46 lines
1.3 KiB
Rust
46 lines
1.3 KiB
Rust
#![forbid(unsafe_code)]
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use gstreamer as gst;
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/// Pick the client-side H.264 decoder in a predictable preference order.
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///
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/// Inputs: none, though operators may override the choice with
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/// `LESAVKA_H264_DECODER=<element>`.
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/// Outputs: the chosen decoder element name, or `decodebin` as a last-resort
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/// fallback when no explicit decoder is present.
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/// Why: `decodebin` is flexible, but a stable preference order makes decode
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/// behavior easier to reason about and compare in diagnostics.
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#[must_use]
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pub fn pick_h264_decoder() -> String {
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if let Ok(raw) = std::env::var("LESAVKA_H264_DECODER") {
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let name = raw.trim();
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if name.eq_ignore_ascii_case("decodebin") {
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return "decodebin".to_string();
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}
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if !name.is_empty() && buildable_decoder(name) {
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return name.to_string();
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}
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}
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for name in [
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"avdec_h264",
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"openh264dec",
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"nvh264dec",
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"nvh264sldec",
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"vah264dec",
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"vaapih264dec",
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"v4l2h264dec",
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"v4l2slh264dec",
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] {
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if buildable_decoder(name) {
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return name.to_string();
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}
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}
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"decodebin".to_string()
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}
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fn buildable_decoder(name: &str) -> bool {
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gst::ElementFactory::find(name).is_some() && gst::ElementFactory::make(name).build().is_ok()
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}
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