Python BitstreamRecorder.build方法代码示例

# 需要导入模块: from audiotools.bitstream import BitstreamRecorder [as 别名]
# 或者: from audiotools.bitstream.BitstreamRecorder import build [as 别名]
def aiff_header(sample_rate,
                channels,
                bits_per_sample,
                total_pcm_frames):
    """given a set of integer stream attributes,
    returns header string of everything before an AIFF's PCM data

    may raise ValueError if the total size of the file is too large"""

    from audiotools.bitstream import (BitstreamRecorder, format_size)

    header = BitstreamRecorder(False)

    data_size = (bits_per_sample // 8) * channels * total_pcm_frames
    total_size = ((format_size("4b" + "4b 32u" +
                               "16u 32u 16u 1u 15u 64U" +
                               "4b 32u 32u 32u") // 8) +
                  data_size + (data_size % 2))

    if total_size < (2 ** 32):
        header.build("4b 32u 4b", (b"FORM", total_size, b"AIFF"))
        header.build("4b 32u", (b"COMM", 0x12))
        header.build("16u 32u 16u", (channels,
                                     total_pcm_frames,
                                     bits_per_sample))
        build_ieee_extended(header, sample_rate)
        header.build("4b 32u 32u 32u", (b"SSND", data_size + 8, 0, 0))

        return header.data()
    else:
        raise ValueError("total size too large for aiff file")

# 需要导入模块: from audiotools.bitstream import BitstreamRecorder [as 别名]
# 或者: from audiotools.bitstream.BitstreamRecorder import build [as 别名]
    def update_metadata(self, metadata):
        """takes this track's current MetaData object
        as returned by get_metadata() and sets this track's metadata
        with any fields updated in that object

        raises IOError if unable to write the file
        """

        import os
        from audiotools import TemporaryFile
        from audiotools.ogg import (PageReader,
                                    PacketReader,
                                    PageWriter,
                                    packet_to_pages,
                                    packets_to_pages)
        from audiotools.vorbiscomment import VorbisComment
        from audiotools.bitstream import BitstreamRecorder

        if (metadata is None):
            return
        elif (not isinstance(metadata, VorbisComment)):
            from .text import ERR_FOREIGN_METADATA
            raise ValueError(ERR_FOREIGN_METADATA)
        elif (not os.access(self.filename, os.W_OK)):
            raise IOError(self.filename)

        original_ogg = PacketReader(PageReader(file(self.filename, "rb")))
        new_ogg = PageWriter(TemporaryFile(self.filename))

        sequence_number = 0

        #transfer current file's identification packet in its own page
        identification_packet = original_ogg.read_packet()
        for (i, page) in enumerate(packet_to_pages(
                identification_packet,
                self.__serial_number__,
                starting_sequence_number=sequence_number)):
            page.stream_beginning = (i == 0)
            new_ogg.write(page)
            sequence_number += 1

        #discard the current file's comment packet
        comment_packet = original_ogg.read_packet()

        #generate new comment packet
        comment_writer = BitstreamRecorder(True)
        comment_writer.build("8u 6b", (3, "vorbis"))
        vendor_string = metadata.vendor_string.encode('utf-8')
        comment_writer.build("32u %db" % (len(vendor_string)),
                             (len(vendor_string), vendor_string))
        comment_writer.write(32, len(metadata.comment_strings))
        for comment_string in metadata.comment_strings:
            comment_string = comment_string.encode('utf-8')
            comment_writer.build("32u %db" % (len(comment_string)),
                                 (len(comment_string), comment_string))

        comment_writer.build("1u a", (1,))  # framing bit

        #transfer codebooks packet from original file to new file
        codebooks_packet = original_ogg.read_packet()

        for page in packets_to_pages(
                [comment_writer.data(), codebooks_packet],
                self.__serial_number__,
                starting_sequence_number=sequence_number):
            new_ogg.write(page)
            sequence_number += 1

        #transfer remaining pages after re-sequencing
        page = original_ogg.read_page()
        page.sequence_number = sequence_number
        sequence_number += 1
        new_ogg.write(page)
        while (not page.stream_end):
            page = original_ogg.read_page()
            page.sequence_number = sequence_number
            page.bitstream_serial_number = self.__serial_number__
            sequence_number += 1
            new_ogg.write(page)

        original_ogg.close()
        new_ogg.close()

