diff --git a/src/formats.rs b/src/formats.rs
new file mode 100644
index 0000000..a18bb36
--- /dev/null
+++ b/src/formats.rs
@@ -0,0 +1,576 @@
+fn image_apng() -> mime::Mime {
+    "image/apng".parse().unwrap()
+}
+
+fn image_avif() -> mime::Mime {
+    "image/avif".parse().unwrap()
+}
+
+fn image_jxl() -> mime::Mime {
+    "image/jxl".parse().unwrap()
+}
+
+fn image_webp() -> mime::Mime {
+    "image/webp".parse().unwrap()
+}
+
+fn video_mp4() -> mime::Mime {
+    "video/mp4".parse().unwrap()
+}
+
+fn video_webm() -> mime::Mime {
+    "video/webm".parse().unwrap()
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct PrescribedFormats {
+    image: Option<ImageFormat>,
+    animation: Option<AnimationFormat>,
+    video: Option<OutputVideoFormat>,
+    allow_audio: bool,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum ImageFormat {
+    #[serde(rename = "avif")]
+    Avif,
+    #[serde(rename = "png")]
+    Png,
+    #[serde(rename = "jpeg")]
+    Jpeg,
+    #[serde(rename = "jxl")]
+    Jxl,
+    #[serde(rename = "webp")]
+    Webp,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum AnimationFormat {
+    #[serde(rename = "apng")]
+    Apng,
+    #[serde(rename = "avif")]
+    Avif,
+    #[serde(rename = "gif")]
+    Gif,
+    #[serde(rename = "webp")]
+    Webp,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum VideoFormat {
+    Mp4,
+    Webp { alpha: bool },
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum VideoCodec {
+    #[serde(rename = "av1")]
+    Av1,
+    #[serde(rename = "h264")]
+    H264,
+    #[serde(rename = "h265")]
+    H265,
+    #[serde(rename = "vp8")]
+    Vp8,
+    #[serde(rename = "vp9")]
+    Vp9,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum AudioCodec {
+    #[serde(rename = "aac")]
+    Aac,
+    #[serde(rename = "opus")]
+    Opus,
+    #[serde(rename = "vorbis")]
+    Vorbis,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum OutputVideoFormat {
+    Mp4 {
+        video_codec: Mp4Codec,
+        audio_codec: Option<Mp4AudioCodec>,
+    },
+    Webm {
+        video_codec: WebmCodec,
+        audio_codec: Option<WebmAudioCodec>,
+    },
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum Mp4Codec {
+    #[serde(rename = "h264")]
+    H264,
+    #[serde(rename = "h265")]
+    H265,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, serde::Deserialize)]
+pub(crate) enum WebmAlphaCodec {
+    #[serde(rename = "vp8")]
+    Vp8,
+    #[serde(rename = "vp9")]
+    Vp9,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) struct AlphaCodec {
+    pub(crate) alpha: bool,
+    pub(crate) codec: WebmAlphaCodec,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum WebmCodec {
+    Av1,
+    Alpha(AlphaCodec),
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum Mp4AudioCodec {
+    Aac,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum WebmAudioCodec {
+    Opus,
+    Vorbis,
+}
+
+#[derive(Clone, Debug)]
+pub(crate) enum InputFile {
+    Image {
+        format: ImageFormat,
+        needs_reorient: bool,
+    },
+    Animation(AnimationFormat),
+    Video(VideoFormat),
+}
+
+#[derive(Clone, Debug)]
+pub(crate) enum OutputFile {
+    Image {
+        format: ImageFormat,
+        needs_transcode: bool,
+    },
+    Animation {
+        format: AnimationFormat,
+        needs_transcode: bool,
+    },
+    Video(OutputVideoFormat),
+}
+
+impl InputFile {
+    const fn file_extension(&self) -> &'static str {
+        match self {
+            Self::Image { format, .. } => format.file_extension(),
+            Self::Animation(format) => format.file_extension(),
+            Self::Video(format) => format.file_extension(),
+        }
+    }
+
+    const fn build_output(&self, prescribed: &PrescribedFormats) -> OutputFile {
+        match (self, prescribed) {
+            (
+                InputFile::Image {
+                    format,
+                    needs_reorient,
+                },
+                PrescribedFormats {
+                    image: Some(prescribed),
+                    ..
