List
samplingRates 8000,16000,32000,44100,48000,88200,96000,176400,192000,384000,768000
List
formatas ascending
AUDIO_FORMAT_PCM_16_BIT
AUDIO_FORMAT_PCM_24_BIT_PACKED (mainly used for a2dp profile)
AUDIO_FORMAT_PCM_8_24_BIT
AUDIO_FORMAT_PCM_32_BIT
fast flag
He sound output low-delay 40 ms
<mixPort name = "lowlatency out" role = "source" flags = "AUDIO_OUTPUT_FLAG_FAST">
<profile name = "" format = "AUDIO_FORMAT_PCM_16_BIT"
samplingRates = "48000"
channelMasks = "AUDIO_CHANNEL_OUT_STEREO" />
</ mixPort>
16 bit 48Khz and maksimklno and everything below. It is impossible to deduce hires
Unloading offload
List formats:
AUDIO_OUTPUT_FLAG_DIRECT (direct access)
AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD (compression of the audio output)
AUDIO_OUTPUT_FLAG_NON_BLOCKING (audio output is not blocked)
is used to display the bluetooth device or where appropriate headset, modern devices to compress the signal under mp3 SBC codec if headphones (device) do not support the codec ldac, aptx and hwa
if it is possible to deduce hires through codec, the output goes through 24_BIT_PACKED, simplified format 24bit
<mixPort name = "offload" role = "source" flags = "AUDIO_OUTPUT_FLAG_DIRECT | AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD | AUDIO_OUTPUT_FLAG_NON_BLOCKING">
<profile name = "" format = "AUDIO_FORMAT_MP3"
samplingRates = "8000,11025,12000,16000,22050,24000,32000,44100,48000"
channelMasks = "AUDIO_CHANNEL_OUT_STEREO" />
<profile name = "" format = "AUDIO_FORMAT_PCM_24_BIT_PACKED"
samplingRates = "48000"
channelMasks = "AUDIO_CHANNEL_OUT_STEREO" />
</ mixPort>
Direct output to the sound system to ignore all effects and post treatments, that is the conclusion HIRES
List formats:
AUDIO_OUTPUT_FLAG_DIRECT (direct access)
AUDIO_OUTPUT_FLAG_DIRECT_PCM (direct access to the PCM container)
What's the difference Do not know, you can use 1 of them
<mixPort name = "direct_pcm" role = "source" flags = "AUDIO_OUTPUT_FLAG_DIRECT | AUDIO_OUTPUT_FLAG_DIRECT_PCM | AUDIO_OUTPUT_FLAG_VOIP_RX">
<profile name = "" format = "AUDIO_FORMAT_PCM_16_BIT"
samplingRates = "8000,16000,32000,44100,48000,88200,96000,176400,192000,384000"
channelMasks = "AUDIO_CHANNEL_OUT_MONO, AUDIO_CHANNEL_OUT_STEREO" />
<profile name = "" format = "AUDIO_FORMAT_PCM_8_24_BIT"
samplingRates = "8000,16000,32000,44100,48000,88200,96000,176400,192000,384000"
channelMasks = "AUDIO_CHANNEL_OUT_MONO, AUDIO_CHANNEL_OUT_STEREO" />
<profile name = "" format = "AUDIO_FORMAT_PCM_32_BIT"
samplingRates = "8000,16000,32000,44100,48000,88200,96000,176400,192000,384000"
channelMasks = "AUDIO_CHANNEL_OUT_MONO, AUDIO_CHANNEL_OUT_STEREO" />
</ mixPort>
Audio output flags
AUDIO_OUTPUT_FLAG_PRIMARY (primary audio output, used as standard on most devices)
AUDIO_OUTPUT_FLAG_DEEP_BUFFER (Deep Buffer)
other flags
AUDIO_OUTPUT_FLAG_RAW
AUDIO_OUTPUT_FLAG_SLOW
AUDIO_OUTPUT_FLAG_DEEP_BUFFER
The list of audio compression formats from the highest to the lowest quality (this is not the entire list, but the most normal ones) (not all will be supported)
AUDIO_FORMAT_FLAC
AUDIO_FORMAT_ALAC
AUDIO_FORMAT_APE
AUDIO_FORMAT_VORBIS
AUDIO_FORMAT_WMA
AUDIO_FORMAT_WMA_PRO
AUDIO_FORMAT_MP3 (default)