Adding upstream version 1.4.3+ds.upstream/1.4.3+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 666 insertions, 0 deletions

diff --git a/doc/isoflac.txt b/doc/isoflac.txt
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+Encapsulation of FLAC in ISO Base Media File Format
+Version 0.0.4
+
+Table of Contents
+1 Scope
+2 Supporting Normative References
+3 Design Rules of Encapsulation
+  3.1 File Type Identification
+  3.2 Overview of Track Structure
+  3.3 Definition of FLAC sample
+        3.3.1 Sample entry format
+        3.3.2 FLAC Specific Box
+        3.3.3 Sample format
+        3.3.4 Duration of FLAC sample
+        3.3.5 Sub-sample
+        3.3.6 Random Access
+            3.3.6.1 Random Access Point
+   3.4 Basic Structure (informative)
+        3.4.1 Initial Movie
+   3.5 Example of Encapsulation (informative)
+4 Acknowledgements
+5 Author's Address
+
+1 Scope
+
+    This document specifies the normative mapping for encapsulation of
+    FLAC coded audio bitstreams in ISO Base Media file format and its
+    derivatives. The encapsulation of FLAC coded bitstreams in
+    QuickTime file format is outside the scope of this specification.
+
+2 Supporting Normative References
+
+    [1] ISO/IEC 14496-12:2012 Corrected version
+
+        Information technology — Coding of audio-visual objects — Part
+        12: ISO base media file format
+
+    [2] ISO/IEC 14496-12:2012/Amd.1:2013
+
+        Information technology — Coding of audio-visual objects — Part
+        12: ISO base media file format AMENDMENT 1: Various
+        enhancements including support for large metadata
+
+    [3] FLAC format specification
+
+        https://xiph.org/flac/format.html
+
+        Definition of the FLAC Audio Codec stream format
+
+    [4] FLAC-in-Ogg mapping specification
+
+        https://xiph.org/flac/ogg_mapping.html
+
+        Ogg Encapsulation for the FLAC Audio Codec
+
+    [5] Matroska specification
+
+3 Design Rules of Encapsulation
+
+    3.1 File Type Identification
+    
+        This specification does not define any brand to declare files
+        which conform to this specification.  Files which conform to
+        this specification shall contain at least one brand which
+        supports the requirements and the requirements described in
+        this clause without contradiction in the compatible brands
+        list of the File Type Box.  The minimal support of the
+        encapsulation of FLAC bitstreams in ISO Base Media file format
+        requires the 'isom' brand.
+        
+    3.2 Overview of Track Structure
+
+        FLAC coded audio shall be encapsulated into the ISO Base
+        Media File Format as media data within an audio track.
+        
+            + The handler_type field in the Handler Reference Box
+              shall be set to 'soun'.
+            
+            + The Media Information Box shall contain the Sound Media
+              Header Box.
+            
+            + The codingname of the sample entry is 'fLaC'.
+            
+                This specification does not define any encapsulation
+                using MP4AudioSampleEntry with objectTypeIndication
+                specified by the MPEG-4 Registration Authority
+                (http://www.mp4ra.org/).  See section 'Sample entry
+                format' for the definition of the sample entry.
+                
+            + The 'dfLa' box is added to the sample entry to convey
+                initializing information for the decoder.
+
+                See section 'FLAC Specific Box' for the definition of
+                the box contents.
+
+            + A FLAC sample is exactly one FLAC frame as described
+                in the format specification[3].  See section
+                'Sample format' for details of the frame contents.
+
+            + Every FLAC sample is a sync sample.  No pre-roll or
+                lapping is required.  See section 'Random Access' for
+                further details.
+
+    3.3 Definition of a FLAC sample
+    
+        3.3.1 Sample entry format
+
+            For any track containing one or more FLAC bitstreams, a
+            sample entry describing the corresponding FLAC bitstream
+            shall be present inside the Sample Table Box. This version
+            of the specification defines only one sample entry format
+            named FLACSampleEntry whose codingname is 'fLaC'.  This
+            sample entry includes exactly one FLAC Specific Box
+            defined in section 'FLAC specific box' as a mandatory box
+            and indicates that FLAC samples described by this sample
+            entry are stored by the sample format described in section
+            'Sample format'.
