Docs: Restructure Chapter 7.8
- Restructure CDD with new ID rule
Bug: 64811960
Change-Id: I4d9d88723f0e57ce0f76cbd3d1fffc26f3186c14
diff --git a/7_hardware-compatibility/7_8_audio.md b/7_hardware-compatibility/7_8_audio.md
index 4b13d00..0279da4 100644
--- a/7_hardware-compatibility/7_8_audio.md
+++ b/7_hardware-compatibility/7_8_audio.md
@@ -2,50 +2,55 @@
### 7.8.1\. Microphone
-<div class="note">
-Android Handheld, Watch, and Automotive implementations MUST include a
-microphone.
+* [H-0-1] Handheld device implementations MUST include a microphone.
+* [W-0-1] Watch device implementations MUST include a microphone.
+* [A-0-1] Automotive device implementations MUST include a microphone.
-</div>
+If device implementations include a microphone, they:
-Device implementations MAY omit a microphone. However, if a device
-implementation omits a microphone, it MUST NOT report the
-android.hardware.microphone feature constant, and MUST implement the audio
-recording API at least as no-ops, per [section 7](#7_hardware_compatibility).
-Conversely, device implementations that do possess a microphone:
+* [C-1-1] MUST report the `android.hardware.microphone` feature constant.
+* [C-1-2] MUST meet the audio recording requirements in
+[section 5.4](#5_4_audio_recording).
+* [C-1-3] MUST meet the audio latency requirements in
+[section 5.6](#5_6_audio_latency).
+* [SR] STRONGLY RECOMMENDED to support near-ultrasound recording as described
+in [section 7.8.3](#7_8_3_near_ultrasound).
-* MUST report the android.hardware.microphone feature constant.
-* MUST meet the audio recording requirements in [section 5.4](#5_4_audio_recording).
-* MUST meet the audio latency requirements in [section 5.6](#5_6_audio_latency).
-* STRONGLY RECOMMENDED to support near-ultrasound recording as described in
-[section 7.8.3](#7_8_3_near_ultrasound).
+If device implementations omit a microphone, they:
+
+* [C-2-1] MUST NOT report the `android.hardware.microphone` feature constant.
+* [C-2-2] MUST implement the audio recording API at least as no-ops, per
+ [section 7](#7_hardware_compatibility).
+
### 7.8.2\. Audio Output
-<div class="note">
-
-Android Watch devices MAY include an audio output.
-
-</div>
-
-Device implementations including a speaker or with an audio/multimedia output
+If device implementations include a speaker or an audio/multimedia output
port for an audio output peripheral such as a 4 conductor 3.5mm audio jack or
-USB host mode port using [USB audio class](https://source.android.com/devices/audio/usb#audioClass):
+USB host mode port using [USB audio class](
+https://source.android.com/devices/audio/usb#audioClass), they:
-* MUST report the android.hardware.audio.output feature constant.
-* MUST meet the audio playback requirements in [section 5.5](#5_5_audio_playback).
-* MUST meet the audio latency requirements in [section 5.6](#5_6_audio_latency).
-* STRONGLY RECOMMENDED to support near-ultrasound playback as described in
-[section 7.8.3](#7_8_3_near_ultrasound).
+* [C-1-1] MUST report the `android.hardware.audio.output` feature constant.
+* [C-1-2] MUST meet the audio playback requirements in
+[section 5.5](#5_5_audio_playback).
+* [C-1-3] MUST meet the audio latency requirements in
+[section 5.6](#5_6_audio_latency).
+* [SR] STRONGLY RECOMMENDED to support near-ultrasound playback as described
+in [section 7.8.3](#7_8_3_near_ultrasound).
-Conversely, if a device implementation does not include a speaker or audio
-output port, it MUST NOT report the android.hardware.audio output feature, and
-MUST implement the Audio Output related APIs as no-ops at least.
+If device implementations do not include a speaker or audio output port, they:
-Android Watch device implementation MAY but SHOULD NOT have audio output, but
-other types of Android device implementations MUST have an audio output and
-declare android.hardware.audio.output.
+* [C-2-1] MUST NOT report the `android.hardware.audio output` feature.
+* [C-2-2] MUST implement the Audio Output related APIs as no-ops at least.
+
+* [H-0-1] Handheld device implementations MUST have an audio output and
+declare `android.hardware.audio.output`.
+* [T-0-1] Television device implementations MUST have an audio output and
+declare `android.hardware.audio.output`.
+* [A-0-1] Automotive device implementations MUST have an audio output and
+declare `android.hardware.audio.output`.
+* Watch device implementations MAY but SHOULD NOT have audio output.
For the purposes of this section, an "output port" is a
[physical interface](https://en.wikipedia.org/wiki/Computer_port_%28hardware%29)
@@ -55,53 +60,68 @@
#### 7.8.2.1\. Analog Audio Ports
-In order to be compatible with the
-[headsets and other audio accessories](http://source.android.com/accessories/headset-spec.html)
+In order to be compatible with the [headsets and other audio accessories](
+http://source.android.com/accessories/headset-spec.html)
using the 3.5mm audio plug across the Android ecosystem, if a device
implementation includes one or more analog audio ports, at least one of the
-audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device
-implementation has a 4 conductor 3.5mm audio jack, it:
+audio port(s) SHOULD be a 4 conductor 3.5mm audio jack.
