source: ammosreader/AmmosAudioReader.py@ c063328

import math
import os

from AmmosGlobalFrameBody import AmmosGlobalFrameBody
from AmmosAudioDataHeader import AmmosAudioDataHeader
from AmmosExtendedAudioDataHeader import AmmosExtendedAudioDataHeader
from AmmosGlobalFrameHeader import AmmosGlobalFrameHeader
from AmmosSingleFrame import AmmosSingleFrame
from AmmosContainer import AmmosContainer


class AmmosAudioReader():

    def __init__(self, file_name):

        self.file_name = file_name
        self.file = open(self.file_name, "rb")
        self.file_size = os.path.getsize(self.file_name)

        self.container = AmmosContainer(self.file_name, [])

        self.tags = []

    def rewind_to_start(self):
        self.file.seek(0)

    def add_tag(self, tag):
        self.tags.append(tag)

    def read_all_frames_left(self):

        frames_read = 0

        while True:
            print("Reading single frame", frames_read, '...')
            current_frame = self.read_next_single_frame()
            if current_frame is not None:
                frames_read += 1
                self.container.add_frame(current_frame)
                if frames_read % 10000 == 0:
                    print("#", end="")
            else:
                print("Frame:", frames_read+1, " incomplete")
                break

        print(len(self.container.global_frames), "frames read")

    def read_next_global_frame_header(self):
        bytes = self.file.read(24)
        print("Reading next global frame header")
        if ((not bytes) or (len(bytes) < 24)):
            print("Can not read all 24 bytes of global frame header")
            return None

        current_global_frame_header = AmmosGlobalFrameHeader.from_bytes(bytes)
        print("Current global frame header", current_global_frame_header)
        return current_global_frame_header

    def read_next_global_frame_body_data_header(self):

        bytes = self.file.read(56)

        # print("\nReading global frame body standard data header\n")
        if ((not bytes) or (len(bytes) < 56)):
            print("Can not read all 56 bytes of global frame body data header")
            return None

        data_header = AmmosAudioDataHeader.from_bytes(bytes)
        # print("Data header", data_header)
        return data_header

    def read_next_global_frame_body_extended_data_header(self):

        bytes = self.file.read(44)
        # print("\nReading global frame body extended data header\n")

        if ((not bytes) or (len(bytes) < 44)):
            print("Can not read all ", 44, "bytes of global frame extended data header")
            return None
        extended_data_header = AmmosExtendedAudioDataHeader.from_bytes(bytes)
        # print("Extended data header", extended_data_header)
        return extended_data_header

    def read_next_audio_data_body(self, sample_count, channel_count, sample_size):

        # FIXME: Describe the parameters better

        total = sample_count*channel_count*sample_size

        byte_string = self.file.read(total)

        if len(byte_string) != total:
            print("Can not read all", total, "bytes of data body")
            return None
        print([hex(c) for c in byte_string])
        return byte_string

    def read_next_global_frame_body(self, global_frame_header):

        audio_data_header = None

        if global_frame_header.data_header_length == 36:
            print("Read standard data header")
            audio_data_header = self.read_next_global_frame_body_data_header()

        else:
            print("Read extended data header")
            audio_data_header = self.read_next_global_frame_body_extended_data_header()

        if audio_data_header is None:
            print("Data header missing")
            return None

        audio_data_body = self.read_next_audio_data_body(audio_data_header.sample_count,
                                                         audio_data_header.channel_count,
                                                         audio_data_header.sample_size)

        if audio_data_body is None:
            print("Data body missing")
            return None

        return AmmosGlobalFrameBody(audio_data_header, audio_data_body)

    def read_next_single_frame(self):

        global_frame_header = self.read_next_global_frame_header()

        if global_frame_header is None:
            print("Global frame header missing")
            return None

        if global_frame_header.data_header_length is None:
            print("Data header length empty")
            return None

        if global_frame_header.frame_type == 256:
            print("Audio Datastream found")
            global_frame_body = self.read_next_global_frame_body(global_frame_header)
            if global_frame_body is None:
                return None
        else:
            print("Unsupported frame type", global_frame_header.frame_type, "found")
            return None

        ammos_single_frame = AmmosSingleFrame(global_frame_header, global_frame_body)
        return ammos_single_frame