+
+            The syntax and semantics of the FLACSampleEntry is shown
+            as follows.  The data fields of this box and native
+            FLAC[3] structures encoded within FLAC blocks are both
+            stored in big-endian format, though for purposes of the
+            ISO BMFF container, FLAC native metadata and data blocks
+            are treated as unstructured octet streams.
+ 
+            class FLACSampleEntry() extends AudioSampleEntry ('fLaC'){
+                FLACSpecificBox();
+            }
+
+            The fields of the AudioSampleEntry portion shall be set as
+            follows:
+
+            + channelcount:
+
+                The channelcount field shall be set equal to the
+                channel count specified by the FLAC bitstream's native
+                METADATA_BLOCK_STREAMINFO header as described in [3].
+                Note that the FLAC FRAME_HEADER structure that begins
+                each FLAC sample redundantly encodes channel number;
+                the number of channels declared in each FRAME_HEADER
+                MUST match the number of channels declared here and in
+                the METADATA_BLOCK_STREAMINFO header.
+
+            + samplesize:
+
+                The samplesize field shall be set equal to the bits
+                per sample specified by the FLAC bitstream's native
+                METADATA_BLOCK_STREAMINFO header as described in [3].
+                Note that the FLAC FRAME_HEADER structure that begins
+                each FLAC sample redundantly encodes the number of
+                bits per sample; the bits per sample declared in each
+                FRAME_HEADER MUST match the samplesize declared here
+                and the bits per sample field declared in the
+                METADATA_BLOCK_STREAMINFO header.
+                
+            + samplerate:
+
+                When possible, the samplerate field shall be set
+                equal to the sample rate specified by the FLAC
+                bitstream's native METADATA_BLOCK_STREAMINFO header
+                as described in [3], left-shifted by 16 bits to
+                create the appropriate 16.16 fixed-point
+                representation.
+
+                When the bitstream's native sample rate is greater
+                than the maximum expressible value of 65535 Hz,
+                the samplerate field shall hold the greatest
+                expressible regular division of that rate. I.e.
+                the samplerate field shall hold 48000.0 for
+                native sample rates of 96 and 192 kHz. In the
+                case of unusual sample rates which do not have
+                an expressible regular division, the maximum value
+                of 65535.0 Hz should be used.
+
+                High-rate FLAC bitstreams are common, and the native
+                value from the METADATA_BLOCK_STREAMINFO header in
+                the FLACSpecificBox MUST be read to determine the
+                correct sample rate of the bitstream.
+
+                Note that the FLAC FRAME_HEADER structure that begins
+                each FLAC sample redundantly encodes the sample rate;
+                the sample rate declared in each FRAME_HEADER MUST
+                match the sample rate declared in the
+                METADATA_BLOCK_STREAMINFO header, and here in the
+                AudioSampleEntry portion of the FLACSampleEntry
+                as much as is allowed by the encoding restrictions
+                described above.
+                
+            Finally, the FLACSpecificBox carries codec headers:
+
+            + FLACSpecificBox
+            
+                This box contains initializing information for the
+                decoder as defined in section 'FLAC specific box'.
+
+        3.3.2 FLAC Specific Box
+        
+            Exactly one FLAC Specific Box shall be present in each
+            FLACSampleEntry.  This specification defines version 0
+            of this box.  If incompatible changes occur in future
+            versions of this specification, another version number
+            will be defined.  The data fields of this box and native
+            FLAC[3] structures encoded within FLAC blocks are both
+            stored in big-endian format, though for purposes of the
+            ISO BMFF container, FLAC native metadata and data blocks
+            are treated as unstructured octet streams.
