Generating keyframes for ffmpeg HLS encoding

gistfile1.txt

def keyframe_string(video_length, keyframe_int):
    # Generates a string of times in ffmpeg format hh:mm:ss.000, hh:mm:ss.000
    # Creates times for 0 to video length every keyframe_int
    # video_length: in milliseconds
    # keyframe_int: in seconds
    keyframe_str = ""
    if (keyframe_int > 0):
        # convert to secs from millisecs
        length_secs = float(video_length) / 1000
        num_keyframes = length_secs / keyframe_int
        
        i=0
        for x in range(0, int(num_keyframes)):
            mykeyframe = keyframe_int + i
            mytime = str(datetime.timedelta(seconds=mykeyframe))
            keyframe_str+= "%s," % mytime
            i+=keyframe_int
        # Strip the last comma
        keyframe_str = keyframe_str[:-1]   
    else:
        keyframe_str = "0"
    #print keyframe_str 
    return keyframe_str