+                },
+            ) => OutputFile::Image {
+                format: *prescribed,
+                needs_transcode: *needs_reorient || !format.const_eq(*prescribed),
+            },
+            (
+                InputFile::Animation(format),
+                PrescribedFormats {
+                    animation: Some(prescribed),
+                    ..
+                },
+            ) => OutputFile::Animation {
+                format: *prescribed,
+                needs_transcode: !format.const_eq(*prescribed),
+            },
+            (
+                InputFile::Video(VideoFormat::Webp { alpha }),
+                PrescribedFormats {
+                    video:
+                        Some(OutputVideoFormat::Webm {
+                            video_codec: WebmCodec::Alpha(AlphaCodec { codec, .. }),
+                            audio_codec,
+                        }),
+                    ..
+                },
+            ) => OutputFile::Video(OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: *alpha,
+                    codec: *codec,
+                }),
+                audio_codec: *audio_codec,
+            }),
+            (
+                InputFile::Video(_),
+                PrescribedFormats {
+                    video: Some(prescribed),
+                    ..
+                },
+            ) => OutputFile::Video(*prescribed),
+            (
+                InputFile::Image {
+                    format,
+                    needs_reorient,
+                },
+                PrescribedFormats { image: None, .. },
+            ) => OutputFile::Image {
+                format: *format,
+                needs_transcode: *needs_reorient,
+            },
+            (
+                InputFile::Animation(input),
+                PrescribedFormats {
+                    animation: None, ..
+                },
+            ) => OutputFile::Animation {
+                format: *input,
+                needs_transcode: false,
+            },
+            (
+                InputFile::Video(input),
+                PrescribedFormats {
+                    video: None,
+                    allow_audio: true,
+                    ..
+                },
+            ) => match input {
+                VideoFormat::Mp4 => OutputFile::Video(OutputVideoFormat::Mp4 {
+                    video_codec: Mp4Codec::H264,
+                    audio_codec: Some(Mp4AudioCodec::Aac),
+                }),
+                VideoFormat::Webp { alpha } => OutputFile::Video(OutputVideoFormat::Webm {
+                    video_codec: WebmCodec::Alpha(AlphaCodec {
+                        alpha: *alpha,
+                        codec: WebmAlphaCodec::Vp9,
+                    }),
+                    audio_codec: Some(WebmAudioCodec::Opus),
+                }),
+            },
+            (
+                InputFile::Video(input),
+                PrescribedFormats {
+                    video: None,
+                    allow_audio: false,
+                    ..
+                },
+            ) => match input {
+                VideoFormat::Mp4 => OutputFile::Video(OutputVideoFormat::Mp4 {
+                    video_codec: Mp4Codec::H264,
+                    audio_codec: None,
+                }),
+                VideoFormat::Webp { alpha } => OutputFile::Video(OutputVideoFormat::Webm {
+                    video_codec: WebmCodec::Alpha(AlphaCodec {
+                        alpha: *alpha,
+                        codec: WebmAlphaCodec::Vp9,
+                    }),
+                    audio_codec: None,
+                }),
+            },
+        }
+    }
+}
+
+impl ImageFormat {
+    const fn const_eq(self, rhs: Self) -> bool {
+        match (self, rhs) {
+            (Self::Avif, Self::Avif)
+            | (Self::Jpeg, Self::Jpeg)
+            | (Self::Jxl, Self::Jxl)
+            | (Self::Png, Self::Png)
+            | (Self::Webp, Self::Webp) => true,
+            (Self::Avif, _)
+            | (Self::Jpeg, _)
+            | (Self::Jxl, _)
+            | (Self::Png, _)
+            | (Self::Webp, _) => false,
