[SR] STRONGLY RECOMMENDED to report support for feature
android.hardware.audio.pro
via
the
android.content.pm.PackageManager
class.
If device implementations include a 4 conductor 3.5mm audio jack, they:
[C-2-1] MUST have the continuous round-trip audio latency to be 20 milliseconds or less
over the audio jack path.
[SR] STRONGLY RECOMMENDED to comply with section
Mobile device (jack)
specifications
of the
Wired Audio Headset Specification (v1.1)
.
The continuous round-trip audio latency SHOULD be 10 milliseconds or less over the
audio jack path.
If device implementations omit a 4 conductor 3.5mm audio jack and include a USB port(s) supporting
USB host mode, they:
[C-3-1] MUST implement the USB audio class.
[C-3-2] MUST have a continuous round-trip audio latency of 20 milliseconds or less over
the USB host mode port using USB audio class.
The continuous round-trip audio latency SHOULD be 10 milliseconds or less over the USB
host mode port using USB audio class.
If device implementations include an HDMI port, they:
[C-4-1] MUST support output in stereo and eight channels at 20-bit or 24-bit depth and
192 kHz without bit-depth loss or resampling, in at least one configuration.
5.11. Capture for Unprocessed
Android includes support for recording of unprocessed audio via the
android.media.MediaRecorder.AudioSource.UNPROCESSED
audio source. In OpenSL ES, it can be accessed
with the record preset
SL_ANDROID_RECORDING_PRESET_UNPROCESSED
.
If device implementations intent to support unprocessed audio source and make it available to third-
party apps, they:
[C-1-1] MUST report the support through the
android.media.AudioManager
property
PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED
.
[C-1-2] MUST exhibit approximately flat amplitude-versus-frequency characteristics in the
mid-frequency range: specifically ±10dB from 100 Hz to 7000 Hz for each and every
microphone used to record the unprocessed audio source.
[C-1-3] MUST exhibit amplitude levels in the low frequency range: specifically from ±20 dB
from 5 Hz to 100 Hz compared to the mid-frequency range for each and every
microphone used to record the unprocessed audio source.
[C-1-4] MUST exhibit amplitude levels in the high frequency range: specifically from ±30
dB from 7000 Hz to 22 KHz compared to the mid-frequency range for each and every
microphone used to record the unprocessed audio source.
[C-1-5] MUST set audio input sensitivity such that a 1000 Hz sinusoidal tone source
played at 94 dB Sound Pressure Level (SPL) yields a response with RMS of 520 for 16 bit-
samples (or -36 dB Full Scale for floating point/double precision samples) for each and
every microphone used to record the unprocessed audio source.
[C-1-6] MUST have a signal-to-noise ratio (SNR) at 60 dB or higher for each and every
microphone used to record the unprocessed audio source. (whereas the SNR is measured
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