技术背景
随着国产化操作系统的推进，市场对国产化操作系统下的生态构建，需求越来越迫切，特别是音视频这块，今天我们讨论的是如何在linux平台实现屏幕|摄像头采集，并推送至RTMP服务。
我们知道，Linux平台，如果需要采集摄像头，可使用V4L2相关接口，屏幕采集用X相关接口实现，如果是Wayland协议, 用PipeWire相关接口实现采集就好。 麦克风采集使用ALSA或者PulseAudio，采集播放音频用PulseAudio。
FFmpeg VS SmartPublisher
今天我们探讨的是，两种技术选型下的linux平台同屏摄像头RTMP推送实现：
FFmpeg技术方案
在Linux平台上采集屏幕和摄像头内容，并将其推送到RTMP服务器，可结合使用ffmpeg和x11grab（用于屏幕捕获）以及摄像头设备。
1 安装 FFmpeg
首先，确保你的Linux系统上安装了ffmpeg。你可以通过包管理器安装它。例如，在Ubuntu上，你可以使用以下命令：
sudo apt update
sudo apt install ffmpeg2 确定摄像头设备在Linux上，摄像头通常被识别为/dev/videoX设备，其中X是设备的编号（通常是0, 1, 2等）。你可以使用ls /dev/video*来查看所有视频设备。
3 编写FFmpeg命令
使用ffmpeg，你可以同时捕获屏幕和摄像头，并将它们合并到一个RTMP流中。以下是一个基本的命令示例，它假设你的摄像头是/dev/video0，并且你想要捕获整个屏幕：
ffmpeg \
-f x11grab -r 30 -s 1920x1080 -i :0.0+100,200 \
-f video4linux2 -r 30 -s 640x480 -i /dev/video0 \
-filter_complex "[0:v]pad=iw+640:ih:640:0[main];[main][1:v]overlay=640:0[out]" \
-map "[out]" -c:v libx264 -preset veryfast -maxrate 3000k -bufsize 6000k -pix_fmt yuv420p \
-f flv rtmp://192.168.0.103:1935/live/streamkey命令解析：
-f x11grab：指定输入格式为X11屏幕捕获。-r 30：设置帧率为30fps。-s 1920x1080：设置屏幕捕获的分辨率为1920x1080。-i :0.0+100,200：指定屏幕捕获的起始位置（可选，这里从屏幕左上角向右100像素，向下200像素开始）。-f video4linux2：指定摄像头输入格式。-filter_complex：使用ffmpeg的过滤器图（filtergraph）来合并视频流。这里，它首先将屏幕捕获的视频向右填充640像素（摄像头宽度），然后将摄像头视频覆盖在填充后的屏幕视频的右侧。-map "[out]"：选择过滤器图的输出作为最终输出。-c:v libx264：设置视频编码器为libx264。-preset veryfast：设置编码预设以平衡编码速度和压缩率。-maxrate和-bufsize：设置比特率和缓冲区大小。-pix_fmt yuv420p：设置像素格式为YUV420P，这是大多数RTMP服务器所需的格式。-f flv：设置输出格式为FLV，适用于RTMP流。rtmp://192.168.0.103:1935/live/streamkey：替换为你的RTMP服务器的URL和流密钥。
SmartPublisher
SmartPublisher是大牛直播SDK旗下SmartMediaKit系列的跨平台的RTMP推送模块，Linux平台已支持x86_64架构和aarch64架构，SDK始于2015年，先后覆盖了Windows、Android、iOS、Linux平台的RTMP|RTSP的音视频推拉流模块。
Linux平台x64_64架构|aarch64架构RTMP直播推送模块功能支持如下：
- 音频编码：AAC/SPEEX；
- 视频编码：H.264；
- 推流协议：RTMP；
- [音视频]支持纯音频/纯视频/音视频推送；
- 支持X11屏幕采集；
- 支持部分V4L2摄像头设备采集；
- [屏幕/V4L2摄像头]支持帧率、关键帧间隔(GOP)、码率(bit-rate)设置；
- [V4L2摄像头]支持V4L2摄像头设备选择(设备文件名范围:[/dev/video0, /dev/video63])、分辨率设置、帧率设置；
- [V4L2摄像头]支持水平反转、垂直反转、0° 90° 180° 270°旋转；
- [音频]支持基于alsa-lib接口的音频采集；
- [音频]支持基于libpulse接口采集本机PulseAudio服务音频；
- [预览]支持推送端实时预览；
- [对接服务器]支持自建标准RTMP服务器或CDN；
- 支持断网自动重连、网络状态回调；
- 屏幕和摄像头合成/多层合成；
- 支持窗口采集(一般不建议使用)；
- 支持实时快照；
- 支持降噪处理、自动增益控制、VAD端点检测；
- 支持扬声器和麦克风混音；
- 支持外部编码前音视频数据对接；
- 支持外部编码后音视频数据对接；
- 支持实时音量调节；
- 支持扩展录像模块;
- 支持Unity接口；
- 支持H.264扩展SEI发送模块；
- 支持x64_64架构、aarch64架构（需要glibc-2.21及以上版本的Linux系统, 需要libX11.so.6, 需要GLib–2.0, 需安装 libstdc++.so.6.0.21、GLIBCXX_3.4.21、 CXXABI_1.3.9）；
技术实现如下：
/*
* publisherdemo.cpp
* Author: daniusdk.com
* WeChat: xinsheng120
*/
int main(int argc, char *argv[])
{
struct sigaction act;
sigemptyset(&act.sa_mask);
act.sa_sigaction = OnSaSigaction;
act.sa_flags = SA_SIGINFO;
sigaction(SIGINT, &act, NULL);
sigaction(SIGFPE, &act, NULL);
XInitThreads(); // X支持多线程, 必须调用
auto display = XOpenDisplay(nullptr);
