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ffmpeg / tests / ref / acodec / ac3_fixed @ 7e0a284b

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# Date Author Comment
7e0a284b 03/08/2011 06:44 PM Justin Ruggles

ac3enc: shift coefficients to 24-bit following MDCT rather than using an exponent offset.

This makes channel coupling more accurate, increasing quality for stereo
content. It also simplifies exponent extraction and mantissa quantization
by no longer needing to apply an offset to the exponents....

6159bd0d 02/18/2011 06:52 PM Justin Ruggles

ac3enc: fix bug in stereo rematrixing decision.

The rematrixing strategy reuse flags are not reset between frames, so they
need to be initialized for all blocks, not just block 0.

Signed-off-by: Mans Rullgard <>
(cherry picked from commit 5b54d4b376fbd2c291b8a6dba7d425e28f654bcf)

660ab0e6 02/16/2011 10:00 PM Justin Ruggles

ac3enc: change default floor code to 7.

This is to match the value in every (E-)AC-3 file from commercial sources.
It has a negligible effect on audio quality.

Signed-off-by: Mans Rullgard <>
(cherry picked from commit 50d7140441b61809ad4ba4ea7b4ad8fe77bc6888)

10030226 02/04/2011 02:08 AM Justin Ruggles

ac3enc: Change EXP_DIFF_THRESHOLD to 500.

This patch changes the exponent difference threshold in the exponent
strategy decision function of the AC-3 encoder. I tested lowering in
increments of 100. From 1000 down to 500 generally increased in quality
with each step, but 400 was generally much worse....

dc7e07ac 01/08/2011 11:21 PM Justin Ruggles

Add stereo rematrixing support to the AC-3 encoders.
This improves the audio quality significantly for stereo source with both the
fixed-point and floating-point AC-3 encoders.
Update acodec-ac3_fixed and seek-ac3_rm test references.

Originally committed as revision 26271 to svn://

6fd96d1a 01/04/2011 11:53 AM Justin Ruggles

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://