Add utils for ptr->&str conversion

src/codec/codec.rs

@@ -1,9 +1,6 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use super::{Audio, Capabilities, Id, Profile, Video};
 use crate::ffi::*;
-use crate::{media, Error};
+use crate::{media, utils, Error};
 
 #[derive(PartialEq, Eq, Copy, Clone)]
 pub struct Codec {
@@ -37,18 +34,11 @@ impl Codec {
     }
 
     pub fn name(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).name) }
     }
 
     pub fn description(&self) -> &str {
-        unsafe {
-            let long_name = (*self.as_ptr()).long_name;
-            if long_name.is_null() {
-                ""
-            } else {
-                from_utf8_unchecked(CStr::from_ptr(long_name).to_bytes())
-            }
-        }
+        unsafe { utils::optional_str_from_c_ptr((*self.as_ptr()).long_name).unwrap_or("") }
     }
 
     pub fn medium(&self) -> media::Type {

src/codec/id.rs

@@ -1,9 +1,7 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::AVCodecID::*;
 use crate::ffi::*;
 use crate::util::media;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -661,7 +659,7 @@ impl Id {
     }
 
     pub fn name(&self) -> &'static str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr(avcodec_get_name((*self).into())).to_bytes()) }
+        unsafe { utils::str_from_c_ptr(avcodec_get_name((*self).into())) }
     }
 }
 

src/codec/mod.rs

@@ -48,19 +48,17 @@ pub mod decoder;
 pub mod encoder;
 pub mod traits;
 
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::*;
+use crate::utils;
 
 pub fn version() -> u32 {
     unsafe { avcodec_version() }
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avcodec_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avcodec_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avcodec_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avcodec_license()) }
 }

src/codec/subtitle/rect.rs

@@ -1,9 +1,8 @@
-use std::ffi::CStr;
 use std::marker::PhantomData;
-use std::str::from_utf8_unchecked;
 
 use super::{Flags, Type};
 use crate::ffi::*;
+use crate::utils;
 #[cfg(not(feature = "ffmpeg_5_0"))]
 use crate::{format, Picture};
 
@@ -122,7 +121,7 @@ impl<'a> Text<'a> {
 
 impl<'a> Text<'a> {
     pub fn get(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).text).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).text) }
     }
 }
 
@@ -147,6 +146,6 @@ impl<'a> Ass<'a> {
 
 impl<'a> Ass<'a> {
     pub fn get(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).ass).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).ass) }
     }
 }

src/device/mod.rs

@@ -2,11 +2,10 @@ pub mod extensions;
 pub mod input;
 pub mod output;
 
-use std::ffi::CStr;
 use std::marker::PhantomData;
-use std::str::from_utf8_unchecked;
 
 use crate::ffi::*;
+use crate::utils;
 
 pub struct Info<'a> {
     ptr: *mut AVDeviceInfo,
@@ -33,13 +32,11 @@ impl<'a> Info<'a> {
 
 impl<'a> Info<'a> {
     pub fn name(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).device_name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).device_name) }
     }
 
     pub fn description(&self) -> &str {
-        unsafe {
-            from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).device_description).to_bytes())
-        }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).device_description) }
     }
 }
 
@@ -54,9 +51,9 @@ pub fn version() -> u32 {
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avdevice_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avdevice_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avdevice_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avdevice_license()) }
 }

src/filter/filter.rs

@@ -1,9 +1,8 @@
-use std::ffi::CStr;
 use std::marker::PhantomData;
-use std::str::from_utf8_unchecked;
 
 use super::{Flags, Pad};
 use crate::ffi::*;
+use crate::utils;
 
 pub struct Filter {
     ptr: *mut AVFilter,
@@ -25,19 +24,11 @@ impl Filter {
 
 impl Filter {
     pub fn name(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).name) }
     }
 
     pub fn description(&self) -> Option<&str> {
-        unsafe {
-            let ptr = (*self.as_ptr()).description;
-
-            if ptr.is_null() {
-                None
-            } else {
-                Some(from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
-            }
-        }
+        unsafe { utils::optional_str_from_c_ptr((*self.as_ptr()).description) }
     }
 
     pub fn inputs(&self) -> Option<PadIter> {

src/filter/mod.rs

@@ -13,10 +13,10 @@ pub use self::context::{Context, Sink, Source};
 pub mod graph;
 pub use self::graph::Graph;
 
