Commit Graph

60 Commits

Author SHA1 Message Date
Justin Ruggles
f1efbca5e9 ac3enc: add SIMD-optimized shifting functions for use with the fixed-point AC3 encoder. 2011-03-14 08:45:31 -04:00
Justin
323e6fead0 ac3enc: do not right-shift fixed-point coefficients in the final MDCT stage.
This increases the accuracy of coefficients, leading to improved quality.
Rescaling of the coefficients to full 25-bit accuracy is done rather than
offsetting the exponent values. This requires coefficient scaling to be done
before determining the rematrixing strategy. Also, the rematrixing strategy
calculation must use 64-bit math to prevent overflow due to the higher
precision coefficients.
2011-03-14 08:45:26 -04:00
Justin Ruggles
fbb6b49dab ac3enc: Add x86-optimized function to speed up log2_tab().
AC3DSPContext.ac3_max_msb_abs_int16() finds the maximum MSB of the absolute
value of each element in an array of int16_t.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
2011-02-13 16:49:39 -05:00
Justin Ruggles
626264b11b ac3enc: Remove unneeded clipping of shift amount.
s->windowed_samples will always have a range of [-32767,32767] due to the
window function, so the return value from log2_tab() will always be in the
range [0,14].

Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-02-10 23:16:23 +00:00
Justin Ruggles
d4582889ee ac3enc: remove right shifting from lshift_tab() and make lshift unsigned.
Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-02-10 23:16:22 +00:00
Diego Elio Pettenò
d36beb3f69 Add ff_ prefix to data symbols of encoders, decoders, hwaccel, parsers, bsf.
None of these symbols should be accessed directly, so declare them as
hidden.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-01-26 16:08:45 +00:00
Justin Ruggles
3b924294ea ac3enc: use dsputil functions in apply_window()
Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-01-22 17:53:28 +00:00
Justin Ruggles
ac05f9030e Convert floating-point MDCT coefficients to 24-bit fixed-point all at once
instead of doing it separately in 2 different functions.
This makes float AC-3 encoding approx. 3-7% faster overall.
Also, the coefficient conversion can now be easily SIMD-optimized.

Originally committed as revision 26232 to svn://svn.ffmpeg.org/ffmpeg/trunk
2011-01-05 20:35:36 +00:00
Justin Ruggles
6fd96d1a85 Change the AC-3 encoder to use floating-point.
Fixed-point AC-3 encoder renamed to ac3_fixed.
Regression test acodec-ac3 renamed to acodec-ac3_fixed.
Regression test lavf-rm changed to use ac3_fixed encoder.

Originally committed as revision 26209 to svn://svn.ffmpeg.org/ffmpeg/trunk
2011-01-04 11:53:44 +00:00
Justin Ruggles
ad6b2c1f6d Move fixed-point parts of the AC-3 encoder to separate files.
Originally committed as revision 26206 to svn://svn.ffmpeg.org/ffmpeg/trunk
2011-01-03 16:08:56 +00:00