| Next Release | 
 |   - Incompatible changes: | 
 |     The VP9 encoder's default keyframe interval changed to 128 from 9999. | 
 |  | 
 | 2015-11-09 v1.5.0 "Javan Whistling Duck" | 
 |   This release improves upon the VP9 encoder and speeds up the encoding and | 
 |   decoding processes. | 
 |  | 
 |   - Upgrading: | 
 |     This release is ABI incompatible with 1.4.0. It drops deprecated VP8 | 
 |     controls and adds a variety of VP9 controls for testing. | 
 |  | 
 |     The vpxenc utility now prefers VP9 by default. | 
 |  | 
 |   - Enhancements: | 
 |     Faster VP9 encoding and decoding | 
 |     Smaller library size by combining functions used by VP8 and VP9 | 
 |  | 
 |   - Bug Fixes: | 
 |     A variety of fuzzing issues | 
 |  | 
 | 2015-04-03 v1.4.0 "Indian Runner Duck" | 
 |   This release includes significant improvements to the VP9 codec. | 
 |  | 
 |   - Upgrading: | 
 |     This release is ABI incompatible with 1.3.0. It drops the compatibility | 
 |     layer, requiring VPX_IMG_FMT_* instead of IMG_FMT_*, and adds several codec | 
 |     controls for VP9. | 
 |  | 
 |   - Enhancements: | 
 |     Faster VP9 encoding and decoding | 
 |     Multithreaded VP9 decoding (tile and frame-based) | 
 |     Multithreaded VP9 encoding - on by default | 
 |     YUV 4:2:2 and 4:4:4 support in VP9 | 
 |     10 and 12bit support in VP9 | 
 |     64bit ARM support by replacing ARM assembly with intrinsics | 
 |  | 
 |   - Bug Fixes: | 
 |     Fixes a VP9 bitstream issue in Profile 1. This only affected non-YUV 4:2:0 | 
 |     files. | 
 |  | 
 |   - Known Issues: | 
 |     Frame Parallel decoding fails for segmented and non-420 files. | 
 |  | 
 | 2013-11-15 v1.3.0 "Forest" | 
 |   This release introduces the VP9 codec in a backward-compatible way. | 
 |   All existing users of VP8 can continue to use the library without | 
 |   modification. However, some VP8 options do not map to VP9 in the same manner. | 
 |  | 
 |   The VP9 encoder in this release is not feature complete. Users interested in | 
 |   the encoder are advised to use the git master branch and discuss issues on | 
 |   libvpx mailing lists. | 
 |  | 
 |   - Upgrading: | 
 |     This release is ABI and API compatible with Duclair (v1.0.0). Users | 
 |     of older releases should refer to the Upgrading notes in this document | 
 |     for that release. | 
 |  | 
 |   - Enhancements: | 
 |       Get rid of bashisms in the main build scripts | 
 |       Added usage info on command line options | 
 |       Add lossless compression mode | 
 |       Dll build of libvpx | 
 |       Add additional Mac OS X targets: 10.7, 10.8 and 10.9 (darwin11-13) | 
 |       Add option to disable documentation | 
 |       configure: add --enable-external-build support | 
 |       make: support V=1 as short form of verbose=yes | 
 |       configure: support mingw-w64 | 
 |       configure: support hardfloat armv7 CHOSTS | 
 |       configure: add support for android x86 | 
 |       Add estimated completion time to vpxenc | 
 |       Don't exit on decode errors in vpxenc | 
 |       vpxenc: support scaling prior to encoding | 
 |       vpxdec: support scaling output | 
 |       vpxenc: improve progress indicators with --skip | 
 |       msvs: Don't link to winmm.lib | 
 |       Add a new script for producing vcxproj files | 
 |       Produce Visual Studio 10 and 11 project files | 
 |       Produce Windows Phone project files | 
 |       msvs-build: use msbuild for vs >= 2005 | 
 |       configure: default configure log to config.log | 
 |       Add encoding option --static-thresh | 
 |  | 
 |   - Speed: | 
 |       Miscellaneous speed optimizations for VP8 and VP9. | 
 |  | 
 |   - Quality: | 
 |       In general, quality is consistent with the Eider release. | 
 |  | 
 |   - Bug Fixes: | 
 |       This release represents approximately a year of engineering effort, | 
 |       and contains multiple bug fixes. Please refer to git history for details. | 
 |  | 
 |  | 
 | 2012-12-21 v1.2.0 | 
 |   This release acts as a checkpoint for a large amount of internal refactoring | 
 |   and testing. It also contains a number of small bugfixes, so all users are | 
 |   encouraged to upgrade. | 
 |  | 
 |   - Upgrading: | 
