Refactor crate::codec (#78)

* Refactor AVCodec wrapper

* Implement new config interface

* Move ProfileIter to codec::profile

* Add CodecDescriptor

examples/codec-info.rs

@@ -20,7 +20,7 @@ fn main() {
                 println!("\t profiles: none");
             }
 
-            if let Ok(video) = codec.video() {
+            if let Some(video) = codec.video() {
                 if let Some(rates) = video.rates() {
                     println!("\t rates: {:?}", rates.collect::<Vec<_>>());
                 } else {
@@ -34,7 +34,7 @@ fn main() {
                 }
             }
 
-            if let Ok(audio) = codec.audio() {
+            if let Some(audio) = codec.audio() {
                 if let Some(rates) = audio.rates() {
                     println!("\t rates: {:?}", rates.collect::<Vec<_>>());
                 } else {
@@ -71,7 +71,7 @@ fn main() {
                 println!("\t profiles: {:?}", profiles.collect::<Vec<_>>());
             }
 
-            if let Ok(video) = codec.video() {
+            if let Some(video) = codec.video() {
                 if let Some(rates) = video.rates() {
                     println!("\t rates: {:?}", rates.collect::<Vec<_>>());
                 } else {
@@ -85,7 +85,7 @@ fn main() {
                 }
             }
 
-            if let Ok(audio) = codec.audio() {
+            if let Some(audio) = codec.audio() {
                 if let Some(rates) = audio.rates() {
                     println!("\t rates: {:?}", rates.collect::<Vec<_>>());
                 } else {

examples/transcode-audio.rs

@@ -83,7 +83,8 @@ fn transcoder<P: AsRef<Path>>(
     let mut decoder = context.decoder().audio()?;
     let codec = ffmpeg::encoder::find(octx.format().codec(path, media::Type::Audio))
         .expect("failed to find encoder")
-        .audio()?;
+        .audio()
+        .expect("encoder is not audio encoder");
     let global = octx
         .format()
         .flags()

src/codec/audio.rs

@@ -1,215 +0,0 @@
-use std::ops::Deref;
-
-use super::codec::Codec;
-use crate::ffi::*;
-use crate::format;
-
-#[cfg(not(feature = "ffmpeg_7_0"))]
-use crate::ChannelLayoutMask;
-
-#[derive(PartialEq, Eq, Copy, Clone)]
-pub struct Audio {
-    codec: Codec,
-}
-
-impl Audio {
-    pub unsafe fn new(codec: Codec) -> Audio {
-        Audio { codec }
-    }
-}
-
-impl Audio {
-    pub fn rates(&self) -> Option<RateIter> {
-        unsafe {
-            if (*self.as_ptr()).supported_samplerates.is_null() {
-                None
-            } else {
-                Some(RateIter::new((*self.codec.as_ptr()).supported_samplerates))
-            }
-        }
-    }
-
-    pub fn formats(&self) -> Option<FormatIter> {
-        unsafe {
-            if (*self.codec.as_ptr()).sample_fmts.is_null() {
-                None
-            } else {
-                Some(FormatIter::new((*self.codec.as_ptr()).sample_fmts))
-            }
-        }
-    }
-
-    #[cfg(not(feature = "ffmpeg_7_0"))]
-    pub fn channel_layouts(&self) -> Option<ChannelLayoutMaskIter> {
-        unsafe {
-            if (*self.codec.as_ptr()).channel_layouts.is_null() {
-                None
-            } else {
-                Some(ChannelLayoutMaskIter::new(
-                    (*self.codec.as_ptr()).channel_layouts,
-                ))
-            }
-        }
-    }
-
-    #[cfg(feature = "ffmpeg_5_1")]
-    pub fn ch_layouts(&self) -> Option<ChannelLayoutIter> {
-        unsafe { ChannelLayoutIter::from_raw((*self.codec.as_ptr()).ch_layouts) }
-    }
-}
-
-impl Deref for Audio {
-    type Target = Codec;
-
-    fn deref(&self) -> &Self::Target {
-        &self.codec
-    }
-}
-
-pub struct RateIter {
-    ptr: *const i32,
-}
-
-impl RateIter {
-    pub fn new(ptr: *const i32) -> Self {
-        RateIter { ptr }
-    }
-}
-
-impl Iterator for RateIter {
-    type Item = i32;
-
-    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-        unsafe {
-            if *self.ptr == 0 {
-                return None;
-            }
-
-            let rate = *self.ptr;
-            self.ptr = self.ptr.offset(1);
-
-            Some(rate)
-        }
-    }
-}
-
-pub struct FormatIter {
-    ptr: *const AVSampleFormat,
-}
-
-impl FormatIter {
-    pub fn new(ptr: *const AVSampleFormat) -> Self {
-        FormatIter { ptr }
-    }
-}
-
-impl Iterator for FormatIter {
-    type Item = format::Sample;
-
-    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-        unsafe {
-            if *self.ptr == AVSampleFormat::AV_SAMPLE_FMT_NONE {
-                return None;
-            }
-
-            let format = (*self.ptr).into();
-            self.ptr = self.ptr.offset(1);
-
-            Some(format)
-        }
-    }
-}
-
-#[cfg(not(feature = "ffmpeg_7_0"))]
-pub struct ChannelLayoutMaskIter {
-    ptr: *const u64,
-}
-
-#[cfg(not(feature = "ffmpeg_7_0"))]
-impl ChannelLayoutMaskIter {
-    pub fn new(ptr: *const u64) -> Self {
-        ChannelLayoutMaskIter { ptr }
-    }
-
-    pub fn best(self, max: i32) -> ChannelLayoutMask {
-        self.fold(ChannelLayoutMask::MONO, |acc, cur| {
-            if cur.channels() > acc.channels() && cur.channels() <= max {
-                cur
-            } else {
-                acc
-            }
-        })
-    }
-}
-
-#[cfg(not(feature = "ffmpeg_7_0"))]
-impl Iterator for ChannelLayoutMaskIter {
-    type Item = ChannelLayoutMask;
-
-    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-        unsafe {
-            if *self.ptr == 0 {
-                return None;
-            }
-
-            let layout = ChannelLayoutMask::from_bits_truncate(*self.ptr);
-            self.ptr = self.ptr.offset(1);
-
-            Some(layout)
-        }
-    }
-}
-
-#[cfg(feature = "ffmpeg_5_1")]
-pub use ch_layout::ChannelLayoutIter;
-
-#[cfg(feature = "ffmpeg_5_1")]
-mod ch_layout {
-    use super::*;
-    use crate::ChannelLayout;
-
-    pub struct ChannelLayoutIter<'a> {
-        next: &'a AVChannelLayout,
-    }
-
-    impl<'a> ChannelLayoutIter<'a> {
-        pub unsafe fn from_raw(ptr: *const AVChannelLayout) -> Option<Self> {
-            ptr.as_ref().map(|next| Self { next })
-        }
-    }
-
-    impl<'a> ChannelLayoutIter<'a> {
-        pub fn best(self, max: u32) -> ChannelLayout<'a> {
-            self.fold(ChannelLayout::MONO, |acc, cur| {
-                if cur.channels() > acc.channels() && cur.channels() <= max {
-                    cur
-                } else {
-                    acc
-                }
-            })
-        }
-    }
-
-    impl<'a> Iterator for ChannelLayoutIter<'a> {
-        type Item = ChannelLayout<'a>;
-
-        fn next(&mut self) -> Option<Self::Item> {
-            unsafe {
-                let curr = self.next;
-                if *curr == zeroed_layout() {
-                    return None;
-                }
-
-                // SAFETY: We trust that there is always an initialized layout up until
-                // the zeroed-out AVChannelLayout, which signals the end of iteration.
-                self.next = (curr as *const AVChannelLayout).add(1).as_ref().unwrap();
-                Some(ChannelLayout::from(curr))
-            }
-        }
-    }
-
-    // TODO: Remove this with a const variable when zeroed() is const (1.75.0)
-    unsafe fn zeroed_layout() -> AVChannelLayout {
-        std::mem::zeroed()
-    }
-}

