libstagefright: Adds some parsing capability

o Adds AC3, EAC3 and DTS mime types
o Adds AC3/EAC3 support in MP4 parser
o Adds MPEG4 video, MPEG Audio, AC3, DTS, EAC3 support
in mkv extractor.

Change-Id: I9895c0e40e5ad38976004a9569200f1340d525de
Audio stops after seeking AVI clip with MP3 audio (special contents without proper key samples)

During seek in AVI, nearest Sync sample was searched both for
audio and video. Sync samples are useful only in case of
video. We can ignore Sync field for non-video tracks.

Change-Id: Ibaeda8f14afb83905e19087625a7d72fb1b3c8d6
Signed-off-by: Arulselvan M <arulselvan.m@intel.com>
Signed-off-by: Jin Wei <wei.a.jin@intel.com>
Correct the time returned by AudioPlayer::getMediaTime

The change 80a68deec52c9a1b47215ed68526206ec88197f8 was added to
eliminate returning negative media positions.

In the change all negative values of realTimeOffset were discarded.
The value realTimeOffset accounts for the latency and the
number of samples played since last feeding the AudioTrack and is
generally negative. By discarding this value for negative values the
time returned does not account for latency or the number of samples
played.

Change-Id: I470450934228732e34539c227365a225be74ccc8
stagefright: Fix seeking in MPEG4 container - do not merge

- seek based on user-visible timestamp
- seek to previous, next and closest exactly
- also update OggExtractor seek to same logic

Bug: 12786906
Change-Id: I2d5e1fbff6469b6f081a284be2222a4cb50aa754
stagefright: Enable 24-bit mode for DTS audio

 * FFMPEG will convert floating point samples to 24-bit PCM
   if the system is capable of it.

Change-Id: I14fb015468166e567a17bf8758474788e1c285e9