Initial tag support

Gir_Gst.toml

@@ -48,6 +48,7 @@ generate = [
     "Gst.PadLinkReturn",
     "Gst.ProgressType",
     "Gst.BusSyncReply",
+    "Gst.TagMergeMode",
 ]
 
 manual = [

gstreamer/src/auto/enums.rs

@@ -1120,6 +1120,57 @@ impl FromGlib<ffi::GstStructureChangeType> for StructureChangeType {
     }
 }
 
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub enum TagMergeMode {
+    Undefined,
+    ReplaceAll,
+    Replace,
+    Append,
+    Prepend,
+    Keep,
+    KeepAll,
+    Count,
+    #[doc(hidden)]
+    __Unknown(i32),
+}
+
+#[doc(hidden)]
+impl ToGlib for TagMergeMode {
+    type GlibType = ffi::GstTagMergeMode;
+
+    fn to_glib(&self) -> ffi::GstTagMergeMode {
+        match *self {
+            TagMergeMode::Undefined => ffi::GST_TAG_MERGE_UNDEFINED,
+            TagMergeMode::ReplaceAll => ffi::GST_TAG_MERGE_REPLACE_ALL,
+            TagMergeMode::Replace => ffi::GST_TAG_MERGE_REPLACE,
+            TagMergeMode::Append => ffi::GST_TAG_MERGE_APPEND,
+            TagMergeMode::Prepend => ffi::GST_TAG_MERGE_PREPEND,
+            TagMergeMode::Keep => ffi::GST_TAG_MERGE_KEEP,
+            TagMergeMode::KeepAll => ffi::GST_TAG_MERGE_KEEP_ALL,
+            TagMergeMode::Count => ffi::GST_TAG_MERGE_COUNT,
+            TagMergeMode::__Unknown(value) => unsafe{std::mem::transmute(value)}
+        }
+    }
+}
+
+#[doc(hidden)]
+impl FromGlib<ffi::GstTagMergeMode> for TagMergeMode {
+    fn from_glib(value: ffi::GstTagMergeMode) -> Self {
+        skip_assert_initialized!();
+        match value as i32 {
+            0 => TagMergeMode::Undefined,
+            1 => TagMergeMode::ReplaceAll,
+            2 => TagMergeMode::Replace,
+            3 => TagMergeMode::Append,
+            4 => TagMergeMode::Prepend,
+            5 => TagMergeMode::Keep,
+            6 => TagMergeMode::KeepAll,
+            7 => TagMergeMode::Count,
+            value => TagMergeMode::__Unknown(value),
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
 pub enum URIError {
     UnsupportedProtocol,

gstreamer/src/auto/mod.rs

@@ -93,6 +93,7 @@ pub use self::enums::StateChangeReturn;
 pub use self::enums::StreamError;
 pub use self::enums::StreamStatusType;
 pub use self::enums::StructureChangeType;
+pub use self::enums::TagMergeMode;
 pub use self::enums::URIError;
 pub use self::enums::URIType;
 

gstreamer/src/lib.rs

@@ -52,6 +52,8 @@ pub mod structure;
 pub use structure::Structure;
 pub mod caps;
 pub use caps::Caps;
+pub mod tags;
+pub use tags::*;
 
 mod element;
 mod bin;

gstreamer/src/structure.rs

@@ -15,8 +15,8 @@ use std::borrow::{Borrow, ToOwned, BorrowMut};
 use std::marker::PhantomData;
 
 use glib;
-use glib::translate::{from_glib, from_glib_full, Stash, StashMut, ToGlibPtr,
+use glib::translate::{from_glib, from_glib_full, Stash, StashMut, ToGlibPtr, ToGlibPtrMut,
-                      ToGlibPtrMut, FromGlibPtrNone, FromGlibPtrFull};
+                      FromGlibPtrNone, FromGlibPtrFull};
 use glib::value::{Value, ToValue, FromValueOptional};
 use ffi;
 