src/codec/codec.rs

@@ -1,30 +1,58 @@
-use super::{Audio, Capabilities, Id, Profile, Video};
+use std::marker::PhantomData;
+use std::ptr::NonNull;
+
+use super::config::{
+    FrameRateIter, PixelFormatIter, SampleFormatIter, SampleRateIter, TerminatedPtrIter,
+};
+use super::descriptor::{CodecDescriptor, CodecDescriptorIter};
+use super::profile::ProfileIter;
+use super::{Capabilities, Id};
 use crate::ffi::*;
-use crate::{media, utils, Error};
+use crate::{media, utils};
+
+#[cfg(feature = "ffmpeg_7_1")]
+use crate::codec::config::{ColorRangeIter, ColorSpaceIter, Supported};
+
+pub fn list_descriptors() -> CodecDescriptorIter {
+    CodecDescriptorIter::new()
+}
+
+pub type Audio = Codec<AudioType>;
+pub type Video = Codec<VideoType>;
 
 #[derive(PartialEq, Eq, Copy, Clone)]
-pub struct Codec {
+pub struct Codec<Type = UnknownType> {
-    ptr: *mut AVCodec,
+    ptr: NonNull<AVCodec>,
+    _marker: PhantomData<Type>,
 }
 
-unsafe impl Send for Codec {}
+#[derive(PartialEq, Eq, Copy, Clone)]
-unsafe impl Sync for Codec {}
+pub struct UnknownType;
+#[derive(PartialEq, Eq, Copy, Clone)]
+pub struct AudioType;
+#[derive(PartialEq, Eq, Copy, Clone)]
+pub struct VideoType;
 
-impl Codec {
+unsafe impl<T> Send for Codec<T> {}
-    pub unsafe fn wrap(ptr: *mut AVCodec) -> Self {
+unsafe impl<T> Sync for Codec<T> {}
-        Codec { ptr }
-    }
 
-    pub unsafe fn as_ptr(&self) -> *const AVCodec {
+impl Codec<UnknownType> {
-        self.ptr as *const _
+    /// Create a new reference to a codec from a raw pointer.
-    }
+    ///
-
+    /// Returns `None` if `ptr` is null.
-    pub unsafe fn as_mut_ptr(&mut self) -> *mut AVCodec {
+    pub unsafe fn from_raw(ptr: *const AVCodec) -> Option<Self> {
-        self.ptr
+        NonNull::new(ptr as *mut _).map(|ptr| Self {
+            ptr,
+            _marker: PhantomData,
+        })
     }
 }
 
-impl Codec {
+impl<T> Codec<T> {
+    pub fn as_ptr(&self) -> *const AVCodec {
+        self.ptr.as_ptr()
+    }
+
     pub fn is_encoder(&self) -> bool {
         unsafe { av_codec_is_encoder(self.as_ptr()) != 0 }
     }
@@ -53,13 +81,14 @@ impl Codec {
         self.medium() == media::Type::Video
     }
 
-    pub fn video(self) -> Result<Video, Error> {
+    pub fn video(self) -> Option<Video> {
-        unsafe {
         if self.medium() == media::Type::Video {
-                Ok(Video::new(self))
+            Some(Codec {
+                ptr: self.ptr,
+                _marker: PhantomData,
+            })
         } else {
-                Err(Error::InvalidData)
+            None
-            }
         }
     }
 
@@ -67,13 +96,14 @@ impl Codec {
         self.medium() == media::Type::Audio
     }
 
-    pub fn audio(self) -> Result<Audio, Error> {
+    pub fn audio(self) -> Option<Audio> {
-        unsafe {
         if self.medium() == media::Type::Audio {
-                Ok(Audio::new(self))
+            Some(Codec {
+                ptr: self.ptr,
+                _marker: PhantomData,
+            })
         } else {
-                Err(Error::InvalidData)
+            None
-            }
         }
     }
 
@@ -94,32 +124,217 @@ impl Codec {
             }
         }
     }
-}
 
-pub struct ProfileIter {
+    pub fn descriptor(self) -> Option<CodecDescriptor> {
-    id: Id,
+        unsafe {
-    ptr: *const AVProfile,
+            let ptr = avcodec_descriptor_get(self.id().into());
+            CodecDescriptor::from_raw(ptr)
         }
-
-impl ProfileIter {
-    pub fn new(id: Id, ptr: *const AVProfile) -> Self {
-        ProfileIter { id, ptr }
     }
 }
 
