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

tx_st22_pipeline_sample.c: A tx compressed video(st2110-22) application based on pipeline interface, library will call the registered encoder plugins. Application only need focus on the frame buffer producer.

./build/app/TxSt22PipelineSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.22

rx_st22_pipeline_sample.c: A rx compressed video(st2110-22) application based on pipeline interface, library will call the registered decoder plugins. Application only need focus on the frame buffer consumer.

tx_st30_pipeline_sample.c: A tx audio(st2110-30) application based on pipeline get/put interface.

./build/app/TxSt30PipelineSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.30

rx_st30_pipeline_sample.c: A rx audio(st2110-30) application based on pipeline get/put interface.

./build/app/RxSt30PipelineSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.30

./build/app/RxSt22PipelineSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.22

2.1. ST40 ancillary pipeline samples#

TxSt40PipelineSample and RxSt40PipelineSample live in this directory (see tx_st40_pipeline_sample.c / rx_st40_pipeline_sample.c) and are built automatically by ./build.sh. They leverage the same CLI foundation as the other pipeline samples, so familiar options such as --p_port, --udp_port, --sessions_cnt, --multi_inc_addr, --ext_frame, and destination MAC overrides behave identically.

Tx workflow#

Prepare (or reuse) an ancillary payload. Any binary file works because frames are looped forever:
```
head -c 4096 /dev/urandom > /tmp/anc_payload.bin
```

Launch the TX sample. The example below keeps every frame below the 255-byte UDW limit returned by st40p_tx_max_udw_buff_size() so that each payload fits into a single RFC 8331 RTP packet.

./build/app/TxSt40PipelineSample \
 --p_port 0000:af:01.0 \
 --p_tx_ip 239.1.1.1 \
 --p_sip 192.168.96.2 \
 --udp_port 20000 \
 --payload_type 40 \
 --sessions_cnt 1 \
 --tx_url /tmp/anc_payload.bin \
 --ext_frame

Helpful switches:

--ext_frame keeps the sample in user-supplied buffer mode, mirroring how most applications integrate the pipeline API.
--multi_inc_addr increments the destination multicast address per session instead of the UDP port so you can spin up multiple ancillary streams on one NIC queue.

Rx workflow#

Match the TX parameters on the receiver. Enabling --rx_dump writes a human-readable metadata block per frame to --rx_url (foo.txt_0, _1, … if multiple sessions are active):

./build/app/RxSt40PipelineSample \
        --p_port 0000:af:01.0 \
        --p_rx_ip 239.1.1.1 \
        --p_sip 192.168.96.2 \
        --udp_port 20000 \
        --payload_type 40 \
        --sessions_cnt 1 \
        --rx_url /tmp/anc_dump.txt \
        --rx_dump

The runtime log summarizes the number of metadata entries and UDW bytes received per frame, while the dump files capture DID/SDID/line information followed by the raw payload so you can diff TX/RX easily.

Troubleshooting and USDT hooks#

Use --rx_dump/--tx_url first to confirm that metadata completes the round trip.
When st40_total_pkts exceeds 1, the payload overflowed the 255-byte UDW buffer; trim the input file or drop the session count on slower links.
For end-to-end tracing, follow the ST40P probe examples in doc/usdt.md §2.5.6 (they cover usdt::st40p:* plus usdt::sys:log_msg combinations) instead of keeping scripts here.

3. Forward pipeline samples#

rx_st20p_tx_st22p_fwd.c: A demo application which receive a st20 stream and output as st22 compressed stream with logo rendering.

./build/app/RxSt20pTxSt22pFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21

rx_st20p_tx_st20p_fwd.c: A demo application which receive a st20 stream and output as st20 stream with logo rendering.

./build/app/RxSt20pTxSt20pFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21

rx_st20p_tx_st20p_downsample_fwd.c: A demo application which receive a 4k st20 stream and output as st20 stream downscaled to 1080p.

./build/app/RxSt20pTxSt20pDownsampleFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21 --width 3840 --height 2160

rx_st20p_tx_st20p_split_fwd.c: Receive 4k frames from rx, do square quad division and send with 4 1080p sessions.

