mediaway-decoder 0.1.1

Hardware-accelerated video/audio decoding (OS-native backends)
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//! Map [`CodecKind`] / SPS `profile_idc` to VA-API profile candidates for decode.

use crate::DecodeError;
use mediaway_common::CodecKind;

/// VA-API profile candidates for a parsed SPS `profile_idc`, best match first.
///
/// This crate's [`super::sps::Sps::parse`] already rejects any `profile_idc` outside
/// `{66, 77}` (baseline / main — this session's scope, see
/// `adr/0001-vaapi-h264-cpu-out.md`), so the `_` arm here is unreachable in practice but kept
/// exhaustive and honest rather than assuming the caller always validates first.
///
/// # Errors
///
/// Returns [`DecodeError::Unsupported`] for any `profile_idc` this crate does not decode.
pub(super) fn h264_profile_candidates(
    profile_idc: u8,
) -> Result<Vec<cros_libva::VAProfile::Type>, DecodeError> {
    match profile_idc {
        // Baseline: most drivers only expose the Constrained Baseline VA-API profile.
        66 => Ok(vec![
            cros_libva::VAProfile::VAProfileH264ConstrainedBaseline,
        ]),
        // Main: prefer an exact match, fall back to Constrained Baseline (a strict decode
        // subset of Main for VLD purposes on drivers that do not enumerate Main separately).
        77 => Ok(vec![
            cros_libva::VAProfile::VAProfileH264Main,
            cros_libva::VAProfile::VAProfileH264ConstrainedBaseline,
        ]),
        _ => Err(DecodeError::Unsupported),
    }
}

/// Whether this crate's video decode path accepts `codec`.
#[must_use]
pub(super) const fn is_supported_video_codec(codec: CodecKind) -> bool {
    matches!(codec, CodecKind::H264)
}

#[cfg(test)]
#[path = "codec_tests.rs"]
mod tests;