 |     This release is ABI and API compatible with Duclair (v1.0.0). Users | 
 |     of older releases should refer to the Upgrading notes in this | 
 |     document for that release. | 
 |  | 
 |   - Enhancements: | 
 |       VP8 optimizations for MIPS dspr2 | 
 |       vpxenc: add -quiet option | 
 |  | 
 |   - Speed: | 
 |       Encoder and decoder speed is consistent with the Eider release. | 
 |  | 
 |   - Quality: | 
 |       In general, quality is consistent with the Eider release. | 
 |  | 
 |       Minor tweaks to ARNR filtering | 
 |       Minor improvements to real time encoding with multiple temporal layers | 
 |  | 
 |   - Bug Fixes: | 
 |       Fixes multithreaded encoder race condition in loopfilter | 
 |       Fixes multi-resolution threaded encoding | 
 |       Fix potential encoder dead-lock after picture resize | 
 |  | 
 |  | 
 | 2012-05-09 v1.1.0 "Eider" | 
 |   This introduces a number of enhancements, mostly focused on real-time | 
 |   encoding. In addition, it fixes a decoder bug (first introduced in | 
 |   Duclair) so all users of that release are encouraged to upgrade. | 
 |  | 
 |   - Upgrading: | 
 |     This release is ABI and API compatible with Duclair (v1.0.0). Users | 
 |     of older releases should refer to the Upgrading notes in this | 
 |     document for that release. | 
 |  | 
 |     This release introduces a new temporal denoiser, controlled by the | 
 |     VP8E_SET_NOISE_SENSITIVITY control. The temporal denoiser does not | 
 |     currently take a strength parameter, so the control is effectively | 
 |     a boolean - zero (off) or non-zero (on). For compatibility with | 
 |     existing applications, the values accepted are the same as those | 
 |     for the spatial denoiser (0-6). The temporal denoiser is enabled | 
 |     by default, and the older spatial denoiser may be restored by | 
 |     configuring with --disable-temporal-denoising. The temporal denoiser | 
 |     is more computationally intensive than the spatial one. | 
 |  | 
 |     This release removes support for a legacy, decode only API that was | 
 |     supported, but deprecated, at the initial release of libvpx | 
 |     (v0.9.0). This is not expected to have any impact. If you are | 
 |     impacted, you can apply a reversion to commit 2bf8fb58 locally. | 
 |     Please update to the latest libvpx API if you are affected. | 
 |  | 
 |   - Enhancements: | 
 |       Adds a motion compensated temporal denoiser to the encoder, which | 
 |       gives higher quality than the older spatial denoiser. (See above | 
 |       for notes on upgrading). | 
 |  | 
 |       In addition, support for new compilers and platforms were added, | 
 |       including: | 
 |         improved support for XCode | 
 |         Android x86 NDK build | 
 |         OS/2 support | 
 |         SunCC support | 
 |  | 
 |       Changing resolution with vpx_codec_enc_config_set() is now | 
 |       supported. Previously, reinitializing the codec was required to | 
 |       change the input resolution. | 
 |  | 
 |       The vpxenc application has initial support for producing multiple | 
 |       encodes from the same input in one call. Resizing is not yet | 
 |       supported, but varying other codec parameters is. Use -- to | 
 |       delineate output streams. Options persist from one stream to the | 
 |       next. | 
 |  | 
 |       Also, the vpxenc application will now use a keyframe interval of | 
 |       5 seconds by default. Use the --kf-max-dist option to override. | 
 |  | 
 |   - Speed: | 
 |       Decoder performance improved 2.5% versus Duclair. Encoder speed is | 
 |       consistent with Duclair for most material. Two pass encoding of | 
 |       slideshow-like material will see significant improvements. | 
 |  | 
 |       Large realtime encoding speed gains at a small quality expense are | 
 |       possible by configuring the on-the-fly bitpacking experiment with | 
 |       --enable-onthefly-bitpacking. Realtime encoder can be up to 13% | 
 |       faster (ARM) depending on the number of threads and bitrate | 
 |       settings. This technique sees constant gain over the 5-16 speed | 
 |       range. For VC style input the loss seen is up to 0.2dB. See commit | 
 |       52cf4dca for further details. | 