gstreamer/src/tags.rs

@@ -0,0 +1,273 @@
+// Copyright (C) 2016-2017 Sebastian Dröge <sebastian@centricular.com>
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::fmt;
+use std::mem;
+use std::ffi::{CStr, CString};
+use std::marker::PhantomData;
+
+use glib;
+use ffi;
+use glib::StaticType;
+use glib::value::{Value, TypedValue, FromValueOptional, SetValue, ToValue};
+use glib::translate::{from_glib, from_glib_none, from_glib_full, ToGlib, ToGlibPtr, ToGlibPtrMut};
+
+use miniobject::*;
+
+use TagMergeMode;
+
+pub trait Tag<'a> {
+    type TagType: FromValueOptional<'a> + SetValue;
+    fn tag_name() -> &'static str;
+}
+
+macro_rules! impl_tag(
+    ($name:ident, $t:ty, $tag:expr) => {
+        pub struct $name;
+        impl<'a> Tag<'a> for $name {
+            type TagType = $t;
+            fn tag_name() -> &'static str {
+                $tag
+            }
+        }
+    };
+);
+
+impl_tag!(Title, &'a str, "title");
+impl_tag!(Album, &'a str, "album");
+impl_tag!(Artist, &'a str, "artist");
+impl_tag!(Encoder, &'a str, "encoder");
+impl_tag!(AudioCodec, &'a str, "audio-codec");
+impl_tag!(VideoCodec, &'a str, "video-codec");
+impl_tag!(SubtitleCodec, &'a str, "subtitle-codec");
+impl_tag!(ContainerFormat, &'a str, "container-format");
+// TODO: Should ideally enforce this to be ISO-639
+impl_tag!(LanguageCode, &'a str, "language-code");
+impl_tag!(Duration, u64, "duration");
+impl_tag!(NominalBitrate, u32, "nominal-bitrate");
+
+pub type TagList = GstRc<TagListRef>;
+pub struct TagListRef(ffi::GstTagList);
+
+unsafe impl MiniObject for TagListRef {
+    type GstType = ffi::GstTagList;
+}
+
+impl GstRc<TagListRef> {
+    pub fn new() -> Self {
+        assert_initialized_main_thread!();
+        unsafe { from_glib_full(ffi::gst_tag_list_new_empty()) }
+    }
+}
+
+impl TagListRef {
+    pub fn add<'a, T: Tag<'a>>(&mut self, value: T::TagType, mode: TagMergeMode)
+    where
+        T::TagType: ToValue,
+    {
+        unsafe {
+            let v = value.to_value();
+
+            ffi::gst_tag_list_add_value(
+                self.as_mut_ptr(),
+                mode.to_glib(),
+                T::tag_name().to_glib_none().0,
+                v.to_glib_none().0,
+            );
+        }
+    }
+
+    pub fn get<'a, T: Tag<'a>>(&self) -> Option<TypedValue<T::TagType>> {
+        unsafe {
+            let mut value: Value = mem::zeroed();
+
+            let found: bool = from_glib(ffi::gst_tag_list_copy_value(
+                value.to_glib_none_mut().0,
+                self.as_ptr(),
+                T::tag_name().to_glib_none().0,
+            ));
+
+            if !found {
+                return None;
+            }
+
+            value.downcast().ok()
+        }
+    }
+
+    pub fn get_index<'a, T: Tag<'a>>(&'a self, idx: u32) -> Option<&'a TypedValue<T::TagType>> {
+        unsafe {
+            let value = ffi::gst_tag_list_get_value_index(
+                self.as_ptr(),
+                T::tag_name().to_glib_none().0,
+                idx,
+            );
+
+            if value.is_null() || (*value).g_type != T::TagType::static_type().to_glib() {
+                return None;
+            }
+
+            Some(&*(value as *const TypedValue<T::TagType>))
+        }
+    }
+
+    pub fn get_size<'a, T: Tag<'a>>(&'a self) -> u32 {
+        unsafe { ffi::gst_tag_list_get_tag_size(self.as_ptr(), T::tag_name().to_glib_none().0) }
+    }
+
+    pub fn iter_tag<'a, T: Tag<'a>>(&'a self) -> TagIterator<'a, T> {
+        TagIterator::new(self)
+    }
+
+    pub fn to_string(&self) -> String {