-impl Iterator for ProfileIter {
+impl Codec<AudioType> {
-    type Item = Profile;
+    /// Checks if the given sample rate is supported by this audio codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_rate(self, rate: libc::c_int) -> bool {
+        self.supported_rates().supports(rate)
+    }
+
+    /// Returns a [`Supported`] representing the supported sample rates.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_rates(self) -> Supported<SampleRateIter<'static>> {
+        use super::config::supported_sample_rates;
+        supported_sample_rates(self, None).expect("audio codec returns supported sample rates")
+    }
+
+    pub fn rates(&self) -> Option<SampleRateIter> {
+        unsafe { SampleRateIter::from_raw((*self.as_ptr()).supported_samplerates) }
+    }
+
+    /// Checks if the given sample format is supported by this audio codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_format(self, format: crate::format::Sample) -> bool {
+        self.supported_formats().supports(format)
+    }
+
+    /// Returns a [`Supported`] representing the supported sample formats.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_formats(self) -> Supported<SampleFormatIter<'static>> {
+        use super::config::supported_sample_formats;
+        supported_sample_formats(self, None).expect("audio codec returns supported sample formats")
+    }
+
+    pub fn formats(&self) -> Option<SampleFormatIter> {
+        unsafe { SampleFormatIter::from_raw((*self.as_ptr()).sample_fmts) }
+    }
+
+    #[cfg(not(feature = "ffmpeg_7_0"))]
+    pub fn channel_layouts(&self) -> Option<ChannelLayoutMaskIter> {
+        unsafe { ChannelLayoutMaskIter::from_raw((*self.as_ptr()).channel_layouts) }
+    }
+
+    #[cfg(feature = "ffmpeg_5_1")]
+    pub fn ch_layouts(&self) -> Option<ChannelLayoutIter> {
+        unsafe { ChannelLayoutIter::from_raw((*self.as_ptr()).ch_layouts) }
+    }
+}
+
+impl Codec<VideoType> {
+    /// Checks if the given frame rate is supported by this video codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_rate(self, rate: crate::Rational) -> bool {
+        self.supported_rates().supports(rate)
+    }
+
+    /// Returns a [`Supported`] representing the supported frame rates.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_rates(self) -> Supported<FrameRateIter<'static>> {
+        use crate::codec::config::supported_frame_rates;
+        supported_frame_rates(self, None).expect("video codec returns supported frame rates")
+    }
+
+    pub fn rates(&self) -> Option<FrameRateIter> {
+        unsafe { FrameRateIter::from_raw((*self.as_ptr()).supported_framerates) }
+    }
+
+    /// Checks if the given pixel format is supported by this video codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_format(self, format: crate::format::Pixel) -> bool {
+        self.supported_formats().supports(format)
+    }
+
+    /// Returns a [`Supported`] representing the supported pixel formats.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_formats(self) -> Supported<PixelFormatIter<'static>> {
+        use crate::codec::config::supported_pixel_formats;
+        supported_pixel_formats(self, None).expect("video codec returns supported pixel formats")
+    }
+
+    pub fn formats(&self) -> Option<PixelFormatIter> {
+        unsafe { PixelFormatIter::from_raw((*self.as_ptr()).pix_fmts) }
+    }
+
+    /// Checks if the given color space is supported by this video codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_color_space(self, space: crate::color::Space) -> bool {
+        self.supported_color_spaces().supports(space)
+    }
+
+    /// Returns a [`Supported`] representing the supported color spaces.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_color_spaces(self) -> Supported<ColorSpaceIter<'static>> {
+        use crate::codec::config::supported_color_spaces;
+        supported_color_spaces(self, None).expect("video codec returns supported color spaces")
+    }
+
+    /// Checks if the given color range is supported by this video codec.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supports_color_range(self, range: crate::color::Range) -> bool {
+        self.supported_color_ranges().supports(range)
+    }
+
+    /// Returns a [`Supported`] representing the supported color ranges.
+    #[cfg(feature = "ffmpeg_7_1")]
+    pub fn supported_color_ranges(self) -> Supported<ColorRangeIter<'static>> {
+        use crate::codec::config::supported_color_ranges;
+        supported_color_ranges(self, None).expect("video codec returns supported color ranges")
+    }
+}
+
+#[cfg(not(feature = "ffmpeg_7_0"))]
+use crate::ChannelLayoutMask;
+
+#[cfg(not(feature = "ffmpeg_7_0"))]
+pub struct ChannelLayoutMaskIter {
+    ptr: NonNull<u64>,
+}
+
+#[cfg(not(feature = "ffmpeg_7_0"))]
+impl ChannelLayoutMaskIter {
+    pub fn from_raw(ptr: *const u64) -> Option<Self> {
+        NonNull::new(ptr as *mut _).map(|ptr| Self { ptr })
+    }
+
+    pub fn best(self, max: i32) -> ChannelLayoutMask {
+        self.fold(ChannelLayoutMask::MONO, |acc, cur| {
+            if cur.channels() > acc.channels() && cur.channels() <= max {
+                cur
+            } else {
+                acc
+            }
+        })
+    }
+}
+
+#[cfg(not(feature = "ffmpeg_7_0"))]
+impl Iterator for ChannelLayoutMaskIter {
+    type Item = ChannelLayoutMask;
 
     fn next(&mut self) -> Option<<Self as Iterator>::Item> {
         unsafe {
-            if (*self.ptr).profile == FF_PROFILE_UNKNOWN {
+            let ptr = self.ptr.as_ptr();
+            if *ptr == 0 {
                 return None;
             }
 
-            let profile = Profile::from((self.id, (*self.ptr).profile));
+            let layout = ChannelLayoutMask::from_bits_truncate(*ptr);
-            self.ptr = self.ptr.offset(1);
+            self.ptr = NonNull::new_unchecked(ptr.add(1));
 
-            Some(profile)
+            Some(layout)
         }
     }
 }
+
+#[cfg(feature = "ffmpeg_5_1")]
+pub use ch_layout::ChannelLayoutIter;
+
+#[cfg(feature = "ffmpeg_5_1")]
+mod ch_layout {
+    use super::*;
+    use crate::ChannelLayout;
+
+    pub struct ChannelLayoutIter<'a> {
+        next: &'a AVChannelLayout,
+    }
+
+    impl<'a> ChannelLayoutIter<'a> {
+        pub unsafe fn from_raw(ptr: *const AVChannelLayout) -> Option<Self> {
+            ptr.as_ref().map(|next| Self { next })
+        }
+    }
+
+    impl<'a> ChannelLayoutIter<'a> {
+        pub fn best(self, max: u32) -> ChannelLayout<'a> {
+            self.fold(ChannelLayout::MONO, |acc, cur| {
+                if cur.channels() > acc.channels() && cur.channels() <= max {
+                    cur
+                } else {
+                    acc
+                }
+            })
+        }
+    }
+
+    impl<'a> Iterator for ChannelLayoutIter<'a> {
+        type Item = ChannelLayout<'a>;
+
+        fn next(&mut self) -> Option<Self::Item> {
+            unsafe {
+                let curr = self.next;
+                if *curr == zeroed_layout() {
+                    return None;
+                }
+
+                // SAFETY: We trust that there is always an initialized layout up until
+                // the zeroed-out AVChannelLayout, which signals the end of iteration.
+                self.next = (curr as *const AVChannelLayout).add(1).as_ref().unwrap();
+                Some(ChannelLayout::from(curr))
+            }
+        }
+    }
+
+    // TODO: Remove this with a const variable when zeroed() is const (1.75.0)
+    unsafe fn zeroed_layout() -> AVChannelLayout {
+        std::mem::zeroed()
+    }
+}

