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 mad - MPEG audio decoder

 Copyright (C) 2000-2001 Robert Leslie

 $Id: CHANGES,v 1.1.1.1 2001-11-04 19:00:18 lampret Exp $

===============================================================================

Version 0.13.0 (beta)

  * The last complete audio frame should now be properly decoded even when

    it is not followed by other data [fixed in both `madplay' and the

    plug-in for Winamp.]

  * The plug-in for Winamp now reads Xing VBR headers for fast length

    calculation.

  * The plug-in for Winamp should now display visuals correctly for 24- and

    32-bit output.

  * Ancillary data is now properly extracted from Layer III streams.

  * Rewrote the Layer III joint stereo decoding routine to correct a major

    MPEG-2 problem and a minor MPEG-1 problem decoding intensity stereo.

  * Eliminated the dependency on sign-extending right shifts for Layer I and

    Layer II.

  * Renamed `private' field to `private_bits' for better C++ compatibility.

  * Gratuitously renamed `sfreq' field to `samplerate' and

    MAD_ERROR_BADSAMPLEFREQ constant to MAD_ERROR_BADSAMPLERATE.

  * Added `samplerate' and `channels' fields to synth.pcm struct to allow

    these to be different from the decoded frame, and for simpler access.

  * Added new mad_stream_options() and mad_decoder_options() API entries for

    special runtime decoding options.

  * Added new MAD_OPTION_IGNORECRC and MAD_OPTION_HALFSAMPLERATE options.

  * Added new --downsample option to `madplay'.

  * Added new MAD_FLAG_FREEFORMAT indicator flag.

  * Fixed some bugs in the async decoder.

  * Added a new mad_timer_multiply() API routine.

  * Eliminated `+' from asm constraints under Intel for better compatibility

    with some compilers.

  * Fixed a PIC-related problem in libmad/imdct_l_arm.S.

  * Eliminated a static variable to make libmad thread-safe.

Version 0.12.5 (beta)

  * Modified Layer III requantization to occur during Huffman decoding for

    significant performance gains.

  * Optimized short block IMDCT by eliminating redundant calculations.

  * Made several other Layer III performance improvements; added

    ASO_INTERLEAVE1, ASO_INTERLEAVE2, and ASO_ZEROCHECK

    architecture-specific options for best performance on various

    architectures.

  * Optimized synthesis DCT to store result values as soon as they are

    calculated.

Version 0.12.4 (beta)

  * New PowerPC fixed-point assembly courtesy of David Blythe.

  * Reorganized fixed-point assembly routines for easier maintenance and

    better performance.

  * Improved performance of subband synthesis through better indexing and

    fewer local variables.

  * Added alias reduction for the lower two subbands of mixed short blocks,

    per a report of ambiguity with ISO/IEC 11172-3 and for uniformity with

    most other implementations. Also improved alias reduction performance

    using multiply/accumulate.

  * Added --enable-strict-iso option to `configure' to override best

    accepted practices such as the alias reduction for mixed short blocks.

  * Improved performance of Layer III IMDCT by using longer

    multiply/accumulate runs where possible.

Version 0.12.3 (beta)

  * Added MPEG 2.5 support.

  * Added preliminary support for parameterizing the binary point position in

    the fixed-point representation.

  * Added calls to madvise() on supported systems to reduce memory overhead

    when using mmap().

  * Added support for automatic mono/stereo channel selection based on output

    capability.

  * Added a new option to force stereo output of single or dual channel

    streams.

  * Added a new option to amplify/attenuate the output signal by an amount

    expressed in decibels.

  * Output statistics (peak amplitude, clipped samples) are now gathered and

    displayed after decoding.

  * Added multiply/accumulate optimization to the Layer III IMDCT for long

    blocks.

  * Fixed a bug in the handling of Layer III mixed_block_flag.

  * Many Winamp plug-in enhancements.

  * Fixed a problem calling setlocale() when NLS is disabled.

  * Fixed a configure problem when multiple -O CFLAGS are present.

