update post

Author: bitnpc

_posts/2022-05-27-hls_intro.md

@@ -92,7 +92,76 @@ Easy to integrate with existing key server infrastructure
 流程
 ![HLS_fair_play](/assets/img/post/post-2022-05-27/hls_fair_play.png){: width="972" height="589" .normal}_HLS Fair Play_
 
-## 遇到的问题
+## 推流 Demo
+Conceptually, HTTP Live Streaming consists of three parts: the server component, the distribution component, and the client software.
+In a typical configuration, a hardware encoder takes audio-video input, encodes it as HEVC video and AC-3 audio, and outputs a fragmented MPEG-4 file or an MPEG-2 transport stream. A software stream segmenter then breaks the stream into a series of short media files, which are placed on a web server. The segmenter also creates and maintains an index file containing a list of the media files. The URL of the index file is published on the web server. Client software reads the index, then requests the listed media files in order and displays them without any pauses or gaps between segments.
+
+### 下载工具
+下载地址: https://developer.apple.com/download/all/?q=HLS
+
+安装完发现有个 `go` 的 `example`
+![HLS_go_server](/assets/img/post/post-2022-05-27/hls_go_server.png){: width="972" height="589" .normal}_HLS Go Server_
+`brew install go`，安装 `go`，然后启动该服务
+
+```bash
+# tony @ tonyMBP in ~/Desktop/hls_server [14:48:18]
+$ go run ll-hls-origin-example.go
+ll-hls-origin-example.go:43:2: no required module provides package github.com/fsnotify/fsnotify: go.mod file not found in current directory or any parent directory; see 'go help modules'
+
+
+# tony @ tonyMBP in ~/Desktop/hls_server [14:48:25] C:1
+$ go mod init hls_server
+go: creating new go.mod: module hls_server
+go: to add module requirements and sums:
+        go mod tidy
+        
+        
+# tony @ tonyMBP in ~/Desktop/hls_server [14:49:23]
+$ go build
+ll-hls-origin-example.go:43:2: no required module provides package github.com/fsnotify/fsnotify; to add it:
+        go get github.com/fsnotify/fsnotify
+        
+        
+# tony @ tonyMBP in ~/Desktop/hls_server [14:49:28] C:1
+$ go get github.com/fsnotify/fsnotify
+go: downloading github.com/fsnotify/fsnotify v1.5.4
+go: downloading golang.org/x/sys v0.0.0-20220412211240-33da011f77ad
+go: added github.com/fsnotify/fsnotify v1.5.4
+go: added golang.org/x/sys v0.0.0-20220412211240-33da011f77ad
+
+
+# tony @ tonyMBP in ~/Desktop/hls_server [14:49:48]
+$ go run ll-hls-origin-example.go
+Listening on http://:8443/
+```
+### 启动 mediastreamsegmenter 服务
+```bash
+$ mediastreamsegmenter -w 499 -t 1 224.0.0.50:9121 -s 16 -D -T -f ~/Desktop/hls_server/hls
+```
+
+### 使用 ffmpeg 推流
+1. 使用 mac 内置采集设备
+```bash
+$ ffmpeg -f avfoundation -list_devices true -i ""
+
+[AVFoundation indev @ 0x7f924d904400] AVFoundation video devices:
+[AVFoundation indev @ 0x7f924d904400] [0] FaceTime高清摄像头（内建）
+[AVFoundation indev @ 0x7f924d904400] [1] Capture screen 0
+[AVFoundation indev @ 0x7f924d904400] AVFoundation audio devices:
+[AVFoundation indev @ 0x7f924d904400] [0] LarkAudioDevice
+[AVFoundation indev @ 0x7f924d904400] [1] 外置麦克风
+[AVFoundation indev @ 0x7f924d904400] [2] MacBook Pro麦克风  
+
+
+$ ffmpeg -f avfoundation -framerate 30 -pixel_format uyvy422 -i "0:" -c:v h264 -fflags nobuffer -tune zerolatency -f mpegts udp://192.168.1.5:9121
+```
+
+2. 使用指定文件
+```bash
+$ ffmpeg -re -i "/Users/tony/Downloads/sample.mp4" -c:v h264 -fflags nobuffer -tune zerolatency -f mpegts udp://192.168.1.5:9121
+```
+
+## 疑难问题
 1. `seek` 不准确如何解决？
 `mp4` 可以 `seek` 到指定的时间戳， `ts` 是 `seek` 到文件的某个 `position`，而不能直接 `seek` 到指定的时间点。
 在 `ffplay.c` 中的 `event_loop` 函数中包含了 `seek` 的相关代码。