Module: M3u8::Codecs

Defined in:
lib/m3u8/codecs.rb

Overview

Codec lookup tables for HLS playlist items

Constant Summary collapse

AUDIO_CODECS = 
{
  'aac-lc' => 'mp4a.40.2',
  'he-aac' => 'mp4a.40.5',
  'mp3' => 'mp4a.40.34',
  'ac-3' => 'ac-3',
  'ec-3' => 'ec-3',
  'e-ac-3' => 'ec-3',
  'flac' => 'fLaC',
  'opus' => 'Opus'
}.freeze
BASELINE_CODECS = 
{
  3.0 => 'avc1.66.30',
  3.1 => 'avc1.42001f'
}.freeze
MAIN_CODECS = 
{
  3.0 => 'avc1.77.30',
  3.1 => 'avc1.4d001f',
  4.0 => 'avc1.4d0028',
  4.1 => 'avc1.4d0029'
}.freeze
HIGH_LEVELS = 
[3.0, 3.1, 3.2, 4.0, 4.1, 4.2,
5.0, 5.1, 5.2].freeze
HEVC_CODECS = 
{
  ['hevc-main', 3.1] => 'hvc1.1.6.L93.B0',
  ['hevc-main', 4.0] => 'hvc1.1.6.L120.B0',
  ['hevc-main', 5.0] => 'hvc1.1.6.L150.B0',
  ['hevc-main', 5.1] => 'hvc1.1.6.L153.B0',
  ['hevc-main-10', 3.1] => 'hvc1.2.4.L93.B0',
  ['hevc-main-10', 4.0] => 'hvc1.2.4.L120.B0',
  ['hevc-main-10', 5.0] => 'hvc1.2.4.L150.B0',
  ['hevc-main-10', 5.1] => 'hvc1.2.4.L153.B0'
}.freeze
AV1_CODECS = 
{
  ['av1-main', 3.1] => 'av01.0.04M.08',
  ['av1-main', 4.0] => 'av01.0.08M.08',
  ['av1-main', 5.0] => 'av01.0.12M.08',
  ['av1-main', 5.1] => 'av01.0.13M.08',
  ['av1-high', 3.1] => 'av01.1.04H.10',
  ['av1-high', 4.0] => 'av01.1.08H.10',
  ['av1-high', 5.0] => 'av01.1.12H.10',
  ['av1-high', 5.1] => 'av01.1.13H.10'
}.freeze

Class Method Summary collapse

Class Method Details

.audio_codec(codec) ⇒ String?

Look up the codec string for an audio codec name.

Parameters:

  • codec (String, nil) —

    audio codec name

Returns:

  • (String, nil) —

    codec string



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# File 'lib/m3u8/codecs.rb', line 57

def self.audio_codec(codec)
  return if codec.nil?

  AUDIO_CODECS[codec.downcase]
end

.video_codec(profile, level) ⇒ String?

Look up the codec string for a video profile and level.

Parameters:

  • profile (String, nil) —

    video profile name

  • level (Float, Integer, nil) —

    video level

Returns:

  • (String, nil) —

    codec string



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# File 'lib/m3u8/codecs.rb', line 67

def self.video_codec(profile, level)
  return if profile.nil? || level.nil?

  level = level.to_f
  name = profile.downcase
  return BASELINE_CODECS[level] if name == 'baseline'
  return MAIN_CODECS[level] if name == 'main'
  return high_codec_string(level) if name == 'high'
  return HEVC_CODECS[[profile, level]] if name.start_with?('hevc-')

  AV1_CODECS[[profile, level]] if name.start_with?('av1-')
end