src/codec/config.rs

@@ -0,0 +1,397 @@
+use std::ptr::NonNull;
+
+#[cfg(feature = "ffmpeg_7_1")]
+use crate::codec::Context;
+#[cfg(feature = "ffmpeg_7_1")]
+use crate::ffi::*;
+#[cfg(feature = "ffmpeg_7_1")]
+use crate::Codec;
+#[cfg(feature = "ffmpeg_7_1")]
+use crate::Error;
+
+#[cfg(feature = "ffmpeg_7_1")]
+#[derive(Debug, Clone)]
+pub enum Supported<I> {
+    All,
+    Specific(I),
+}
+
+#[cfg(feature = "ffmpeg_7_1")]
+impl<T, I> Supported<I>
+where
+    T: PartialEq,
+    I: Iterator<Item = T>,
+{
+    /// Check if all possible configuration values are supported.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use ffmpeg_the_third::codec::{encoder, Id};
+    ///
+    /// let codec = encoder::find(Id::VP9)
+    ///     .expect("Can find a VP9 encoder")
+    ///     .video()
+    ///     .unwrap();
+    ///
+    /// let supported = codec.supported_rates();
+    /// assert!(supported.all())
+    /// ```
+    pub fn all(&self) -> bool {
+        matches!(self, Supported::All)
+    }
+
+    /// Check if a specific configuration value is supported.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use ffmpeg_the_third::codec::{encoder, Id};
+    /// use ffmpeg_the_third::format::sample::{Sample, Type};
+    ///
+    /// let codec = encoder::find(Id::MP3)
+    ///     .expect("Can find an MP3 encoder")
+    ///     .audio()
+    ///     .unwrap();
+    ///
+    /// let supported = codec.supported_formats();
+    /// assert!(supported.supports(Sample::F32(Type::Planar)));
+    /// ```
+    pub fn supports(self, t: T) -> bool {
+        match self {
+            Supported::All => true,
+            Supported::Specific(mut iter) => iter.any(|elem| elem == t),
+        }
+    }
+}
+
+#[cfg(feature = "ffmpeg_7_1")]
+fn supported<WrapperType, AVType, CodecType, I>(
+    codec: Codec<CodecType>,
+    ctx: Option<&Context>,
+    cfg: AVCodecConfig,
+) -> Result<Supported<I>, Error>
+where
+    I: TerminatedPtrIter<AVType, WrapperType>,
+    AVType: Into<WrapperType>,
+{
+    let mut out_ptr: *const libc::c_void = std::ptr::null();
+
+    unsafe {
+        let avctx = ctx.map_or(std::ptr::null(), |ctx| ctx.as_ptr());
+
+        let ret = avcodec_get_supported_config(
+            avctx,
+            codec.as_ptr(),
+            cfg,
+            0, // flags: unused as of 7.1, set to zero
+            &mut out_ptr,
+            std::ptr::null_mut(), // out_num_configs: optional, we don't support it currently
+        );
+
+        if ret < 0 {
+            return Err(Error::from(ret));
+        }
+
+        match NonNull::new(out_ptr as *mut _) {
+            // non-nullptr -> Specific list of values is supported.
+            Some(ptr) => Ok(Supported::Specific(I::from_ptr(ptr))),
+            // nullptr -> Everything is supported
+            None => Ok(Supported::All),
+        }
+    }
+}
+
+/// Pointer-based iterator, stepped through via pointer arithmetic and ended
+/// when a dereferenced pointer equals a terminator value.
+pub(crate) trait TerminatedPtrIter<AVType, WrapperType>:
+    Sized + Iterator<Item = WrapperType>
+{
+    /// Create a new iterator from a non-null pointer to any value in the iteration.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` and all following pointers must be dereferenceable until the terminator is reached.
+    unsafe fn from_ptr(ptr: NonNull<AVType>) -> Self;
+
+    /// Create a new iterator from a pointer to any value in the iteration.
+    ///
+    /// Returns `None` if `ptr` is null. See also [`from_ptr`][TerminatedPtrIter::from_ptr].
+    ///
+    /// # Safety
+    ///
+    /// See [`from_ptr`][TerminatedPtrIter::from_ptr].
+    unsafe fn from_raw(ptr: *const AVType) -> Option<Self> {
+        unsafe { NonNull::new(ptr as *mut _).map(|ptr| Self::from_ptr(ptr)) }
+    }
+}
+
+macro_rules! impl_config_iter {
+    (
+        $fn_name:ident,
+        $codec_cfg:expr,
+        $iter:ident,
+        $ty:ty,
+        $av_ty:ty,
+        $terminator:expr
+    ) => {
+        impl_config_iter_fn!($fn_name, $iter, $codec_cfg);
+        impl_config_iter_struct!($iter, $av_ty);
+        impl_config_iter_traits!($iter, $ty, $av_ty, $terminator);
+    };
+}
+
+macro_rules! impl_config_iter_struct {
+    ($iter:ident, $av_ty:ty) => {
+        #[derive(Debug, Clone)]
+        pub struct $iter<'a> {
+            next: std::ptr::NonNull<$av_ty>,
+            _marker: std::marker::PhantomData<&'a $av_ty>,
+        }
+    };
+}
+
+macro_rules! impl_config_iter_fn {
+    ($fn_name:ident, $iter:ident, $codec_cfg:expr) => {
+        /// Low-level function interacting with the FFmpeg API via
+        /// `avcodec_get_supported_config()`. Consider using one of the convenience methods
+        /// on the codecs or codec contexts instead.
+        #[cfg(feature = "ffmpeg_7_1")]
+        pub fn $fn_name<T>(
+            codec: Codec<T>,
+            ctx: Option<&Context>,
+        ) -> Result<Supported<$iter>, Error> {
+            supported(codec, ctx, $codec_cfg)
+        }
+    };
+}
+
+macro_rules! impl_config_iter_traits {
+    ($iter:ident, $ty:ty, $av_ty:ty, $terminator:expr) => {
+        impl<'a> TerminatedPtrIter<$av_ty, $ty> for $iter<'a> {
+            unsafe fn from_ptr(ptr: std::ptr::NonNull<$av_ty>) -> Self {
+                Self {
+                    next: ptr,
+                    _marker: std::marker::PhantomData,
+                }
+            }
+        }
+
+        // We make sure that this is true by not incrementing self.ptr after the
+        // terminator has been reached.
+        impl<'a> std::iter::FusedIterator for $iter<'a> {}
+
+        // TODO: Maybe add ExactSizeIterator? This would require using the out_num_configs
+        //       parameter and storing it inside $iter. Not sure it's too important unless
+        //       many people want to use .collect() or something else that benefits from
+        //       ExactSizeIterator.
+
+        impl<'a> Iterator for $iter<'a> {
+            type Item = $ty;
+
+            fn next(&mut self) -> Option<Self::Item> {
+                // SAFETY: The FFmpeg API guarantees that the pointer is safe to deref and
+                //         increment until the terminator is reached.
+                unsafe {
