ServingVideo.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using System.IO;
using Microsoft.AspNetCore.Hosting;

namespace VideoServing.Controllers
{
    [Route("api/[controller]")]
    public class VideoController : Controller
    {
        private IHostingEnvironment _evn;
        public VideoController(IHostingEnvironment env)
        {
            _evn = env;
        }
        // GET api/values
        [HttpGet]
        public async Task Get()
        {
            const int PART_SIZE = 0x100000;

            var fileLocation = "/home/vzota/lotr.mp4";
            if (_evn.IsDevelopment())
            {
                fileLocation = "C:/users/admin/1.mp4";
            }
            Response.ContentType = "video/mp4";
            Response.Headers["Accept-Ranges"] = "bytes";
            Stream file = new FileStream(fileLocation, FileMode.Open, FileAccess.Read, FileShare.Read, PART_SIZE);
            string rangeRequest = Request.Headers["Range"];
            long start = 0L;
            long end = Math.Min(PART_SIZE, file.Length);
            if (!string.IsNullOrEmpty(rangeRequest))
            {
                var byteIndex = rangeRequest.ToLower().IndexOf("bytes=");
                if (byteIndex != -1)
                {
                    var pr = rangeRequest.Substring("bytes=".Length);
                    var split = pr.Split('-');
                    start = int.Parse(split[0]);
                    if (split.Length > 1 && !string.IsNullOrEmpty(split[1]))
                        end = int.Parse(split[1]);
                    else
                        end = Math.Min(start + PART_SIZE, file.Length);
                }
                if (start > file.Length || end > file.Length)
                {
                    Response.StatusCode = 416;
                    return;
                }
            }else
            {
                Response.StatusCode = 200;
                return;
            }

            file.Seek(start, SeekOrigin.Begin);
            var contentLength = end - start;
            if (contentLength < PART_SIZE)
            {
                Response.Cookies.Append("hehe", "huhu");
            }
            Response.ContentLength = contentLength;
            Response.StatusCode = 206;
            Response.Headers["Content-Range"] = $"bytes {start}-{end}/{file.Length}";
            byte[] buffer = new byte[0x1000];
            var wrote = 0;

            if (end == file.Length)
            {
                await file.CopyToAsync(Response.Body);
            }
            else
                while (wrote < Response.ContentLength)
                {
                    var read = await file.ReadAsync(buffer, 0, 4096);
                    await Response.Body.WriteAsync(buffer, 0, read);
                    wrote += read;
                }
            Response.Body.Flush();
        }
    }
}