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ffmpeg / tests / ref / acodec / ac3_fixed @ c47d3835

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# Date Author Comment
323e6fea 03/14/2011 12:45 PM Justin

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...

5b54d4b3 02/16/2011 11:39 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 <>

50d71404 02/15/2011 09:40 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 <>

c3beafa0 02/02/2011 08:00 PM 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://