./build/app/RxSt20pTxSt20pSplitFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21 --width 3840 --height 2160

rx_st20p_tx_st20p_merge_fwd.c: Receive 4 1080p sessions from rx, merge to single 4k st20 stream and send out.

./build/app/RxSt20pTxSt20pMergeFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21 --width 3840 --height 2160

rx_st20p_tx_st20p_downsample_merge_fwd.c: Receive 4 1080p sessions from rx, downsample and merge to single 1080p st20 stream and send out.

./build/app/RxSt20pTxSt20pDownsampleMergeFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21

rx_st20_tx_st20_split_fwd.c: Receive 4k frames from rx, do square quad division and send with 4 1080p sessions.

./build/app/RxSt20TxSt20SplitFwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21 --width 3840 --height 2160

4. Misc samples#

tx_video_split_sample.c: A tx video(st2110-20) application based on frame interface, application reads a series of 4k frames from the file, square splits them to 4 parts and sends with 4 1080p sessions.

./build/app/TxVideoSplitSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_st20_redundant_sample.c: A rx video(st2110-22-7) redundant application based on frame interface, application need handle the color format conversion in case the user format is not the one defined in RFC4175.

./build/app/RxSt20RedundantSample --p_port 0000:af:01.0 --r_port 0000:af:01.1 --p_sip 192.168.77.11 --r_sip 192.168.77.12 --p_rx_ip 239.168.77.20 --r_rx_ip 239.168.77.21

5. Legacy samples which based on notify APIs#

tx_video_sample.c: A tx video(st2110-20) application based on frame notify interface, application need charge the color format conversion in case the user format is not the one defined in RFC4175.

./build/app/TxVideoSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_video_sample.c: A rx video(st2110-20) application based on frame notify interface, application need charge the color format conversion in case the user format is not the one defined in RFC4175.

./build/app/RxVideoSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

tx_st22_video_sample.c: A tx video(st2110-22) application based on frame notify interface, application need handle the encoder.

./build/app/TxSt22VideoSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_st22_video_sample.c: A rx video(st2110-22) application based on frame notify interface, application need handle the decoder.

./build/app/RxSt22VideoSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

rx_st20_tx_st20_fwd.c: A forward demo application which receive a st20 stream and output as st20 stream with logo rendering.

./build/app/RxSt20TxSt20Fwd --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20 --p_fwd_ip 239.168.75.21

6. Samples which based on low level APIs for advanced usage#

tx_slice_video_sample.c: A tx video(st2110-20) application based on slice interface for low latency requirement, application need handle the color format conversion in case the user format is not the one defined in RFC4175.

./build/app/TxSliceVideoSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_slice_video_sample.c: A rx video(st2110-20) application based on slice interface for low latency requirement, application need handle the color format conversion in case the user format is not the one defined in RFC4175.

./build/app/RxSliceVideoSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

tx_rtp_video_sample.c: A tx video(st2110-20) application based on rtp interface, application need handle all rtp pack.

./build/app/TxRtpVideoSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_rtp_video_sample.c: A rx video(st2110-20) application based on rtp interface application need handle all rtp unpack.

./build/app/RxRtpVideoSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

7. DMA sample#

dma_sample.c: A DMA sample code.

8. Ext frame sample#

tx_st20_pipeline_ext_frame_sample.c: A tx video(st2110-20) application based on pipeline interface, library will not allocate memory for sending buffers but use those provided by user.

./build/app/TxSt20pExtFrameSample --p_port 0000:af:01.0 --p_sip 192.168.75.11 --p_tx_ip 239.168.75.20

rx_st20_pipeline_dyn_ext_frame_sample.c: A rx video(st2110-20) application based on pipeline interface, library will not allocate memory for receiving buffers but queries for user frame buffer to fill.

./build/app/RxSt20pDynExtFrameSample --p_port 0000:af:01.1 --p_sip 192.168.75.22 --p_rx_ip 239.168.75.20

Sample code for how to develop application

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