物联网开发平台 Linux & RTOS 设备（设备端接入）

一、前提条件

在开始之前，请你先完成 快速接入 文档中跑通 tc_iot_login 登录功能。如果你已经完成，可以跳过该操作。

二、步骤 1：注册监控事件回调

登录成功后，调用 tc_iot_av_init 注册 tc_iot_av_observer_s，实时监控相关的回调如下：

#include "tc_iot_av.h"static void on_monitor_begin(int channel_id, tc_iot_call_option_t option);static void on_monitor_end(int channel_id);static void on_monitor_switch(int channel_id, tc_iot_video_quality_e quality);tc_iot_av_observer_s observer;memset(&observer, 0, sizeof(observer));observer.on_monitor_begin = on_monitor_begin;observer.on_monitor_end = on_monitor_end;observer.on_monitor_switch = on_monitor_switch;tc_iot_error_e av_rc = tc_iot_av_init(&observer);if (av_rc != TC_IOT_ERR_SUCCESS) { printf("tc_iot_av_init failed: %d\\n", av_rc);}

三、步骤 2：响应 on_monitor_begin，创建发送通道

根据 option.media_content，在 on_monitor_begin 回调中创建对应的发送通道：

注意：设备通常只有一路麦克风采集源，tc_iot_create_audio_channel 建议全局只创建一次；多路视频监控同时在线时，可共享同一路音频发送通道，无需重复创建。

static tc_iot_av_channel_t *g_video_channel = NULL;static tc_iot_av_channel_t *g_audio_channel = NULL;static void on_monitor_begin(int channel_id, tc_iot_call_option_t option) { printf("[demo] on_monitor_begin channel_id=%d media=%d quality=%d\\n", channel_id, option.media_content, option.video_quality); if (option.media_content == TC_IOT_MEDIA_CONTENT_VIDEO || option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO_VIDEO) { g_video_channel = tc_iot_create_video_channel(channel_id, option.video_quality); if (!g_video_channel) { printf("[demo] create video channel failed, channel_id=%d\\n", channel_id); } } if ((option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO || option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO_VIDEO) && !g_audio_channel) { g_audio_channel = tc_iot_create_audio_channel(); if (!g_audio_channel) { printf("[demo] create audio channel failed\\n"); } } // 启动本地采集（示意，详见步骤 3/4 推流示例） // start_capture_and_push(…)}

四、步骤 3：推送视频帧

采集到一帧编码后的视频数据后，填充 tc_iot_video_frame 并调用 tc_iot_push_video_frame 推送到视频发送通道：

注意：说明：

注意：建议推送第一个 IDR 关键帧之后才开始持续推流，以保证对端能正常解码；在 IDR 帧之前推送 P 帧，对端可能无法解码画面。

void push_video_frame_sample(tc_iot_av_channel_t *video_channel, const uint8_t *encoded_data, size_t encoded_size, bool is_key_frame) { if (!video_channel) { return; } tc_iot_video_frame frame; memset(&frame, 0, sizeof(frame)); frame.codec = TC_IOT_VIDEO_CODEC_H264; frame.type = is_key_frame ? TC_IOT_VIDEO_FRAME_TYPE_IDR : TC_IOT_VIDEO_FRAME_TYPE_P; frame.rotation = TC_IOT_VIDEO_ROTATION_0; frame.width = 480; frame.height = 320; frame.data = (uint8_t *)encoded_data; frame.data_size = encoded_size; frame.pts_ms = current_time_ms(); // 由业务自行实现，返回当前毫秒时间戳 tc_iot_error_e err = tc_iot_push_video_frame(video_channel, &frame); if (err != TC_IOT_ERR_SUCCESS) { printf("[demo] push video frame failed: %d\\n", err); }}

五、步骤 4：推送音频帧

采集到一帧编码后的音频数据后，填充 tc_iot_audio_frame 并调用 tc_iot_push_audio_frame 推送到音频发送通道：

void push_audio_frame_sample(tc_iot_av_channel_t *audio_channel, const uint8_t *pcm_data, size_t pcm_size) { if (!audio_channel) { return; } tc_iot_audio_frame frame; memset(&frame, 0, sizeof(frame)); frame.codec = TC_IOT_AUDIO_CODEC_PCM; frame.sample_rate = TC_IOT_AUDIO_SAMPLE_RATE_16000; frame.channels = TC_IOT_AUDIO_CHANNEL_MONO; frame.frame_duration_ms = 20; frame.data = (uint8_t *)pcm_data; frame.data_size = pcm_size; frame.pts_ms = current_time_ms(); // 由业务自行实现，返回当前毫秒时间戳 tc_iot_error_e err = tc_iot_push_audio_frame(audio_channel, &frame); if (err != TC_IOT_ERR_SUCCESS) { printf("[demo] push audio frame failed: %d\\n", err); }}

六、步骤 5：响应 on_monitor_switch，切换视频清晰度（可选）

APP 端在监控查看期间切换清晰度时，设备端会通过 on_monitor_switch 回调收到通知，携带 channel_id（对应的监控通道）与 quality（切换后的清晰度）。quality 的可选取值（tc_iot_video_quality_e）如下：

