hi_mpi_ao_send_frame

Applicability

Function Description

Sends AO audio frames.

Prototype

hi_s32 hi_mpi_ao_send_frame(hi_audio_dev ao_dev, hi_ao_chn ao_chn, const hi_audio_frame *data, hi_s32 milli_sec)

Parameters

Returns

• 0: success
• Other values: failure. For details, see Audio Return Codes.

Restrictions

• This MPI is used to send audio frames to the AO module.
• Before calling this MPI to send audio frames to the AO channel, you must call the hi_mpi_ao_enable_chn MPI to enable the corresponding AO channel.
• When the audio-left channel or stereo channel is used for playing, ai_chn must be fixed at 0. When the audio-right channel is used for recording, ai_chn is 1.
• The member variables len and virt_addr of the audio frame structure must match each other. len indicates the frame length (in bytes), and virt_addr indicates the address of the input audio data. It is recommended that the data transferred each time be a frame. That is, len equals point_num_per_frame multiplied by the bit width (2 bytes = 16 bits; 3 bytes = 24 bits).
• The length len is limited as follows: First, a quantity of data points is calculated based on len and a bit width (quantity of data points = len/quantity of bytes corresponding to the bit width). A range of the quantity of data points is [1, frame_num * point_num_per_frame], and a maximum upper limit is 4096.
  • Example 1: If frame_num=2, point_num_per_frame=480 (for details about the range restrictions of frame_num and point_num_per_frame, see the structure hi_aio_attr), frame_num * point_num_per_frame=960, and 960<4096, the range of the number of data points is [1, 960].
  • Example 2: If If frame_num = 30 and point_num_per_frame = 4096, frame_num x point_num_per_frame = 122880. As 122880 > 4096, the range of the number of data points is [1, 4096].
  • Example 3: When the range of data points determined based on frame_num and point_num_per_frame is [1, 960]: If len = 960 and the bit width is 16 bits (2 bytes), the calculated number of data points is 960/2 = 480. The value is within the range of [1, 960] and meets the requirement. If len = 3840 and the bit width is 16 bits (2 bytes), the calculated number of data points is 3840/2 = 1920. The value is beyond the range of [1, 960]and an error is reported.

See Also

For the API call sequence, see Obtaining and Playing Audios.