-* MUST support audio playback to stereo headphones and stereo headsets with a
-microphone, and SHOULD support audio recording from stereo headsets with a
-microphone.
-* MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD
-support audio plugs with the OMTP pin-out order.
-* MUST support the detection of microphone on the plugged in audio accessory,
-if the device implementation supports a microphone, and broadcast the
-android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.
-* MUST support the detection and mapping to the keycodes for the following
-3 ranges of equivalent impedance between the microphone and ground conductors
-on the audio plug:
- * **70 ohm or less**: KEYCODE_HEADSETHOOK
- * **210-290 Ohm**: KEYCODE_VOLUME_UP
- * **360-680 Ohm**: KEYCODE_VOLUME_DOWN
-* STRONGLY RECOMMENDED to detect and map to the keycode for the following
+If device implementations have a 4 conductor 3.5mm audio jack, they:
+
+* [C-1-1] MUST support audio playback to stereo headphones and stereo headsets
+with a microphone.
+* [C-1-2] MUST support TRRS audio plugs with the CTIA pin-out order.
+* [C-1-3] MUST support the detection and mapping to the keycodes for the
+following 3 ranges of equivalent impedance between the microphone and ground
+conductors on the audio plug:
+ * **70 ohm or less**: `KEYCODE_HEADSETHOOK`
+ * **210-290 ohm**: `KEYCODE_VOLUME_UP`
+ * **360-680 ohm**: `KEYCODE_VOLUME_DOWN`
+* [C-1-4] MUST trigger `ACTION_HEADSET_PLUG` upon a plug insert, but
+only after all contacts on plug are touching their relevant segments
+on the jack.
+* [C-1-5] MUST be capable of driving at least 150mV ± 10% of output voltage on
+a 32 ohm speaker impedance.
+* [C-1-6] MUST have a microphone bias voltage between 1.8V ~ 2.9V.
+* [SR] STRONGLY RECOMMENDED to detect and map to the keycode for the following
range of equivalent impedance between the microphone and ground conductors
on the audio plug:
- * **110-180 Ohm:** KEYCODE_VOICE_ASSIST
-* MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all
-contacts on plug are touching their relevant segments on the jack.
-* MUST be capable of driving at least 150mV ± 10% of output voltage on a 32
-Ohm speaker impedance.
-* MUST have a microphone bias voltage between 1.8V ~ 2.9V.
+ * **110-180 ohm:** `KEYCODE_VOICE_ASSIST`
+* SHOULD support audio plugs with the OMTP pin-out order.
+* SHOULD support audio recording from stereo headsets with a microphone.
+
+
+If device implementations have a 4 conductor 3.5mm audio jack and support a
+microphone, and broadcast the `android.intent.action.HEADSET_PLUG` with the
+extra value microphone set as 1, they:
+
+* [C-2-1] MUST support the detection of microphone on the plugged in audio
+accessory.
### 7.8.3\. Near-Ultrasound
-Near-Ultrasound audio is the 18.5 kHz to 20 kHz band. Device implementations
-MUST correctly report the support of near-ultrasound audio capability via the
-[AudioManager.getProperty](http://developer.android.com/reference/android/media/AudioManager.html#getProperty%28java.lang.String%29)
+Near-Ultrasound audio is the 18.5 kHz to 20 kHz band.
+
+Device implementations:
+
+* MUST correctly report the support of
+near-ultrasound audio capability via the [AudioManager.getProperty](
+http://developer.android.com/reference/android/media/AudioManager.html#getProperty%28java.lang.String%29)
API as follows:
-* If
-[PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND](http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND)
-is "true", then the following requirements must be met by the
-VOICE_RECOGNITION and UNPROCESSED audio sources:
- * The microphone's mean power response in the 18.5 kHz to 20 kHz band
-MUST be no more than 15 dB below the response at 2 kHz.
- * The microphone's unweighted signal to noise ratio over 18.5 kHz to 20 kHz
-for a 19 kHz tone at -26 dBFS MUST be no lower than 50 dB.
-* If
-[PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND](http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND)
-is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no
-lower than 40 dB below the response at 2 kHz.
+If [`PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND`](
+http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND)
+is "true", the following requirements MUST be met by the
+`VOICE_RECOGNITION` and `UNPROCESSED` audio sources:
+
+* [C-1-1] The microphone's mean power response in the 18.5 kHz to 20 kHz band
+ MUST be no more than 15 dB below the response at 2 kHz.
+* [C-1-2] The microphone's unweighted signal to noise ratio over 18.5 kHz to 20 kHz
+ for a 19 kHz tone at -26 dBFS MUST be no lower than 50 dB.
+
+If [`PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND`](
+http://developer.android.com/reference/android/media/AudioManager.html#PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND)
+is "true":
+
+* [C-2-1] The speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower
+than 40 dB below the response at 2 kHz.