if (!display)
{
fprintf(stderr, "Cannot connect to X server\n");
return 0;
}
auto screen = DefaultScreen(display);
auto root = XRootWindow(display, screen);
XWindowAttributes root_win_att;
if (!XGetWindowAttributes(display, root, &root_win_att))
{
fprintf(stderr, "Get Root window attri failed\n");
XCloseDisplay(display);
return 0;
}
int main_w = root_win_att.width / 2, main_h = root_win_att.height / 2;
auto black_pixel = BlackPixel(display, screen);
auto white_pixel = WhitePixel(display, screen);
auto main_wid = XCreateSimpleWindow(display, root, 0, 0, main_w, main_h, 0, white_pixel, black_pixel);
if (!main_wid)
{
fprintf(stderr, "Cannot Create Main Window\n");
XCloseDisplay(display);
return 0;
}
XSelectInput(display, main_wid, StructureNotifyMask | KeyPressMask);
auto sub_wid = CreateSubWindow(display, screen, main_wid);
if (!sub_wid)
{
fprintf(stderr, "Cannot Create Render Window\n");
XDestroyWindow(display, main_wid);
XCloseDisplay(display);
return 0;
}
XMapWindow(display, main_wid);
XStoreName(display, main_wid, "Video Preview");
XMapWindow(display, sub_wid);
LogInit();
NT_SmartPublisherSDKAPI push_api;
if (!PushSDKInit(push_api))
{
XDestroyWindow(display, sub_wid);
XDestroyWindow(display, main_wid);
XCloseDisplay(display);
return 0;
}
// auto rtsp_server_handle = start_rtsp_server(&push_api, 8554, "test", "12345");
auto rtsp_server_handle = start_rtsp_server(&push_api, 8554, "", "");
if (nullptr == rtsp_server_handle) {
fprintf(stderr, "start_rtsp_server failed.\n");
XDestroyWindow(display, sub_wid);
XDestroyWindow(display, main_wid);
XCloseDisplay(display);
push_api.UnInit();
return 0;
}
auto push_handle = open_config_instance(&push_api, 20);
if (nullptr == push_handle) {
fprintf(stderr, "open_config_instance failed.\n");
XDestroyWindow(display, sub_wid);
XDestroyWindow(display, main_wid);
XCloseDisplay(display);
stop_rtsp_server(&push_api, rtsp_server_handle);
push_api.UnInit();
return 0;
}
if (!start_rtsp_stream(&push_api, rtsp_server_handle, push_handle, "stream1")) {
fprintf(stderr, "start_rtsp_stream failed.\n");
goto _cleanup_;
}
if (!start_rtmp(&push_api, push_handle, "rtmp://192.168.0.107:1935/live/test1")) {
fprintf(stderr, "start_rtmp failed.\n");
goto _cleanup_;
}
// 开启预览，也可以不开启, 根据需求来
push_api.SetPreviewXWindow(push_handle, "", sub_wid);
push_api.StartPreview(push_handle, 0, nullptr);
while (!g_is_exit)
{
while (MY_X11_Pending(display, 10))
{
XEvent xev;
memset(&xev, 0, sizeof(xev));
XNextEvent(display, &xev);
if (xev.type == ConfigureNotify)
{
if (xev.xconfigure.window == main_wid)
{
if (xev.xconfigure.width != main_w || xev.xconfigure.height != main_h)
{
main_w = xev.xconfigure.width;
main_h = xev.xconfigure.height;
XMoveResizeWindow(display, sub_wid, 0, 0, main_w - 4, main_h - 4);
}
}
}
