diff --git a/miniaudio.h b/miniaudio.h index b74c7f81..20c3958b 100644 --- a/miniaudio.h +++ b/miniaudio.h @@ -3336,7 +3336,7 @@ When `backends` is NULL, the default priority order will be used. Below is a lis |-------------|-----------------------|--------------------------------------------------------| The context can be configured via the `pConfig` argument. The config object is initialized with `ma_context_config_init()`. Individual configuration settings -can then be set directly on the structure. See examples below for a usage. Below are the members of the `ma_context_config` object. +can then be set directly on the structure. Below are the members of the `ma_context_config` object. logCallback Callback for handling log messages from miniaudio. @@ -3678,69 +3678,215 @@ ma_bool32 ma_context_is_loopback_supported(ma_context* pContext); /* Initializes a device. -The context can be null in which case it uses the default. This is equivalent to passing in a -context that was initialized like so: +A device represents a physical audio device. The idea is you send or receive audio data from the device to either play it back through a speaker, or capture it +from a microphone. Whether or not you should send or receive data from the device (or both) depends on the type of device you are initializing which can be +playback, capture, full-duplex or loopback. (Note that loopback mode is only supported on select backends.) Sending and receiving audio data to and from the +device is done via a callback which is fired by miniaudio at periodic time intervals. +The frequency at which data is deilvered to and from a device depends on the size of it's period which is defined by a buffer size and a period count. The size +of the buffer can be defined in terms of PCM frames or milliseconds, whichever is more convenient. The size of a period is the size of this buffer, divided by +the period count. Generally speaking, the smaller the period, the lower the latency at the expense of higher CPU usage and increased risk of glitching due to +the more frequent and granular data deliver intervals. The size of a period will depend on your requirements, but miniaudio's defaults should work fine for +most scenarios. If you're building a game you should leave this fairly small, whereas if you're building a simple media player you can make it larger. Note +that the period size you request is actually just a hint - miniaudio will tell the backend what you want, but the backend is ultimately responsible for what it +gives you. You cannot assume you will get exactly what you ask for. + +When delivering data to and from a device you need to make sure it's in the correct format which you can set through the device configuration. You just set the +format that you want to use and miniaudio will perform all of the necessary conversion for you internally. When delivering data to and from the callback you +can assume the format is the same as what you requested when you initialized the device. See Remarks for more details on miniaudio's data conversion pipeline. + + +Parameters +---------- +pContext (in, optional) + A pointer to the context that owns the device. This can be null, in which case it creates a default context internally. + +pConfig (in) + A pointer to the device configuration. Cannot be null. See remarks for details. + +pDevice (out) + A pointer to the device object being initialized. + + +Return Value +------------ +MA_SUCCESS if successful; any other error code otherwise. + + +Thread Safety +------------- +Unsafe. It is not safe to call this function simultaneously for different devices because some backends depend on and mutate global state. The same applies to +calling this at the same time as `ma_device_uninit()`. + + +Callback Safety +--------------- +Unsafe. It is not safe to call this inside any callback. + + +Remarks +------- +Setting `pContext` to NULL will result in miniaudio creating a default context internally and is equivalent to passing in a context initialized like so: + + ```c ma_context_init(NULL, 0, NULL, &context); + ``` -Do not pass in null for the context if you are needing to open multiple devices. You can, -however, use null when initializing the first device, and then use device.pContext for the -initialization of other devices. +Do not set `pContext` to NULL if you are needing to open multiple devices. You can, however, use NULL when initializing the first device, and then use +device.pContext for the initialization of other devices. -The device's configuration is controlled with pConfig. This allows you to configure the sample -format, channel count, sample rate, etc. Before calling ma_device_init(), you will need to -initialize a ma_device_config object using ma_device_config_init(). You must set the callback in -the device config. Once initialized, the device's config is immutable. If you need to change the -config you will need to initialize a new device. +The device can be configured via the `pConfig` argument. The config object is initialized with `ma_device_config_init()`. Individual configuration settings can +then be set directly on the structure. Below are the members of the `ma_device_config` object. -Passing in 0 to any property in pConfig will force the use of a default value. In the case of -sample format, channel count, sample rate and channel map it will default to the values used by -the backend's internal device. For the size of the buffer you can set bufferSizeInFrames or -bufferSizeInMilliseconds (if both are set it will prioritize bufferSizeInFrames). If both are -set to zero, it will default to MA_BASE_BUFFER_SIZE_IN_MILLISECONDS_LOW_LATENCY or -MA_BASE_BUFFER_SIZE_IN_MILLISECONDS_CONSERVATIVE, depending on whether or not performanceProfile -is set to ma_performance_profile_low_latency or ma_performance_profile_conservative. + deviceType + Must be `ma_device_type_playback`, `ma_device_type_capture`, `ma_device_type_duplex` of `ma_device_type_loopback`. -If you request exclusive mode