-use std::ffi::{CStr, CString};
-use std::str::from_utf8_unchecked;
+use std::ffi::CString;
 
 use crate::ffi::*;
+use crate::utils;
 #[cfg(not(feature = "ffmpeg_5_0"))]
 use crate::Error;
 
@@ -42,11 +42,11 @@ pub fn version() -> u32 {
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avfilter_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avfilter_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avfilter_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avfilter_license()) }
 }
 
 pub fn find(name: &str) -> Option<Filter> {

src/filter/pad.rs

@@ -1,9 +1,8 @@
-use std::ffi::CStr;
 use std::marker::PhantomData;
-use std::str::from_utf8_unchecked;
 
 use crate::ffi::*;
 use crate::media;
+use crate::utils;
 
 pub struct Pad<'a> {
     ptr: *const AVFilterPad,
@@ -34,12 +33,7 @@ impl<'a> Pad<'a> {
     pub fn name(&self) -> Option<&str> {
         unsafe {
             let ptr = avfilter_pad_get_name(self.ptr, self.idx as i32);
-
-            if ptr.is_null() {
-                None
-            } else {
-                Some(from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
-            }
+            utils::optional_str_from_c_ptr(ptr)
         }
     }
 

src/format/format/input.rs

@@ -1,7 +1,5 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::*;
+use crate::utils;
 
 pub struct Input {
     ptr: *mut AVInputFormat,
@@ -23,19 +21,11 @@ impl Input {
 
 impl Input {
     pub fn name(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).name) }
     }
 
     pub fn description(&self) -> &str {
-        unsafe {
-            let long_name = (*self.as_ptr()).long_name;
-
-            if long_name.is_null() {
-                ""
-            } else {
-                from_utf8_unchecked(CStr::from_ptr(long_name).to_bytes())
-            }
-        }
+        unsafe { utils::optional_str_from_c_ptr((*self.as_ptr()).long_name).unwrap_or("") }
     }
 
     pub fn extensions(&self) -> Vec<&str> {
@@ -45,9 +35,7 @@ impl Input {
             if ptr.is_null() {
                 Vec::new()
             } else {
-                from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes())
-                    .split(',')
-                    .collect()
+                utils::str_from_c_ptr(ptr).split(',').collect()
             }
         }
     }
@@ -59,9 +47,7 @@ impl Input {
             if ptr.is_null() {
                 Vec::new()
             } else {
-                from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes())
-                    .split(',')
-                    .collect()
+                utils::str_from_c_ptr(ptr).split(',').collect()
             }
         }
     }

src/format/format/output.rs

@@ -1,12 +1,11 @@
 use std::path::Path;
 
-use std::ffi::{CStr, CString};
+use std::ffi::CString;
 use std::ptr;
-use std::str::from_utf8_unchecked;
 
 use super::Flags;
 use crate::ffi::*;
-use crate::{codec, media};
+use crate::{codec, media, utils};
 
 pub struct Output {
     ptr: *mut AVOutputFormat,
@@ -28,19 +27,11 @@ impl Output {
 
 impl Output {
     pub fn name(&self) -> &str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).name) }
     }
 
     pub fn description(&self) -> &str {
-        unsafe {
-            let long_name = (*self.as_ptr()).long_name;
-
-            if long_name.is_null() {
-                ""
-            } else {
-                from_utf8_unchecked(CStr::from_ptr(long_name).to_bytes())
-            }
-        }
+        unsafe { utils::optional_str_from_c_ptr((*self.as_ptr()).long_name).unwrap_or("") }
     }
 
     pub fn extensions(&self) -> Vec<&str> {
@@ -50,9 +41,7 @@ impl Output {
             if ptr.is_null() {
                 Vec::new()
             } else {
-                from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes())
-                    .split(',')
-                    .collect()
+                utils::str_from_c_ptr(ptr).split(',').collect()
             }
         }
     }
@@ -64,9 +53,7 @@ impl Output {
             if ptr.is_null() {
                 Vec::new()
             } else {
-                from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes())
-                    .split(',')
-                    .collect()
+                utils::str_from_c_ptr(ptr).split(',').collect()
             }
         }
     }

src/format/mod.rs

@@ -15,12 +15,12 @@ pub use self::format::{Input, Output};
 
 pub mod network;
 
