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
The merge includes hooks to for CQ mode and other code
changes merged from the test branch.
CQ mode attempts to maintain a more stable quantizer within a clip
whilst also trying to adhere to a guidline maximum bitrate.
The existing target data rate parameter is used to specify the
guideline maximum bitrate.
A new parameter allows the user to specify a target CQ level.
For normal (non kf/gf/arf) frames, the quantizer will not drop BELOW the
user specified value (0-63). However, in some cases the encoder may
choose to impose a target CQ that is above that specified by the user,
if it estimates that consistent use of the target value is not compatible
with guideline maximum bitrate.
Change-Id: I2221f9eecae8cc3c431d36caf83503941b25e4c1
When auto_golden wasn't set it forced all frames to be a golden
frame. Now the manual configured frequency is adhered to.
Change-Id: I360acac9bc487db0d9c4d4da6ee41f70c227c539
On a keyframe alt ref and golden are refreshed. The flag was
not being set and so on the frame after a keyframe, motion
search would occur on the alt ref frame. This is not necessary
because the alt ref frame identical to the last frame in this
scenario.
Handle corner case where a forward alt-ref frame is put
directly after a keyframe.
Change-Id: I9be4cf290d694f8cf2f9a31852014b5ccf1504d3
The baseline bits per MB prediction tables have been
re calibrated based on the assumption that bits per mb
is inversely proportional to the quantizer level.
Change-Id: Ibd355c7acac4b8053dda1baf1032fe35f11da7f7
Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.
Fixes issue #97.
Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
These changes improve the behaviour of the code with
forced key frames sent in by a calling application.
The sizing of the frames is still suboptimal for two pass in
particular but the behaviour is much better than it was.
Change-Id: I35fae610c67688ccc69d11f385e87dfc884e65a1
Previously we had assumed that it was necessary to give a full frame's
bit allocation to the alt ref frame if it has been created through temporal
filtering. This is not the case. The active max quantizer control
insures that sufficient bits are allocated if needed and allocating a
full frame's worth of bits creates an excessive overhead for the ARF.
Change-Id: I83c95ed7bc7ce0e53ccae6ff32db5a97f145937a
When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.
Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