# 需要导入模块: from audiotools.bitstream import BitstreamRecorder [as 别名]
# 或者: from audiotools.bitstream.BitstreamRecorder import build [as 别名]
def wave_header(sample_rate,
                channels,
                channel_mask,
                bits_per_sample,
                total_pcm_frames):
    """given a set of integer stream attributes,
    returns header string of everything before a RIFF WAVE's PCM data

    may raise ValueError if the total size of the file is too large"""

    from audiotools.bitstream import (BitstreamRecorder, format_size)

    assert(isinstance(sample_rate, int))
    assert(isinstance(channels, int))
    assert(isinstance(channel_mask, int))
    assert(isinstance(bits_per_sample, int))
    assert(isinstance(total_pcm_frames, int) or
           isinstance(total_pcm_frames, long))

    header = BitstreamRecorder(True)

    avg_bytes_per_second = sample_rate * channels * (bits_per_sample // 8)
    block_align = channels * (bits_per_sample // 8)

    # build a regular or extended fmt chunk
    # based on the reader's attributes
    if ((channels <= 2) and (bits_per_sample <= 16)):
        fmt = "16u 16u 32u 32u 16u 16u"
        fmt_fields = (1,   # compression code
                      channels,
                      sample_rate,
                      avg_bytes_per_second,
                      block_align,
                      bits_per_sample)
    else:
        if channel_mask == 0:
            channel_mask = {1: 0x4,
                            2: 0x3,
                            3: 0x7,
                            4: 0x33,
                            5: 0x37,
                            6: 0x3F}.get(channels, 0)
        fmt = "16u 16u 32u 32u 16u 16u" + "16u 16u 32u 16b"
        fmt_fields = (0xFFFE,   # compression code
                      channels,
                      sample_rate,
                      avg_bytes_per_second,
                      block_align,
                      bits_per_sample,
                      22,       # CB size
                      bits_per_sample,
                      channel_mask,
                      b'\x01\x00\x00\x00\x00\x00\x10\x00' +
                      b'\x80\x00\x00\xaa\x00\x38\x9b\x71'  # sub format
                      )

    data_size = (bits_per_sample // 8) * channels * total_pcm_frames
    total_size = ((format_size("4b" + "4b 32u" + fmt + "4b 32u") // 8) +
                  data_size + (data_size % 2))

    if total_size < (2 ** 32):
        header.build("4b 32u 4b", (b"RIFF", total_size, b"WAVE"))
        header.build("4b 32u", (b"fmt ", format_size(fmt) // 8))
        header.build(fmt, fmt_fields)
        header.build("4b 32u", (b"data", data_size))

        return header.data()
    else:
        raise ValueError("total size too large for wave file")

# 需要导入模块: from audiotools.bitstream import BitstreamRecorder [as 别名]
# 或者: from audiotools.bitstream.BitstreamRecorder import build [as 别名]
    def update_metadata(self, metadata):
        """takes this track's current MetaData object
        as returned by get_metadata() and sets this track's metadata
        with any fields updated in that object

        raises IOError if unable to write the file
        """

        import os
        from audiotools import TemporaryFile
        from audiotools.ogg import (PageReader, PacketReader,
                                    PageWriter, packet_to_pages)
        from audiotools.bitstream import BitstreamRecorder

        if (metadata is None):
            return
        elif (not isinstance(metadata, VorbisComment)):
            from .text import ERR_FOREIGN_METADATA
            raise ValueError(ERR_FOREIGN_METADATA)
        elif (not os.access(self.filename, os.W_OK)):
            raise IOError(self.filename)

        original_ogg = PacketReader(PageReader(file(self.filename, "rb")))
        new_ogg = PageWriter(TemporaryFile(self.filename))

        #transfer current file's identification page/packet
        #(the ID packet is always fixed size, and fits in one page)
        identification_page = original_ogg.read_page()
        new_ogg.write(identification_page)
        sequence_number = 1

        #discard the current file's comment packet
        original_ogg.read_packet()

        #write the new comment packet in its own page(s)
        comment_writer = BitstreamRecorder(True)
        comment_writer.write_bytes("OpusTags")
        vendor_string = metadata.vendor_string.encode('utf-8')
        comment_writer.build("32u %db" % (len(vendor_string)),
                             (len(vendor_string), vendor_string))
        comment_writer.write(32, len(metadata.comment_strings))
        for comment_string in metadata.comment_strings:
            comment_string = comment_string.encode('utf-8')
            comment_writer.build("32u %db" % (len(comment_string)),
                                 (len(comment_string), comment_string))

        for page in packet_to_pages(
                comment_writer.data(),
                identification_page.bitstream_serial_number,
                starting_sequence_number=sequence_number):
            new_ogg.write(page)
            sequence_number += 1

        #transfer remaining pages after re-sequencing
        page = original_ogg.read_page()
        page.sequence_number = sequence_number
        sequence_number += 1
        new_ogg.write(page)
        while (not page.stream_end):
            page = original_ogg.read_page()
            page.sequence_number = sequence_number
            sequence_number += 1
            new_ogg.write(page)

        original_ogg.close()
        new_ogg.close()