assertion failed: sbo.0.x % (1 << sb_shift) == 0 since earlier this week

[sdroege]

If you run cargo test in
https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/tree/master/gst-plugin-rav1e
it will fail with panics

thread 'test_encode_y444' panicked at 'assertion failed: sbo.0.x % (1 << sb_shift) == 0', /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/tiling/tile_restoration_state.rs:369:1
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:47
   3: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:36
   4: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:200
   5: std::panicking::default_hook
             at src/libstd/panicking.rs:211
   6: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:477
   7: std::panicking::begin_panic
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/libstd/panicking.rs:411
   8: rav1e::tiling::tile_restoration_state::TileRestorationStateMut::new
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/tiling/tile_state.rs:0
   9: rav1e::tiling::tile_state::TileStateMut<T>::new
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/tiling/tile_state.rs:110
  10: <rav1e::tiling::tiler::TileContextIterMut<T> as core::iter::traits::iterator::Iterator>::next
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/tiling/tiler.rs:187
  11: alloc::vec::Vec<T>::extend_desugared
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/liballoc/vec.rs:2003
  12: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T,I>>::spec_extend
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/liballoc/vec.rs:1900
  13: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T,I>>::from_iter
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/liballoc/vec.rs:1895
  14: <alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/liballoc/vec.rs:1796
  15: core::iter::traits::iterator::Iterator::collect
             at /rustc/eae3437dfe991621e8afdc82734f4a172d7ddf9b/src/libcore/iter/traits/iterator.rs:1466
  16: rav1e::api::ContextInner<T>::compute_lookahead_motion_vectors
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/api/mod.rs:1464
  17: rav1e::api::ContextInner<T>::compute_lookahead_data
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/api/mod.rs:1681
  18: rav1e::api::ContextInner<T>::send_frame
             at /home/slomo/.cargo/git/checkouts/rav1e-14e16d25dd5cd9c0/aa4271e/src/api/mod.rs:1181

This was working fine with the version of rav1e on Tuesday.

[shssoichiro]

I think the test that was disabled here was catching this.

[sdroege]

This only happens when setting tile rows/cols to some value, at least setting both to 2 makes it happen.

[YaLTeR]

Reproducible with one tile with the following test:

#[test]
fn get_units_region_assert() {
  let config = Config {
    enc: EncoderConfig {
      width: 65,
      height: 158,
      bit_depth: 8,
      chroma_sampling: ChromaSampling::Cs420,
      chroma_sample_position: ChromaSamplePosition::Unknown,
      pixel_range: PixelRange::Limited,
      color_description: None,
      mastering_display: None,
      content_light: None,
      still_picture: true,
      time_base: Rational { num: 4294977800, den: 6004234345560342528 },
      min_key_frame_interval: 12,
      max_key_frame_interval: 240,
      reservoir_frame_delay: None,
      low_latency: true,
      quantizer: 100,
      min_quantizer: 0,
      bitrate: 0,
      tune: Tune::Psychovisual,
      tile_cols: 0,
      tile_rows: 0,
      tiles: 0,
      rdo_lookahead_frames: 0,
      speed_settings: SpeedSettings {
        min_block_size: BlockSize::BLOCK_64X64,
        multiref: false,
        fast_deblock: true,
        reduced_tx_set: true,
        tx_domain_distortion: true,
        tx_domain_rate: false,
        encode_bottomup: false,
        rdo_tx_decision: false,
        prediction_modes: PredictionModesSetting::Simple,
        include_near_mvs: false,
        no_scene_detection: true,
        diamond_me: true,
        cdef: true,
        quantizer_rdo: false,
        use_satd_subpel: false,
      },
      show_psnr: false,
      train_rdo: false,
    },
    threads: 1,
  };

  let mut ctx: Context<u8> = config.new_context().unwrap();
  ctx.send_frame(ctx.new_frame()).unwrap();
  ctx.flush();

  ctx.receive_packet().unwrap();
}

Weird time base seems essential (1/25 doesn't trigger the assertion).

EDIT: this triggers sbo.0.y % (1 << sb_shift) == 0 (rather than x).

[xiphmont]

Weird time base seems essential (1/25 doesn't trigger the assertion).

wat. Well, you have my attention, that's for sure. I mean you had it, I am working on this 'right now' which means today around other tasks. Monty

[xiphmont]

The above example isn't one tile. There's three tiles stacked vertically. The framerate is causing the tiler to... overpartition.
In any case, still fits evidence of bug as understood, testing the fix against it too.