Version 0.12.2 (beta)

  * Rearranged the synthesis polyphase filterbank memory vector for better

    locality of reference, and rewrote mad_synth_frame() to accommodate,

    resulting in improved performance.

  * Discovered a combination of compiler optimization flags that further

    improve performance.

  * Changed some array references in layer3.c to pointer derefs.

  * Fixed another FreeBSD sound compatibility problem in audio_oss.c.

Version 0.12.1 (beta)

  * New code for a Winamp plug-in.

  * Resolved the intensity + MS joint stereo issue (a simple bug).

    OPT_ISKLUGE is no longer considered to be a kluge.

  * Fixed another, hopefully last main_data memory bug.

  * Split part of struct mad_frame into struct mad_header for convenience

    and size.

  * Rewrote the audio PCM packing routines for (hopefully) somewhat better

    performance.

  * Fixed a FreeBSD sound compatibility problem in audio_oss.c with help

    from Graham Guttocks.

  * Moved ID3 genre table into a separate file (shared by Winamp plug-in)

    and updated extensions with current list from Winamp.

  * New Croatian, Norwegian, and Spanish translations courtesy of Mario

    Horvat, Christoffer Nicolaisen, and Damian Brizuela, respectively.

  * Added a simple ABX testing script.

Version 0.12.0 (alpha)

  * Changed the build environment to use automake and libtool. A libmad

    shared library can now be built using the --enable-shared option to

    `configure'.

  * Added internationalization support via GNU gettext. New French

    translation added courtesy of Gabriel Bouvigne.

  * Changed raw output module to use host-endian byte order.

  * Added --disable-mmap option to `configure' per suggestion of Erik

    Andersen.

  * Debug builds now link with -lefence, if available.

  * Added another callback to MAD's high-level decoder API after the frame

    header has been read but before the frame's audio data is decoded.

  * Streamlined header processing so that mad_frame_decode() can be called

    with or without having already called mad_frame_header().

  * Fixed some other header reading miscellany, including CRC handling and

    free bitrate detection, and frame length verification with free

    bitrates.

  * Fixed a problem with Layer III free bitrates > 320 kbps. The main_data

    buffer size should now be large enough to handle any size frame, by

    virtue of the maximum possible part2_3_length.

  * Further developed the async API; arbitrary messages can now be passed

    to the subsidiary decoding process.

  * Streamlined libmad/timer.c and extended its interface. It now has

    support for video frame/field lengths, including output support for

    drop-frame encoding.

  * Replaced many constant integer preprocessor defines with enums.

  * Added `madplay' support for filter chains. This could eventually be

    extended to support dynamically loaded filters.

  * Added a new optional fade-in filter.

  * Rewrote madplay.c to use GNU getopt, and added many new options (use

    `madplay --help' to see them all.)

  * Updated the man page for `madplay'.

Version 0.11.4 (beta)

  * Fixed free format bitrate discovery.

  * Added Sun/NeXT audio file output module (audio_au.c).

  * Added 32-bit (really 24-bit) output support to OSS module.

  * Changed the timer implementation and extended its interface.

  * Relaxed output sample frequency match requirement.

  * Fixed endian assumption problem in audio_sun.c.

  * Integrated Nicolas Pitre's patch for pre-shifting at compile-time and

    for better multiply/accumulate code output.

  * Applied Simon Burge's patch to imdct_l_arm.S for a.out compatibility.

  * Added -mtune=strongarm for all ARM targets.

Version 0.11.3 (beta)

  * Added new --enable-speed and --enable-accuracy options for `configure'

    to automatically select appropriate SSO/ASO options, et al.

  * Modified subband synthesis to use multiply/accumulate optimization

    (if available) for better speed and/or accuracy.

  * Incorporated Andre McCurdy's changes for further rounding optimizations

    in the rest of his code.

  * Joint stereo mode now shows LR indicator during playback.

Version 0.11.2 (beta)

  * Incorporated Nicolas Pitre's ARM assembly and parameterized scaling

    changes.

