libmad - MPEG audio decoder library Copyright (C) 2000-2004 Underbit Technologies, Inc. $Id: CHANGES,v 1.14 2004/02/17 02:02:03 rob Exp $===============================================================================Version 0.15.1 (beta)  * Updated to autoconf 2.59, automake 1.8.2, libtool 1.5.2.  * Replaced Layer III IMDCT routine with one based on a faster algorithm,    improving both speed and accuracy.  * Improved portability of the Huffman table initialization.  * Fixed a problem that could result in an assertion failure in layer3.c    due to an invalid Layer III free format bitrate.  * Improved the robustness of Layer II bitrate/mode combinations, and added    a new MAD_ERROR_BADMODE error enum. The allowability of low-bitrate    stereo streams is influenced by the --enable-strict-iso option to    `configure'.Version 0.15.0 (beta)  * Updated to autoconf 2.57, automake 1.7.5, libtool 1.4.3.  * Added new mad_f_div() API routine.  * Added a 64th entry to the Layer I/Layer II scalefactor table, for better    compatibility with existing streams. The --enable-strict-iso option to    `configure' can be used to disable use of this entry.  * Modified the header decoding routine to allow the reserved emphasis    value, for better compatibility with existing streams. The    --enable-strict-iso option to `configure' can be used to restore the    previous behavior of reporting this value as an error.  * Added new MAD_EMPHASIS_RESERVED enumeration constant.  * Fixed a bug in the ARM version of mad_f_scale64() discovered by Andre    McCurdy.  * Rewrote PowerPC assembly for minor gains.  * Modified mad_timer_fraction() to avoid the possibility of division by    zero when 0 is passed as the second argument.  * Fixed a non-fatal problem caused by attempting to designate ancillary    bits in Layer III after a decoding error.  * Changed to build a shared library by default.  * Changed to use native Cygwin build by default; give --host=mingw32 to    `configure' to use MinGW (and avoid a dependency on the Cygwin DLL).Version 0.14.2 (beta)  * Changed Cygwin builds to use MinGW; resulting Win32 executables no    longer have a dependency on Cygwin DLLs.  * Added a new mad_stream_errorstr() API function to libmad for retrieving    a string description of the current error condition.Version 0.14.1 (beta)  * Updated config.guess and config.sub to latest upstream versions.  * Enabled libtool versioning rather than release numbering.  * Improved the documentation in minimad.c.  * Several other small fixes.Version 0.14.0 (beta)  * Added a 64-bit FPM negation operation to improve performance of subband    synthesis on some platforms.  * Improved MSVC++ portability and added MSVC++ project files.  * Added rounding to Layer III requantization for slightly better accuracy.Version 0.13.0 (beta)  * 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 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 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 multiply/accumulate optimization to the Layer III IMDCT for long    blocks.  * Fixed a bug in the handling of Layer III mixed_block_flag.  * 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.Version 0.12.1 (beta)  * 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.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 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 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.Version 0.11.4 (beta)  * Fixed free format bitrate discovery.  * Changed the timer implementation and extended its interface.  * 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.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.  * Improved sync discovery by checking for a sync word in the following    frame.  * 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.  * 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.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.  * 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.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.  * 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.===============================================================================