Release v3.4.0 Fluttershy

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

Bug: aomedia:3281