+                    let curr = self.next.as_ptr();
+                    if *curr == $terminator {
+                        return None;
+                    }
+
+                    // TODO: Replace with the following if MSRV >= 1.80:
+                    // self.next = NonNull::from(self.next).add(1).as_ref();
+                    self.next = std::ptr::NonNull::new_unchecked(curr.add(1));
+
+                    Some((*curr).into())
+                }
+            }
+        }
+    };
+}
+
+impl_config_iter!(
+    supported_pixel_formats,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_PIX_FORMAT,
+    PixelFormatIter,
+    crate::format::Pixel,
+    crate::ffi::AVPixelFormat,
+    crate::ffi::AVPixelFormat::AV_PIX_FMT_NONE
+);
+
+impl_config_iter!(
+    supported_frame_rates,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_FRAME_RATE,
+    FrameRateIter,
+    crate::Rational,
+    crate::ffi::AVRational,
+    crate::ffi::AVRational { num: 0, den: 0 }
+);
+
+impl_config_iter!(
+    supported_sample_rates,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_SAMPLE_RATE,
+    SampleRateIter,
+    libc::c_int,
+    libc::c_int,
+    0 as libc::c_int
+);
+
+impl_config_iter!(
+    supported_sample_formats,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_SAMPLE_FORMAT,
+    SampleFormatIter,
+    crate::format::Sample,
+    crate::ffi::AVSampleFormat,
+    crate::ffi::AVSampleFormat::AV_SAMPLE_FMT_NONE
+);
+
+#[cfg(feature = "ffmpeg_7_1")]
+impl_config_iter!(
+    supported_color_ranges,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_COLOR_RANGE,
+    ColorRangeIter,
+    crate::color::Range,
+    crate::ffi::AVColorRange,
+    crate::ffi::AVColorRange::AVCOL_RANGE_UNSPECIFIED
+);
+
+#[cfg(feature = "ffmpeg_7_1")]
+impl_config_iter!(
+    supported_color_spaces,
+    crate::ffi::AVCodecConfig::AV_CODEC_CONFIG_COLOR_SPACE,
+    ColorSpaceIter,
+    crate::color::Space,
+    crate::ffi::AVColorSpace,
+    crate::ffi::AVColorSpace::AVCOL_SPC_UNSPECIFIED
+);
+
+#[cfg(test)]
+#[cfg(feature = "ffmpeg_7_1")]
+mod test {
+    use super::*;
+
+    use crate::codec::{decoder, encoder, Compliance, Id};
+    use crate::color::Range;
+    use crate::format::Pixel;
+    use crate::Rational;
+
+    // These tests can fail if the FFmpeg build does not contain the required de/encoder.
+    // TODO: Check if tests can be hidden behind feature flags.
+
+    #[test]
+    fn audio_decoder() {
+        let codec = decoder::find(Id::MP3).expect("can find mp3 decoder");
+
+        // Audio decoder does not have color ranges
+        assert!(supported_color_ranges(codec, None).is_err());
+
+        let format_iter = match supported_sample_formats(codec, None) {
+            Ok(Supported::Specific(f)) => f,
+            sup => panic!("Should be Supported::Specific, got {sup:#?}"),
+        };
+
+        for format in format_iter {
+            println!("format: {format:#?}");
+        }
+    }
+
+    #[test]
+    fn audio_encoder() {
+        let codec = encoder::find(Id::MP3).expect("can find mp3 encoder");
+
+        // looks like every codec returns Supported::All for color space.
+        // might change in a future FFmpeg release
+        assert!(matches!(
+            supported_color_spaces(codec, None),
+            Ok(Supported::All)
+        ));
+        let format_iter = match supported_sample_formats(codec, None) {
+            Ok(Supported::Specific(f)) => f,
+            sup => panic!("Should be Supported::Specific, got {sup:#?}"),
+        };
+
+        for format in format_iter {
+            println!("format: {format:#?}");
+        }
+    }
+
+    #[test]
+    fn video_decoder() {
+        let codec = decoder::find(Id::H264).expect("can find H264 decoder");
+
+        assert!(supported_sample_rates(codec, None).is_err());
+        assert!(matches!(
+            supported_color_spaces(codec, None),
+            Ok(Supported::All)
+        ));
+    }
+
+    #[test]
+    fn video_encoder() {
+        let codec = encoder::find(Id::VP9).expect("can find VP9 encoder");
+
+        let color_ranges = match supported_color_ranges(codec, None) {
+            Ok(Supported::Specific(c)) => c,
+            sup => panic!("Should be Supported::Specific, got {sup:#?}"),
+        };
+
+        for range in color_ranges {
+            println!("{range:#?}");
+        }
+
+        assert!(matches!(
+            supported_pixel_formats(codec, None),
+            Ok(Supported::Specific(_))
+        ));
+
+        assert!(matches!(
+            supported_frame_rates(codec, None),
+            Ok(Supported::All)
+        ));
+    }
+
+    #[test]
+    fn supports() {
+        let codec = encoder::find(Id::VP9).expect("can find VP9 encoder");
+
+        assert!(supported_color_ranges(codec, None)
+            .expect("can check color range support")
+            .supports(Range::JPEG));
+
+        assert!(!supported_pixel_formats(codec, None)
+            .expect("can check color range support")
+            .supports(Pixel::BGR8));
+
+        assert!(supported_frame_rates(codec, None)
+            .expect("can check frame rate support")
+            .supports(Rational(123, 456)));
+
+        supported_sample_formats(codec, None)
+            .expect_err("can NOT check sample format support (video codec)");
+    }
+
+    #[test]
+    fn with_context() {
+        let codec = encoder::find(Id::MJPEG).expect("can find MJPEG encoder");
+
+        let mut ctx = unsafe {
+            let avctx = crate::ffi::avcodec_alloc_context3(codec.as_ptr());
+            crate::codec::Context::wrap(avctx, None)
+        };
+
+        ctx.compliance(Compliance::Strict);
+
+        assert!(!supported_color_ranges(ctx.codec().unwrap(), Some(&ctx))
+            .expect("can check color range support")
+            .supports(Range::MPEG));
+
+        ctx.compliance(Compliance::Unofficial);
+
+        // Note that we check for NOT supported above, and YES supported here
+        // MJPEG encoder only supports MPEG color range if compliance is
+        // Unofficial or lower (less strict)
+        assert!(supported_color_ranges(ctx.codec().unwrap(), Some(&ctx))
+            .expect("can check color range support")
+            .supports(Range::MPEG));
+    }
+}