 |  | 
 |   - Quality: | 
 |       On the whole, quality is consistent with the Duclair release. Some | 
 |       tweaks: | 
 |  | 
 |         Reduced blockiness in easy sections by applying a penalty to | 
 |         intra modes. | 
 |  | 
 |         Improved quality of static sections (like slideshows) with | 
 |         two pass encoding. | 
 |  | 
 |         Improved keyframe sizing with multiple temporal layers | 
 |  | 
 |   - Bug Fixes: | 
 |       Corrected alt-ref contribution to frame rate for visible updates | 
 |       to the alt-ref buffer. This affected applications making manual | 
 |       usage of the frame reference flags, or temporal layers. | 
 |  | 
 |       Additional constraints were added to disable multi-frame quality | 
 |       enhancement (MFQE) in sections of the frame where there is motion. | 
 |       (#392) | 
 |  | 
 |       Fixed corruption issues when vpx_codec_enc_config_set() was called | 
 |       with spatial resampling enabled. | 
 |  | 
 |       Fixed a decoder error introduced in Duclair where the segmentation | 
 |       map was not being reinitialized on keyframes (#378) | 
 |  | 
 |  | 
 | 2012-01-27 v1.0.0 "Duclair" | 
 |   Our fourth named release, focused on performance and features related to | 
 |   real-time encoding. It also fixes a decoder crash bug introduced in | 
 |   v0.9.7, so all users of that release are encouraged to upgrade. | 
 |  | 
 |   - Upgrading: | 
 |       This release is ABI incompatible with prior releases of libvpx, so the | 
 |       "major" version number has been bumped to 1. You must recompile your | 
 |       applications against the latest version of the libvpx headers. The | 
 |       API remains compatible, and this should not require code changes in most | 
 |       applications. | 
 |  | 
 |   - Enhancements: | 
 |       This release introduces several substantial new features to the encoder, | 
 |       of particular interest to real time streaming applications. | 
 |  | 
 |       Temporal scalability allows the encoder to produce a stream that can | 
 |       be decimated to different frame rates, with independent rate targetting | 
 |       for each substream. | 
 |  | 
 |       Multiframe quality enhancement postprocessing can make visual quality | 
 |       more consistent in the presence of frames that are substantially | 
 |       different quality than the surrounding frames, as in the temporal | 
 |       scalability case and in some forced keyframe scenarios. | 
 |  | 
 |       Multiple-resolution encoding support allows the encoding of the | 
 |       same content at different resolutions faster than encoding them | 
 |       separately. | 
 |  | 
 |   - Speed: | 
 |       Optimization targets for this release included the decoder and the real- | 
 |       time modes of the encoder. Decoder speed on x86 has improved 10.5% with | 
 |       this release. Encoder improvements followed a curve where speeds 1-3 | 
 |       improved 4.0%-1.5%, speeds 4-8 improved <1%, and speeds 9-16 improved | 
 |       1.5% to 10.5%, respectively. "Best" mode speed is consistent with the | 
 |       Cayuga release. | 
 |  | 
 |   - Quality: | 
 |       Encoder quality in the single stream case is consistent with the Cayuga | 
 |       release. | 
 |  | 
 |   - Bug Fixes: | 
 |       This release fixes an OOB read decoder crash bug present in v0.9.7 | 
 |       related to the clamping of motion vectors in SPLITMV blocks. This | 
 |       behavior could be triggered by corrupt input or by starting | 
 |       decoding from a P-frame. | 
 |  | 
 |  | 
 | 2011-08-15 v0.9.7-p1 "Cayuga" patch 1 | 
 |   This is an incremental bugfix release against Cayuga. All users of that | 
 |   release are strongly encouraged to upgrade. | 
 |  | 
 |     - Fix potential OOB reads (cdae03a) | 
 |  | 
 |           An unbounded out of bounds read was discovered when the | 
 |           decoder was requested to perform error concealment (new in | 
 |           Cayuga) given a frame with corrupt partition sizes. | 
 |  | 
 |           A bounded out of bounds read was discovered affecting all | 
 |           versions of libvpx. Given an multipartition input frame that | 
 |           is truncated between the mode/mv partition and the first | 
