tree f1a3cf02593ec16c97b9a86e5f9ba7bf0121894e
parent 09f1516686d1fd62bc6e89fb9ff1874cbbc45fc5
author Jaana Burcu Dogan <jbd@google.com> 1467398403 -0700
committer Jaana Burcu Dogan <jbd@google.com> 1468113566 +0000

design: tweak Clip interface to separate seeking

Seeking within the audio source is not always a trivial problem, e.g.
the cases where the underlying source is encoded with a VBR
compression algorithm, optimistic seeking and slurping the entire
data source may be required.

Separation of the Seek method allows us to explain the requirements
from the implementors more easily. Since different encoders will have
different stragies to Seek, it is also easy to document the cost and
the underlying algorithm to the users.

Also, the seperation helps us document the requirements of
implementing an efficient Clip.Frames. We are explecting decoders
to have a cursor on the data source and move forward as new Frames
calls arrive. We only expect them to modify the cursor if seeking
is required. Without a separate Seek method, implementors need to
check if the offset is matching with their current internal cursor
and seek if it is not. Separation saves them figuring out the
conditional case for a requirement of seeking.

Change-Id: I0b15d56df9457a462953aaaf915445e268462f97
Reviewed-on: https://go-review.googlesource.com/24702
Reviewed-by: David Crawshaw <crawshaw@golang.org>