jellyfin/Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs
gnattu 5df171b3f9 Add remuxing support for VP9
Add VP9 as a valid HLS format to enable remuxing. This is useful when audio processing is required, but the VP9 video can be passed as-is to avoid unnecessary video transcoding.

No VP9 encoder is enabled and should not be enabled. AV1 and HEVC should be preferred over VP9 if video transcoding is required.

Signed-off-by: gnattu <gnattuoc@me.com>
2024-05-16 09:34:21 +08:00

305 lines
8.8 KiB
C#

using System;
using System.Globalization;
using System.Text;
namespace Jellyfin.Api.Helpers;
/// <summary>
/// Helpers to generate HLS codec strings according to
/// <a href="https://datatracker.ietf.org/doc/html/rfc6381#section-3.3">RFC 6381 section 3.3</a>
/// and the <a href="https://mp4ra.org">MP4 Registration Authority</a>.
/// </summary>
public static class HlsCodecStringHelpers
{
/// <summary>
/// Codec name for MP3.
/// </summary>
public const string MP3 = "mp4a.40.34";
/// <summary>
/// Codec name for AC-3.
/// </summary>
public const string AC3 = "mp4a.a5";
/// <summary>
/// Codec name for E-AC-3.
/// </summary>
public const string EAC3 = "mp4a.a6";
/// <summary>
/// Codec name for FLAC.
/// </summary>
public const string FLAC = "fLaC";
/// <summary>
/// Codec name for ALAC.
/// </summary>
public const string ALAC = "alac";
/// <summary>
/// Codec name for OPUS.
/// </summary>
public const string OPUS = "Opus";
/// <summary>
/// Gets a MP3 codec string.
/// </summary>
/// <returns>MP3 codec string.</returns>
public static string GetMP3String()
{
return MP3;
}
/// <summary>
/// Gets an AAC codec string.
/// </summary>
/// <param name="profile">AAC profile.</param>
/// <returns>AAC codec string.</returns>
public static string GetAACString(string? profile)
{
StringBuilder result = new StringBuilder("mp4a", 9);
if (string.Equals(profile, "HE", StringComparison.OrdinalIgnoreCase))
{
result.Append(".40.5");
}
else
{
// Default to LC if profile is invalid
result.Append(".40.2");
}
return result.ToString();
}
/// <summary>
/// Gets an AC-3 codec string.
/// </summary>
/// <returns>AC-3 codec string.</returns>
public static string GetAC3String()
{
return AC3;
}
/// <summary>
/// Gets an E-AC-3 codec string.
/// </summary>
/// <returns>E-AC-3 codec string.</returns>
public static string GetEAC3String()
{
return EAC3;
}
/// <summary>
/// Gets an FLAC codec string.
/// </summary>
/// <returns>FLAC codec string.</returns>
public static string GetFLACString()
{
return FLAC;
}
/// <summary>
/// Gets an ALAC codec string.
/// </summary>
/// <returns>ALAC codec string.</returns>
public static string GetALACString()
{
return ALAC;
}
/// <summary>
/// Gets an OPUS codec string.
/// </summary>
/// <returns>OPUS codec string.</returns>
public static string GetOPUSString()
{
return OPUS;
}
/// <summary>
/// Gets a H.264 codec string.
/// </summary>
/// <param name="profile">H.264 profile.</param>
/// <param name="level">H.264 level.</param>
/// <returns>H.264 string.</returns>
public static string GetH264String(string? profile, int level)
{
StringBuilder result = new StringBuilder("avc1", 11);
if (string.Equals(profile, "high", StringComparison.OrdinalIgnoreCase))
{
result.Append(".6400");
}
else if (string.Equals(profile, "main", StringComparison.OrdinalIgnoreCase))
{
result.Append(".4D40");
}
else if (string.Equals(profile, "baseline", StringComparison.OrdinalIgnoreCase))
{
result.Append(".42E0");
}
else
{
// Default to constrained baseline if profile is invalid
result.Append(".4240");
}
string levelHex = level.ToString("X2", CultureInfo.InvariantCulture);
result.Append(levelHex);
return result.ToString();
}
/// <summary>
/// Gets a H.265 codec string.
/// </summary>
/// <param name="profile">H.265 profile.</param>
/// <param name="level">H.265 level.</param>