+
+            The syntax and semantics of the FLAC Specific Box is shown
+            as follows.
+
+            class FLACMetadataBlock {
+               unsigned int(1) LastMetadataBlockFlag;
+               unsigned int(7) BlockType;
+               unsigned int(24) Length;
+               unsigned int(8) BlockData[Length];
+            }
+
+            aligned(8) class FLACSpecificBox
+                  extends FullBox('dfLa', version=0, 0){
+               for (i=0; ; i++) { // to end of box
+                  FLACMetadataBlock();
+               }
+            }
+
+            + Version:
+
+                The Version field shall be set to 0.
+
+                In the future versions of this specification, this
+                field may be set to other values. And without support
+                of those values, the reader shall not read the fields
+                after this within the FLACSpecificBox.
+
+            + Flags:
+
+                The Flags field shall be set to 0.
+
+            After the FullBox header, the box contains a sequence of
+            FLAC[3] native-metadata block structures that fill the
+            remainder of the box.
+
+            Each FLACMetadataBlock structure consists of three fields
+            filling a total of four bytes that form a FLAC[3] native
+            METADATA_BLOCK_HEADER, followed by raw octet bytes that
+            comprise the FLAC[3] native METADATA_BLOCK_DATA.
+
+            + LastMetadataBlockFlag:
+
+                The LastMetadataBlockFlag field maps semantically to
+                the FLAC[3] native METADATA_BLOCK_HEADER
+                Last-metadata-block flag as defined in the FLAC[3]
+                file specification.
+                
+                The LastMetadataBlockFlag is set to 1 if this
+                MetadataBlock is the last metadata block in the
+                FLACSpecificBox.  It is set to 0 otherwise.
+               
+            + BlockType:
+
+                The BlockType field maps semantically to the FLAC[3]
+                native METADATA_BLOCK_HEADER BLOCK_TYPE field as
+                defined in the FLAC[3] file specification.
+
+                The BlockType is set to a valid FLAC[3] BLOCK_TYPE
+                value that identifies the type of this native metadata
+                block.  The BlockType of the first FLACMetadataBlock
+                must be set to 0, signifying this is a FLAC[3] native
+                METADATA_BLOCK_STREAMINFO block.
+               
+            + Length:
+
+                The Length field maps semantically to the FLAC[3]
+                native METADATA_BLOCK_HEADER Length field as
+                defined in the FLAC[3] file specification.
+
+                The length field specifies the number of bytes of
+                MetadataBlockData to follow.
+
+            + BlockData
+
+                The BlockData field maps semantically to the FLAC[3]
+                native METADATA_BLOCK_HEADER METADATA_BLOCK_DATA as
+                defined in the FLAC[3] file specification.
+
+            Taken together, the bytes of the FLACMetadataBlock form a
+            complete FLAC[3] native METADATA_BLOCK structure.
+
+            Note that a minimum of a single FLACMetadataBlock,
+            consisting of a FLAC[3] native METADATA_BLOCK_STREAMINFO
+            structure, is required.  Should the FLACSpecificBox
+            contain more than a single FLACMetadataBlock structure,
+            the FLACMetadataBlock containing the FLAC[3] native
+            METADATA_BLOCK_STREAMINFO must occur first in the list.
+
+            Other containers that package FLAC audio streams, such as
+            Ogg[4] and Matroska[5], wrap FLAC[3] native metadata without
+            modification similar to this specification.  When
+            repackaging or remuxing FLAC[3] streams from another
+            format that contains FLAC[3] native metadata into an ISO
+            BMFF file, the complete FLAC[3] native metadata should be
+            preserved in the ISO BMFF stream as described above.  It
+            is also allowed to parse this native metadata and include
+            contextually redundant ISO BMFF-native repackagings and/or
+            reparsings of FLAC[3] native metadata, so long as the
+            native metadata is also preserved.
