From 2d5eaf3d09ccdb99bed3428a4d706cf0b4be7c1e Mon Sep 17 00:00:00 2001
From: sunghee-hwang <97494915+sunghee-hwang@users.noreply.github.com>
Date: Fri, 12 Jul 2024 12:09:39 +0900
Subject: [PATCH 1/2] Grammar and typo correction
---
index.bs | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/index.bs b/index.bs
index 74066c50..963fc484 100644
--- a/index.bs
+++ b/index.bs
@@ -326,7 +326,7 @@ This specification defines a model for representing [=Immersive Audio=] contents
Processing flow to decode, reconstruct, render, and mix the 3D audio signals for immersive audio playback.
-The model comprises a number of coded [=Audio Substream=]s and the metadata that describes how to decode, render and mix the [=Audio Substream=]s for playback. The model itself is codec-agnostic; any supported audio codec may be used to code the [=Audio Substream=]s.
+The model comprises a number of coded [=Audio Substream=]s and the metadata that describes how to decode, render, and mix the [=Audio Substream=]s for playback. The model itself is codec-agnostic; any supported audio codec may be used to code the [=Audio Substream=]s.
The model includes one or more [=Audio Element=]s, each of which consists of one or more [=Audio Substream=]s. The [=Audio Substream=]s that make up an [=Audio Element=] are grouped into one or more [=Channel Group=]s. The model further includes [=Mix Presentation=]s and [=Parameter Substream=]s.
@@ -406,8 +406,8 @@ A coded [=Audio Substream=] is made of consecutive [=Audio Frame OBU=]s. Each [=
A [=Parameter Substream=] is made of consecutive [=Parameter Block OBU=]s. Each [=Parameter Block OBU=] is made of parameter values at a given sample rate. The decode duration of a [=Parameter Block OBU=] is the number of parameter values divided by the sample rate. The decode start time of a [=Parameter Block OBU=] is the sum of the decode duration of previous [=Parameter Block OBU=]s if any, 0 otherwise. The decode duration of a [=Parameter Substream=] is the sum of all its [=Parameter Block OBU=]s' decode durations. The start time of a [=Parameter Substream=] is the decode start time of its first [=Parameter Block OBU=]. When all parameter values in a [=Parameter Substream=] are constant, no [=Parameter Block OBU=]s may be present in the [=IA Sequence=].
-Within an [=Audio Element=], the presentation start times of all [=Audio Substream=]s coincide and is the presentation start time of the [=Audio Element=]. All [=Audio Substream=]s have the same presentation duration which is the presentation duration of the [=Audio Element=].
-- The decode start times of all coded [=Audio Substream=]s and all [=Parameter Substream=]s coincide and is the decode start time of the [=Audio Element=].
+Within an [=Audio Element=], the presentation start times of all [=Audio Substream=]s coincide and are the presentation start time of the [=Audio Element=]. All [=Audio Substream=]s have the same presentation duration which is the presentation duration of the [=Audio Element=].
+- The decode start times of all coded [=Audio Substream=]s and all [=Parameter Substream=]s coincide and are the decode start times of the [=Audio Element=].
- All coded [=Audio Substream=]s and all [=Parameter Substream=]s have the same decode duration which is the decode duration of the [=Audio Element=].
Within a [=Mix Presentation=], the presentation start time of all [=Audio Element=]s coincide and all [=Audio Element=]s have the same duration defining the duration of the [=Mix Presentation=].
@@ -622,7 +622,7 @@ class CodecConfig() {
codec_config_id defines an identifier for a codec configuration. Within an [=IA Sequence=], there SHALL be one unique [=codec_config_obu/codec_config_id=] per codec. There SHALL be exactly one [=Codec Config OBU=] with a given identifier in a set of [=Descriptors=]. [=Audio Element=]s use this identifier to indicate that its corresponding [=Audio Substream=]s are coded with this codec configuration.
-codec_config is an instance of the [=CodecConfig()=] class, which provides codec-specific information for seting up the decoder.