 |           residiual paritition (in the block of partition offsets), up | 
 |           to 3 extra bytes could have been read from the source buffer. | 
 |           The code will not take any action regardless of the contents | 
 |           of these undefined bytes, as the truncated buffer is detected | 
 |           immediately following the read based on the calculated | 
 |           starting position of the coefficient partition. | 
 |  | 
 |     - Fix potential error concealment crash when the very first frame | 
 |       is missing or corrupt (a609be5) | 
 |  | 
 |     - Fix significant artifacts in error concealment (a4c2211, 99d870a) | 
 |  | 
 |     - Revert 1-pass CBR rate control changes (e961317) | 
 |       Further testing showed this change produced undesirable visual | 
 |       artifacts, rolling back for now. | 
 |  | 
 |  | 
 | 2011-08-02 v0.9.7 "Cayuga" | 
 |   Our third named release, focused on a faster, higher quality, encoder. | 
 |  | 
 |   - Upgrading: | 
 |     This release is backwards compatible with Aylesbury (v0.9.5) and | 
 |     Bali (v0.9.6). Users of older releases should refer to the Upgrading | 
 |     notes in this document for that release. | 
 |  | 
 |   - Enhancements: | 
 |           Stereo 3D format support for vpxenc | 
 |           Runtime detection of available processor cores. | 
 |           Allow specifying --end-usage by enum name | 
 |           vpxdec: test for frame corruption | 
 |           vpxenc: add quantizer histogram display | 
 |           vpxenc: add rate histogram display | 
 |           Set VPX_FRAME_IS_DROPPABLE | 
 |           update configure for ios sdk 4.3 | 
 |           Avoid text relocations in ARM vp8 decoder | 
 |           Generate a vpx.pc file for pkg-config. | 
 |           New ways of passing encoded data between encoder and decoder. | 
 |  | 
 |   - Speed: | 
 |       This release includes across-the-board speed improvements to the | 
 |       encoder. On x86, these measure at approximately 11.5% in Best mode, | 
 |       21.5% in Good mode (speed 0), and 22.5% in Realtime mode (speed 6). | 
 |       On ARM Cortex A9 with Neon extensions, real-time encoding of video | 
 |       telephony content is 35% faster than Bali on single core and 48% | 
 |       faster on multi-core. On the NVidia Tegra2 platform, real time | 
 |       encoding is 40% faster than Bali. | 
 |  | 
 |       Decoder speed was not a priority for this release, but improved | 
 |       approximately 8.4% on x86. | 
 |  | 
 |           Reduce motion vector search on alt-ref frame. | 
 |           Encoder loopfilter running in its own thread | 
 |           Reworked loopfilter to precalculate more parameters | 
 |           SSE2/SSSE3 optimizations for build_predictors_mbuv{,_s}(). | 
 |           Make hor UV predict ~2x faster (73 vs 132 cycles) using SSSE3. | 
 |           Removed redundant checks | 
 |           Reduced structure sizes | 
 |           utilize preload in ARMv6 MC/LPF/Copy routines | 
 |           ARM optimized quantization, dfct, variance, subtract | 
 |           Increase chrow row alignment to 16 bytes. | 
 |           disable trellis optimization for first pass | 
 |           Write SSSE3 sub-pixel filter function | 
 |           Improve SSE2 half-pixel filter funtions | 
 |           Add vp8_sub_pixel_variance16x8_ssse3 function | 
 |           Reduce unnecessary distortion computation | 
 |           Use diamond search to replace full search | 
 |           Preload reference area in sub-pixel motion search (real-time mode) | 
 |  | 
 |   - Quality: | 
 |       This release focused primarily on one-pass use cases, including | 
 |       video conferencing. Low latency data rate control was significantly | 
 |       improved, improving streamability over bandwidth constrained links. | 
 |       Added support for error concealment, allowing frames to maintain | 
 |       visual quality in the presence of substantial packet loss. | 
 |  | 
 |           Add rc_max_intra_bitrate_pct control | 
 |           Limit size of initial keyframe in one-pass. | 
 |           Improve framerate adaptation | 
 |           Improved 1-pass CBR rate control | 
 |           Improved KF insertion after fades to still. | 
