长沙网络推广小公司,seo关键词挖掘工具,wordpress医院,visual composer wordpress 汉化这里写目录标题 前言个人的总结v4l2src插件的简单使用 前言
因为涉及很多细节的GStreamer官方论坛有详细解链接: GStreamer官网#xff0c;这里不做说明#xff0c;以下只是涉及到个人的理解和认知#xff0c;方便后续的查阅。 个人的总结
1)了解pipeline的使用#xff0… 这里写目录标题 前言个人的总结v4l2src插件的简单使用 前言
因为涉及很多细节的GStreamer官方论坛有详细解链接: GStreamer官网这里不做说明以下只是涉及到个人的理解和认知方便后续的查阅。 个人的总结
1)了解pipeline的使用简单说就是通道的概念, 因为涉及到数据的复用和拓展 里面有一个filter(tee插件), 通过tee和后续拓展 的绑定关系复用数据很像许多Soc编解码芯片中的vpss通道的概念。 数据复用为视频编码通道 数据jpeg通道以及对数据处理的通道。
2)重点是去了解Pad Templates 中的Availability,这个关系到link的方式另外关注Element Properties的属性设置。
3)工作使用最多的不是作为播放器而是将采集数据获取后做后续的图像处理因此以下是从v4l2src插件中获取到数据的方式 4)GStreamer复用的拓展性导致其复杂性, 还涉及到glib的学习因此学习成本还是比较高的 但现主流的流媒体芯片或边缘化芯片大部分都用到GStreamer 比如NVIDIA和瑞芯微,特别是瑞芯微直接将GStreamer作为框架增加自己的硬编解码。 5) GStreamer的许多控件非常适合拓展 比如推流rtp/rtsp/rtmp/webrtc开发非常快但走API这套的调试以及对API的理解和学习周期比较长。 这里只花了3天时间学习 做一个记录。
v4l2src插件的简单使用
/*** brief 实现从v4l2src中拿到数据,方便后续数据的操作比如用作重新硬编解码用appsink关键属性 emit-signals默认是关闭emit-signals : Emit new-preroll and new-sample signalsflags: readable, writableBoolean. Default: falseElement Signals:eos : void user_function (GstElement* object,gpointer user_data);new-preroll : GstFlowReturn user_function (GstElement* object,gpointer user_data);new-sample : GstFlowReturn user_function (GstElement* object,gpointer user_data);Element Actions:pull-preroll : GstSample * user_function (GstElement* object);pull-sample : GstSample * user_function (GstElement* object);try-pull-preroll : GstSample * user_function (GstElement* object,guint64 arg0);try-pull-sample : GstSample * user_function (GstElement* object,guint64 arg0);*/
#include unistd.h
#include gst/gst.h
#include pthread.h#include time.h
#include sys/time.h#define TEST_MODULE//#define VIDEO_X_RAWtypedef struct ExtraCtrl_
{int s32brightness;int s32Contrast;int s32Saturation;int s32Hue;int s32Sharpness;}Extra_Ctrl_S;/*
* brief 设置ISP图像质量主要是图像增强类prams[in] source - SRC plugin extraCtrl - 外部的图像喜好return nulltest:1. 通过inspect查看插件支持的图像属性有哪些
*/
void setCameraQuality(GstElement *source, const Extra_Ctrl_S *extraCtrl)
{g_object_set(source, do-timestamp, TRUE, NULL);
#if 0GstStructure* extraCtrls gst_structure_new(logitech_controls,brightness, extraCtrl-s32brightness,contrast, G_TYPE_INT, extraCtrl-s32Contrast,saturation, G_TYPE_INT, extraCtrl-s32Saturation,hue, G_TYPE_INT, extraCtrl-s32Hue,sharpness, G_TYPE_INT, extraCtrl-s32Sharpness,// focus_auto, G_TYPE_BOOLEAN, FALSE,// white_balance_temperature_auto, G_TYPE_BOOLEAN, FALSE,// white_balance_temperature, G_TYPE_INT, 3500,NULL);
#else /*gst-1.0 无sharpness默认值 brightness 0 hue 0 contrast 36 saturation:54*/int brightness 1, hue 1, contrast 1, saturation 1;g_object_get(source , brightness, brightness, hue, hue, contrast, contrast, saturation, saturation, NULL);g_print(get: brightness:%d, hue:%d, contrast:%d, saturation:%d\n, brightness, hue, contrast, saturation);#if 1int setBrightness 0;GstStructure* extraCtrls gst_structure_new(logitech_controls,brightness, G_TYPE_INT, brightness ,hue, G_TYPE_INT, hue,contrast, G_TYPE_INT, contrast,saturation, G_TYPE_INT, saturation,//160,NULL);g_object_set(source, extra-controls , extraCtrls, NULL);#endif
