The wavpack open function gives us an option called OPEN_STREAMING. This
provides more robust and error tolerant playback, but it automatically
disables seeking. (More exactly the wavpack lib will not return the
length information.) So, if the stream is already not seekable we can
use this option safely.
According to the documentation, mpc_decoder_decode() returns an
mpc_uint32_t. Since the special return value (mpc_uint32_t)-1
translates to a very large long integer, this may cause segmentation
faults if not interpreted properly.
Don't split the buffer conversion loop. When libmpcdec returns a
chunk, convert and send the whole chunk at a time. This moves several
checks out of the loop, and greatly improves performance.
Parse ID3 tags, even when they are in the middle of the stream. Very
few streams provide embedded ID3 tags. Most of them send only
Shoutcast "icy" tags, which limits the practical usefulness of this
patch.
When a command is received, decode_next_frame_header() and
decodeNextFrame() return DECODE_BREAK. This is already checked by
both callers, which means that we can eliminate lots of
decoder_get_command() checks.
The stream_decode() and file_decode() methods returned a boolean,
indicating whether they were able to decode the song. This is
redundant, since we already know that: if decoder_initialized() has
been called (and dc.state==DECODE), the plugin succeeded. Change both
methods to return void.
The function simplifies wavpack_replaygain(), because it already
contains the float parser, and it works with a fixed buffer instead of
doing expensive heap allocations.
The flac plugin wasn't initialized properly when an OGG file was being
decoded. For some reason, flac_process_metadata() was explicitly not
called for OGG files. Since that seems to fix the issue, make it
always call flac_process_metadata().
Since decoder_list.c does not include the libflac headers, it cannot
know whether to add the oggflac plugin to the decoder list. Solve
this by always enabling the oggflac sub-plugin, even with older
libflac versions. When the libflac API cannot support oggflac,
disable the plugin at runtime by returning "false" from its init()
method.
At this moment the wavpack lib doesn't use the return value of the
push_back function, which has an equivalent meaning of the return
value of ungetc(). This is a lucky situation, because so far it
simply returned with 1 as a hard coded value. From now on the
function will return EOF on error. (This function makes exactly one
byte pushable back.)
There are some functions in the wavpack-mpd input streams wrapper
which had too commonly used names (especially can_seek). I prefixed
these with "wavpack_input_".