and the backend does not support it an error will be returned. For -robustness, you may want to first try initializing the device in exclusive mode, and then fall back -to shared mode if required. Alternatively you can just request shared mode (the default if you -leave it unset in the config) which is the most reliable option. Some backends do not have a -practical way of choosing whether or not the device should be exclusive or not (ALSA, for example) -in which case it just acts as a hint. Unless you have special requirements you should try avoiding -exclusive mode as it's intrusive to the user. Starting with Windows 10, miniaudio will use low-latency -shared mode where possible which may make exclusive mode unnecessary. + sampleRate + The sample rate, in hertz. The most common sample rates are 48000 and 44100. Setting this to 0 will use the device's native sample rate. -When sending or receiving data to/from a device, miniaudio will internally perform a format -conversion to convert between the format specified by pConfig and the format used internally by -the backend. If you pass in NULL for pConfig or 0 for the sample format, channel count, -sample rate _and_ channel map, data transmission will run on an optimized pass-through fast path. + bufferSizeInFrames + The total size of the buffer in PCM frames. If this is 0, `bufferSizeInMilliseconds` will be used instead. If both are 0 the default buffer size will + be used depending on the selected performance profile. See below for details. -The buffer size should be treated as a hint. miniaudio will try it's best to use exactly what you -ask for, but it may differ. You should not assume the number of frames specified in each call to -the data callback is exactly what you originally specified. + bufferSizeInMilliseconds + The total size of the buffer in milliseconds. If this is 0, `bufferSizeInFrames` will be used instead. If both are 0 the default buffer size will be + used depending on the selected performance profile. See below for details. -The property controls how frequently the background thread is woken to check for more -data. It's tied to the buffer size, so as an example, if your buffer size is equivalent to 10 -milliseconds and you have 2 periods, the CPU will wake up approximately every 5 milliseconds. + periods + The number of periods making up the device's entire buffer. The total buffer size, defined by `bufferSizeInFrames` or `bufferSizeInMilliseconds`, will + be dividied by this number to determine the approximate latency. This is just a hint as backends will be the ones who ultimately decide how your + buffers and periods will be configured. -When compiling for UWP you must ensure you call this function on the main UI thread because the -operating system may need to present the user with a message asking for permissions. Please refer -to the official documentation for ActivateAudioInterfaceAsync() for more information. + performanceProfile + A hint to miniaudio as to the performance requirements of your program. Can be either `ma_performance_profile_low_latency` (default) or + `ma_performance_profile_conservative`. This mainly affects the size of default buffers and can usually be left at it's default value. -ALSA Specific: When initializing the default device, requesting shared mode will try using the -"dmix" device for playback and the "dsnoop" device for capture. If these fail it will try falling -back to the "hw" device. + noPreZeroedOutputBuffer + When set to true, the contents of the output buffer passed into the data callback will be left undefined. When set to false (default), the contents of + the output buffer will be cleared the zero. You can use this to avoid the overhead of zeroing out the buffer if you know can guarantee that your data + callback will write to every sample in the output buffer, or if you are doing your own clearing. -Return Value: - MA_SUCCESS if successful; any other error code otherwise. + noClip + When set to true, the contents of the output buffer passed into the data callback will be clipped after returning. When set to false (default), the + contents of the output buffer are left alone after returning and it will be left up to the backend itself to decide whether or not the clip. This only + applies when the playback sample format is f32. -Thread Safety: UNSAFE - It is not safe to call this function simultaneously for different devices because some backends - depend on and mutate global state (such as OpenSL|ES). The same applies to calling this at the - same time as ma_device_uninit(). + dataCallback + The callback to fire whenever data is ready to be delivered to or from the device. -Callback Safety: UNSAFE - It is not safe to call this inside any callback. + stopCallback + The callback to fire whenever the device has stopped, either explicitly via `ma_device_stop()`, or implicitly due to things like the device being + disconnected. + + pUserData + The user data pointer to use with the device. You can access this directly from the device object like `device.pUserData`. + + resampling.algorithm + The resampling algorithm to use when miniaudio needs to perform resampling between the rate specified by `sampleRate` and the device's native rate. The + default value is `ma_resample_algorithm_linear`, and the quality can be configured with `resampling.linear.lpfCount`. + + resampling.linear.lpfCount + The linear resampler applies a low-pass filter as part of it's procesing for anti-aliasing. This setting controls the quality of the filter. The higher + the value, the better the quality. Setting this to 0 will disable low-pass filtering altogether. The maximum value is `MA_MAX_RESAMPLER_LPF_FILTERS`. + The default value is `min(2, MA_MAX_RESAMPLER_LPF_FILTERS)`. + + playback.pDeviceID + A pointer to a `ma_device_id` structure containing the ID of the playback device to initialize. Setting this NULL (default) will use the system's + default playback device. Retrieve the device ID from the `ma_device_info` structure, which