jellyfin/Jellyfin.Api/Helpers/HlsHelpers.cs
2021-07-12 20:21:51 +02:00

140 lines
5.8 KiB
C#

using System;
using System.Globalization;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Api.Models.StreamingDtos;
using MediaBrowser.Controller.MediaEncoding;
using MediaBrowser.Model.IO;
using Microsoft.Extensions.Logging;
namespace Jellyfin.Api.Helpers
{
/// <summary>
/// The hls helpers.
/// </summary>
public static class HlsHelpers
{
/// <summary>
/// Waits for a minimum number of segments to be available.
/// </summary>
/// <param name="playlist">The playlist string.</param>
/// <param name="segmentCount">The segment count.</param>
/// <param name="logger">Instance of the <see cref="ILogger"/> interface.</param>
/// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
/// <returns>A <see cref="Task"/> indicating the waiting process.</returns>
public static async Task WaitForMinimumSegmentCount(string playlist, int? segmentCount, ILogger logger, CancellationToken cancellationToken)
{
logger.LogDebug("Waiting for {0} segments in {1}", segmentCount, playlist);
while (!cancellationToken.IsCancellationRequested)
{
try
{
// Need to use FileShare.ReadWrite because we're reading the file at the same time it's being written
var fileStream = new FileStream(
playlist,
FileMode.Open,
FileAccess.Read,
FileShare.ReadWrite,
IODefaults.FileStreamBufferSize,
FileOptions.SequentialScan);
await using (fileStream.ConfigureAwait(false))
{
using var reader = new StreamReader(fileStream);
var count = 0;
while (!reader.EndOfStream)
{
var line = await reader.ReadLineAsync().ConfigureAwait(false);
if (line == null)
{
// Nothing currently in buffer.
break;
}
if (line.IndexOf("#EXTINF:", StringComparison.OrdinalIgnoreCase) != -1)
{
count++;
if (count >= segmentCount)
{
logger.LogDebug("Finished waiting for {0} segments in {1}", segmentCount, playlist);
return;
}
}
}
}
await Task.Delay(100, cancellationToken).ConfigureAwait(false);
}
catch (IOException)
{
// May get an error if the file is locked
}
await Task.Delay(50, cancellationToken).ConfigureAwait(false);
}
}
/// <summary>
/// Gets the #EXT-X-MAP string.
/// </summary>
/// <param name="outputPath">The output path of the file.</param>
/// <param name="state">The <see cref="StreamState"/>.</param>
/// <param name="isOsDepends">Get a normal string or depends on OS.</param>
/// <returns>The string text of #EXT-X-MAP.</returns>
public static string GetFmp4InitFileName(string outputPath, StreamState state, bool isOsDepends)
{
var directory = Path.GetDirectoryName(outputPath) ?? throw new ArgumentException($"Provided path ({outputPath}) is not valid.", nameof(outputPath));
var outputFileNameWithoutExtension = Path.GetFileNameWithoutExtension(outputPath);
var outputPrefix = Path.Combine(directory, outputFileNameWithoutExtension);
var outputExtension = EncodingHelper.GetSegmentFileExtension(state.Request.SegmentContainer);
// on Linux/Unix
// #EXT-X-MAP:URI="prefix-1.mp4"
var fmp4InitFileName = outputFileNameWithoutExtension + "-1" + outputExtension;
if (!isOsDepends)
{
return fmp4InitFileName;
}
if (OperatingSystem.IsWindows())
{
// on Windows
// #EXT-X-MAP:URI="X:\transcodes\prefix-1.mp4"
fmp4InitFileName = outputPrefix + "-1" + outputExtension;
}
return fmp4InitFileName;
}
/// <summary>
/// Gets the hls playlist text.
/// </summary>
/// <param name="path">The path to the playlist file.</param>
/// <param name="state">The <see cref="StreamState"/>.</param>
/// <returns>The playlist text as a string.</returns>
public static string GetLivePlaylistText(string path, StreamState state)
{
var text = File.ReadAllText(path);
var segmentFormat = EncodingHelper.GetSegmentFileExtension(state.Request.SegmentContainer).TrimStart('.');
if (string.Equals(segmentFormat, "mp4", StringComparison.OrdinalIgnoreCase))
{
var fmp4InitFileName = GetFmp4InitFileName(path, state, true);
var baseUrlParam = string.Format(
CultureInfo.InvariantCulture,
"hls/{0}/",
Path.GetFileNameWithoutExtension(path));
var newFmp4InitFileName = baseUrlParam + GetFmp4InitFileName(path, state, false);
// Replace fMP4 init file URI.
text = text.Replace(fmp4InitFileName, newFmp4InitFileName, StringComparison.InvariantCulture);
}
return text;
}
}
}