fix short block imdct.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9670 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Redundant code cleanup.
Optimized dither generation.
Minor optimization in bit allocation.
Comments.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9669 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Cosmetics, white space removal.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9668 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Fix the bugs:
1. The quality of output because of incorrect windowing coefficients.
New code for window generation.

2. Dynrng values were reset where dynrng value is present in the first block,
but not in the subsequent block.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9667 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Further optimizations.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9666 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Optimization as suggested by Benjamin.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9665 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Acknowledgements.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9664 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Remove more unnecessary headers.
Codec initialization changed to use name => argument notation.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9663 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Remove unnecessary header files.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9662 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Converted the window from double to float.
Now sound produced is as good as sound produced by liba52.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9661 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Reset the blksw and dithflag to 0 at the begining of each block.
Otherwise blockswitching propagates over multiple frames even if
block switching is not enabled for that frame.
Also reuse rematflg.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9660 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

I realized that the bug was not in the imdct routine but in the
get_transform_coeffs.
Fixed it.
Code now uses the ffmpeg's imdct routines.
All the mplayer's ac3 samples are decoded
successfully.
Also improved downmixing.
Now all the downmixing coeffcients for channels
are normalized such that the sum of coefficients
used to construct the output for single channel
never exceeds 1.0.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9659 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

More code cleanup.
Window is now runtime generated.
Fixed the bugs in rematrixing routine and
in Decoding AC3 Bitstreams when coupling is in use.

Still struggling to find out what affects the quality of
the produced sound. Can anybody have a look at the
imdct routines do_imdct_256 and do_imdct_512 and tell me
whether it is the correctly implemented as described in
standard.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9658 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

major code cleanup.
correct implementation of imdct.
implemented imdct for block switching also.
when coupling is not in use all the
ac3 streams are decoded correctly.
but when coupling is in use there is a bug.
i am currently finding the root of the bug.
if anybody can help.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9657 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

working decoder
imdct for block switching is to be implemented
various other things to do

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9656 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

getting weired output
but its working

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9655 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Latest commit.
There is no error in parsing and or recovering transform coefficients.
Double checked with ac3dec.
Getting consistent results with the bit allocation routine and transform
coefficients.
The code is able to parse valid ac3 bitstreams without error from start
to end.
I have also implemented the imdct when block switching is not enabled.
However, can anybody provide an insight into how to convert float samples to
int16_t ? lrint is of no help cuz it produces output -1, 0 or 1 whereas the
output should be between -32768 to 32767.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9654 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Removed _ from names
Removed temporary storage for the exponents
Removed ctx->samples
Now each transform coefficients are stored in audio block as an array of transform coefficients for each channel
added ctx->delay (output of later half of previous block)
added audio_block->block_output(output of this block)

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9653 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

Mersenne Twister
Dynamic Range
Downmixing
IMDCT

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9652 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

initial commit
NOTE: This and all subsequent ac3dec.c revisions from the soc repository
violate the GPL. This will be fixed after all soc revisions are imported.
This file is not compiled yet, so the license compliance of any builds in
the meantime will not be affected.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9651 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols
  --enable-muxer=mpeg1system


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9650 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols
  --enable-demuxer=vc1


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9649 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols
  --enable-demuxer=mpegtsraw


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9648 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols --enable-demuxer=dxa


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9647 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9646 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols
  --enable-demuxer=dv1394


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9645 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9644 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9643 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols --enable-demuxer=c93


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9642 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following option set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols
  --enable-parser=mpegaudio


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9641 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following options set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols --enable-decoder=vp6f


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9640 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9639 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

This fixes the following options set:
  --disable-encoders --disable-decoders --disable-parsers --disable-bsfs
  --disable-muxers --disable-demuxers --disable-protocols --enable-decoder=svq3


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9638 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9637 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

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git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9635 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

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git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9631 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b