/**
 * Add background music
 * 
 * @param path Music file path
 * @param startAtVideoTimeUS Time point in the video where background music appears (microseconds)
 * @param startTimeUS Start playback time of the background music itself (microseconds)
 * @param duration Background music playback duration (microseconds)
 * @return Unique background music ID
 */
int bgmId = editor.addBgm(path, startAtVideoTimeUS, startTimeUS, duration);

/**
 * Remove background music
 * 
 * @param bgmId Background music ID
 * @return Whether deletion was successful
 */
boolean success = editor.removeBgm(bgmId);

/**
 * Adjust background music position in the video
 * 
 * @param bgmId Background music ID
 * @param videoStartTime New video time point (microseconds)
 */
editor.updateBgmPlayOffset(bgmId, videoStartTime);

/**
 * Adjust background music play range
 * 
 * @param bgmId Background music ID
 * @param startTime New start time (microseconds)
 * @param duration New playback duration (microseconds)
 */
editor.updateBgmPlayRange(bgmId, startTime, duration);

/**
 * Set individual background music volume
 * 
 * @param bgmId Background music ID
 * @param volume Volume value, recommended range: 0-3f
 */
editor.setBgmVolume(bgmId, volume);

/**
 * Set all background music volume
 * 
 * @param volume Volume value, recommended range: 0-3f
 */
editor.setAllBgmVolume(volume);

/**
 * Get background music volume
 * 
 * @param bgmId Background music ID
 * @return Current volume value
 */
float volume = editor.getBgmVolume(bgmId);

/**
 * Set background music playback speed
 * 
 * @param bgmId Background music ID
 * @param speed Playback speed (1.0 = normal speed)
 */
editor.setBgmSpeed(bgmId, speed);

/**
 * Get background music playback speed
 * 
 * @param bgmId Background music ID
 * @return Current playback speed
 */
float speed = editor.getBgmSpeed(bgmId);

// Add background music (starts at 2s in video, plays the first 3s of music, lasts 4s)
int bgmId = editor.addBgm("/sdcard/music.mp3", 
                          2_000_000,   // Start time in video
                          0,           // Music start time
                          4_000_000);  // Playback duration

// Adjust volume to 70%
editor.setBgmVolume(bgmId, 0.7f);

// Adjust playback speed to 1.5x
editor.setBgmSpeed(bgmId, 1.5f);

// Start playing music at 5s in the video
editor.updateBgmPlayOffset(bgmId, 5_000_000);

// Adjust music play range (start at 1s, play for 2s)
editor.updateBgmPlayRange(bgmId, 
                          1_000_000,  // Start time
                          2_000_000); // Playback duration

// Remove background music
boolean success = editor.removeBgm(bgmId);

// Get background music volume by ID
float currentVolume = editor.getBgmVolume(bgmId);