+        }
+    }
+
+    const fn file_extension(self) -> &'static str {
+        match self {
+            Self::Avif => ".avif",
+            Self::Jpeg => ".jpeg",
+            Self::Jxl => ".jxl",
+            Self::Png => ".png",
+            Self::Webp => ".webp",
+        }
+    }
+
+    const fn magick_format(self) -> &'static str {
+        match self {
+            Self::Avif => "AVIF",
+            Self::Jpeg => "JPEG",
+            Self::Jxl => "JXL",
+            Self::Png => "PNG",
+            Self::Webp => "Webp",
+        }
+    }
+
+    fn media_type(self) -> mime::Mime {
+        match self {
+            Self::Avif => image_avif(),
+            Self::Jpeg => mime::IMAGE_JPEG,
+            Self::Jxl => image_jxl(),
+            Self::Png => mime::IMAGE_PNG,
+            Self::Webp => image_webp(),
+        }
+    }
+}
+
+impl AnimationFormat {
+    const fn const_eq(self, rhs: Self) -> bool {
+        match (self, rhs) {
+            (Self::Apng, Self::Apng)
+            | (Self::Avif, Self::Avif)
+            | (Self::Gif, Self::Gif)
+            | (Self::Webp, Self::Webp) => true,
+            (Self::Apng, _) | (Self::Avif, _) | (Self::Gif, _) | (Self::Webp, _) => false,
+        }
+    }
+
+    const fn file_extension(self) -> &'static str {
+        match self {
+            Self::Apng => ".apng",
+            Self::Avif => ".avif",
+            Self::Gif => ".gif",
+            Self::Webp => ".webp",
+        }
+    }
+
+    const fn magick_format(self) -> &'static str {
+        match self {
+            Self::Apng => "APNG",
+            Self::Avif => "AVIF",
+            Self::Gif => "GIF",
+            Self::Webp => "WEBP",
+        }
+    }
+
+    fn media_type(self) -> mime::Mime {
+        match self {
+            Self::Apng => image_apng(),
+            Self::Avif => image_avif(),
+            Self::Gif => mime::IMAGE_GIF,
+            Self::Webp => image_webp(),
+        }
+    }
+}
+
+impl VideoFormat {
+    const fn file_extension(self) -> &'static str {
+        match self {
+            Self::Mp4 => ".mp4",
+            Self::Webp { .. } => ".webm",
+        }
+    }
+}
+
+impl OutputVideoFormat {
+    const fn from_parts(
+        video_codec: VideoCodec,
+        audio_codec: Option<AudioCodec>,
+        allow_audio: bool,
+    ) -> Self {
+        match (video_codec, audio_codec) {
+            (VideoCodec::Av1, Some(AudioCodec::Vorbis)) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Av1,
+                audio_codec: Some(WebmAudioCodec::Vorbis),
+            },
+            (VideoCodec::Av1, _) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Av1,
+                audio_codec: Some(WebmAudioCodec::Opus),
+            },
+            (VideoCodec::Av1, _) => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Av1,
+                audio_codec: None,
+            },
+            (VideoCodec::H264, _) if allow_audio => OutputVideoFormat::Mp4 {
+                video_codec: Mp4Codec::H264,
+                audio_codec: Some(Mp4AudioCodec::Aac),
+            },
+            (VideoCodec::H264, _) => OutputVideoFormat::Mp4 {
+                video_codec: Mp4Codec::H264,
+                audio_codec: None,
+            },
+            (VideoCodec::H265, _) if allow_audio => OutputVideoFormat::Mp4 {
+                video_codec: Mp4Codec::H265,
+                audio_codec: Some(Mp4AudioCodec::Aac),
+            },
+            (VideoCodec::H265, _) => OutputVideoFormat::Mp4 {
+                video_codec: Mp4Codec::H265,
+                audio_codec: None,
+            },
+            (VideoCodec::Vp8, Some(AudioCodec::Vorbis)) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp8,
+                }),
+                audio_codec: Some(WebmAudioCodec::Vorbis),
+            },
+            (VideoCodec::Vp8, _) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp8,
+                }),
+                audio_codec: Some(WebmAudioCodec::Opus),
+            },
+            (VideoCodec::Vp8, _) => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp8,
+                }),
