Commit Graph

9 Commits

Author SHA1 Message Date
Paul Wilkins
7748d833e8 Experiment with old Q range:
Experiment with old Q range but new higher precision quantizer
and transform code.

Change-Id: Id1ff4cb433e5775d709d0133e2aec0322975c292
2011-12-09 16:19:08 +00:00
Paul Wilkins
8487a68baf Further work on extended Q range.
Fixed some further QIndex related issues and replaced some tables
(eg zbin and rounding)

Also Added function (currently disabled by default) to populate the
main AC and DC quantizer tables. Using the original AC range the
resulting computed DC values give behavior broadly comparable
on the DERF set. That is not to say that the equations will hold good
over a more extended range. The purpose of this code is to make it
easier to experiment with further alterations to the Q range and distribution
of Q values plus the relative weights given to AC and DC.

The function find_fp_qindex() ensures that changes to the Q tables
are reflected in the value passed in to the first pass code.

Slight experimental adjustment to static segment Q offset.

Change-Id: I36186267d55dfc2a3d565d0cff7218ef300d1cd5
2011-12-02 15:30:01 +00:00
Paul Wilkins
99df6bb629 Further work on extended Q range.
Fixed bug in firspass.c call to vp8_initialize_rd_consts()

This was passing in vp8_dc_quant(cm->base_qindex, cm->y1dc_delta_q)
 instead of (cm->base_qindex + cm->y1dc_delta_q).

It just so happens that for the value 26 used for cm->base_qindex in the
unextended Q case,  the two give similar results. However, when using
the extended Q range the two are very different.

Also added more stats output and partly disabled another broken feature.

Change-Id: Iddf6cf5ea8467c44b7c133f38e629f6ba6f2581e
2011-11-29 17:59:23 +00:00
Paul Wilkins
9bac509ac5 Extended Q range Experiment.
Corrected dc lookup table to maintain ac/dc balance
close to what it was previously.

Firstpass not being passed the adjusted Q index for
the extended range.

Change-Id: Ic0200dabda445fea03bf81067999cb2670e99b77
2011-11-21 15:53:40 +00:00
Yaowu Xu
5b42ae09ae experiment extending the quantizer range
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
2011-01-19 13:22:35 -08:00
John Koleszar
c2140b8af1 Use WebM in copyright notice for consistency
Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.

Fixes issue #97.

Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
2010-09-09 10:01:21 -04:00
John Koleszar
94c52e4da8 cosmetics: trim trailing whitespace
When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.

Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
2010-06-18 13:06:11 -04:00
John Koleszar
09202d8071 LICENSE: update with latest text
Change-Id: Ieebea089095d9073b3a94932791099f614ce120c
2010-06-04 16:19:40 -04:00
John Koleszar
0ea50ce9cb Initial WebM release 2010-05-18 11:58:33 -04:00