Use 'auto' as the default value.

channel.

Move bit counting to the bit allocation function. Move exponent grouping to
after bit allocation. This will allow for adjustment of bandwidth parameters
during bit allocation without having to do exponent grouping multiple times.

This checks if the set of selected exponent strategies for all blocks in a
channel are in the frame exponent strategy table, and if so, writes the
table index instead of each strategy. This saves up to 7 bits per channel per
frame, so the overall effect on quality is small.

Since both the fixed-point and floating-point encoders use the FFTContext,
this no longer needs to be in a separate context. Also, when a short-transform
context is added, the same MDCT window will be used.

This avoids using function pointers for quite a few small functions, most of
which just call DSP functions.

They introduce too much complexity for very little benefit. The result is that
encoding will be more likely to fail at extremely low bitrates where quality
would be awful anyway.

quantized mantissas.

sizeof(SampleType) is different for fixed and float encoders.

Function pointers are used for templated functions instead of needlessly
duplicating many functions.

This will allow the same struct to be used for both the fixed and float ac3
encoders.

functions.

The AC-3 encoder unconditionally references some symbols from the E-AC-3
encoder; make those references conditional to fix linking.

Signed-off-by: Mans Rullgard <mans@mansr.com>

instead of just 0 to 4.

This does all the actual bit counting as a final step.

No speed difference. This is to allow for more flexible bit counting.

rather than in the AC3Block struct.

This will make it easier to access the bap values without having to chase
the reference block pointers each time.

Aligned local variables must use the LOCAL_ALIGNED macro to ensure
correct alignment on all systems.  The unusual size argument to
memset is required since the implementation of LOCAL_ALIGNED may
use a pointer to an array.

Signed-off-by: Mans Rullgard <mans@mansr.com>

This adds basic stream format support and allows for arbitrary bit rates
rather than just those supported in AC-3.

use only selected options for the different AC-3 encoder types.

Uninitialized coefficients were being used to generate exponents, some
of which actually ended up in the final stream.  Even though, they were
just extra exponents that are not used by any decoder, it is still
better to have consistent output for testing. This also fixes valgrind
errors.

Channel coupling is an optional AC-3 feature that increases quality by
combining high frequency information from multiple channels into a
single channel. The per-channel high frequency information is sent with
less accuracy in both the frequency and time domains. This allows more
bits to be used for lower frequencies while preserving enough
information to reconstruct the high frequencies.

make the code easier to understand.

This breaks API and ABI.

Although AC-3 allows it, it's not very useful. The encoder uses the same code
for all full-bandwidth channels.

It was only needed at low bitrates, which now already use a low bandwidth, so
the bandwidth reduction is no longer needed.

av_assert2().

This can occur in some very rare cases with low bitrates.

on exponent group sizes.

Signed-off-by: Reinhard Tartler <siretart@tauware.de>