src/codec/context.rs

@@ -62,13 +62,7 @@ impl Context {
     }
 
     pub fn codec(&self) -> Option<Codec> {
-        unsafe {
+        unsafe { Codec::from_raw((*self.as_ptr()).codec) }
-            if (*self.as_ptr()).codec.is_null() {
-                None
-            } else {
-                Some(Codec::wrap((*self.as_ptr()).codec as *mut _))
-            }
-        }
     }
 
     pub fn medium(&self) -> media::Type {

src/codec/decoder/decoder.rs

@@ -18,7 +18,7 @@ impl Decoder {
         }
     }
 
-    pub fn open_as<D: traits::Decoder>(mut self, codec: D) -> Result<Opened, Error> {
+    pub fn open_as<T, D: traits::Decoder<T>>(mut self, codec: D) -> Result<Opened, Error> {
         unsafe {
             if let Some(codec) = codec.decoder() {
                 match avcodec_open2(self.as_mut_ptr(), codec.as_ptr(), ptr::null_mut()) {
@@ -31,7 +31,7 @@ impl Decoder {
         }
     }
 
-    pub fn open_as_with<D: traits::Decoder>(
+    pub fn open_as_with<T, D: traits::Decoder<T>>(
         mut self,
         codec: D,
         options: Dictionary,

src/codec/decoder/mod.rs

@@ -34,25 +34,16 @@ pub fn new() -> Decoder {
 
 pub fn find(id: Id) -> Option<Codec> {
     unsafe {
-        let ptr = avcodec_find_decoder(id.into()) as *mut AVCodec;
+        let ptr = avcodec_find_decoder(id.into());
-
+        Codec::from_raw(ptr)
-        if ptr.is_null() {
-            None
-        } else {
-            Some(Codec::wrap(ptr))
-        }
     }
 }
 
 pub fn find_by_name(name: &str) -> Option<Codec> {
     unsafe {
         let name = CString::new(name).unwrap();
-        let ptr = avcodec_find_decoder_by_name(name.as_ptr()) as *mut AVCodec;
+        let ptr = avcodec_find_decoder_by_name(name.as_ptr());
 
-        if ptr.is_null() {
+        Codec::from_raw(ptr)
-            None
-        } else {
-            Some(Codec::wrap(ptr))
-        }
     }
 }

src/codec/descriptor.rs

@@ -0,0 +1,158 @@
+use std::ffi::CStr;
+use std::ptr::NonNull;
+use std::str::from_utf8_unchecked;
+
+use crate::ffi::*;
+use crate::media;
+
+use super::profile::ProfileIter;
+use super::{CodecProperties, Id};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct CodecDescriptor {
+    ptr: NonNull<AVCodecDescriptor>,
+}
+
+impl CodecDescriptor {
+    pub unsafe fn from_raw(ptr: *const AVCodecDescriptor) -> Option<Self> {
+        NonNull::new(ptr as *mut _).map(|ptr| Self { ptr })
+    }
+
+    pub fn as_ptr(self) -> *const AVCodecDescriptor {
+        self.ptr.as_ptr()
+    }
+
+    pub fn id(self) -> Id {
+        unsafe { (*self.as_ptr()).id.into() }
+    }
+
+    pub fn kind(self) -> media::Type {
+        unsafe { (*self.as_ptr()).type_.into() }
+    }
+
+    pub fn name(self) -> &'static str {
+        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+    }
+
+    pub fn description(self) -> Option<&'static str> {
+        unsafe {
+            let long_name = (*self.as_ptr()).long_name;
+            if long_name.is_null() {
+                None
+            } else {
+                Some(from_utf8_unchecked(CStr::from_ptr(long_name).to_bytes()))
+            }
+        }
+    }
+
+    pub fn props(self) -> CodecProperties {
+        unsafe { CodecProperties::from_bits_truncate((*self.as_ptr()).props) }
+    }
+
+    pub fn mime_types(self) -> Option<MimeTypeIter> {
+        unsafe { MimeTypeIter::from_raw((*self.as_ptr()).mime_types) }
+    }
+
+    pub fn profiles(self) -> Option<ProfileIter> {
+        unsafe {
+            if (*self.as_ptr()).profiles.is_null() {
+                None
+            } else {
+                Some(ProfileIter::new(self.id(), (*self.as_ptr()).profiles))
+            }
+        }
+    }
+}
+
+pub struct CodecDescriptorIter {
+    ptr: *const AVCodecDescriptor,
+}
+
+impl CodecDescriptorIter {
+    pub fn new() -> Self {
+        Self {
+            ptr: std::ptr::null(),
+        }
+    }
+}
+
+impl Default for CodecDescriptorIter {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Iterator for CodecDescriptorIter {
+    type Item = CodecDescriptor;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        unsafe {
+            let next = avcodec_descriptor_next(self.ptr);
+            if let Some(desc) = CodecDescriptor::from_raw(next) {
+                self.ptr = next;
+                Some(desc)
+            } else {
+                None
+            }
+        }
+    }
+}
+
+pub struct MimeTypeIter {
+    ptr: NonNull<*const libc::c_char>,
+}
+
+impl MimeTypeIter {
+    pub unsafe fn from_raw(ptr: *const *const libc::c_char) -> Option<Self> {
+        NonNull::new(ptr as *mut _).map(|ptr| Self { ptr })
+    }
+}
+
+impl Iterator for MimeTypeIter {
+    type Item = &'static str;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        unsafe {
+            let next = *self.ptr.as_ptr();
+            if next.is_null() {
+                return None;
+            }
+
+            self.ptr = NonNull::new_unchecked(self.ptr.as_ptr().add(1));
+            Some(from_utf8_unchecked(CStr::from_ptr(next).to_bytes()))
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::decoder::find;
+
+    #[test]
+    fn descriptor() {
+        let targa = find(Id::TARGA).expect("can find targa decoder");
+        let desc = targa.descriptor().expect("targa has descriptor");
+        assert_eq!(desc.id(), Id::TARGA);
+        assert_eq!(desc.kind(), media::Type::Video);
+        assert_eq!(desc.name(), "targa");
+
+        // --enable-small will remove all `long_name`s. So this can either be null/None
+        // or the correct description
+        assert!(matches!(
+            desc.description(),
+            None | Some("Truevision Targa image")
+        ));
+
+        let props = desc.props();
+        assert!(
+            props.contains(CodecProperties::INTRA_ONLY)
+                && props.contains(CodecProperties::LOSSLESS)
+        );
+
+        let mut mime_types = desc.mime_types().expect("has mime types");
+        assert_eq!(mime_types.next(), Some("image/x-targa"));
+        assert_eq!(mime_types.next(), Some("image/x-tga"));
+        assert_eq!(mime_types.next(), None);
+    }
+}

src/codec/encoder/audio.rs

@@ -30,7 +30,7 @@ impl Audio {
         }
     }
 
-    pub fn open_as<E: traits::Encoder>(mut self, codec: E) -> Result<Encoder, Error> {
+    pub fn open_as<T, E: traits::Encoder<T>>(mut self, codec: E) -> Result<Encoder, Error> {
         unsafe {
             if let Some(codec) = codec.encoder() {
                 match avcodec_open2(self.as_mut_ptr(), codec.as_ptr(), ptr::null_mut()) {
@@ -57,7 +57,7 @@ impl Audio {
         }
     }
 