can be retrieved using device enumeration. + + playback.format + The sample format to use for playback. When set to `ma_format_unknown` the device's native format will be used. This can be retrieved after + initialization from the device object directly with `device.playback.format`. + + playback.channels + The number of channels to use for playback. When set to 0 the device's native channel count will be used. This can be retrieved after initialization + from the device object directly with `device.playback.channels`. + + playback.channelMap + The channel map to use for playback. When left empty, the device's native channel map will be used. This can be retrieved after initialization from the + device object direct with `device.playback.channelMap`. + + playback.shareMode + The preferred share mode to use for playback. Can be either `ma_share_mode_shared` (default) or `ma_share_mode_exclusive`. Note that if you specify + exclusive mode, but it's not supported by the backend, initialization will fail. You can then fall back to shared mode if desired. + + playback.pDeviceID + A pointer to a `ma_device_id` structure containing the ID of the playback device to initialize. Setting this NULL (default) will use the system's + default playback device. Retrieve the device ID from the `ma_device_info` structure, which can be retrieved using device enumeration. + + capture.format + The sample format to use for capture. When set to `ma_format_unknown` the device's native format will be used. This can be retrieved after + initialization from the device object directly with `device.capture.format`. + + capture.channels + The number of channels to use for capture. When set to 0 the device's native channel count will be used. This can be retrieved after initialization + from the device object directly with `device.capture.channels`. + + capture.channelMap + The channel map to use for capture. When left empty, the device's native channel map will be used. This can be retrieved after initialization from the + device object direct with `device.capture.channelMap`. + + capture.shareMode + The preferred share mode to use for capture. Can be either `ma_share_mode_shared` (default) or `ma_share_mode_exclusive`. Note that if you specify + exclusive mode, but it's not supported by the backend, initialization will fail. You can then fall back to shared mode if desired. + + wasapi.noAutoConvertSRC + WASAPI only. When set to true, disables WASAPI's automatic resampling and forces the use of miniaudio's resampler. Defaults to false. + + wasapi.noDefaultQualitySRC + WASAPI only. Only used when `wasapi.noAutoConvertSRC` is set to false. When set to true, disables the use of `AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY`. + You should usually leave this set to false, which is the default. + + wasapi.noAutoStreamRouting + WASAPI only. When set to true, disables automatic stream routing on the WASAPI backend. Defaults to false. + + wasapi.noHardwareOffloading + WASAPI only. When set to true, disables the use of WASAPI's hardware offloading feature. Defaults to false. + + alsa.noMMap + ALSA only. When set to true, disables MMap mode. Defaults to false. + + pulse.pStreamNamePlayback + PulseAudio only. Sets the stream name for playback. + + pulse.pStreamNameCapture + PulseAudio only. Sets the stream name for capture. + + +Once initialized, the device's config is immutable. If you need to change the config you will need to initialize a new device. + +If both `bufferSizeInFrames` and `bufferSizeInMilliseconds` are set to zero, it will default to `MA_BASE_BUFFER_SIZE_IN_MILLISECONDS_LOW_LATENCY` or +`MA_BASE_BUFFER_SIZE_IN_MILLISECONDS_CONSERVATIVE`, depending on whether or not `performanceProfile` is set to `ma_performance_profile_low_latency` or +`ma_performance_profile_conservative`. + +If you request exclusive mode and the backend does not support it an error will be returned. For robustness, you may want to first try initializing the device +in exclusive mode, and then fall back to shared mode if required. Alternatively you can just request shared mode (the default if you leave it unset in the +config) which is the most reliable option. Some backends do not have a practical way of choosing whether or not the device should be exclusive or not (ALSA, +for example) in which case it just acts as a hint. Unless you have special requirements you should try avoiding exclusive mode as it's intrusive to the user. +Starting with Windows 10, miniaudio will use low-latency shared mode where possible which may make exclusive mode unnecessary. + +After initializing the device it will be in a stopped state. To start it, use `ma_device_start()`. + +When sending or receiving data to/from a device, miniaudio will internally perform a format conversion to convert between the format specified by pConfig and +the format used internally by the backend. If you pass in 0 for the sample format, channel count, sample rate _and_ channel map, data transmission will run on +an optimized pass-through fast path. You can retrieve the format, channel count and sample rate by inspecting the `playback/capture.format`, +`playback/capture.channels` and `sampleRate` members of the device object. + +When compiling for UWP you must ensure you call this function on the main UI thread because the operating system may need to present the user with a message +asking for permissions. Please refer to the official documentation for ActivateAudioInterfaceAsync() for more information. + +ALSA Specific: When initializing the default device, requesting shared mode will try using the "dmix" device for playback and the "dsnoop" device for capture. +If these fail it will try falling back to the "hw" device. + + +See Also +-------- +ma_device_config_init() +ma_device_uninit() +ma_device_start() +ma_context_init() +ma_context_get_devices() +ma_context_enumerate_devices() */ ma_result ma_device_init(ma_context* pContext, const ma_device_config* pConfig, ma_device* pDevice);