视频发送通道创建时已固定清晰度，无法直接修改，因此收到 on_monitor_switch 后需要销毁旧通道、按新清晰度重新创建，后续视频帧继续推送到新通道即可：

static void on_monitor_switch(int channel_id, tc_iot_video_quality_e quality) { printf("[demo] on_monitor_switch channel_id=%d quality=%d\\n", channel_id, quality); if (g_video_channel) { tc_iot_destroy_video_channel(g_video_channel); g_video_channel = NULL; } g_video_channel = tc_iot_create_video_channel(channel_id, quality); if (!g_video_channel) { printf("[demo] recreate video channel failed, channel_id=%d\\n", channel_id); } // 后续采集到的视频帧继续调用 tc_iot_push_video_frame 推送到新的 g_video_channel}

注意：重建通道期间会短暂中断视频推流，建议尽快完成切换，并在重建后尽快推送一个 IDR 关键帧，保证画面能快速恢复。

七、步骤 6：响应 on_monitor_end，销毁发送通道

对端结束监控查看时触发 on_monitor_end，此时应停止采集并销毁对应的发送通道：

static void on_monitor_end(int channel_id) { printf("[demo] on_monitor_end channel_id=%d\\n", channel_id); // 停止本地采集（示意，详见业务实现） // stop_capture(…) if (g_video_channel) { tc_iot_destroy_video_channel(g_video_channel); g_video_channel = NULL; } if (g_audio_channel) { tc_iot_destroy_audio_channel(g_audio_channel); g_audio_channel = NULL; }}

注意：说明：

注意：单个设备可同时存在多路监控发送通道（对应不同的 channel_id），这篇仅演示单路场景；多路并发时建议用数组或列表管理各 channel_id 对应的通道指针与采集资源。