+
+        3.3.3 Sample format
+        
+            A FLAC sample is exactly one FLAC audio FRAME (as defined
+            in the FLAC[3] file specification) belonging to a FLAC
+            bitstreams. The FLAC sample data begins with a complete
+            FLAC FRAME_HEADER, followed by one FLAC SUBFRAME per
+            channel, any necessary bit padding, and ends with the
+            usual FLAC FRAME_FOOTER.
+
+            Note that the FLAC native FRAME_HEADER structure that
+            begins each FLAC sample redundantly encodes channel count,
+            sample rate, and sample size.  The values of these fields
+            must agree both with the values declared in the FLAC
+            METADATA_BLOCK_STREAMINFO structure as well as the
+            FLACSampleEntry box.
+
+        3.3.4 Duration of a FLAC sample
+
+            The duration of any given FLAC sample is determined by
+            dividing the decoded block size of a FLAC frame, as
+            encoded in the FLAC FRAME's FRAME_HEADER structure, by the
+            value of the timescale field in the Media Header Box.
+            FLAC samples are permitted to have variable durations
+            within a given audio stream.  FLAC does not use padding
+            values.
+
+        3.3.5 Sub-sample
+
+            Sub-samples are not defined for FLAC samples in this
+            specification.
+
+        3.3.6 Random Access
+        
+            This subclause describes the nature of the random access
+            of FLAC sample.
+
+            3.3.6.1 Random Access Point
+            
+                All FLAC samples can be independently decoded
+                i.e. every FLAC sample is a sync sample. The Sync
+                Sample Box shall not be present as long as there are
+                no samples other than FLAC samples in the same
+                track. The sample_is_non_sync_sample field for FLAC
+                samples shall be set to 0.
+
+    3.4 Basic Structure (informative)
+
+        3.4.1 Initial Movie
+        
+            This subclause shows a basic structure of the Movie Box as follows:
+
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |moov|    |    |    |    |    |    |    | Movie Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |mvhd|    |    |    |    |    |    | Movie Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |trak|    |    |    |    |    |    | Track Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |tkhd|    |    |    |    |    | Track Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |edts|*   |    |    |    |    | Edit Box                     |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |elst|*   |    |    |    | Edit List Box                |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |mdia|    |    |    |    |    | Media Box                    |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |mdhd|    |    |    |    | Media Header Box             |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |hdlr|    |    |    |    | Handler Reference Box        |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |minf|    |    |    |    | Media Information Box        |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |smhd|    |    |    | Sound Media Header Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |dinf|    |    |    | Data Information Box         |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |dref|    |    | Data Reference Box           |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |url |    | DataEntryUrlBox              |
+            +----+----+----+----+----+----+ or +----+------------------------------+
+            |    |    |    |    |    |    |urn |    | DataEntryUrnBox              |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |stbl|    |    |    | Sample Table                 |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsd|    |    | Sample Description Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |fLaC|    | FLACSampleEntry              |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |    |    |dfLa| FLAC Specific Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stts|    |    | Decoding Time to Sample Box  |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsc|    |    | Sample To Chunk Box          |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stsz|    |    | Sample Size Box              |
+            +----+----+----+----+----+ or +----+----+------------------------------+
+            |    |    |    |    |    |stz2|    |    | Compact Sample Size Box      |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |    |    |    |stco|    |    | Chunk Offset Box             |
+            +----+----+----+----+----+ or +----+----+------------------------------+
+            |    |    |    |    |    |co64|    |    | Chunk Large Offset Box       |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |mvex|*   |    |    |    |    |    | Movie Extends Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+            |    |    |trex|*   |    |    |    |    | Track Extends Box            |
+            +----+----+----+----+----+----+----+----+------------------------------+
+
+                    Figure 1 - Basic structure of Movie Box
+
+            It is strongly recommended that the order of boxes should
+            follow the above structure.  Boxes marked with an asterisk
+            (*) may or may not be present depending on context.  For
+            most boxes listed above, the definition is as is defined
+            in ISO/IEC 14496-12 [1]. The additional boxes and the
+            additional requirements, restrictions and recommendations
+            to the other boxes are described in this specification.
