Benchmark error: UnsupportedError { format: Exact(Jpeg), kind: Color(Rgba8) }

[zamazan4ik]

Hi!

I observed an error during the library benchmarking.

Expected

The benchmark completes successfully with the documented command.

Actual behaviour

The benchmark fails with the following error:

taskset -c 0 cargo +nightly bench --features=benchmarks

<lines are omitted for clarity>
...
encode-jpeg/zero-Rgb8-file/256
                        time:   [1.2626 ms 1.2630 ms 1.2635 ms]
Found 1 outliers among 100 measurements (1.00%)
  1 (1.00%) high mild
Benchmarking encode-jpeg/zero-Rgba8-rawvec/64: Warming up for 3.0000 sthread 'main' panicked at benches/encode.rs:132:41:
called `Result::unwrap()` on an `Err` value: Unsupported(UnsupportedError { format: Exact(Jpeg), kind: Color(Rgba8) })
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

error: bench failed, to rerun pass `--bench encode`

Reproduction steps

1. Run cargo +nightly bench --features=benchmarks
2. Wait until the encode-jpeg/zero-Rgba8-rawvec/64 the benchmark will start
3. Get the error

Environment info:

• OS: Fedora 39
• Kernel: 6.8.7
• Rustc version: 1.80.0-nightly
• image version: main branch, 5013041c830c2f5aa189cccc7f8902ce22e283c7 commit

[fintelia]

The JPEG format cannot store an alpha channel. See #2211

Looks like the benchmark needs to be updated to strip the alpha channel or skip those images