八、完整示例代码

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <stdbool.h>#include <unistd.h>#include <pthread.h>#include <sys/time.h>#include "tc_iot.h"#include "tc_iot_av.h"static volatile int s_login_done = 0;static tc_iot_error_e s_login_rc = TC_IOT_ERR_SUCCESS;static tc_iot_av_channel_t *g_video_channel = NULL;static tc_iot_av_channel_t *g_audio_channel = NULL;static volatile bool g_pushing = false;static pthread_t g_video_thread;static pthread_t g_audio_thread;static uint64_t current_time_ms(void) { struct timeval tv; gettimeofday(&tv, NULL); return (uint64_t)tv.tv_sec * 1000 + tv.tv_usec / 1000;}// 登录回调：与快速接入一致static void on_login(tc_iot_error_e error_code, const char *error_message) { s_login_rc = error_code; s_login_done = 1; if (error_code != TC_IOT_ERR_SUCCESS) { printf("[demo] login failed: %d, msg=%s\\n", error_code, error_message ? error_message : ""); }}// 模拟视频采集：独立线程定时生成占位视频帧（首帧标记为 IDR）并推送。// 实际接入时替换为真实摄像头采集与 H264/H265 编码逻辑。static void *video_push_thread_func(void *arg) { static uint8_t dummy_video[64] = {0}; bool first_frame = true; while (g_pushing) { if (g_video_channel) { tc_iot_video_frame vframe; memset(&vframe, 0, sizeof(vframe)); vframe.codec = TC_IOT_VIDEO_CODEC_H264; vframe.type = first_frame ? TC_IOT_VIDEO_FRAME_TYPE_IDR : TC_IOT_VIDEO_FRAME_TYPE_P; vframe.rotation = TC_IOT_VIDEO_ROTATION_0; vframe.width = 480; vframe.height = 320; vframe.data = dummy_video; vframe.data_size = sizeof(dummy_video); vframe.pts_ms = current_time_ms(); tc_iot_push_video_frame(g_video_channel, &vframe); first_frame = false; } usleep(40 * 1000); // 模拟 25fps } return NULL;}// 模拟音频采集：独立线程定时生成占位音频帧并推送。// 实际接入时替换为真实麦克风采集与 PCM/AAC 编码逻辑。static void *audio_push_thread_func(void *arg) { static uint8_t dummy_audio[320] = {0}; // 16kHz/mono/20ms 对应的 PCM 采样点数 while (g_pushing) { if (g_audio_channel) { tc_iot_audio_frame aframe; memset(&aframe, 0, sizeof(aframe)); aframe.codec = TC_IOT_AUDIO_CODEC_PCM; aframe.sample_rate = TC_IOT_AUDIO_SAMPLE_RATE_16000; aframe.channels = TC_IOT_AUDIO_CHANNEL_MONO; aframe.frame_duration_ms = 20; aframe.data = dummy_audio; aframe.data_size = sizeof(dummy_audio); aframe.pts_ms = current_time_ms(); tc_iot_push_audio_frame(g_audio_channel, &aframe); } usleep(20 * 1000); // 20ms 一帧 } return NULL;}static void on_monitor_begin(int channel_id, tc_iot_call_option_t option) { printf("[demo] on_monitor_begin channel_id=%d media=%d quality=%d\\n", channel_id, option.media_content, option.video_quality); if (option.media_content == TC_IOT_MEDIA_CONTENT_VIDEO || option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO_VIDEO) { g_video_channel = tc_iot_create_video_channel(channel_id, option.video_quality); } if ((option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO || option.media_content == TC_IOT_MEDIA_CONTENT_AUDIO_VIDEO) && !g_audio_channel) { g_audio_channel = tc_iot_create_audio_channel(); } if (!g_pushing) { g_pushing = true; pthread_create(&g_video_thread, NULL, video_push_thread_func, NULL); pthread_create(&g_audio_thread, NULL, audio_push_thread_func, NULL); }}static void on_monitor_end(int channel_id) { printf("[demo] on_monitor_end channel_id=%d\\n", channel_id); if (g_pushing) { g_pushing = false; pthread_join(g_video_thread, NULL); pthread_join(g_audio_thread, NULL); } if (g_video_channel) { tc_iot_destroy_video_channel(g_video_channel); g_video_channel = NULL; } if (g_audio_channel) { tc_iot_destroy_audio_channel(g_audio_channel); g_audio_channel = NULL; }}// 切换清晰度（这篇步骤 5 核心内容，可选实现）static void on_monitor_switch(int channel_id, tc_iot_video_quality_e quality) { printf("[demo] on_monitor_switch channel_id=%d quality=%d\\n", channel_id, quality); if (g_video_channel) { tc_iot_destroy_video_channel(g_video_channel); g_video_channel = NULL; } g_video_channel = tc_iot_create_video_channel(channel_id, quality); if (!g_video_channel) { printf("[demo] recreate video channel failed, channel_id=%d\\n", channel_id); }}int main(int argc, char **argv) { if (argc < 7) { printf("Usage: %s -p <product_id> -d <device_id> -s <device_secret>\\n", argv[0]); return 0; } const char *product_id = NULL; const char *device_id = NULL; const char *device_secret = NULL; for (int i = 1; i < argc; i++) { if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) { product_id = argv[++i]; } else if (strcmp(argv[i], "-d") == 0 && i + 1 < argc) { device_id = argv[++i]; } else if (strcmp(argv[i], "-s") == 0 && i + 1 < argc) { device_secret = argv[++i]; } } if (!product_id || !device_id || !device_secret) { printf("device info error\\n"); return 1; } // 初始化与登录：与快速接入一致 tc_iot_config_s config; memset(&config, 0, sizeof(config)); config.storage_path = "./"; config.log_level = TC_IOT_LOG_LEVEL_INFO; tc_iot_error_e rc = tc_iot_init(&config); if (rc != TC_IOT_ERR_SUCCESS) { printf("tc_iot_init failed: %d\\n", rc); return 1; } tc_iot_device_info_s device_info; device_info.product_id = product_id; device_info.device_id = device_id; device_info.device_secret = device_secret; rc = tc_iot_login(&device_info, on_login); if (rc != TC_IOT_ERR_SUCCESS) { printf("tc_iot_login call failed: %d\\n", rc); tc_iot_deinit(); return 1; } int waited_ms = 0; while (!s_login_done && waited_ms < 5000) { usleep(100 * 1000); waited_ms += 100; } if (!s_login_done || s_login_rc != TC_IOT_ERR_SUCCESS) { printf("login timeout or failed\\n"); tc_iot_deinit(); return 1; } printf("[demo] login success\\n"); // 注册监控事件回调（这篇核心内容） tc_iot_av_observer_s observer; memset(&observer, 0, sizeof(observer)); observer.on_monitor_begin = on_monitor_begin; observer.on_monitor_end = on_monitor_end; observer.on_monitor_switch = on_monitor_switch; rc = tc_iot_av_init(&observer); if (rc != TC_IOT_ERR_SUCCESS) { printf("tc_iot_av_init failed: %d\\n", rc); tc_iot_deinit(); return 1; } printf("[demo] ready, waiting for monitor request from app/cloud (60s)…\\n"); sleep(60); // 释放资源 if (g_pushing) { g_pushing = false; pthread_join(g_video_thread, NULL); pthread_join(g_audio_thread, NULL); } if (g_video_channel) { tc_iot_destroy_video_channel(g_video_channel); } if (g_audio_channel) { tc_iot_destroy_audio_channel(g_audio_channel); } tc_iot_av_deinit(); tc_iot_logout(); tc_iot_deinit(); printf("[demo] main exit\\n"); return 0;}

九、编译并运行

将上述代码覆盖到 快速接入 中已创建的项目 main.c，CMakeLists.txt 无需改动，重新编译并运行即可。

1. 重新编译。

cmake –build build -j

2. 运行可执行文件，传入设备三元组。

./build/iot_quickstart_demo -p YOUR_PRODUCT_ID -d YOUR_DEVICE_NAME -s 'YOUR_DEVICE_SECRET'

3. 通过 APP 控制台对该设备发起监控查看请求，观察设备端日志输出 on_monitor_begin 及后续推流日志，即代表监控推流链路验证成功。

十、常见问题

十一、联系我们

如果你在接入或使用过程中有任何疑问或者建议，欢迎 联系我们 提交反馈。