libaom v3.4.0 Fluttershy Released

[Wan-Teh Chang]

Hello everyone,

libaom v3.4.0 Fluttershy has been released. The source code of the
release can be checked out from the git repository[1] using the
release tag v3.4.0. Alternatively, the release tarball[2], along with
the signature file[3], can be downloaded.

Thanks.

[1] https://aomedia.googlesource.com/aom
[2] https://storage.googleapis.com/aom-releases/libaom-3.4.0.tar.gz
[3] https://storage.googleapis.com/aom-releases/libaom-3.4.0.tar.gz.asc

2022-06-17 v3.4.0
This release includes compression efficiency and perceptual quality
improvements, speedup and memory optimizations, and some new features.
There are no ABI or API breaking changes in this release.

- New Features
* New --dist-metric flag with "qm-psnr" value to use quantization
matrices in the distortion computation for RD search. The default
value is "psnr".
* New command line option "--auto-intra-tools-off=1" to make
all-intra encoding faster for high bit rate under
"--deltaq-mode=3" mode.
* New rate control library aom_av1_rc for real-time hardware
encoders. Supports CBR for both one spatial layer and SVC.
* New image format AOM_IMG_FMT_NV12 can be used as input to the
encoder. The presence of AOM_IMG_FMT_NV12 can be detected at
compile time by checking if the macro AOM_HAVE_IMG_FMT_NV12 is
defined.
* New codec controls for the encoder:
o AV1E_SET_AUTO_INTRA_TOOLS_OFF. Only in effect if
--deltaq-mode=3.
o AV1E_SET_RTC_EXTERNAL_RC
o AV1E_SET_FP_MT. Only supported if libaom is built with
-DCONFIG_FRAME_PARALLEL_ENCODE=1.
o AV1E_GET_TARGET_SEQ_LEVEL_IDX
* New key-value pairs for the key-value API:
o --auto-intra-tools-off=0 (default) or 1. Only in effect if
--deltaq-mode=3.
o --strict-level-conformance=0 (default) or 1
o --fp-mt=0 (default) or 1. Only supported if libaom is built
with -DCONFIG_FRAME_PARALLEL_ENCODE=1.
* New aomenc options (not supported by the key-value API):
o --nv12

- Compression Efficiency Improvements
* Correctly calculate SSE for high bitdepth in skip mode, 0.2% to
0.6% coding gain.
* RTC at speed 9/10: BD-rate gain of ~4/5%
* RTC screen content coding: many improvements for real-time screen
at speed 10 (quality, speedup, and rate control), up to high
resolutions (1080p).
* RTC-SVC: fixes to make intra-only frames work for spatial layers.
* RTC-SVC: quality improvements for temporal layers.
* AV1 RT: A new passive rate control strategy for screen content, an
average of 7.5% coding gain, with some clips of 20+%. The feature
is turned off by default due to higher bit rate variation.

- Perceptual Quality Improvements
* RTC: Visual quality improvements for high speeds (9/10)
* Improvements in coding quality for all intra mode

- Speedup and Memory Optimizations
* ~10% speedup in good quality mode encoding.
* ~7% heap memory reduction in good quality encoding mode for speed
5 and 6.
* Ongoing improvements to intra-frame encoding performance on Arm
* Faster encoding speed for "--deltaq-mode=3" mode.
* ~10% speedup for speed 5/6, ~15% speedup for speed 7/8, and
~10% speedup for speed 9/10 in real time encoding mode
* ~20% heap memory reduction in still-picture encoding mode for
360p-720p resolutions with multiple threads
* ~13% speedup for speed 6 and ~12% speedup for speed 9 in
still-picture encoding mode.
* Optimizations to improve multi-thread efficiency for still-picture
encoding mode.

- Bug Fixes
* b/204460717: README.md: replace master with main
* b/210677928: libaom disable_order is surprising for
max_reference_frames=3
* b/222461449: -DCONFIG_TUNE_BUTTERAUGLI=1 broken
* b/227207606: write_greyscale writes incorrect chroma in highbd
mode
* b/229955363: Integer-overflow in linsolve_wiener
* https://crbug.com/aomedia/2032
* https://crbug.com/aomedia/2397
* https://crbug.com/aomedia/2563
* https://crbug.com/aomedia/2815
* https://crbug.com/aomedia/3009
* https://crbug.com/aomedia/3018
* https://crbug.com/aomedia/3045
* https://crbug.com/aomedia/3101
* https://crbug.com/aomedia/3130
* https://crbug.com/aomedia/3173
* https://crbug.com/aomedia/3184
* https://crbug.com/aomedia/3187
* https://crbug.com/aomedia/3190
* https://crbug.com/aomedia/3195
* https://crbug.com/aomedia/3197
* https://crbug.com/aomedia/3201
* https://crbug.com/aomedia/3202
* https://crbug.com/aomedia/3204
* https://crbug.com/aomedia/3205
* https://crbug.com/aomedia/3207
* https://crbug.com/aomedia/3208
* https://crbug.com/aomedia/3209
* https://crbug.com/aomedia/3213
* https://crbug.com/aomedia/3214
* https://crbug.com/aomedia/3219
* https://crbug.com/aomedia/3222
* https://crbug.com/aomedia/3223
* https://crbug.com/aomedia/3225
* https://crbug.com/aomedia/3226
* https://crbug.com/aomedia/3228
* https://crbug.com/aomedia/3232
* https://crbug.com/aomedia/3236
* https://crbug.com/aomedia/3237
* https://crbug.com/aomedia/3238
* https://crbug.com/aomedia/3240
* https://crbug.com/aomedia/3243
* https://crbug.com/aomedia/3244
* https://crbug.com/aomedia/3246
* https://crbug.com/aomedia/3248
* https://crbug.com/aomedia/3250
* https://crbug.com/aomedia/3251
* https://crbug.com/aomedia/3252
* https://crbug.com/aomedia/3255
* https://crbug.com/aomedia/3257
* https://crbug.com/aomedia/3259
* https://crbug.com/aomedia/3260
* https://crbug.com/aomedia/3267
* https://crbug.com/aomedia/3268
* https://crbug.com/aomedia/3269
* https://crbug.com/aomedia/3276
* https://crbug.com/aomedia/3278
* https://crbug.com/chromium/1290068
* https://crbug.com/chromium/1303237
* https://crbug.com/chromium/1304990
* https://crbug.com/chromium/1321141
* https://crbug.com/chromium/1321388
* https://crbug.com/oss-fuzz/44846
* https://crbug.com/oss-fuzz/44856
* https://crbug.com/oss-fuzz/44862
* https://crbug.com/oss-fuzz/44904
* https://crbug.com/oss-fuzz/45056