AV Processor Component (Audio/Video Processing)
This component provides a unified encapsulation for audio recording/playback/data feeding and video capture/decoding/rendering on ESP platforms, implemented based on middleware such as GMF (General Media Framework), esp-audio-render, esp-video-codec, and esp-capture.
Feature Overview 🎛️
- Audio 🎧:
- Recording (AEC/VAD/AFE optional)
- Playback (supports URL and local files, decoding depends on configuration)
- Data feeding (feeder, suitable for scenarios like RTC/streaming where receiving and playing happen simultaneously)
- Optional mixer with volume fade and focus control between multiple streams
- Video 🎥:
- Multi-channel video capture
- Video decoding and rendering callbacks
Quick Start
1. Audio Usage
- Initialize audio manager:
// Method 1: Use default configuration macro (recommended)
audio_manager_config_t cfg = DEFAULT_AUDIO_MANAGER_CONFIG();
cfg.play_dev = your_play_dev;
cfg.rec_dev = your_rec_dev;
strcpy(cfg.mic_layout, "RMNM"); // Microphone layout (optional, for AFE configuration)
cfg.board_sample_rate = 16000;
cfg.board_bits = 32;
cfg.board_channels = 2;
cfg.play_volume = 80;
cfg.rec_volume = 60;
cfg.rec_ref_volume = 60;
cfg.enable_mixer = true; // Enable when mixing feeder and playback is needed
audio_manager_init(&cfg);
- Recording (polling read):
// Recording event callback (optional)
void recorder_event_cb(void *event, void *ctx) {
// Handle recording events (e.g., AFE events)
}
// Configure recorder (using default configuration macro)
audio_recorder_config_t recorder_cfg = DEFAULT_AUDIO_RECORDER_CONFIG();
// Optional: Configure AFE (runtime configuration, takes priority over Kconfig)
recorder_cfg.afe_config.vad_enable = true;
recorder_cfg.afe_config.vad_mode = 4;
recorder_cfg.afe_config.agc_enable = true;
recorder_cfg.recorder_event_cb = recorder_event_cb;
// Open recorder
audio_recorder_open(&recorder_cfg);
uint8_t buf[2048];
audio_recorder_read_data(buf, sizeof(buf));
audio_recorder_close();
- Feeder playback (suitable for external stream → local playback):
// Configure feeder (using default configuration macro)
audio_feeder_config_t feeder_cfg = DEFAULT_AUDIO_FEEDER_CONFIG();
// Optional: When using OPUS decoder, task_stack is recommended to be >= 4096 * 10
// feeder_cfg.feeder_task_config.task_stack = 4096 * 10;
audio_feeder_open(&feeder_cfg);
audio_feeder_run();
// Feed external data blocks multiple times as needed
audio_feeder_feed_data(pkt, pkt_len);
audio_feeder_stop();
audio_feeder_close();
- Normal playback (URL or local):
// Configure player (using default configuration macro)
audio_playback_config_t playback_cfg = DEFAULT_AUDIO_PLAYBACK_CONFIG();
audio_playback_open(&playback_cfg);
audio_playback_play("http://<ip>:<port>/audio.mp3");
audio_playback_pause();
audio_playback_resume();
audio_playback_stop();
audio_playback_close();
- Focus/fade control (when mixer is enabled):
// Note: Mixer must be opened after both playback and feeder are opened
audio_processor_mixer_open();
audio_processor_ramp_control(AUDIO_MIXER_FOCUS_FEEDER); // Focus on feeder audio
audio_processor_ramp_control(AUDIO_MIXER_FOCUS_PLAYBACK); // Focus on playback audio
audio_processor_mixer_close();
2. Video Usage
- Render (decode) callback:
void decoded_cb(void *ctx, const uint8_t *data, size_t size) {
// Handle decoded frame data
}
video_render_config_t rcfg = {
.decode_cfg = your_vdec_cfg,
.resolution = {.width = 640, .height = 480},
.decode_cb = decoded_cb,
};
video_render_handle_t r = video_render_open(&rcfg);
video_render_start(r);
video_frame_t f = {.data = enc_frame, .size = enc_size};
video_render_frame_feed(r, &f);
video_render_stop(r);
video_render_close(r);
- Capture (multi-channel):
void capture_cb(void *ctx, int index, video_frame_t *frame) {
// Handle captured video frame
}
video_capture_config_t ccfg = {0};
ccfg.camera_config = &your_cam_cfg;
ccfg.sink_num = 2;
ccfg.sink_cfg[0] = your_sink0_cfg;
ccfg.sink_cfg[1] = your_sink1_cfg;
ccfg.capture_frame_cb = capture_cb;
video_capture_handle_t c = video_capture_open(&ccfg);
video_capture_start(c);
video_capture_stop(c);
video_capture_close(c);
Media Dump 💾
- Enable condition ✅: Takes effect after enabling
MEDIA_DUMP_ENABLEinmenuconfig. - Save methods 📤: Supports SD card and UDP outputs (choose one).