else if (xev.type == KeyPress)
{
if (xev.xkey.keycode == XKeysymToKeycode(display, XK_Escape))
{
fprintf(stdout, "ESC Key Press\n");
g_is_exit = true;
}
}
if (g_is_exit)
break;
}
}
}其中，PushSDKInit()实现如下：
/*
* publisherdemo.cpp
* Author: daniusdk.com
*/
bool PushSDKInit(NT_SmartPublisherSDKAPI& push_api)
{
memset(&push_api, 0, sizeof(push_api));
NT_GetSmartPublisherSDKAPI(&push_api);
auto ret = push_api.Init(0, nullptr);
if (NT_ERC_OK != ret)
{
fprintf(stderr, "push_api.Init failed!\n");
return false;
}
else
{
fprintf(stdout, "push_api.Init ok!\n");
}
return true;
}open_config_instance()实现如下，可以获取摄像头或屏幕数据，并做基础的编码等参数配置，看似复杂，实际和Windows平台相差不大：
NT_HANDLE open_config_instance(NT_SmartPublisherSDKAPI* push_api, int dst_fps) {
NT_INT32 pulse_device_number = 0;
if (NT_ERC_OK == push_api->GetAuidoInputDeviceNumber(2, &pulse_device_number))
{
fprintf(stdout, "[daniusdk.com]Pulse device num:%d\n", pulse_device_number);
char device_name[512];
for (auto i = 0; i < pulse_device_number; ++i)
{
if (NT_ERC_OK == push_api->GetAuidoInputDeviceName(2, i, device_name, 512))
{
fprintf(stdout, "[daniusdk.com]index:%d name:%s\n", i, device_name);
}
}
}
NT_INT32 alsa_device_number = 0;
if (pulse_device_number < 1)
{
if (NT_ERC_OK == push_api->GetAuidoInputDeviceNumber(1, &alsa_device_number))
{
fprintf(stdout, "Alsa device num:%d\n", alsa_device_number);
char device_name[512];
for (auto i = 0; i < alsa_device_number; ++i)
{
if (NT_ERC_OK == push_api->GetAuidoInputDeviceName(1, i, device_name, 512))
{
fprintf(stdout, "[daniusdk.com]index:%d name:%s\n", i, device_name);
}
}
}
}
NT_INT32 capture_speaker_flag = 0;
if (NT_ERC_OK == push_api->IsCanCaptureSpeaker(2, &capture_speaker_flag))
{
if (capture_speaker_flag)
fprintf(stdout, "[daniusdk.com]Support speaker capture\n");
else
fprintf(stdout, "[daniusdk.com]UnSupport speaker capture\n");
}
NT_INT32 is_support_window_capture = 0;
if (NT_ERC_OK == push_api->IsCaptureXWindowSupported(NULL, &is_support_window_capture))
{
if (is_support_window_capture)
fprintf(stdout, "[daniusdk.com]Support window capture\n");
else
fprintf(stdout, "[daniusdk.com]UnSupport window capture\n");
}
if (is_support_window_capture)
{
NT_INT32 win_count = 0;
if (NT_ERC_OK == push_api->UpdateCaptureXWindowList(NULL, &win_count) && win_count > 0)
{
fprintf(stdout, "X Capture Winows list++\n");
for (auto i = 0; i < win_count; ++i)
{
NT_UINT64 wid;
char title[512];
if (NT_ERC_OK == push_api->GetCaptureXWindowInfo(i, &wid, title, sizeof(title) / sizeof(char)))
{
x_win_list.push_back(wid);
fprintf(stdout, "wid:%llu, title:%s\n", wid, title);
}
}
fprintf(stdout, "[daniusdk.com]X Capture Winows list--\n");
}
}
std::vector<CameraInfo> cameras;
GetCameraInfo(push_api, cameras);
if (!cameras.empty())
{
fprintf(stdout, "cameras count:%d\n", (int)cameras.size());
