Put the new raw GSM demuxer in its own file.
Fixes raw GSM demuxing.

calculate it from c->code_size instead.

This is an easy alternative to setting bit_rate. This patch also selects the
closest bit_rate to the requested one rather than requiring an exact value.

This should never happen, but the check avoids a divide-by-zero.

This requires some workarounds in the WAV muxer and demuxer. We need to write
the correct bits_per_coded_sample and block_align in the muxer. In the
demuxer, we cannot rely on the bits_per_coded_sample value, so we use the bit
rate and sample rate to determine the value.

This avoids having the decoder rely on AVCodecContext.bit_rate, which is not
required to be set by the user for decoding according to our API.

This also allows for not having a decoder close function.

Allows for checking output buffer size and simplification of decoding loop.

Signed-off-by: Martin Storsjö <martin@martin.st>

This symbol name clashes with a symbol in gnutls, if linking
statically to that library.
Signed-off-by: Martin Storsjö <martin@martin.st>

The names used in the libdirac/libschroedinger wrappers are long enough as-is.
Bloating them with unnecessary prefixes makes them even more unwieldy.

Also check output buffer size instead of truncating output.

bits_per_coded_sample should be 8.
block_align is calculated incorrectly, but it is not needed anyway.
packet pts should be calculated in samples.
packet duration can be set.

Return error if core block decoding fails.
Do not enable XCh if XCh extension block decoding fails.

If the frame is filled with the same colour, encoder may produce no data
and the fill value is indicated by zero code length (the rest of symbols
will have 0xFF for code length, meaning invalid).  So such Huffman trees
should be treated specially.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>