+        unsafe { from_glib_full(ffi::gst_tag_list_to_string(self.as_ptr())) }
+    }
+}
+
+impl fmt::Debug for TagListRef {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.to_string())
+    }
+}
+
+impl PartialEq for TagListRef {
+    fn eq(&self, other: &TagListRef) -> bool {
+        unsafe { from_glib(ffi::gst_tag_list_is_equal(self.as_ptr(), other.as_ptr())) }
+    }
+}
+
+impl Eq for TagListRef {}
+
+impl ToOwned for TagListRef {
+    type Owned = GstRc<TagListRef>;
+
+    fn to_owned(&self) -> GstRc<TagListRef> {
+        unsafe { from_glib_none(self.as_ptr()) }
+    }
+}
+
+unsafe impl Sync for TagListRef {}
+unsafe impl Send for TagListRef {}
+
+pub struct TagIterator<'a, T: Tag<'a>> {
+    taglist: &'a TagListRef,
+    idx: u32,
+    size: u32,
+    phantom: PhantomData<T>,
+}
+
+impl<'a, T: Tag<'a>> TagIterator<'a, T> {
+    fn new(taglist: &'a TagListRef) -> TagIterator<'a, T> {
+        TagIterator {
+            taglist: taglist,
+            idx: 0,
+            size: taglist.get_size::<T>(),
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<'a, T: Tag<'a>> Iterator for TagIterator<'a, T>
+where
+    <T as Tag<'a>>::TagType: 'a,
+    T: 'a,
+{
+    type Item = &'a TypedValue<T::TagType>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.idx >= self.size {
+            return None;
+        }
+
+        let item = self.taglist.get_index::<T>(self.idx);
+        self.idx += 1;
+
+        item
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if self.idx == self.size {
+            return (0, Some(0));
+        }
+
+        let remaining = (self.size - self.idx) as usize;
+
+        (remaining, Some(remaining))
+    }
+}
+
+impl<'a, T: Tag<'a>> DoubleEndedIterator for TagIterator<'a, T>
+where
+    <T as Tag<'a>>::TagType: 'a,
+    T: 'a,
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if self.idx == self.size {
+            return None;
+        }
+
+        self.size -= 1;
+        self.taglist.get_index::<T>(self.size)
+    }
+}
+
+impl<'a, T: Tag<'a>> ExactSizeIterator for TagIterator<'a, T>
+where
+    <T as Tag<'a>>::TagType: 'a,
+    T: 'a,
+{
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_add() {
+        ::init().unwrap();
+
+        let mut tags = TagList::new();
+        assert_eq!(tags.to_string(), "taglist;");
+        {
+            let tags = tags.get_mut().unwrap();
+            tags.add::<Title>("some title".into(), TagMergeMode::Append);
+            tags.add::<Duration>((1000u64 * 1000 * 1000 * 120).into(), TagMergeMode::Append);
+        }
+        assert_eq!(
+            tags.to_string(),
+            "taglist, title=(string)\"some\\ title\", duration=(guint64)120000000000;"
+        );
+    }
+
+    #[test]
+    fn test_get() {
+        ::init().unwrap();
+
+        let mut tags = TagList::new();
+        assert_eq!(tags.to_string(), "taglist;");
+        {
+            let tags = tags.get_mut().unwrap();
+            tags.add::<Title>("some title".into(), TagMergeMode::Append);
+            tags.add::<Duration>((1000u64 * 1000 * 1000 * 120).into(), TagMergeMode::Append);
+        }
+
+        assert_eq!(tags.get::<Title>().unwrap().get(), Some("some title"));
+        assert_eq!(
+            tags.get::<Duration>().unwrap().get_some(),
+            (1000u64 * 1000 * 1000 * 120)
+        );
+        assert_eq!(
+            tags.get_index::<Title>(0).unwrap().get(),
+            Some("some title")
+        );
+        assert_eq!(
+            tags.get_index::<Duration>(0).unwrap().get_some(),
+            (1000u64 * 1000 * 1000 * 120)
+        );
+    }
+}