for (const auto& c : cameras)
{
fprintf(stdout, "camera name:%s, id:%s, cap_num:%d\n", c.name_.c_str(), c.id_.c_str(), (int)c.capabilities_.size());
for (const auto& i : c.capabilities_)
{
fprintf(stdout, "[daniusdk.com]cap w:%d, h:%d, fps:%d\n", i.width_, i.height_, i.max_frame_rate_);
}
}
}
NT_UINT32 auido_option = NT_PB_E_AUDIO_OPTION_NO_AUDIO;
if (pulse_device_number > 0 || alsa_device_number > 0)
{
auido_option = NT_PB_E_AUDIO_OPTION_CAPTURE_MIC;
}
else if (capture_speaker_flag)
{
auido_option = NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER;
}
//auido_option = NT_PB_E_AUDIO_OPTION_CAPTURE_MIC_SPEAKER_MIXER;
NT_UINT32 video_option = NT_PB_E_VIDEO_OPTION_SCREEN;
if (!cameras.empty())
{
video_option = NT_PB_E_VIDEO_OPTION_CAMERA;
}
else if (is_support_window_capture)
{
video_option = NT_PB_E_VIDEO_OPTION_WINDOW;
}
// video_option = NT_PB_E_VIDEO_OPTION_LAYER;
//video_option = NT_PB_E_VIDEO_OPTION_NO_VIDEO;
NT_HANDLE push_handle = nullptr;
//if (NT_ERC_OK != push_api->Open(&push_handle, NT_PB_E_VIDEO_OPTION_LAYER, NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER, 0, NULL))
if (NT_ERC_OK != push_api->Open(&push_handle, video_option, auido_option, 0, NULL))
{
return nullptr;
}
push_api->SetEventCallBack(push_handle, nullptr, OnSDKEventHandle);
//push_api->SetXDisplayName(push_handle, ":0");
//push_api->SetXDisplayName(push_handle, NULL);
// 视频层配置方式
if (NT_PB_E_VIDEO_OPTION_LAYER == video_option)
{
std::vector<std::shared_ptr<nt_pb_sdk::layer_conf_wrapper_base> > layer_confs;
auto index = 0;
//// 第0层填充RGBA矩形, 目的是保证帧率, 颜色就填充全黑
auto rgba_layer_c0 = std::make_shared<nt_pb_sdk::RGBARectangleLayerConfigWrapper>(index++, true, 0, 0, 1280, 720);
rgba_layer_c0->conf_.red_ = 200;
rgba_layer_c0->conf_.green_ = 200;
rgba_layer_c0->conf_.blue_ = 200;
rgba_layer_c0->conf_.alpha_ = 255;
layer_confs.push_back(rgba_layer_c0);
////// 第一层为桌面层
//auto screen_layer_c1 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapper>(index++, true, 0, 0, 1280, 720);
//screen_layer_c1->conf_.scale_filter_mode_ = 3;
//layer_confs.push_back(screen_layer_c1);
//// 第一层为窗口
if (!x_win_list.empty())
{
auto window_layer_c1 = std::make_shared<nt_pb_sdk::WindowLayerConfigWrapper>(index++, true, 0, 0, 640, 360);
window_layer_c1->conf_.xwindow_ = x_win_list.back();
layer_confs.push_back(window_layer_c1);
}
//// 摄像头层
if (!cameras.empty())
{
auto camera_layer_c1 = std::make_shared<nt_pb_sdk::CameraLayerConfigWrapper>(index++, true,
640, 0, 640, 360);
strcpy(camera_layer_c1->conf_.device_unique_id_, cameras.front().id_.c_str());
camera_layer_c1->conf_.is_flip_horizontal_ = 0;
camera_layer_c1->conf_.is_flip_vertical_ = 0;
camera_layer_c1->conf_.rotate_degress_ = 0;
layer_confs.push_back(camera_layer_c1);
if (cameras.size() > 1)
{