 |           Improved key frame detection. | 
 |           Improved activity masking (lower PSNR impact for same SSIM boost) | 
 |           Improved interaction between GF and ARFs | 
 |           Adding error-concealment to the decoder. | 
 |           Adding support for independent partitions | 
 |           Adjusted rate-distortion constants | 
 |  | 
 |  | 
 |   - Bug Fixes: | 
 |           Removed firstpass motion map | 
 |           Fix parallel make install | 
 |           Fix multithreaded encoding for 1 MB wide frame | 
 |           Fixed iwalsh_neon build problems with RVDS4.1 | 
 |           Fix semaphore emulation, spin-wait intrinsics on Windows | 
 |           Fix build with xcode4 and simplify GLOBAL. | 
 |           Mark ARM asm objects as allowing a non-executable stack. | 
 |           Fix vpxenc encoding incorrect webm file header on big endian | 
 |  | 
 |  | 
 | 2011-03-07 v0.9.6 "Bali" | 
 |   Our second named release, focused on a faster, higher quality, encoder. | 
 |  | 
 |   - Upgrading: | 
 |     This release is backwards compatible with Aylesbury (v0.9.5). Users | 
 |     of older releases should refer to the Upgrading notes in this | 
 |     document for that release. | 
 |  | 
 |   - Enhancements: | 
 |       vpxenc --psnr shows a summary when encode completes | 
 |       --tune=ssim option to enable activity masking | 
 |       improved postproc visualizations for development | 
 |       updated support for Apple iOS to SDK 4.2 | 
 |       query decoder to determine which reference frames were updated | 
 |       implemented error tracking in the decoder | 
 |       fix pipe support on windows | 
 |  | 
 |   - Speed: | 
 |       Primary focus was on good quality mode, speed 0. Average improvement | 
 |       on x86 about 40%, up to 100% on user-generated content at that speed. | 
 |       Best quality mode speed improved 35%, and realtime speed 10-20%. This | 
 |       release also saw significant improvement in realtime encoding speed | 
 |       on ARM platforms. | 
 |  | 
 |         Improved encoder threading | 
 |         Dont pick encoder filter level when loopfilter is disabled. | 
 |         Avoid double copying of key frames into alt and golden buffer | 
 |         FDCT optimizations. | 
 |         x86 sse2 temporal filter | 
 |         SSSE3 version of fast quantizer | 
 |         vp8_rd_pick_best_mbsegmentation code restructure | 
 |         Adjusted breakout RD for SPLITMV | 
 |         Changed segmentation check order | 
 |         Improved rd_pick_intra4x4block | 
 |         Adds armv6 optimized variance calculation | 
 |         ARMv6 optimized sad16x16 | 
 |         ARMv6 optimized half pixel variance calculations | 
 |         Full search SAD function optimization in SSE4.1 | 
 |         Improve MV prediction accuracy to achieve performance gain | 
 |         Improve MV prediction in vp8_pick_inter_mode() for speed>3 | 
 |  | 
 |   - Quality: | 
 |       Best quality mode improved PSNR 6.3%, and SSIM 6.1%. This release | 
 |       also includes support for "activity masking," which greatly improves | 
 |       SSIM at the expense of PSNR. For now, this feature is available with | 
 |       the --tune=ssim option. Further experimentation in this area | 
 |       is ongoing. This release also introduces a new rate control mode | 
 |       called "CQ," which changes the allocation of bits within a clip to | 
 |       the sections where they will have the most visual impact. | 
 |  | 
 |         Tuning for the more exact quantizer. | 
 |         Relax rate control for last few frames | 
 |         CQ Mode | 
 |         Limit key frame quantizer for forced key frames. | 
 |         KF/GF Pulsing | 
 |         Add simple version of activity masking. | 
 |         make rdmult adaptive for intra in quantizer RDO | 
 |         cap the best quantizer for 2nd order DC | 
 |         change the threshold of DC check for encode breakout | 
 |  | 
 |   - Bug Fixes: | 
 |       Fix crash on Sparc Solaris. | 
 |       Fix counter of fixed keyframe distance | 
 |       ARNR filter pointer update bug fix | 
 |       Fixed use of motion percentage in KF/GF group calc | 
 |       Changed condition for using RD in Intra Mode | 