-use std::ffi::{CStr, CString};
+use std::ffi::CString;
 use std::path::Path;
 use std::ptr;
-use std::str::from_utf8_unchecked;
 
 use crate::ffi::*;
+use crate::utils;
 use crate::{Dictionary, Error};
 
 #[cfg(not(feature = "ffmpeg_5_0"))]
@@ -49,11 +49,11 @@ pub fn version() -> u32 {
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avformat_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avformat_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avformat_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avformat_license()) }
 }
 
 // XXX: use to_cstring when stable

src/lib.rs

@@ -77,6 +77,8 @@ pub use crate::filter::Filter;
 
 pub mod software;
 
+pub(crate) mod utils;
+
 fn init_error() {
     util::error::register_all();
 }

src/software/resampling/mod.rs

@@ -18,19 +18,17 @@ pub use self::context::Context;
 
 mod extensions;
 
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::*;
+use crate::utils;
 
 pub fn version() -> u32 {
     unsafe { swresample_version() }
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(swresample_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(swresample_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(swresample_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(swresample_license()) }
 }

src/software/scaling/mod.rs

@@ -17,19 +17,17 @@ pub use self::context::Context;
 
 mod extensions;
 
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::*;
+use crate::utils;
 
 pub fn version() -> u32 {
     unsafe { swscale_version() }
 }
 
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(swscale_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(swscale_configuration()) }
 }
 
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(swscale_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(swscale_license()) }
 }

src/util/color/primaries.rs

@@ -1,8 +1,6 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::AVColorPrimaries::*;
 use crate::ffi::*;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -40,8 +38,7 @@ impl Primaries {
         }
         unsafe {
             let ptr = av_color_primaries_name((*self).into());
-            ptr.as_ref()
-                .map(|ptr| from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
+            utils::optional_str_from_c_ptr(ptr)
         }
     }
 }

src/util/color/range.rs

@@ -1,8 +1,6 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::AVColorRange::*;
 use crate::ffi::*;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -21,8 +19,7 @@ impl Range {
         }
         unsafe {
             let ptr = av_color_range_name((*self).into());
-            ptr.as_ref()
-                .map(|ptr| from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
+            utils::optional_str_from_c_ptr(ptr)
         }
     }
 }

src/util/color/space.rs

@@ -1,8 +1,6 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::AVColorSpace::*;
 use crate::ffi::*;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -43,8 +41,7 @@ impl Space {
         }
         unsafe {
             let ptr = av_color_space_name((*self).into());
-            ptr.as_ref()
-                .map(|ptr| from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
+            utils::optional_str_from_c_ptr(ptr)
         }
     }
 }

src/util/color/transfer_characteristic.rs

@@ -1,8 +1,6 @@
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::AVColorTransferCharacteristic::*;
 use crate::ffi::*;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -37,8 +35,7 @@ impl TransferCharacteristic {
         }
         unsafe {
             let ptr = av_color_transfer_name((*self).into());
-            ptr.as_ref()
-                .map(|ptr| from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()))
+            utils::optional_str_from_c_ptr(ptr)
         }
     }
 }

src/util/dictionary/iter.rs

@@ -1,9 +1,9 @@
-use std::ffi::{CStr, CString};
+use std::ffi::CString;
 use std::marker::PhantomData;
 use std::ptr;
-use std::str::from_utf8_unchecked;
 
 use crate::ffi::*;
+use crate::utils;
 
 pub struct Iter<'a> {
     ptr: *const AVDictionary,
@@ -32,8 +32,8 @@ impl<'a> Iterator for Iter<'a> {
             let entry = av_dict_get(self.ptr, empty.as_ptr(), self.cur, AV_DICT_IGNORE_SUFFIX);
 
             if !entry.is_null() {
-                let key = from_utf8_unchecked(CStr::from_ptr((*entry).key).to_bytes());
-                let val = from_utf8_unchecked(CStr::from_ptr((*entry).value).to_bytes());
+                let key = utils::str_from_c_ptr((*entry).key);
+                let val = utils::str_from_c_ptr((*entry).value);
 
