The inputs are generated with dav1d layout.

Address #686

Also, add simple reference tests for u8 prediction.

* Generate downsampled versions of input frames and store them with reference frames

* Add hierarchical ME, where initial ME is done using 4x subsampled 64x64 blocks. MVs are refined using 2x subsampled 32x32 blocks. In the refinement step, search is done around MV found for colocated 64x64 block, and also around MVs found for neighboring 64x64 blocks

Use transform domain distortion during RDO-based mode decision.
- Turn on tx-domain distortion when speed >= 1.
-  For CfL mode, use pixel domain distortion since reconstructed luma pixels are required for CfL mode of chroma channels.

For default speed = 3, there is a regression of 0.35% PSNR bd-rate increase on AWCY.

  PSNR | PSNR Cb | PSNR Cr | PSNR HVS |   SSIM  | MS SSIM | CIEDE 2000
0.3440 |  0.4580   |  0.3700   |   0.2730     | 0.2714 |  0.2616    |     0.5526

Frame reordering should be applied when low_latency is false

OBUs of reordered frames are combined with OBUs of a non-reordered
frame into a single packet. May address #674

As a simple example, call ipred_dc_128.

Support linking asm on macOS; the linker trips over a dependency on
src/tables.c in mc.asm if we include it.

Avoid linking asm with MSVC for now as static library not found.

* Enable coding of compound mode

* Modify inter prediction function to support compound mode

* Call motion estimation function early and store results for use by compound mode

* Add compound as an RDO candidate

* Increase frame coding structure pyramid size

* Make ME search range dependent on frame distance

The nasm provided by the current travis distribution is too old.

Add a generic bound for u8 and u16 and convert `pred_dc`, `pred_dc_128`,
`pred_dc_left`, `pred_dc_top`, `pred_h`, `pred_v` and `pred_paeth`.

Fixes issue #653.

Josh Holmer authored 6 years ago and Luca Barbato committed 6 years ago

- Rewrite fwd transform functions from C to Rust
- Rewrite 32x32 inv transform functions from C to Rust
- Refactor transform.rs into smaller modules

This commit temporarily removes the calls into the
SIMD optimized functions. These will be rewritten
into Rust and readded in an upcoming PR.

Second part of #650

Solves half #650

The rust compiler DCE works in a different way so conditionals on `cfg!`
should not be used if the code in the branches may not compile.

While at it move the `use` statements where they are needed to avoid
warnings.

Fix #657

Document NASM dependency.

Otherwise cargo-bench would try to call the test runner with --bench and
criterion-only options, making the process fail.

- Don't do duplicate tx_type rdo with bottom-up partition rdo.
- Set tx_type  as DCT_DCT when skip==true during mode decision rdo.
- Add set_tx_size() if rdo_tx_size_type() is not called.

Unbreak encoding without producing the reconstructed video.