codec - Multimedia-Codec

Adapted Air780E/Air700E Air780EP Air601 Air101/Air103 Air105

Note

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Tip

This library has its own demo,click this link to view the demo example of codec

Constant

constant	type	explanation
codec.MP3	number	MP3 Format
codec.WAV	number	WAV Format
codec.AMR	number	AMR-NB format, in a general sense AMR
codec.AMR_WB	number	AMR-WB Format

codec.create(type, isDecoder, quality)

Create a codec codec

Parameters

Incoming Value Type	Explanation
int	multimedia type, currently supported codec.MP3 codec.AMR
boolean	Is it a decoder, true decoder, false encoder, default true, is a decoder
int	encoding level. some bsps have internal encoders. you may need to enter the encoding level in advance, such as the internal amr encoder of a air780ep.

Return Value

return value type	explanation
userdata	Returns a data structure on success, otherwise nil

Examples

-- Create Decoder
local decoder = codec.create(codec.MP3)--Create an mp3 decoder
-- Create Encoder
local encoder = codec.create(codec.AMR, false)--Create an AMR encoder
-- Create Encoder
local encoder = codec.create(codec.AMR_WB, false, 8)--Create a amr-wb encoder with the default encoding level 8

---

codec.info(decoder, file_path)

decoder Parsing audio information from a file

Parameters

Incoming Value Type	Explanation
userdata	for decoding decoder
string	File Path

Return Value

return value type	explanation
boolean	Whether the resolution was successful
int	Audio Format
int	Number of sound channels
int	Sampling frequency
int	Number of sampling bits
boolean	Is there a symbol

Examples

local result, audio_format, num_channels, sample_rate, bits_per_sample, is_signed= codec.info(coder, "xxx")

---

codec.data(decoder, out_buff)

decoder Parse the original audio data from the file, for example, parse the PCM data from the MP3 file. The file path here has already been passed in to codec.info and does not need to be passed in again.

Parameters

Incoming Value Type	Explanation
userdata	for decoding decoder
zbuff	Zbuff for storing output data, space must be no less 16KB
int	How many bytes of audio data are decoded at least, by default 16384

Return Value

return value type	explanation
boolean	Whether the resolution was successful

Examples

-- Large Memory Device
local buff = zbuff.create(16*1024)
local result = codec.data(coder, buff)
-- Small Memory Device
local buff = zbuff.create(8*1024)
local result = codec.data(coder, buff, 4096)

---

codec.encode(coder, in_buffer, out_buffer, mode)

for encoding audio data, flash and ram space are generally limited, except that some bsps have internal amr encoding function, currently only amr-nb encoding is supported.

Parameters

Incoming Value Type	Explanation
userdata	codec.create Used for the created codec coder
zbuff	input data, zbuff form, from 0 used
zbuff	The output data, in the form of zbuff, is automatically added to the tail of the buff. If the space is insufficient, it will automatically expand, but it will consume extra time and even fail, so try to give enough space at the beginning.
int	amr_nb The larger the encoding level of 0 to 7 (that is, MR475 to MR122), the more space consumed and the higher the sound quality. The default encoding level of 0 amr_wb is 0 to 8. The larger the value, the more space consumed and the higher the sound quality. The default 0

Return Value

return value type	explanation
boolean	Returns true on success and true on failure false

Examples

codec.encode(amr_coder, inbuf, outbuf, codec.AMR_)

---

codec.release(coder)

For release codec coder

Parameters

Incoming Value Type	Explanation
coder	codec.create Used for the created codec coder

Return Value

None

Examples

codec.release(coder)

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