fix: fail build for older versions

Dockerfile

@@ -0,0 +1,34 @@
+FROM rust:bookworm
+WORKDIR /src
+RUN apt update && \
+    apt install -y \
+    build-essential \
+    libx264-dev \
+    libx265-dev \
+    libwebp-dev \
+    libvpx-dev \
+    libopus-dev \
+    libdav1d-dev \
+    nasm \
+    libclang-dev && \
+    rm -rf /var/lib/apt/lists/*
+RUN git clone --single-branch --branch release/7.1 https://git.v0l.io/ffmpeg/FFmpeg.git && \
+    cd FFmpeg && \
+    ./configure \
+    --prefix=${FFMPEG_DIR} \
+    --disable-programs \
+    --disable-doc \
+    --disable-network \
+    --enable-gpl \
+    --enable-libx264 \
+    --enable-libx265 \
+    --enable-libwebp \
+    --enable-libvpx \
+    --enable-libopus \
+    --enable-libdav1d \
+    --disable-static \
+    --disable-postproc \
+    --enable-shared && \
+    make -j$(nproc) install
+COPY . .
+RUN cargo build --release

build.rs

@@ -6,7 +6,6 @@ fn main() {
     for (name, _value) in env::vars() {
         if name.starts_with("DEP_FFMPEG_") && !name.starts_with("DEP_FFMPEG_CHECK_") {
             let feature_name = name["DEP_FFMPEG_".len()..name.len()].to_lowercase();
-            println!(r#"cargo::rustc-check-cfg=cfg(feature, values("{feature_name}"))"#);
             println!(r#"cargo::rustc-cfg=feature="{feature_name}""#);
         }
     }

src/encode.rs

@@ -265,7 +265,6 @@ impl Encoder {
 mod tests {
     use super::*;
     use crate::generate_test_frame;
-    use ffmpeg_sys_the_third::AVPixelFormat::AV_PIX_FMT_YUV420P;
 
     #[test]
     fn test_encode_png() -> Result<(), Error> {

src/lib.rs

@@ -18,6 +18,11 @@ mod scale;
 mod stream_info;
 mod transcode;
 
+#[cfg(not(feature = "avcodec_version_greater_than_59_24"))]
+compile_error!("avcodec version too old, < 59.24");
+#[cfg(not(feature = "avutil_version_greater_than_57_24"))]
+compile_error!("avutil version too old, <57.24");
+
 #[macro_export]
 macro_rules! bail_ffmpeg {
     ($x:expr) => {