/// <returns>H.265 string.</returns>
public static string GetH265String(string? profile, int level)
{
// The h265 syntax is a bit of a mystery at the time this comment was written.
// This is what I've found through various sources:
// FORMAT: [codecTag].[profile].[constraint?].L[level * 30].[UNKNOWN]
StringBuilder result = new StringBuilder("hvc1", 16);
if (string.Equals(profile, "main10", StringComparison.OrdinalIgnoreCase)
|| string.Equals(profile, "main 10", StringComparison.OrdinalIgnoreCase))
{
result.Append(".2.4");
}
else
{
// Default to main if profile is invalid
result.Append(".1.4");
}
result.Append(".L")
.Append(level)
.Append(".B0");
return result.ToString();
}
/// <summary>
/// Gets a VP9 codec string.
/// </summary>
/// <param name="width">Video width.</param>
/// <param name="height">Video height.</param>
/// <param name="pixelFormat">Video pixel format.</param>
/// <param name="framerate">Video framerate.</param>
/// <param name="bitDepth">Video bitDepth.</param>
/// <returns>The VP9 codec string.</returns>
public static string GetVp9String(int width, int height, string pixelFormat, float framerate, int bitDepth)
{
// refer: https://www.webmproject.org/vp9/mp4/
StringBuilder result = new StringBuilder("vp09", 13);
var profileString = pixelFormat switch
{
"yuv420p" => "00",
"yuvj420p" => "00",
"yuv422p" => "01",
"yuv444p" => "01",
"yuv420p10le" => "02",
"yuv420p12le" => "02",
"yuv422p10le" => "03",
"yuv422p12le" => "03",
"yuv444p10le" => "03",
"yuv444p12le" => "03",
_ => "00"
};
var lumaPictureSize = width * height;
var lumaSampleRate = lumaPictureSize * framerate;
var levelString = lumaPictureSize switch
{
<= 0 => "00",
<= 36864 => "10",
<= 73728 => "11",
<= 122880 => "20",
<= 245760 => "21",
<= 552960 => "30",
<= 983040 => "31",
<= 2228224 => lumaSampleRate <= 83558400 ? "40" : "41",
<= 8912896 => lumaSampleRate <= 311951360 ? "50" : (lumaSampleRate <= 588251136 ? "51" : "52"),
<= 35651584 => lumaSampleRate <= 1176502272 ? "60" : (lumaSampleRate <= 4706009088 ? "61" : "62"),
_ => "00" // This should not happen
};
if (bitDepth != 8
&& bitDepth != 10
&& bitDepth != 12)
{
// Default to 8 bits
bitDepth = 8;
}
result.Append('.').Append(profileString).Append('.').Append(levelString);
var bitDepthD2 = bitDepth.ToString("D2", CultureInfo.InvariantCulture);
result.Append('.')
.Append(bitDepthD2);
return result.ToString();
}
/// <summary>
/// Gets an AV1 codec string.
/// </summary>
/// <param name="profile">AV1 profile.</param>
/// <param name="level">AV1 level.</param>
/// <param name="tierFlag">AV1 tier flag.</param>
/// <param name="bitDepth">AV1 bit depth.</param>
/// <returns>The AV1 codec string.</returns>
public static string GetAv1String(string? profile, int level, bool tierFlag, int bitDepth)
{
// https://aomediacodec.github.io/av1-isobmff/#codecsparam
// FORMAT: [codecTag].[profile].[level][tier].[bitDepth]
StringBuilder result = new StringBuilder("av01", 13);
if (string.Equals(profile, "Main", StringComparison.OrdinalIgnoreCase))
{
result.Append(".0");
}
else if (string.Equals(profile, "High", StringComparison.OrdinalIgnoreCase))
{
result.Append(".1");
}
else if (string.Equals(profile, "Professional", StringComparison.OrdinalIgnoreCase))
{
result.Append(".2");
}
else
{
// Default to Main
result.Append(".0");
}
if (level is <= 0 or > 31)
{
// Default to the maximum defined level 6.3
level = 19;
}
if (bitDepth != 8
&& bitDepth != 10
&& bitDepth != 12)
{
// Default to 8 bits
bitDepth = 8;
}
result.Append('.')
// Needed to pad it double digits; otherwise, browsers will reject the stream.
.AppendFormat(CultureInfo.InvariantCulture, "{0:D2}", level)
.Append(tierFlag ? 'H' : 'M');
string bitDepthD2 = bitDepth.ToString("D2", CultureInfo.InvariantCulture);
result.Append('.')
.Append(bitDepthD2);
return result.ToString();
}
}