#endif g_object_get(source , brightness, brightness, hue, hue, contrast, contrast, saturation, saturation, NULL);g_print(get: brightness:%d, hue:%d, contrast:%d, saturation:%d\n, brightness, hue, contrast, saturation);
}TEST_MODULE void *ispCtlProc(void *arg)
{while(1){GstElement * element (GstElement*)arg;if(element){static int rec 0;g_print(rec:%d\n, rec);Extra_Ctrl_S s;memset(s, 0, sizeof(s));static int count 0;s.s32brightness count % 255;s.s32Contrast 128;s.s32Saturation 128;s.s32Hue 128;s.s32Sharpness 128;setCameraQuality(element, s);}usleep(1000*100);}return NULL;
}/*brief 原始数据回调
*/
GstFlowReturn cb_appsink_new_sample(GstElement* appsink, gpointer user_data){// LOG_INFO_MSG (cb_appsink_new_sample called, user data: %p, user_data);
#if 0SinkPipeline* sp reinterpret_castSinkPipeline* (user_data);
#endifGstSample* sample NULL;GstBuffer* buffer NULL;GstMapInfo map;const GstStructure* info NULL;GstCaps* caps NULL;GstFlowReturn ret GST_FLOW_OK;int sample_width 0;int sample_height 0;// equals to gst_app_sink_pull_sample (GST_APP_SINK_CAST (appsink), sample);g_signal_emit_by_name (appsink, pull-sample, sample, ret);if (ret ! GST_FLOW_OK) {g_print (cant pull GstSample.\n);return ret;}if (sample) {buffer gst_sample_get_buffer (sample);if ( buffer NULL ) {g_print (get buffer is null\n);goto exit;}gboolean mapret gst_buffer_map (buffer, map, GST_MAP_READ);if(mapret FALSE){goto exit;}/**/caps gst_sample_get_caps (sample);if ( caps NULL ) {g_print (get caps is null\n);goto exit;}info gst_caps_get_structure (caps, 0);if ( info NULL ) {g_print (get info is null\n);goto exit;}// -------- Read frame and convert to opencv format --------// convert gstreamer data to OpenCV Mat, you could actually// resolve height / width from caps...gst_structure_get_int (info, width, sample_width);gst_structure_get_int (info, height, sample_height);g_print(format:%s, width:%d, height:%d\n, gst_structure_get_string(info, format), sample_width, sample_height);if(NULL map.data){g_print(appsink buffer data empty\n);goto exit;} static struct timeval s, e;static int flag 1;if(flag){gettimeofday(s, 0); e s;flag 0;}gettimeofday(e, 0);static int frameNo 0;frameNo;unsigned int timespan (e.tv_sec - s.tv_sec )*1000*1000 e.tv_usec - s.tv_usec;if(timespan 1000000){g_print(frame siz:%d, max_siz:%d, %02d FPS\n, map.size, map.maxsize, frameNo);frameNo 0;gettimeofday(s, 0);}//FILE *fp
#if 0// customized user action{// init a cv::Mat with gst buffer address: deep copy// sometime you may got a empty bufferif (map.data NULL) {LOG_ERROR_MSG(appsink buffer data empty\n);return GST_FLOW_OK;}cv::Mat img (sample_height, sample_width, CV_8UC3,(unsigned char*)map.data, cv::Mat::AUTO_STEP);img img.clone();// redirection outside operation: for decoupling useif (sp-m_putDataFunc) {sp-m_putDataFunc(std::make_sharedcv::Mat (img),sp-m_putDataArgs);} else {goto exit;}}#endifexit:if (buffer) {gst_buffer_unmap (buffer, map);}if (sample) {gst_sample_unref (sample);}return GST_FLOW_OK;}}
/*brief 创造线程设置图像数据 TEST 模块
*/
TEST_MODULE int ispInit(GstElement *source)
{int ret 0;pthread_t ispControlThread;pthread_create(ispControlThread, 0, ispCtlProc, (void *)source);
}int main(int argc, char *argv[])
