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path: root/vp8/encoder/dct.c
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2011-11-11Make 8x8 and extend_qrange to work togetherYaowu Xu
This commit added scaling factors to 8x8 transform, quant, dequant and inverse transform pipeline to make 8x8 transform to work when configed with enable-extend_qrange. This commit also disabled the trellis-quant when extend_qrange is configured. Change-Id: Icfb3192e4746f70a4bb35ad18b7b47705b657e52
2011-07-21fix more merge issuesYaowu Xu
With this fix, the experimental branch now builds and encodes correctly with the following two configure options respectively: --enable-experimental --enable-t8x8 --enable-experimental Change-Id: I3147c33c503fe713a85fd371e4f1a974805778bf
2011-07-20Add 8x8 transform to experimental branchDeb Mukherjee
Please refer to previous commit messages for detailed info: https://on2-git.corp.google.com/g/#change,5940 https://on2-git.corp.google.com/g/#change,6045 Change-Id: I8b16992f2f69c5a808ad40a3e32ef589cce7c59d
2011-01-19experiment extending the quantizer rangeYaowu Xu
Prior to this change, VP8 min quantizer is 4, which caps the highest quality around 51DB. This experimental change extends the min quantizer to 1, removes the cap and allows the highest quality to be around ~73DB, consistent with the fdct/idct round trip error. To test this change, at configure time use options: --enable-experimental --enable-extend_qrange The following is a brief log of changes in each of the patch sets patch set 1: In this commit, the quantization/dequantization constants are kept unchanged, instead scaling factor 4 is rolled into fdct/idct. Fixed Q0 encoding tests on mobile: Before: 9560.567kbps Overall PSNR:50.255DB VPXSSIM:98.288 Now: 18035.774kbps Overall PSNR:73.022DB VPXSSIM:99.991 patch set 2: regenerated dc/ac quantizer lookup tables based on the scaling factor rolled in the fdct/idct. Also slightly extended the range towards the high quantizer end. patch set 3: slightly tweaked the quantizer tables and generated bits_per_mb table based on Paul's suggestions. patch set 4: fix a typo in idct, re-calculated tables relating active max Q to active min Q patch set 5: added rdmult lookup table based on Q patch set 6: fix rdmult scale: dct coefficient has scaled up by 4 patch set 7: make transform coefficients to be within 16bits patch set 8: normalize 2nd order quantizers patch set 9: fix mis-spellings patch set 10: change the configure script and macros to allow experimental code to be enabled at configure time with --enable-extend_qrange patch set 11: rebase for merge Change-Id: Ib50641ddd44aba2a52ed890222c309faa31cc59c
2010-09-09Use WebM in copyright notice for consistencyJohn Koleszar
Changes 'The VP8 project' to 'The WebM project', for consistency with other webmproject.org repositories. Fixes issue #97. Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
2010-06-28Improve the accuracy of forward walsh-hadamard transformYaowu Xu
Besides the slight improvement in round trip error. This also fixes a sign bias in the forward transform, so the round trip errors are evenly distributed between +1s and -1s. The old bias seemed to work well with the dc sign bias in old fdct, which no longer exist in the improved fdct. Change-Id: I8635e7be16c69e69a8669eca5438550d23089cef
2010-06-24Redo the forward 4x4 dctYaowu Xu
The new fdct lowers the round trip sum squared error for a 4x4 block ~0.12. or ~0.008/pixel. For reference, the old matrix multiply version has average round trip error 1.46 for a 4x4 block. Thanks to "derf" for his suggestions and references. Change-Id: I5559d1e81d333b319404ab16b336b739f87afc79
2010-06-18cosmetics: trim trailing whitespaceJohn Koleszar
When the license headers were updated, they accidentally contained trailing whitespace, so unfortunately we have to touch all the files again. Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
2010-06-04LICENSE: update with latest textJohn Koleszar
Change-Id: Ieebea089095d9073b3a94932791099f614ce120c
2010-05-18Initial WebM releaseJohn Koleszar