auto camera_layer_c2 = std::make_shared<nt_pb_sdk::CameraLayerConfigWrapper>(index++, true,
640, 0, 320, 240);
strcpy(camera_layer_c2->conf_.device_unique_id_, cameras.back().id_.c_str());
camera_layer_c2->conf_.is_flip_horizontal_ = 0;
camera_layer_c2->conf_.is_flip_vertical_ = 0;
camera_layer_c2->conf_.rotate_degress_ = 0;
layer_confs.push_back(camera_layer_c2);
}
}
auto image_layer1 = std::make_shared<nt_pb_sdk::ImageLayerConfigWrapper>(index++, true, 650, 120, 324, 300);
strcpy(image_layer1->conf_.file_name_utf8_, "./testpng/tca.png");
layer_confs.push_back(image_layer1);
auto image_layer2 = std::make_shared<nt_pb_sdk::ImageLayerConfigWrapper>(index++, true, 120, 380, 182, 138);
strcpy(image_layer2->conf_.file_name_utf8_, "./testpng/t4.png");
layer_confs.push_back(image_layer2);
std::vector<const NT_PB_LayerBaseConfig* > layer_base_confs;
for (const auto& i : layer_confs)
{
layer_base_confs.push_back(i->getBase());
}
if (NT_ERC_OK != push_api->SetLayersConfig(push_handle, 0, layer_base_confs.data(),
layer_base_confs.size(), 0, nullptr))
{
push_api->Close(push_handle);
push_handle = nullptr;
return nullptr;
}
}
// push_api->SetScreenClip(push_handle, 0, 0, 1280, 720);
if (video_option == NT_PB_E_VIDEO_OPTION_CAMERA)
{
if (!cameras.empty())
{
push_api->SetVideoCaptureDeviceBaseParameter(push_handle, cameras.front().id_.c_str(),
640, 480);
//push_api->FlipVerticalCamera(push_handle, 1);
//push_api->FlipHorizontalCamera(push_handle, 1);
//push_api->RotateCamera(push_handle, 0);
}
}
if (video_option == NT_PB_E_VIDEO_OPTION_WINDOW)
{
if (!x_win_list.empty())
{
//push_api->SetCaptureXWindow(push_handle, x_win_list[0]);
push_api->SetCaptureXWindow(push_handle, x_win_list.back());
}
}
push_api->SetFrameRate(push_handle, dst_fps); // 帧率设置
push_api->SetVideoEncoder(push_handle, 0, 1, NT_MEDIA_CODEC_ID_H264, 0);
push_api->SetVideoBitRate(push_handle, 2000); // 平均码率2000kbps
push_api->SetVideoQuality(push_handle, 26);
push_api->SetVideoMaxBitRate(push_handle, 4000); // 最大码率4000kbps
// openh264 配置特定参数
push_api->SetVideoEncoderSpecialInt32Option(push_handle, "usage_type", 0); //0是摄像头编码, 1是屏幕编码
push_api->SetVideoEncoderSpecialInt32Option(push_handle, "rc_mode", 1); // 0是质量模式, 1是码率模式
push_api->SetVideoEncoderSpecialInt32Option(push_handle, "enable_frame_skip", 0); // 0是关闭跳帧, 1是打开跳帧
push_api->SetVideoKeyFrameInterval(push_handle, dst_fps * 2); // 关键帧间隔
push_api->SetVideoEncoderProfile(push_handle, 3); // H264 high
push_api->SetVideoEncoderSpeed(push_handle, 3); // 编码速度设置到3
if (pulse_device_number > 0)
{
push_api->SetAudioInputLayer(push_handle, 2);
push_api->SetAuidoInputDeviceId(push_handle, 0);
}
else if (alsa_device_number > 0)
{
push_api->SetAudioInputLayer(push_handle, 1);
push_api->SetAuidoInputDeviceId(push_handle, 0);
}
