The MP3 codec is used for MP3 playback. More...

Overview

The MP3 codec is used for MP3 playback.

How to use this module

An example on how to use the MP3 codec APIs and a loudspeaker to play it out.
- 1. Call mp3_codec_open() to open MP3 codec and get MP3 codec handler.
- 2. Open MP3 file.
- 3. Use handler->get_write_buffer() to get the amount of MP3 format data to store and
  get the buffer address to write the MP3 data into.
- 4. Read the amount of MP3 data from the MP3 file and store in the buffer from the previous step.
- 5. Skip the ID3v2 header of the MP3 file.
- 6. Set output device and volume.
- 7. Use handler->play() to play MP3 file.
- 8. Use handler->pause()/handler->resume() to pause/resume playing.
- 9. Use handler->stop() to stop playing MP3 file.
- 10. Use handler->close_codec() to close the MP3 codec.
  - Sample code:
    static void test_sd_event_callback(mp3_codec_media_handle_t *hdl, mp3_codec_event_t event)
    {
    uint8_t *share_buf;
    uint32_t share_buf_len;
    switch (event) {
    case MP3_CODEC_MEDIA_JUMP_FILE_TO:
    res = f_lseek(&fdst, (DWORD)hdl->jump_file_to_specified_position);*
    break;
    case MP3_CODEC_MEDIA_REQUEST:
    case MP3_CODEC_MEDIA_UNDERFLOW:
    uint32_t loop_idx;
    uint32_t loop_cnt = 2;
    for (loop_idx = 0; loop_idx < loop_cnt; loop_idx++) {
    hdl->get_write_buffer(hdl, &share_buf, &share_buf_len);
    f_read(&fdst, share_buf, share_buf_len, &length_read);
    hdl->write_data_done(hdl, share_buf_len);
    }
    hdl->finish_write_data(hdl);
    break;
    }
    }
    void mp3_codec_demo()
    {
    mp3_codec_media_handle_t *hdl = NULL;
    hdl = mp3_codec_open(test_sd_event_callback);
    if (hdl == NULL) {
    log_hal_error("[MP3 Codec ut] Failed to open the codec.");
    return;
    }
    if (open_file_from_sd(&fdst, (const TCHAR *)"SD:/temp/1.mp3") < 0) {
    log_hal_error("[MP3 Codec ut] Failed to open SD:/temp/1.mp3.");
    return;
    }
    //prefill data to share buffer
    hdl->get_write_buffer(hdl, &share_buf, &share_buf_len);
    f_read(&fdst, share_buf, share_buf_len, &length_read);
    hdl->write_data_done(hdl, share_buf_len);
    hdl->finish_write_data(hdl);
    hdl->skip_id3v2_and_reach_next_frame(hdl, (uint32_t)f_size(&fdst));
    hal_audio_set_stream_out_device(HAL_AUDIO_DEVICE_HANDS_FREE_MONO);
    hal_audio_set_stream_out_volume(0x0, 0xFFFFFB50);
    log_hal_info("[MP3 Codec ut] play\n");
    hdl->play(hdl);
    vTaskDelay(20000 / portTICK_RATE_MS);
    hdl->pause(hdl);
    vTaskDelay(5000 / portTICK_RATE_MS);
    hdl->resume(hdl);
    hdl->stop(hdl);
    log_hal_info("[MP3 Codec ut] close mp3 codec\n");
    hdl->close_codec(hdl);

Functions
mp3_codec_function_return_state_t	mp3_codec_get_memory_size (uint32_t *memory_size)
	This function gets the memory requirement of MP3 decoder. More...

mp3_codec_function_return_state_t	mp3_codec_set_memory (uint8_t *memory)
	This function sets the memory for MP3 decoder. More...

mp3_codec_function_return_state_t	mp3_codec_set_memory2 (void)
	This function sets the memory for MP3 decoder. More...

mp3_codec_media_handle_t *	mp3_codec_open (mp3_codec_callback_t callback)
	This function opens the MP3 codec. More...

mp3_codec_function_return_state_t	mp3_codec_close (mp3_codec_media_handle_t *handle)
	This function closes the MP3 codec. More...

mp3_codec_function_return_state_t	mp3_codec_aws_set_flag (mp3_codec_media_handle_t *handle, bool flag)
	This function sets the advanced wireless stereo flag. More...

mp3_codec_function_return_state_t	mp3_codec_aws_set_initial_sync (mp3_codec_media_handle_t *handle)
	This function sets the advanced wireless stereo initial synchronization. More...

Modules
	Enum

	Struct

	Typedef

Function Documentation

mp3_codec_function_return_state_t mp3_codec_aws_set_flag	(	mp3_codec_media_handle_t *	handle,
		bool	flag
	)

This function sets the advanced wireless stereo flag.

Parameters

[in]	handle	is the mp3 codec handle.
[in]	flag	is used to determine to turn on or turn off AWS mechanism. 1: turn on AWS, 0: turn off AWS.

Returns: If the operation completed successfully, the return value is MP3_CODEC_RETURN_OK, otherwise the return value is MP3_CODEC_RETURN_ERROR.

mp3_codec_function_return_state_t mp3_codec_aws_set_initial_sync ( mp3_codec_media_handle_t * handle )

This function sets the advanced wireless stereo initial synchronization.

Parameters

[in] handle is the mp3 codec handle.

Returns: If the operation completed successfully, the return value is MP3_CODEC_RETURN_OK, otherwise the return value is MP3_CODEC_RETURN_ERROR.

mp3_codec_function_return_state_t mp3_codec_close ( mp3_codec_media_handle_t * handle )

This function closes the MP3 codec.

Parameters

[in] handle is the MP3 codec handle.

Returns: Return state from MP3 codec. Please refer to mp3_codec_function_return_state_t.

See also: mp3_codec_open()

mp3_codec_function_return_state_t mp3_codec_get_memory_size ( uint32_t * memory_size )

This function gets the memory requirement of MP3 decoder.

Parameters

[in] memory_size is a pointer to get the memory requirment of MP3 decoder.

Returns: Return status of this API call. Please refer to mp3_codec_function_return_state_t.

See also: mp3_codec_set_memory()

mp3_codec_media_handle_t* mp3_codec_open ( mp3_codec_callback_t callback )

This function opens the MP3 codec.

Parameters

[in] callback is a pointer to the callback function for the MP3 data control.

Returns: Media handle of the MP3 codec. Please refer to #mp3_media_handle_t.

See also: mp3_codec_close()

mp3_codec_function_return_state_t mp3_codec_set_memory ( uint8_t * memory )

This function sets the memory for MP3 decoder.

Parameters

[in] memory is a pointer to set the memory for MP3 decoder. The memory size should be the same size as mp3_codec_get_memory_size().

Returns: Return status of this API call. Please refer to mp3_codec_function_return_state_t.

See also: mp3_codec_get_memory_size()

mp3_codec_function_return_state_t mp3_codec_set_memory2 ( void )

This function sets the memory for MP3 decoder.

Returns: Return status of this API call. Please refer to mp3_codec_function_return_state_t.

Overview

How to use this module

Functions

Modules

Function Documentation