+            
+    3.5 Example of Encapsulation (informative)
+        [File]
+            size = 17790
+            [ftyp: File Type Box]
+                position = 0
+                size = 24
+                major_brand = mp42 : MP4 version 2
+                minor_version = 0
+                compatible_brands
+                    brand[0] = mp42 : MP4 version 2
+                    brand[1] = isom : ISO Base Media file format
+            [moov: Movie Box]
+                position = 24
+                size = 757
+                [mvhd: Movie Header Box]
+                    position = 32
+                    size = 108
+                    version = 0
+                    flags = 0x000000
+                    creation_time = UTC 2014/12/12, 18:41:19
+                    modification_time = UTC 2014/12/12, 18:41:19
+                    timescale = 48000
+                    duration = 33600 (00:00:00.700)
+                    rate = 1.000000
+                    volume = 1.000000
+                    reserved = 0x0000
+                    reserved = 0x00000000
+                    reserved = 0x00000000
+                    transformation matrix
+                        | a, b, u |   | 1.000000, 0.000000, 0.000000 |
+                        | c, d, v | = | 0.000000, 1.000000, 0.000000 |
+                        | x, y, w |   | 0.000000, 0.000000, 1.000000 |
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    pre_defined = 0x00000000
+                    next_track_ID = 2
+                [iods: Object Descriptor Box]
+                    position = 140
+                    size = 33
+                    version = 0
+                    flags = 0x000000
+                    [tag = 0x10: MP4_IOD]
+                        expandableClassSize = 16
+                        ObjectDescriptorID = 1
+                        URL_Flag = 0
+                        includeInlineProfileLevelFlag = 0
+                        reserved = 0xf
+                        ODProfileLevelIndication = 0xff
+                        sceneProfileLevelIndication = 0xff
+                        audioProfileLevelIndication = 0xfe
+                        visualProfileLevelIndication = 0xff
+                        graphicsProfileLevelIndication = 0xff
+                        [tag = 0x0e: ES_ID_Inc]
+                            expandableClassSize = 4
+                            Track_ID = 1
+                [trak: Track Box]
+                    position = 173
+                    size = 608
+                    [tkhd: Track Header Box]
+                        position = 181
+                        size = 92
+                        version = 0
+                        flags = 0x000007
+                            Track enabled
+                            Track in movie
+                            Track in preview
+                        creation_time = UTC 2014/12/12, 18:41:19
+                        modification_time = UTC 2014/12/12, 18:41:19
+                        track_ID = 1
+                        reserved = 0x00000000
+                        duration = 33600 (00:00:00.700)
+                        reserved = 0x00000000
+                        reserved = 0x00000000
+                        layer = 0
+                        alternate_group = 0
+                        volume = 1.000000
+                        reserved = 0x0000
+                        transformation matrix
+                            | a, b, u |   | 1.000000, 0.000000, 0.000000 |
+                            | c, d, v | = | 0.000000, 1.000000, 0.000000 |
+                            | x, y, w |   | 0.000000, 0.000000, 1.000000 |
+                        width = 0.000000
+                        height = 0.000000
+                    [mdia: Media Box]
+                        position = 273
+                        size = 472
+                        [mdhd: Media Header Box]
+                            position = 281
+                            size = 32
+                            version = 0
+                            flags = 0x000000
+                            creation_time = UTC 2014/12/12, 18:41:19
+                            modification_time = UTC 2014/12/12, 18:41:19
+                            timescale = 48000
+                            duration = 34560 (00:00:00.720)
+                            language = und
+                            pre_defined = 0x0000
+                        [hdlr: Handler Reference Box]
+                            position = 313
+                            size = 51
+                            version = 0
+                            flags = 0x000000
+                            pre_defined = 0x00000000
+                            handler_type = soun
+                            reserved = 0x00000000
+                            reserved = 0x00000000
+                            reserved = 0x00000000
+                            name = Xiph Audio Handler
+                        [minf: Media Information Box]
+                            position = 364
+                            size = 381
+                            [smhd: Sound Media Header Box]
+                                position = 372
+                                size = 16
+                                version = 0
+                                flags = 0x000000
+                                balance = 0.000000
+                                reserved = 0x0000
+                            [dinf: Data Information Box]
+                                position = 388
+                                size = 36
+                                [dref: Data Reference Box]