 |       Fix encoder real-time only configuration. | 
 |       Fix ARM encoder crash with multiple token partitions | 
 |       Fixed bug first cluster timecode of webm file is wrong. | 
 |       Fixed various encoder bugs with odd-sized images | 
 |       vp8e_get_preview fixed when spatial resampling enabled | 
 |       quantizer: fix assertion in fast quantizer path | 
 |       Allocate source buffers to be multiples of 16 | 
 |       Fix for manual Golden frame frequency | 
 |       Fix drastic undershoot in long form content | 
 |  | 
 |  | 
 | 2010-10-28 v0.9.5 "Aylesbury" | 
 |   Our first named release, focused on a faster decoder, and a better encoder. | 
 |  | 
 |   - Upgrading: | 
 |     This release incorporates backwards-incompatible changes to the | 
 |     ivfenc and ivfdec tools. These tools are now called vpxenc and vpxdec. | 
 |  | 
 |     vpxdec | 
 |       * the -q (quiet) option has been removed, and replaced with | 
 |         -v (verbose). the output is quiet by default. Use -v to see | 
 |         the version number of the binary. | 
 |  | 
 |       * The default behavior is now to write output to a single file | 
 |         instead of individual frames. The -y option has been removed. | 
 |         Y4M output is the default. | 
 |  | 
 |       * For raw I420/YV12 output instead of Y4M, the --i420 or --yv12 | 
 |         options must be specified. | 
 |  | 
 |           $ ivfdec -o OUTPUT INPUT | 
 |           $ vpxdec --i420 -o OUTPUT INPUT | 
 |  | 
 |       * If an output file is not specified, the default is to write | 
 |         Y4M to stdout. This makes piping more natural. | 
 |  | 
 |           $ ivfdec -y -o - INPUT | ... | 
 |           $ vpxdec INPUT | ... | 
 |  | 
 |       * The output file has additional flexibility for formatting the | 
 |         filename. It supports escape characters for constructing a | 
 |         filename from the width, height, and sequence number. This | 
 |         replaces the -p option. To get the equivalent: | 
 |  | 
 |           $ ivfdec -p frame INPUT | 
 |           $ vpxdec --i420 -o frame-%wx%h-%4.i420 INPUT | 
 |  | 
 |     vpxenc | 
 |       * The output file must be specified with -o, rather than as the | 
 |         last argument. | 
 |  | 
 |           $ ivfenc <options> INPUT OUTPUT | 
 |           $ vpxenc <options> -o OUTPUT INPUT | 
 |  | 
 |       * The output defaults to webm. To get IVF output, use the --ivf | 
 |         option. | 
 |  | 
 |           $ ivfenc <options> INPUT OUTPUT.ivf | 
 |           $ vpxenc <options> -o OUTPUT.ivf --ivf INPUT | 
 |  | 
 |  | 
 |   - Enhancements: | 
 |       ivfenc and ivfdec have been renamed to vpxenc, vpxdec. | 
 |       vpxdec supports .webm input | 
 |       vpxdec writes .y4m by default | 
 |       vpxenc writes .webm output by default | 
 |       vpxenc --psnr now shows the average/overall PSNR at the end | 
 |       ARM platforms now support runtime cpu detection | 
 |       vpxdec visualizations added for motion vectors, block modes, references | 
 |       vpxdec now silent by default | 
 |       vpxdec --progress shows frame-by-frame timing information | 
 |       vpxenc supports the distinction between --fps and --timebase | 
 |       NASM is now a supported assembler | 
 |       configure: enable PIC for shared libs by default | 
 |       configure: add --enable-small | 
 |       configure: support for ppc32-linux-gcc | 
 |       configure: support for sparc-solaris-gcc | 
 |  | 
 |   - Bugs: | 
 |       Improve handling of invalid frames | 
 |       Fix valgrind errors in the NEON loop filters. | 
 |       Fix loopfilter delta zero transitions | 
 |       Fix valgrind errors in vp8_sixtap_predict8x4_armv6(). | 
 |       Build fixes for darwin-icc | 
 |  | 
 |   - Speed: | 
 |       20-40% (average 28%) improvement in libvpx decoder speed, | 
 |       including: | 
 |         Rewrite vp8_short_walsh4x4_sse2() | 
 |         Optimizations on the loopfilters. | 
 |         Miscellaneous improvements for Atom | 
 |         Add 4-tap version of 2nd-pass ARMv6 MC filter. | 
 |         Improved multithread utilization | 
 |         Better instruction choices on x86 | 
 |         reorder data to use wider instructions | 
 |         Update NEON wide idcts | 