push_api->SetEchoCancellation(push_handle, 1, 0);
push_api->SetNoiseSuppression(push_handle, 1);
push_api->SetAGC(push_handle, 1);
push_api->SetVAD(push_handle, 1);
push_api->SetInputAudioVolume(push_handle, 0, 1.0);
push_api->SetInputAudioVolume(push_handle, 1, 0.2);
// 音频配置
push_api->SetPublisherAudioCodecType(push_handle, 1);
//push_api->SetMute(push_handle, 1);
return push_handle;
}其中，push_api->Open(&push_handle, video_option, auido_option, 0, NULL))时，设置音视频采集类型，相关类型如下：
/*
* nt_smart_publisher_define.h
* Author: daniusdk.com
*/
/*定义Video源选项*/
typedef enum _NT_PB_E_VIDEO_OPTION
{
NT_PB_E_VIDEO_OPTION_NO_VIDEO = 0x0,
NT_PB_E_VIDEO_OPTION_SCREEN = 0x1, // 采集屏幕
NT_PB_E_VIDEO_OPTION_CAMERA = 0x2, // 摄像头采集
NT_PB_E_VIDEO_OPTION_LAYER = 0x3, // 视频合并，比如桌面叠加摄像头等
NT_PB_E_VIDEO_OPTION_ENCODED_DATA = 0x4, // 已经编码的视频数据，目前支持H264
NT_PB_E_VIDEO_OPTION_WINDOW = 0x5, // 采集窗口
} NT_PB_E_VIDEO_OPTION;
/*定义Auido源选项*/
typedef enum _NT_PB_E_AUDIO_OPTION
{
NT_PB_E_AUDIO_OPTION_NO_AUDIO = 0x0,
NT_PB_E_AUDIO_OPTION_CAPTURE_MIC = 0x1, // 采集麦克风音频
NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER = 0x2, // 采集扬声器
NT_PB_E_AUDIO_OPTION_CAPTURE_MIC_SPEAKER_MIXER = 0x3, // 麦克风扬声器混音
NT_PB_E_AUDIO_OPTION_ENCODED_DATA = 0x4, // 编码后的音频数据，目前支持AAC, speex宽带(wideband mode)
NT_PB_E_AUDIO_OPTION_EXTERNAL_PCM_DATA = 0x5, /*外部PCM数据*/
NT_PB_E_AUDIO_OPTION_MIC_EXTERNAL_PCM_MIXER = 0x6, /* 麦克风和外部PCM数据混音 当前只支持一路外部音频和内置麦克风混音*/
NT_PB_E_AUDIO_OPTION_TWO_EXTERNAL_PCM_MIXER = 0x7, /* 两路外部PCM数据混音*/
} NT_PB_E_AUDIO_OPTION;推送RTMP流：
bool start_rtmp(NT_SmartPublisherSDKAPI* push_api, NT_HANDLE handle, const std::string& rtmp_url) {
if (NT_ERC_OK != push_api->SetURL(handle, rtmp_url.c_str(), NULL))
return false;
if (NT_ERC_OK != push_api->StartPublisher(handle, NULL))
return false;
return true;
}如果需要本地摄像头或者屏幕预览数据，调研预览接口即可：
// 开启预览，也可以不开启, 根据需求来
push_api.SetPreviewXWindow(push_handle, "", sub_wid);
push_api.StartPreview(push_handle, 0, nullptr);如需停止：
fprintf(stdout, "Skip run loop, is_exit:%d\n", g_is_exit);
fprintf(stdout, "StopRtspStream++\n");
push_api.StopRtspStream(push_handle);
fprintf(stdout, "StopRtspStream--\n");
fprintf(stdout, "stop_rtsp_server++\n");
stop_rtsp_server(&push_api, rtsp_server_handle);
fprintf(stdout, "stop_rtsp_server--\n");
push_api.StopPreview(push_handle);
push_api.StopPublisher(push_handle);
push_api.Close(push_handle);
push_handle = nullptr;
XDestroyWindow(display, sub_wid);
XDestroyWindow(display, main_wid);
XCloseDisplay(display);
push_api.UnInit();
fprintf(stdout, "SDK UnInit..\n");
return 0;总结
FFmpeg是一个开源的多媒体处理工具，支持几乎所有的音视频格式和编码标准，包括常见的H.264、AAC等，这使其在处理不同来源的音视频数据时具有极高的灵活性。并提供了丰富的编解码器选项，用户可根据需求选择合适的编解码器进行音视频数据的压缩和解压，从而优化传输效率和播放质量。大牛直播SDK针对Linux平台x86_64架构和aarch64架构的RTMP推送模块，系SDK，功能更完备，更适合产品化集成，配合自研的SmartPlayer RTMP播放器，延迟可达150-400ms，扩展性更强，以上是二者比较，抛砖引玉，感兴趣的开发者，可以单独跟我沟通。