+                audio_codec: None,
+            },
+            (VideoCodec::Vp9, Some(AudioCodec::Vorbis)) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp9,
+                }),
+                audio_codec: Some(WebmAudioCodec::Vorbis),
+            },
+            (VideoCodec::Vp9, _) if allow_audio => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp9,
+                }),
+                audio_codec: Some(WebmAudioCodec::Opus),
+            },
+            (VideoCodec::Vp9, _) => OutputVideoFormat::Webm {
+                video_codec: WebmCodec::Alpha(AlphaCodec {
+                    alpha: false,
+                    codec: WebmAlphaCodec::Vp9,
+                }),
+                audio_codec: None,
+            },
+        }
+    }
+
+    const fn file_extension(self) -> &'static str {
+        match self {
+            Self::Mp4 { .. } => ".mp4",
+            Self::Webm { .. } => ".webm",
+        }
+    }
+
+    const fn ffmpeg_format(self) -> &'static str {
+        match self {
+            Self::Mp4 { .. } => "mp4",
+            Self::Webm { .. } => "webm",
+        }
+    }
+
+    const fn ffmpeg_video_codec(self) -> &'static str {
+        match self {
+            Self::Mp4 { video_codec, .. } => video_codec.ffmpeg_codec(),
+            Self::Webm { video_codec, .. } => video_codec.ffmpeg_codec(),
+        }
+    }
+
+    const fn ffmpeg_audio_codec(self) -> Option<&'static str> {
+        match self {
+            Self::Mp4 {
+                audio_codec: Some(audio_codec),
+                ..
+            } => Some(audio_codec.ffmpeg_codec()),
+            Self::Webm {
+                audio_codec: Some(audio_codec),
+                ..
+            } => Some(audio_codec.ffmpeg_codec()),
+            _ => None,
+        }
+    }
+
+    const fn pix_fmt(self) -> &'static str {
+        match self {
+            Self::Mp4 { .. } => "yuv420p",
+            Self::Webm { video_codec, .. } => video_codec.pix_fmt(),
+        }
+    }
+
+    fn media_type(self) -> mime::Mime {
+        match self {
+            Self::Mp4 { .. } => video_mp4(),
+            Self::Webm { .. } => video_webm(),
+        }
+    }
+}
+
+impl Mp4Codec {
+    const fn ffmpeg_codec(self) -> &'static str {
+        match self {
+            Self::H264 => "h264",
+            Self::H265 => "hevc",
+        }
+    }
+}
+
+impl WebmAlphaCodec {
+    const fn ffmpeg_codec(self) -> &'static str {
+        match self {
+            Self::Vp8 => "vp8",
+            Self::Vp9 => "vp9",
+        }
+    }
+}
+
+impl WebmCodec {
+    const fn ffmpeg_codec(self) -> &'static str {
+        match self {
+            Self::Av1 => "av1",
+            Self::Alpha(AlphaCodec { codec, .. }) => codec.ffmpeg_codec(),
+        }
+    }
+
+    const fn pix_fmt(self) -> &'static str {
+        match self {
+            Self::Alpha(AlphaCodec { alpha: true, .. }) => "yuva420p",
+            _ => "yuv420p",
+        }
+    }
+}
+
+impl Mp4AudioCodec {
+    const fn ffmpeg_codec(self) -> &'static str {
+        match self {
+            Self::Aac => "aac",
+        }
+    }
+}
+
+impl WebmAudioCodec {
+    const fn ffmpeg_codec(self) -> &'static str {
+        match self {
+            Self::Opus => "libopus",
+            Self::Vorbis => "vorbis",
+        }
+    }
+}
+
+impl OutputFile {
+    const fn file_extension(&self) -> &'static str {
+        match self {
+            Self::Image { format, .. } => format.file_extension(),
+            Self::Animation { format, .. } => format.file_extension(),
+            Self::Video(format) => format.file_extension(),
+        }
+    }
+
+    fn media_type(&self) -> mime::Mime {
+        match self {
+            Self::Image { format, .. } => format.media_type(),
+            Self::Animation { format, .. } => format.media_type(),
+            Self::Video(format) => format.media_type(),
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 26c03b1..862a0ef 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,6 +8,7 @@ mod error;
 mod exiftool;
 mod ffmpeg;
 mod file;
+mod formats;
 mod generate;
 mod ingest;
 mod init_tracing;