|
Class Summary |
| AbstractMp4Box |
Abstract mp4 box, contain a header and then rawdata (which may include child boxes) |
| Mp4AlacBox |
AlacBox ( Apple Lossless Codec information description box),
Normally occurs twice, the first ALAC contaisn the default values, the second ALAC within contains the real
values for this audio. |
| Mp4BoxHeader |
Everything in MP4s are held in boxes (formally known as atoms), they are held as a hierachial tree within the MP4. |
| Mp4DrmsBox |
DrmsBox Replaces mp4a box on drm files
Need to skip over data in order to find esds atom
Specification not known, so just look for byte by byte 'esds' and then step back four bytes for size |
| Mp4EsdsBox |
EsdsBox ( stream specific description box), usually holds the Bitrate/No of Channels
It contains a number of (possibly optional?) sections (section 3 - 6) (containing optional filler) with
differeent info in each section. |
| Mp4FreeBox |
FreeBox ( padding)
|
| Mp4FtypBox |
Ftyp (File Type) is the first atom, can be used to help identify the mp4 container type |
| Mp4HdlrBox |
HdlrBox ( Handler box),
Describes the type of metadata in the following ilst or minf atom |
| Mp4MdhdBox |
MdhdBox ( media (stream) header), holds the Sampling Rate used. |
| Mp4MetaBox |
This MP4 MetaBox is the parent of metadata, it usually contains four bytes of data
that needs to be processed before we can examine the children. |
| Mp4Mp4aBox |
Mp4aBox ( sample (frame encoding) description box)
At first glance appears to hold no of channels but actually always returns 2 even for mono recordings
so just need to skip over data in order to get to child atom esds
|
| Mp4MvhdBox |
MvhdBox (movie (presentation) header box)
|
| Mp4StcoBox |
StcoBox ( media (stream) header), holds offsets into the Audio data |
| Mp4StsdBox |
StsdBox ( sample (frame encoding) description box)
|
| NullPadding |
Some mp4s contain null padding at the end of the file, possibly do with gapless playback. |