  * Incorporated Andre McCurdy's ARM assembly optimization (used only if

    --enable-aso is given to `configure' to enable architecture-specific

    optimizations.)

  * Reduced FPM_INTEL assembly to two instructions.

  * Fixed accuracy problems with certain FPM modes in synth.c.

  * Improved the accuracy of FPM_APPROX.

  * Improved the accuracy of SSO.

  * Added a dual channel output selection option.

  * Improved the OSS output module by falling back on 8-bit format if 16-bit

    is not available, and by using native 16-bit endianness.

  * PCM output is now dithered for better audio quality. A new runtime

    option can disable this feature.

  * Added a resampling feature for unsupported output sampling frequencies.

  * Centralized sample scaling and formatting in audio.c for the output

    modules.

  * Moved the empeg-car audio output support into a separate module.

  * Added bad-CRC frame muting code to madplay.c.

  * Improved sync discovery by checking for a sync word in the following

    frame.

  * Changed `madtime' to indicate average bitrates.

  * Reduced the ID3 genre table memory usage.

  * Minor code clean-up.

  * Added experimental rules for generating a libmad.so shared library.

Version 0.11.1 (beta)

  * Moved libmad code into a separate directory.

  * Improved the robustness of the Win32 audio output module.

  * Changed SSO to be disabled by default, as output accuracy is deemed to

    be more important than speed in the general case.

  * Fixed a bug in Layer III sanity checking that could cause a crash on

    certain random data input.

  * Extended the Layer III requantization table from 8191 to 8206 as some

    encoders are known to use these values, even though ISO/IEC 11172-3

    suggests the maximum should be 8191.

  * Added a short man page for madplay.

  * Wrote most of the code for madtime.

  * Wrote code for an experimental multi-stream mixer `madmix'

    (--enable-experimental to add -x option support for this to madplay).

Version 0.11.0 (beta)

  * Implemented MPEG-2 extension to Lower Sampling Frequencies.

  * Improved Layer III performance by avoiding IMDCT calculation when all

    input samples are zero.

  * Significantly reduced size of Layer II tables.

Version 0.10.3 (beta)

  * Improved SSO output quality.

  * Made portable to cygwin.

  * Wrote new Win32 audio interface module.

  * Localized memory references in III_huffdecode() for better performance.

Version 0.10.2 (beta)

  * Rewrote Layer III long block 36-point IMDCT routine for better

    performance.

  * Improved subband synthesis fixed-point games somewhat.

Version 0.10.1 (beta)

  * Added a subband synthesis optimization (SSO) which involves modifying

    the fixed-point multiplication method during windowing. This produces

    subtle differences in the output but improves performance greatly.

  * Added I_STEREO and MS_STEREO flags to frame struct.

  * Eliminated privately-used CRCFAILED flag.

  * Fixed a bug where Layer III decoding could crash on some badly-formatted

    (e.g. non-MPEG) bitstreams.

  * Miscellaneous code clean-up.

  * Running madplay with no arguments now gives usage info.

Version 0.10.0 (beta)

  * Added SPARC fixed-point math support.

  * Revamped libmad API for better high- and low-level support.

  * Documented more of the code.

  * Changed sync semantics such that new stream buffers are assumed to be

    sync-aligned.

  * Added framework for ID3v2 support.

  * Changed Layer III to dynamically allocate static memory so as not to

    waste it (about 6.4K) when only decoding Layer I or Layer II.

  * Added prefix parsing for output module selection.

  * Added audio_raw output module.

  * Rewrote madplay.c to use high-level interface.

Version 0.9.7 (beta)

  * Added audio_hex module (--enable-debugging) for PCM-level debugging.

  * Fixed bug in audio_sun module; should work correctly now.

  * Added -Q (very quiet) option to omit bitstream error messages.

  * Reduced -v output by eliminating timing tenths.

  * Fixed problem configuring unsupported sample frequencies, and added user

    feedback.

  * Enhanced final frame count reporting to include playing time.

  * Cleaned up madplay.c somewhat.

===============================================================================