-    pub fn open_as_with<E: traits::Encoder>(
+    pub fn open_as_with<T, E: traits::Encoder<T>>(
         mut self,
         codec: E,
         options: Dictionary,

src/codec/encoder/mod.rs

@@ -37,25 +37,15 @@ pub fn new() -> Encoder {
 
 pub fn find(id: Id) -> Option<Codec> {
     unsafe {
-        let ptr = avcodec_find_encoder(id.into()) as *mut AVCodec;
+        let ptr = avcodec_find_encoder(id.into());
-
+        Codec::from_raw(ptr)
-        if ptr.is_null() {
-            None
-        } else {
-            Some(Codec::wrap(ptr))
-        }
     }
 }
 
 pub fn find_by_name(name: &str) -> Option<Codec> {
     unsafe {
         let name = CString::new(name).unwrap();
-        let ptr = avcodec_find_encoder_by_name(name.as_ptr()) as *mut AVCodec;
+        let ptr = avcodec_find_encoder_by_name(name.as_ptr());
-
+        Codec::from_raw(ptr)
-        if ptr.is_null() {
-            None
-        } else {
-            Some(Codec::wrap(ptr))
-        }
     }
 }

src/codec/encoder/subtitle.rs

@@ -20,7 +20,7 @@ impl Subtitle {
         }
     }
 
-    pub fn open_as<E: traits::Encoder>(mut self, codec: E) -> Result<Encoder, Error> {
+    pub fn open_as<T, E: traits::Encoder<T>>(mut self, codec: E) -> Result<Encoder, Error> {
         unsafe {
             if let Some(codec) = codec.encoder() {
                 match avcodec_open2(self.as_mut_ptr(), codec.as_ptr(), ptr::null_mut()) {
@@ -33,7 +33,7 @@ impl Subtitle {
         }
     }
 
-    pub fn open_as_with<E: traits::Encoder>(
+    pub fn open_as_with<T, E: traits::Encoder<T>>(
         mut self,
         codec: E,
         options: Dictionary,

src/codec/encoder/video.rs

@@ -27,7 +27,7 @@ impl Video {
     }
 
     #[inline]
-    pub fn open_as<E: traits::Encoder>(mut self, codec: E) -> Result<Encoder, Error> {
+    pub fn open_as<T, E: traits::Encoder<T>>(mut self, codec: E) -> Result<Encoder, Error> {
         unsafe {
             if let Some(codec) = codec.encoder() {
                 match avcodec_open2(self.as_mut_ptr(), codec.as_ptr(), ptr::null_mut()) {
@@ -56,7 +56,7 @@ impl Video {
     }
 
     #[inline]
-    pub fn open_as_with<E: traits::Encoder>(
+    pub fn open_as_with<T, E: traits::Encoder<T>>(
         mut self,
         codec: E,
         options: Dictionary,

src/codec/mod.rs

@@ -11,8 +11,13 @@ pub mod subtitle;
 #[cfg(not(feature = "ffmpeg_5_0"))]
 pub mod picture;
 
+pub mod descriptor;
+pub use self::descriptor::CodecDescriptor;
+
 pub mod discard;
 
+pub mod config;
+
 pub mod context;
 pub use self::context::Context;
 
@@ -20,16 +25,11 @@ pub mod capabilities;
 pub use self::capabilities::Capabilities;
 
 pub mod codec;
+pub use self::codec::{Audio, Codec, Video};
 
 pub mod parameters;
 pub use self::parameters::Parameters;
 
-pub mod video;
-pub use self::video::Video;
-
-pub mod audio;
-pub use self::audio::Audio;
-
 pub mod audio_service;
 pub mod field_order;
 
@@ -42,6 +42,9 @@ pub use self::debug::Debug;
 pub mod profile;
 pub use self::profile::Profile;
 
+pub mod props;
+pub use self::props::CodecProperties;
+
 pub mod threading;
 
 pub mod decoder;

src/codec/profile.rs

@@ -387,3 +387,31 @@ impl From<Profile> for c_int {
         }
     }
 }
+
+pub struct ProfileIter {
+    id: Id,
+    ptr: *const AVProfile,
+}
+
+impl ProfileIter {
+    pub fn new(id: Id, ptr: *const AVProfile) -> Self {
+        ProfileIter { id, ptr }
+    }
+}
+
+impl Iterator for ProfileIter {
+    type Item = Profile;
+
+    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
+        unsafe {
+            if (*self.ptr).profile == FF_PROFILE_UNKNOWN {
+                return None;
+            }
+
+            let profile = Profile::from((self.id, (*self.ptr).profile));
+            self.ptr = self.ptr.offset(1);
+
+            Some(profile)
+        }
+    }
+}

src/codec/props.rs

@@ -0,0 +1,17 @@
+use crate::ffi::*;
+use libc::c_int;
+
+bitflags! {
+    #[derive(Debug, Clone, Copy, Eq, PartialEq)]
+    pub struct CodecProperties: c_int {
+        const INTRA_ONLY = AV_CODEC_PROP_INTRA_ONLY;
+        const LOSSY      = AV_CODEC_PROP_LOSSY;
+        const LOSSLESS   = AV_CODEC_PROP_LOSSLESS;
+        const REORDER    = AV_CODEC_PROP_REORDER;
+        #[cfg(feature = "ffmpeg_6_1")]
+        const FIELDS     = AV_CODEC_PROP_FIELDS;
+
+        const BITMAP_SUB = AV_CODEC_PROP_BITMAP_SUB;
+        const TEXT_SUB   = AV_CODEC_PROP_TEXT_SUB;
+    }
+}

src/codec/traits.rs

@@ -1,25 +1,26 @@
+use super::codec::UnknownType;
 use super::{decoder, encoder};
-use crate::codec::{Audio, Id, Video};
+use crate::codec::Id;
 use crate::Codec;
 
-pub trait Decoder {
+pub trait Decoder<T> {
-    fn decoder(self) -> Option<Codec>;
+    fn decoder(self) -> Option<Codec<T>>;
 }
 
-impl<'a> Decoder for &'a str {
+impl<'a> Decoder<UnknownType> for &'a str {
-    fn decoder(self) -> Option<Codec> {
+    fn decoder(self) -> Option<Codec<UnknownType>> {
         decoder::find_by_name(self)
     }
 }
 
-impl Decoder for Id {
+impl Decoder<UnknownType> for Id {
-    fn decoder(self) -> Option<Codec> {
+    fn decoder(self) -> Option<Codec<UnknownType>> {
         decoder::find(self)
     }
 }
 
-impl Decoder for Codec {
+impl<T> Decoder<T> for Codec<T> {
-    fn decoder(self) -> Option<Codec> {
+    fn decoder(self) -> Option<Codec<T>> {
         if self.is_decoder() {
             Some(self)
         } else {
@@ -28,50 +29,30 @@ impl Decoder for Codec {
     }
 }
 