+                                    position = 396
+                                    size = 28
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    [url : Data Entry Url Box]
+                                        position = 412
+                                        size = 12
+                                        version = 0
+                                        flags = 0x000001
+                                        location = in the same file
+                            [stbl: Sample Table Box]
+                                position = 424
+                                size = 321
+                                [stsd: Sample Description Box]
+                                    position = 432
+                                    size = 79
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    [fLaC: Audio Description]
+                                        position = 448
+                                        size = 63
+                                        reserved = 0x000000000000
+                                        data_reference_index = 1
+                                        reserved = 0x0000
+                                        reserved = 0x0000
+                                        reserved = 0x00000000
+                                        channelcount = 2
+                                        samplesize = 16
+                                        pre_defined = 0
+                                        reserved = 0
+                                        samplerate = 48000.000000
+                                        [dfLa: FLAC Specific Box]
+                                            position = 484
+                                            size = 50
+                                            version = 0
+                                            flags = 0x000000
+                                            [FLACMetadataBlock]
+                                                LastMetadataBlockFlag = 1
+                                                BlockType = 0
+                                                Length = 34
+                                                BlockData[34];
+                                [stts: Decoding Time to Sample Box]
+                                    position = 492
+                                    size = 24
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 1
+                                    entry[0]
+                                        sample_count = 18
+                                        sample_delta = 1920
+                                [stsc: Sample To Chunk Box]
+                                    position = 516
+                                    size = 40
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 2
+                                    entry[0]
+                                        first_chunk = 1
+                                        samples_per_chunk = 13
+                                        sample_description_index = 1
+                                    entry[1]
+                                        first_chunk = 2
+                                        samples_per_chunk = 5
+                                        sample_description_index = 1
+                                [stsz: Sample Size Box]
+                                    position = 556
+                                    size = 92
+                                    version = 0
+                                    flags = 0x000000
+                                    sample_size = 0 (variable)
+                                    sample_count = 18
+                                    entry_size[0] = 977
+                                    entry_size[1] = 938
+                                    entry_size[2] = 939
+                                    entry_size[3] = 938
+                                    entry_size[4] = 934
+                                    entry_size[5] = 945
+                                    entry_size[6] = 948
+                                    entry_size[7] = 956
+                                    entry_size[8] = 955
+                                    entry_size[9] = 930
+                                    entry_size[10] = 933
+                                    entry_size[11] = 934
+                                    entry_size[12] = 972
+                                    entry_size[13] = 977
+                                    entry_size[14] = 958
+                                    entry_size[15] = 949
+                                    entry_size[16] = 962
+                                    entry_size[17] = 848
+                                [stco: Chunk Offset Box]
+                                    position = 648
+                                    size = 24
+                                    version = 0
+                                    flags = 0x000000
+                                    entry_count = 2
+                                    chunk_offset[0] = 686
+                                    chunk_offset[1] = 12985
+            [free: Free Space Box]
+                position = 672
+                size = 8
+            [mdat: Media Data Box]
+                position = 680
+                size = 17001
+
+4 Acknowledgements
+
+    This spec draws heavily from the Opus-in-ISOBMFF specification
+    work done by Yusuke Nakamura <muken.the.vfrmaniac |at| gmail.com>
+
+    Thank you to Tim Terriberry, David Evans, and Yusuke Nakamura
+    for valuable feedback. Thank you to Ralph Giles for editorial
+    help.
+
+5 Author Address
+
+    Monty Montgomery <cmontgomery@mozilla.com>