+codec_config is an instance of the [=CodecConfig()=] class, which provides codec-specific information for setting up the decoder.
codec_id indicates a ‘four-character code’ (4CC) to identify the codec used to generate the coded [=Audio Substream=]s. This specification supports the following four [=codec_id=] values defined below:
@@ -927,7 +927,7 @@ class ChannelAudioLayerConfig(i) {
- If [=loudspeaker_layout=] is set to Binaural, this field SHALL be set to 1.
-channel_audio_layer_config is an instance of the [=ChannelAudioLayerConfig()=] class, which provides the i-th [=Channel Group=]'s configuration, where i is the layer index provided as input argument to this instance of the [=ChannelAudioLayerConfig()=] class.
+channel_audio_layer_config is an instance of the [=ChannelAudioLayerConfig()=] class, which provides the i-th [=Channel Group=]'s configuration, where i is the layer index provided as an input argument to this instance of the [=ChannelAudioLayerConfig()=] class.
loudspeaker_layout indicates the channel layout to be reconstructed from the precedent [=Channel Group=]s and current [=Channel Group=]. If parsers do not recognize a [=loudspeaker_layout=] for a particular layer, they SHOULD skip the [=channel_audio_layer_config=] for that layer and all subsequent layers.
@@ -1790,7 +1790,7 @@ class ReconGainInfoParameterData() {
recon_gain_flags is a bitmask that indicates which channels [=recon_gain=] is applied to, as shown in the table below.
-Byte postion : Bit position : Assigned Channel Name
+Byte position: Bit position : Assigned Channel Name
: b0 (LSB) : Left channel
: b1 : Centre channel
LSB 7 bits : b2 : Right channel
@@ -1952,7 +1952,7 @@ The sample rate used for computing offsets SHALL be [=sample_rate=].
# Profiles # {#profiles}
-The IA Profiles define a set of capabilities that are REQUIRED to parse, decode and process the corresponding [=IA Sequence=].
+The IA Profiles define a set of capabilities that are REQUIRED to parse, decode, and process the corresponding [=IA Sequence=].
NOTE: In this version of the specification, profiles impose constraints on how many codecs can be used in an [=IA Sequence=] but do not impose constraints on the actual codec used. In particular, this means that if a future version of the specification (or if a derived specification) defines how to use a new codec, the profiles defined in this specification could be used. Derived specifications may constrain the actual codec. The [[#codecsparameter|codecs parameter]] may also be used in content negotiation phases to ensure that an [=IA Sequence=] is supported by a device.
@@ -2095,7 +2095,7 @@ In this version of the specification, IA Track means the tra
The result of encapsulating an [=IA Sequence=] into an [[!ISO-BMFF]] file is as follows:
-- If there are audio samples to be trimmed at the start or at the end, the 'edts' and 'elst' boxes SHALL be present to reflect the trimming status.
+- If there are audio samples to be trimmed at the start or the end, the 'edts' and 'elst' boxes SHALL be present to reflect the trimming status.
- Sample Entry
- An [=IA Sample=] is associated with only one sample entry, and the [=configOBUs=] in that sample entry SHALL contain the [=Descriptors=] required to process the [=IA Sample=]. If a different set of [=Descriptors=] is needed, a new sample entry SHALL be defined.
@@ -2288,7 +2288,7 @@ An [=IA Sequence=] SHALL be decoded and processed to output an [=Immersive Audio
NOTE: The IA decoder MAY choose to lazily parse OBUs to avoid unnecessarily parsing OBUs that are not used by the selected [=Mix Presentation=].
-The figure below depicts an example IA decoder architecture with modules that perform the steps above.
+The figure below depicts an example of IA decoder architecture with modules that perform the steps above.
IA Decoder Configuration. AE: Audio Element, AS: Audio Substream.
@@ -2298,7 +2298,7 @@ The figure below depicts an example IA decoder architecture with modules that pe
- The Audio Element Renderer reconstructs the [=3D audio signal=] from decoded channels of Codec Decoders according to [=Audio Element=] type (specified [=Audio Element OBU=]), and renders the audio channels to the playback layout.
- The Synchronizer synchronizes all rendered and individually processed [=Audio Element=]s.
- The Mixer sums the synchronized [=Audio Element=]s and applies further mixing parameters.
-- Then, Post-Processor outputs the [=Immersive Audio=] for playback after performs loudness normalization and peak-limiting.