 |         Make block access to frame buffer sequential | 
 |         Improved subset block search | 
 |         Bilinear subpixel optimizations for ssse3. | 
 |         Decrease memory footprint | 
 |  | 
 |       Encoder speed improvements (percentage gain not measured): | 
 |         Skip unnecessary search of identical frames | 
 |         Add SSE2 subtract functions | 
 |         Improve bounds checking in vp8_diamond_search_sadx4() | 
 |         Added vp8_fast_quantize_b_sse2 | 
 |  | 
 |   - Quality: | 
 |       Over 7% overall PSNR improvement (6.3% SSIM) in "best" quality | 
 |       encoding mode, and up to 60% improvement on very noisy, still | 
 |       or slow moving source video | 
 |  | 
 |         Motion compensated temporal filter for Alt-Ref Noise Reduction | 
 |         Improved use of trellis quantization on 2nd order Y blocks | 
 |         Tune effect of motion on KF/GF boost in two pass | 
 |         Allow coefficient optimization for good quality speed 0. | 
 |         Improved control of active min quantizer for two pass. | 
 |         Enable ARFs for non-lagged compress | 
 |  | 
 | 2010-09-02 v0.9.2 | 
 |   - Enhancements: | 
 |       Disable frame dropping by default | 
 |       Improved multithreaded performance | 
 |       Improved Force Key Frame Behaviour | 
 |       Increased rate control buffer level precision | 
 |       Fix bug in 1st pass motion compensation | 
 |       ivfenc: correct fixed kf interval, --disable-kf | 
 |   - Speed: | 
 |       Changed above and left context data layout | 
 |       Rework idct calling structure. | 
 |       Removed unnecessary MB_MODE_INFO copies | 
 |       x86: SSSE3 sixtap prediction | 
 |       Reworked IDCT to include reconstruction (add) step | 
 |       Swap alt/gold/new/last frame buffer ptrs instead of copying. | 
 |       Improve SSE2 loopfilter functions | 
 |       Change bitreader to use a larger window. | 
 |       Avoid loopfilter reinitialization when possible | 
 |   - Quality: | 
 |       Normalize quantizer's zero bin and rounding factors | 
 |       Add trellis quantization. | 
 |       Make the quantizer exact. | 
 |       Updates to ARNR filtering algorithm | 
 |       Fix breakout thresh computation for golden & AltRef frames | 
 |       Redo the forward 4x4 dct | 
 |       Improve the accuracy of forward walsh-hadamard transform | 
 |       Further adjustment of RD behaviour with Q and Zbin. | 
 |   - Build System: | 
 |       Allow linking of libs built with MinGW to MSVC | 
 |       Fix target auto-detection on mingw32 | 
 |       Allow --cpu= to work for x86. | 
 |       configure: pass original arguments through to make dist | 
 |       Fix builds without runtime CPU detection | 
 |       msvs: fix install of codec sources | 
 |       msvs: Change devenv.com command line for better msys support | 
 |       msvs: Add vs9 targets. | 
 |       Add x86_64-linux-icc target | 
 |   - Bugs: | 
 |       Potential crashes on older MinGW builds | 
 |       Fix two-pass framrate for Y4M input. | 
 |       Fixed simple loop filter, other crashes on ARM v6 | 
 |       arm: fix missing dependency with --enable-shared | 
 |       configure: support directories containing .o | 
 |       Replace pinsrw (SSE) with MMX instructions | 
 |       apple: include proper mach primatives | 
 |       Fixed rate control bug with long key frame interval. | 
 |       Fix DSO link errors on x86-64 when not using a version script | 
 |       Fixed buffer selection for UV in AltRef filtering | 
 |  | 
 |  | 
 | 2010-06-17 v0.9.1 | 
 |   - Enhancements: | 
 |       * ivfenc/ivfdec now support YUV4MPEG2 input and pipe I/O | 
 |       * Speed optimizations | 
 |   - Bugfixes: | 
 |       * Rate control | 
 |       * Prevent out-of-bounds accesses on invalid data | 
 |   - Build system updates: | 
 |       * Detect toolchain to be used automatically for native builds | 
 |       * Support building shared libraries | 
 |       * Better autotools emulation (--prefix, --libdir, DESTDIR) | 
 |   - Updated LICENSE | 
 |       * http://webmproject.blogspot.com/2010/06/changes-to-webm-open-source-license.html | 
 |  | 
 |  | 
 | 2010-05-18 v0.9.0 | 
 |   - Initial open source release. Welcome to WebM and VP8! | 
 |  |