{GstElement *pipeline, *source;GstElement *converter,*appsink; GstBus *bus;GstMessage *msg;/* Initialize GStreamer */gst_init (argc, argv);/* Create the elements *//*src(always)*/source gst_element_factory_make (v4l2src, v4l2src);converter gst_element_factory_make(videoconvert,converter01);//sinkappsink gst_element_factory_make(appsink, appsink);/* Create the empty pipeline */pipeline gst_pipeline_new (test-pipeline);if ( !pipeline || !source || !appsink ) {g_printerr (Not all elements could be created.\n);return -1;}// set appsink
g_object_set(appsink, emit-signals, TRUE, NULL);g_signal_connect (appsink, new-sample, G_CALLBACK (cb_appsink_new_sample), NULL);/* Link all elements that can be automatically linked because they have Always pads */gst_bin_add_many (GST_BIN (pipeline), source, converter, appsink, NULL);// TEST_MODULE ispInit(source); /*note:1. 需要在gst_bin_add_many之后调用先需要知道摄像头支持的Pixel Format,通过命令可查v4l2-ctl --list-formats-ext --device /dev/video0可以查看支持的格式只有YUYV和MJPG,另外可以查看到具体的分辨率和帧率
*/
#if defined(VIDEO_X_RAW)GstCaps *caps gst_caps_new_simple (video/x-raw, // format, G_TYPE_STRING, YV12, // IF THIS IS SET TO ARGB (THE FORMAT I WANT IT FAILS ON LINKING) // format, G_TYPE_STRING, NV21,framerate, GST_TYPE_FRACTION, 25, 1, // pixel-aspect-ratio, GST_TYPE_FRACTION, 1, 1, width, G_TYPE_INT, 320, height, G_TYPE_INT, 240, NULL);
#elseGstCaps *caps gst_caps_new_simple (video/mpeg, mpegversion, G_TYPE_INT, 2,systemstream, G_TYPE_BOOLEAN, TRUE,NULL); #endif gst_element_link_filtered(source, converter, caps);gst_caps_unref(caps);/*这里做了转换需要逐一连接*/gst_element_link(source, converter);gst_element_link(converter, appsink);/* Start playing the pipeline */gst_element_set_state (pipeline, GST_STATE_PLAYING);/* Wait until error or EOS */bus gst_element_get_bus (pipeline);msg gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE, GST_MESSAGE_ERROR | GST_MESSAGE_EOS);if(msg ! NULL)
{GError *err;gchar *debug_info;switch (GST_MESSAGE_TYPE (msg)) {case GST_MESSAGE_ERROR:gst_message_parse_error (msg, err, debug_info);g_printerr (Error received from element %s: %s\n,GST_OBJECT_NAME (msg-src), err-message);g_printerr (Debugging information: %s\n,debug_info ? debug_info : none);g_clear_error (err);g_free (debug_info);break;case GST_MESSAGE_EOS:g_print (End-Of-Stream reached.\n);break;default:/* We should not reach here because we only asked for ERRORs and EOS */g_printerr (Unexpected message received.\n);break;}gst_message_unref (msg);
}else
{g_printerr(error.);
}/* Release the request pads from the Tee, and unref them *//* Free resources */if (msg ! NULL)gst_message_unref (msg);gst_object_unref (bus);gst_element_set_state (pipeline, GST_STATE_NULL);gst_object_unref (pipeline);return 0;
}
编译:
cmake_minimum_required(VERSION 3.0)
project(test_project)find_package(PkgConfig REQUIRED)
pkg_search_module(GST1 REQUIRED gstreamer-1.0)#查找到gstreamer-1.0 并用GST1代表GST1自己定义add_executable(a.out v4l2src_appsink.c)target_include_directories(a.out PRIVATE ${GST1_INCLUDE_DIRS})
target_link_libraries(a.out ${GST1_LIBRARIES} -lpthread)message(GST1_LIBRARIES
${GST1_LIBRARIES}
)运行结果
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
frame siz:4147200, max_siz:4147200, 07 FPS
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
format:YUY2, width:1920, height:1080
