fuchsia.audio.effects

1

Format of this input stream. Required.

2

Buffer for this input stream. Must provide write access and must have enough space for ProcessorConfiguration.max_frames_per_call.

Required.

1

Format of this output stream. Required.

2

Buffer for this output stream. Must provide write access and must have enough space for ProcessorConfiguration.max_frames_per_call. Write access is needed so the audio system can write to the output buffer in error cases, such as when the Processor disconnects.

If the effect supports in-place updates, this may refer to the same memory range as an input buffer.

Required.

3

If specified, the output signal is shifted by this many frames. If not specified, this is zero. See the explanation at [fuchsia.audio.effects/Processor.Process].

4

If specified, then input frame F will affect the output stream up through frame F + ring_out_frames. If not specified, this is zero.

Put differently, if the effect is given an input stream with N non-silent frames followed by infinite silence, the effect will produce up to N + ring_out_frames non-silent frames before emitting silence.

1

Each process call may be (optionally) divided into multiple stages, each with their own ProcessMetrics. This field names the stage described by this table.

2

Total wall-clock time from the moment the Process call is received to the moment a response is returned.

3

Total amount of time spent running on the CPU. See zx_info_task_runtime.cpu_time.

4

Total amount of time spent waiting to run. Only counts "ready" time. See zx_info_task_runtime.queue_time.

5

Total amount of time spent handling page faults. See zx_info_task_runtime.page_fault_time.

6

Total amount of time spent waiting on contended kernel locks. See zx_info_task_runtime.lock_contention_time.

1

The total gain that has been applied to each input stream by prior processing steps. For example, given an audio pipeline of the form input -> ProcessorA -> ProcessorB, if input is a sine wave with unity amplitude and ProcessorA applies a gain of -5.0dB, then ProcessorB should be called with total_applied_gain_db_per_input[0] = -5.0dB and ProcessorB's input buffer should contain a sine wave with amplitude -5.0dB.

If not specified, the applied gain is 0 dB for each input.

2

All fuchsia.media.AudioRenderUsages that contribute to each input stream. This is a bitmask of (1 << r), for each AudioRenderUsage that contributes. For example, if an input stream contains BACKGROUND (== 0) and INTERRUPTION (== 2), the bitmask is ((1<<0)|(1<<2)) = 0x5.

Note: this field may be removed once we have transitions to the new Fuchsia media APIs.

1

Dedicated FIDL channel for this processor. Required.

2

A description of all input streams for this processor. Must have at least one input.

Each input stream can have a different sample format or channel count, but all inputs must have the same frame rate.

3

A description of all output streams for this processor. Must have at least one output.

Each output stream can have a different sample format or channel count, but all outputs must have the same frame rate as the input(s) -- effects are allowed to perform sample format conversion and rechannelization as long as the frame rate does not change.

4

The maximum number of frames that may be processed per call to fuchsia.audio.effects/Processor.Process. The default limit is the number of frames that can fit in the smallest input buffer. If specified, this must be smaller than the default limit.

5

If specified, all calls to fuchsia.audio.effects/Processor.Process. must set num_frames to a multiple of this number. Must be less than or equal to max_frames_per_call. If not specified, then any block size is allowed.

1

2

1

2

The maximum number of input and output streams. These bounds are somewhat arbitrary; in practice we don't expect more than 1 or 2 inputs and outputs in the vast majority of cases.

The maximum size of the per_stage_metrics array.

The maximum length of the name of a process stage.