                 self.cur = entry;
 

src/util/format/pixel.rs

@@ -1,10 +1,11 @@
 use std::error;
-use std::ffi::{CStr, CString, NulError};
+use std::ffi::{CString, NulError};
 use std::fmt;
-use std::str::{from_utf8_unchecked, FromStr};
+use std::str::FromStr;
 
 use crate::ffi::AVPixelFormat::*;
 use crate::ffi::*;
+use crate::utils;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 
@@ -448,7 +449,7 @@ impl Descriptor {
     }
 
     pub fn name(self) -> &'static str {
-        unsafe { from_utf8_unchecked(CStr::from_ptr((*self.as_ptr()).name).to_bytes()) }
+        unsafe { utils::str_from_c_ptr((*self.as_ptr()).name) }
     }
 
     pub fn nb_components(self) -> u8 {

src/util/format/sample.rs

@@ -1,11 +1,11 @@
-use std::ffi::{CStr, CString};
+use std::ffi::CString;
 use std::ops::Index;
 use std::ptr;
 use std::slice;
-use std::str::from_utf8_unchecked;
 
 use crate::ffi::AVSampleFormat::*;
 use crate::ffi::*;
+use crate::utils;
 use libc::{c_int, c_void};
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
@@ -33,9 +33,7 @@ pub enum Type {
 impl Sample {
     #[inline]
     pub fn name(&self) -> &'static str {
-        unsafe {
-            from_utf8_unchecked(CStr::from_ptr(av_get_sample_fmt_name((*self).into())).to_bytes())
-        }
+        unsafe { utils::str_from_c_ptr(av_get_sample_fmt_name((*self).into())) }
     }
 
     #[inline]

src/util/frame/side_data.rs

@@ -1,11 +1,10 @@
-use std::ffi::CStr;
 use std::marker::PhantomData;
 use std::slice;
-use std::str::from_utf8_unchecked;
 
 use super::Frame;
 use crate::ffi::AVFrameSideDataType::*;
 use crate::ffi::*;
+use crate::utils;
 use crate::DictionaryRef;
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
@@ -74,9 +73,7 @@ pub enum Type {
 impl Type {
     #[inline]
     pub fn name(&self) -> &'static str {
-        unsafe {
-            from_utf8_unchecked(CStr::from_ptr(av_frame_side_data_name((*self).into())).to_bytes())
-        }
+        unsafe { utils::str_from_c_ptr(av_frame_side_data_name((*self).into())) }
     }
 }
 

src/util/mod.rs

@@ -16,10 +16,8 @@ pub mod range;
 pub mod rational;
 pub mod time;
 
-use std::ffi::CStr;
-use std::str::from_utf8_unchecked;
-
 use crate::ffi::*;
+use crate::utils;
 
 #[inline(always)]
 pub fn version() -> u32 {
@@ -28,10 +26,10 @@ pub fn version() -> u32 {
 
 #[inline(always)]
 pub fn configuration() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avutil_configuration()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avutil_configuration()) }
 }
 
 #[inline(always)]
 pub fn license() -> &'static str {
-    unsafe { from_utf8_unchecked(CStr::from_ptr(avutil_license()).to_bytes()) }
+    unsafe { utils::str_from_c_ptr(avutil_license()) }
 }

src/utils.rs

@@ -0,0 +1,21 @@
+//! Internal utils, not related to `avutil`
+
+use std::ffi::CStr;
+
+/// `ptr` must be non-null and valid.
+/// Ensure that the returned lifetime is correctly bounded.
+#[inline]
+pub unsafe fn str_from_c_ptr<'s>(ptr: *const libc::c_char) -> &'s str {
+    unsafe { std::str::from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes()) }
+}
+
+/// `ptr` must be null or valid.
+/// Ensure that the returned lifetime is correctly bounded.
+#[inline]
+pub unsafe fn optional_str_from_c_ptr<'s>(ptr: *const libc::c_char) -> Option<&'s str> {
+    if ptr.is_null() {
+        None
+    } else {
+        Some(str_from_c_ptr(ptr))
+    }
+}