- SD card 💾: Enable
CONFIG_MEDIA_DUMP_SINK_SDCARD, output to fileCONFIG_MEDIA_DUMP_SDCARD_FILENAME, duration controlled byCONFIG_MEDIA_DUMP_DURATION_SEC. - UDP 📡: Enable
CONFIG_MEDIA_DUMP_SINK_UDP, send raw media data viaCONFIG_MEDIA_DUMP_UDP_IPandCONFIG_MEDIA_DUMP_UDP_PORT(can usescript/udp_reciver.pyscript).
- SD card 💾: Enable
- Save point 🎚️ (before/after AEC processing): Select in "Audio Save Mode (AEC point)" in
menuconfigMEDIA_DUMP_AUDIO_BEFORE_AEC(Save Before AEC): Save raw microphone audio before AEC (for analyzing noise/feedback)MEDIA_DUMP_AUDIO_AFTER_AEC(Save After AEC): Save audio after AEC processing (for evaluating AEC effectiveness)
- Typical usage 🔍: Export raw audio/video data when reproducing issues, check saturation, feedback, and format correctness offline using tools like Audacity.
Configuration ⚙️
Runtime Configuration (Recommended)
AFE configuration can be set at runtime via the afe_config field in the audio_recorder_config_t structure, which takes priority over Kconfig configuration:
audio_recorder_config_t recorder_cfg = DEFAULT_AUDIO_RECORDER_CONFIG();
// Configure AFE
recorder_cfg.afe_config.ai_mode_wakeup = false; // AI mode: true=wakeup mode, false=direct mode
recorder_cfg.afe_config.vad_enable = true; // Enable VAD
recorder_cfg.afe_config.vad_mode = 4; // VAD mode (1-4), larger values are more sensitive
recorder_cfg.afe_config.vad_min_speech_ms = 64; // Minimum speech duration (ms)
recorder_cfg.afe_config.vad_min_noise_ms = 1000; // Minimum noise duration (ms)
recorder_cfg.afe_config.agc_enable = true; // Enable AGC
recorder_cfg.afe_config.enable_vcmd_detect = false; // Enable VCMD
recorder_cfg.afe_config.vcmd_timeout_ms = 5000; // VCMD timeout (ms)
recorder_cfg.afe_config.mn_language = "cn"; // Model language: "cn" or "en"
recorder_cfg.afe_config.wakeup_time_ms = 10000; // Wakeup time (ms)
recorder_cfg.afe_config.wakeup_end_time_ms = 2000; // Wakeup end time (ms)
// Pass configuration when opening recorder
audio_recorder_open(&recorder_cfg);
Kconfig Configuration (Alternative)
If fields in audio_recorder_config_t.afe_config use default values or are not set, Kconfig configuration will be used. Configure via idf.py menuconfig:
💾 Media Dump Configuration
Configure under "Component config" -> "Audio/Video Processor Configuration" -> "Media Dump" in menuconfig:
-
MEDIA_DUMP_ENABLE: Enable media data dump functionality, disabled by default- When enabled, raw audio/video data can be saved for debugging and analysis
-
MEDIA_DUMP_AUDIO_POINT: Audio save point selection (choice type)MEDIA_DUMP_AUDIO_BEFORE_AEC: Save raw audio before AEC processing- Useful for analyzing noise and feedback issues
MEDIA_DUMP_AUDIO_AFTER_AEC: Save audio after AEC processing- Useful for evaluating AEC processing effectiveness
MEDIA_DUMP_AUDIO_NONE: Do not save audio (default)
-
MEDIA_DUMP_DURATION_SEC: Save duration in seconds, default 20- Type: integer (int)
- Range: 1-3600 seconds
-
MEDIA_DUMP_SINK: Save method selection (choice type)MEDIA_DUMP_SINK_SDCARD: Save to SD card file (default)- File path configuration:
CONFIG_MEDIA_DUMP_SDCARD_FILENAME(default:/sdcard/media_dump.bin) - Ensure SD card is properly mounted
- File path configuration:
MEDIA_DUMP_SINK_UDP: Send via UDP- Target IP configuration:
CONFIG_MEDIA_DUMP_UDP_IP(default:192.168.1.100) - Target port configuration:
CONFIG_MEDIA_DUMP_UDP_PORT(default: 5000) - Can use
script/udp_reciver.pyscript to receive data
- Target IP configuration:
Task Configuration
The audio processing component uses multiple FreeRTOS tasks internally, which can be customized via task configuration fields in each module's configuration structure:
Task Configuration for Each Module
-
Recorder (
audio_recorder_config_t):afe_feed_task_config: AFE feed task configuration (default stack size 3KB)afe_fetch_task_config: AFE fetch task configuration (default stack size 3KB)recorder_task_config: Recorder task configuration (default stack size 5KB, recommend >= 40KB when using OPUS encoder)
-
Player (
audio_playback_config_t):playback_task_config: Playback task configuration (default stack size 4KB)
-
Feeder (
audio_feeder_config_t):feeder_task_config: Feeder task configuration (default stack size 5KB, recommend >= 40KB when using OPUS decoder)
Important Notes:
- When using OPUS encoder or decoder,
task_stackofrecorder_task_configandfeeder_task_configshould be set to at least4096 * 10bytes (40KB). - When
task_stackin task configuration is set to 0, default values will be used. - When
task_stack_in_extis set totrue, task stack will be allocated in external memory, helping to save internal RAM. - Task configuration should be set in each module's configuration structure (e.g.,
audio_recorder_config_t,audio_playback_config_t,audio_feeder_config_t), not inaudio_manager_config_t.