+- Then, Post-Processor outputs the [=Immersive Audio=] for playback after performing loudness normalization and peak-limiting.
## Ambisonics Decoding and Reconstruction ## {#processing-ambisonics}
@@ -3176,7 +3176,7 @@ Let's define the following:
If \(10 \times \log_{10}(\frac{O_k}{L_{\text{max}}^2})\) is less than the first threshold value (-80dB is preferred), Recon_Gain(k, i) = 0. Where, \(L_{\text{max}} = 32767\) for 16 bits.
-If \(10 \times \log_{10}(\frac{O_k}{M_k})\) is less than the second threshold value (-6dB is preferred), Recon_Gain(k, i) is set to the value which makes \(O_k = (\text{Recon_Gain}(k, 1))^2 \times D_k\). Otherwise, Recon_Gain(k, i) = 1. The actual value (i.e., [=recon_gain=]) to be delivered is \( \left\lfloor{255 \times \text{Recon_Gain}}\right\rfloor \).
+If \(10 \times \log_{10}(\frac{O_k}{M_k})\) is less than the second threshold value (-6dB is preferred), Recon_Gain(k, i) is set to the value which makes \(O_k = (\text{Recon_Gain}(k, i))^2 \times D_k\). Otherwise, Recon_Gain(k, i) = 1. The actual value (i.e., [=recon_gain=]) to be delivered is \( \left\lfloor{255 \times \text{Recon_Gain}}\right\rfloor \).
For example, if we assume that CL #i = 7.1.4ch and CL #i-1 = 5.1.2ch, then the de-mixed channels are D_Lrs7, D_Rrs7, D_Ltb4 and D_Rtb4.
- D_Lrs7 and D_Rrs7 are de-mixed from Ls5 and Rs5 in the (i-1)-th [=Channel Group=] by using Lss7 and Rss7 in the i-th [=Channel Group=] and its relevant demixing parameters (i.e., \(\alpha(k)\) and \(\beta(k)\)) , respectively.
From a6e5c71a3d189065d375578548981103b84a77df Mon Sep 17 00:00:00 2001
From: sunghee-hwang <97494915+sunghee-hwang@users.noreply.github.com>
Date: Fri, 12 Jul 2024 14:20:21 +0900
Subject: [PATCH 2/2] times to time
---
index.bs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/index.bs b/index.bs
index 963fc484..ea6cb440 100644
--- a/index.bs
+++ b/index.bs
@@ -407,7 +407,7 @@ A coded [=Audio Substream=] is made of consecutive [=Audio Frame OBU=]s. Each [=
A [=Parameter Substream=] is made of consecutive [=Parameter Block OBU=]s. Each [=Parameter Block OBU=] is made of parameter values at a given sample rate. The decode duration of a [=Parameter Block OBU=] is the number of parameter values divided by the sample rate. The decode start time of a [=Parameter Block OBU=] is the sum of the decode duration of previous [=Parameter Block OBU=]s if any, 0 otherwise. The decode duration of a [=Parameter Substream=] is the sum of all its [=Parameter Block OBU=]s' decode durations. The start time of a [=Parameter Substream=] is the decode start time of its first [=Parameter Block OBU=]. When all parameter values in a [=Parameter Substream=] are constant, no [=Parameter Block OBU=]s may be present in the [=IA Sequence=].
Within an [=Audio Element=], the presentation start times of all [=Audio Substream=]s coincide and are the presentation start time of the [=Audio Element=]. All [=Audio Substream=]s have the same presentation duration which is the presentation duration of the [=Audio Element=].
-- The decode start times of all coded [=Audio Substream=]s and all [=Parameter Substream=]s coincide and are the decode start times of the [=Audio Element=].
+- The decode start times of all coded [=Audio Substream=]s and all [=Parameter Substream=]s coincide and are the decode start time of the [=Audio Element=].
- All coded [=Audio Substream=]s and all [=Parameter Substream=]s have the same decode duration which is the decode duration of the [=Audio Element=].
Within a [=Mix Presentation=], the presentation start time of all [=Audio Element=]s coincide and all [=Audio Element=]s have the same duration defining the duration of the [=Mix Presentation=].