-impl Decoder for Option<Codec> {
+impl<T> Decoder<T> for Option<Codec<T>> {
-    fn decoder(self) -> Option<Codec> {
+    fn decoder(self) -> Option<Codec<T>> {
         self.and_then(|c| c.decoder())
     }
 }
 
-impl Decoder for Audio {
+pub trait Encoder<T> {
-    fn decoder(self) -> Option<Codec> {
+    fn encoder(self) -> Option<Codec<T>>;
-        if self.is_decoder() {
-            Some(*self)
-        } else {
-            None
-        }
-    }
 }
 
-impl Decoder for Video {
+impl<'a> Encoder<UnknownType> for &'a str {
-    fn decoder(self) -> Option<Codec> {
+    fn encoder(self) -> Option<Codec<UnknownType>> {
-        if self.is_decoder() {
-            Some(*self)
-        } else {
-            None
-        }
-    }
-}
-
-pub trait Encoder {
-    fn encoder(self) -> Option<Codec>;
-}
-
-impl<'a> Encoder for &'a str {
-    fn encoder(self) -> Option<Codec> {
         encoder::find_by_name(self)
     }
 }
 
-impl Encoder for Id {
+impl Encoder<UnknownType> for Id {
-    fn encoder(self) -> Option<Codec> {
+    fn encoder(self) -> Option<Codec<UnknownType>> {
         encoder::find(self)
     }
 }
 
-impl Encoder for Codec {
+impl<T> Encoder<T> for Codec<T> {
-    fn encoder(self) -> Option<Codec> {
+    fn encoder(self) -> Option<Codec<T>> {
         if self.is_encoder() {
             Some(self)
         } else {
@@ -80,28 +61,8 @@ impl Encoder for Codec {
     }
 }
 
-impl Encoder for Option<Codec> {
+impl<T> Encoder<T> for Option<Codec<T>> {
-    fn encoder(self) -> Option<Codec> {
+    fn encoder(self) -> Option<Codec<T>> {
         self.and_then(|c| c.encoder())
     }
 }
-
-impl Encoder for Audio {
-    fn encoder(self) -> Option<Codec> {
-        if self.is_encoder() {
-            Some(*self)
-        } else {
-            None
-        }
-    }
-}
-
-impl Encoder for Video {
-    fn encoder(self) -> Option<Codec> {
-        if self.is_encoder() {
-            Some(*self)
-        } else {
-            None
-        }
-    }
-}

src/codec/video.rs

@@ -1,100 +0,0 @@
-use std::ops::Deref;
-
-use super::codec::Codec;
-use crate::ffi::*;
-use crate::{format, Rational};
-
-#[derive(PartialEq, Eq, Copy, Clone)]
-pub struct Video {
-    codec: Codec,
-}
-
-impl Video {
-    pub unsafe fn new(codec: Codec) -> Video {
-        Video { codec }
-    }
-}
-
-impl Video {
-    pub fn rates(&self) -> Option<RateIter> {
-        unsafe {
-            if (*self.codec.as_ptr()).supported_framerates.is_null() {
-                None
-            } else {
-                Some(RateIter::new((*self.codec.as_ptr()).supported_framerates))
-            }
-        }
-    }
-
-    pub fn formats(&self) -> Option<FormatIter> {
-        unsafe {
-            if (*self.codec.as_ptr()).pix_fmts.is_null() {
-                None
-            } else {
-                Some(FormatIter::new((*self.codec.as_ptr()).pix_fmts))
-            }
-        }
-    }
-}
-
-impl Deref for Video {
-    type Target = Codec;
-
-    fn deref(&self) -> &Self::Target {
-        &self.codec
-    }
-}
-
-pub struct RateIter {
-    ptr: *const AVRational,
-}
-
-impl RateIter {
-    pub fn new(ptr: *const AVRational) -> Self {
-        RateIter { ptr }
-    }
-}
-
-impl Iterator for RateIter {
-    type Item = Rational;
-
-    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-        unsafe {
-            if (*self.ptr).num == 0 && (*self.ptr).den == 0 {
-                return None;
-            }
-
-            let rate = (*self.ptr).into();
-            self.ptr = self.ptr.offset(1);
-
-            Some(rate)
-        }
-    }
-}
-
-pub struct FormatIter {
-    ptr: *const AVPixelFormat,
-}
-
-impl FormatIter {
-    pub fn new(ptr: *const AVPixelFormat) -> Self {
-        FormatIter { ptr }
-    }
-}
-
-impl Iterator for FormatIter {
-    type Item = format::Pixel;
-
-    fn next(&mut self) -> Option<<Self as Iterator>::Item> {
-        unsafe {
-            if *self.ptr == AVPixelFormat::AV_PIX_FMT_NONE {
-                return None;
-            }
-
-            let format = (*self.ptr).into();
-            self.ptr = self.ptr.offset(1);
-
-            Some(format)
-        }
-    }
-}

src/format/context/input.rs

@@ -42,12 +42,7 @@ impl Input {
     pub fn video_codec(&self) -> Option<Codec> {
         unsafe {
             let ptr = (*self.as_ptr()).video_codec;
-
+            Codec::from_raw(ptr)
-            if ptr.is_null() {
-                None
-            } else {
-                Some(Codec::wrap(ptr))
-            }
         }
     }
 
@@ -55,12 +50,7 @@ impl Input {
     pub fn audio_codec(&self) -> Option<Codec> {
         unsafe {
             let ptr = (*self.as_ptr()).audio_codec;
-
+            Codec::from_raw(ptr)
-            if ptr.is_null() {
-                None
-            } else {
-                Some(Codec::wrap(ptr))
-            }
         }
     }
 
@@ -68,12 +58,7 @@ impl Input {
     pub fn subtitle_codec(&self) -> Option<Codec> {
         unsafe {
             let ptr = (*self.as_ptr()).subtitle_codec;
-
+            Codec::from_raw(ptr)
-            if ptr.is_null() {
-                None
-            } else {
-                Some(Codec::wrap(ptr))
-            }
         }
     }
 
@@ -81,12 +66,7 @@ impl Input {
     pub fn data_codec(&self) -> Option<Codec> {
         unsafe {
             let ptr = (*self.as_ptr()).data_codec;
-
+            Codec::from_raw(ptr)
-            if ptr.is_null() {
-                None
-            } else {
-                Some(Codec::wrap(ptr))
-            }
         }
     }
 

src/format/context/output.rs

@@ -68,7 +68,7 @@ impl Output {
         }
     }
 
-    pub fn add_stream<E: traits::Encoder>(&mut self, codec: E) -> Result<StreamMut, Error> {
+    pub fn add_stream<T, E: traits::Encoder<T>>(&mut self, codec: E) -> Result<StreamMut, Error> {
         unsafe {
             let codec = codec.encoder();
             let codec = codec.map_or(ptr::null(), |c| c.as_ptr());