API Reference 📚
Header files:
include/audio_processor.hinclude/video_processor.hinclude/av_processor_type.h
Common functions (selection):
- Audio management:
audio_manager_init/audio_manager_deinit: Initialize/deinitialize audio manager
- Recording:
audio_recorder_open: Open recorder (supports encoder configuration and event callback)audio_recorder_read_data: Read recording dataaudio_recorder_pause/audio_recorder_resume: Pause/resume recordingaudio_recorder_get_afe_manager_handle: Get AFE manager handleaudio_recorder_close: Close recorder
- Feeder:
audio_feeder_open: Open feeder (supports decoder configuration)audio_feeder_run: Start feederaudio_feeder_feed_data: Feed audio dataaudio_feeder_stop: Stop feederaudio_feeder_close: Close feeder
- Playback:
audio_playback_open/audio_playback_close: Open/close playeraudio_playback_play: Play audio (supports URL or local file, e.g.,http://...orfile:///sdcard/...)audio_playback_stop: Stop playbackaudio_playback_pause/audio_playback_resume: Pause/resume playbackaudio_playback_get_state: Get playback state
- Mixer:
audio_processor_mixer_open: Open mixer (must be called after both playback and feeder are opened)audio_processor_mixer_close: Close mixeraudio_processor_ramp_control: Control audio focus and volume fade
- Video rendering:
video_render_open/video_render_close: Open/close video renderervideo_render_start/video_render_stop: Start/stop renderingvideo_render_frame_feed: Feed video frame
- Video capture:
video_capture_open/video_capture_close: Open/close video capturervideo_capture_start/video_capture_stop: Start/stop capture
FAQ ❓
Audio Issues
-
"Self-questioning" phenomenon occurs (device playback sound is repeatedly captured by microphone):
- Enable
MEDIA_DUMP_ENABLEinmenuconfig, reproduce the issue and export saved audio data for further analysis - Open the exported audio file using Audacity, observe waveform/spectrum to determine if saturation or feedback exists
- If saturation clipping occurs, reduce microphone gain (
esp_codec_dev_set_in_gain); or appropriately reduce speaker volume (esp_codec_dev_set_out_vol) to avoid excessive feedback
- Enable
-
Stack overflow when using OPUS encoder/decoder:
- Ensure
task_stackofrecorder_task_configandfeeder_task_configis set to at least4096 * 10bytes (40KB) - Consider allocating task stack in external memory (set
task_stack_in_ext = true)
- Ensure
-
Mixer not working properly:
- Ensure that both player (
audio_playback_open) and feeder (audio_feeder_open) are opened before callingaudio_processor_mixer_open() - Ensure
enable_mixer = trueis set when callingaudio_manager_init
- Ensure that both player (
Development and Debugging
-
Modifying component source code (espressif__av_processor):
- If you need to modify code within
espressif__av_processor, you can execute thescript/move_av_processor.pyscript - The script will copy
managed_components/espressif__av_processorto your project'sPROJECT_DIR/components/espressif__av_processordirectory - The script will automatically delete the original directory under
managed_componentsand updateidf_component.yml - Before using, set the environment variable:
export PROJECT_DIR=/path/to/project
- If you need to modify code within
-
Media data dump (Media Dump):
- UDP method: Can use
script/udp_reciver.pyscript to receive UDP data - SD card method: Ensure SD card is properly mounted and file path is accessible
- UDP method: Can use
Version Information
Current version: v0.5.0
License
This component follows the Apache-2.0 license. See the LICENSE file included in the repository for details.
Related Resources
- Project repository: https://github.com/espressif/esp-gmf/tree/main/components/av_processor
- Issue reporting: https://github.com/espressif/esp-gmf/issues
- Documentation: https://github.com/espressif/esp-gmf/blob/main/components/av_processor/README.md