ndk/media: Add bindings for AMediaCodecCryptoInfo

Author: MarijnS95

ndk/src/media/media_codec_crypto.rs

@@ -0,0 +1,142 @@
+//! Bindings for [`AMediaCodecCryptoInfo`]
+//!
+//! [`AMediaCodecCryptoInfo`]: https://developer.android.com/ndk/reference/group/media#amediacodeccryptoinfo
+
+use std::{mem::MaybeUninit, ptr::NonNull};
+
+use crate::media_error::{MediaError, Result};
+
+/// A native [`AMediaCodecCryptoInfo *`]
+///
+/// [`AMediaCodecCryptoInfo *`]: https://developer.android.com/ndk/reference/group/media#amediacodeccryptoinfo
+#[derive(Debug)]
+#[doc(alias = "AMediaCodecCryptoInfo")]
+pub struct MediaCodecCryptoInfo {
+    inner: NonNull<ffi::AMediaCodecCryptoInfo>,
+}
+
+impl MediaCodecCryptoInfo {
+    /// Create a [`MediaCodecCryptoInfo`] from scratch. Use this if you need to use custom crypto
+    /// info, rather than one obtained from [`super::media_extractor::MediaExtractor`].
+    ///
+    /// [`MediaCodecCryptoInfo`] describes the structure of an (at least partially) encrypted input
+    /// sample.
+    ///
+    /// A buffer's data is considered to be partitioned into "subsamples", each subsample starts
+    /// with a (potentially empty) run of plain, unencrypted bytes followed by a (also potentially
+    /// empty) run of encrypted bytes.
+    ///
+    /// `clearbytes` can be null to indicate that all data is encrypted. This information
+    /// encapsulates per-sample metadata as outlined in ISO/IEC FDIS 23001-7:2011 "Common encryption
+    /// in ISO base media file format files".
+    #[doc(alias = "AMediaCodecCryptoInfo_new")]
+    pub fn new(
+        num_sub_samples: i32,
+        key: &[u8; 16],
+        iv: &[u8; 16],
+        mode: ffi::cryptoinfo_mode_t,
+    ) -> Option<Self> {
+        let mut clear_bytes = 0;
+        let mut encrypted_bytes = 0;
+        NonNull::new(unsafe {
+            ffi::AMediaCodecCryptoInfo_new(
+                num_sub_samples,
+                key.as_ptr().cast_mut(),
+                iv.as_ptr().cast_mut(),
+                mode,
+                // TODO: Set the value and/or store it?
+                &mut clear_bytes,
+                &mut encrypted_bytes,
+            )
+        })
+        .map(|inner| Self { inner })
+    }
+
+    /// Assumes ownership of `ptr`
+    ///
+    /// # Safety
+    /// `ptr` must be a valid pointer to an Android [`ffi::AMediaCodecCryptoInfo`].
+    pub unsafe fn from_ptr(ptr: NonNull<ffi::AMediaCodecCryptoInfo>) -> Self {
+        Self { inner: ptr }
+    }
+
+    pub fn as_ptr(&self) -> *mut ffi::AMediaCodecCryptoInfo {
+        self.inner.as_ptr()
+    }
+
+    /// Set the crypto pattern on an AMediaCryptoInfo object.
+    #[doc(alias = "AMediaCodecCryptoInfo_setPattern")]
+    pub fn set_pattern(&self, pattern: &ffi::cryptoinfo_pattern_t) {
+        unsafe {
+            ffi::AMediaCodecCryptoInfo_setPattern(
+                self.inner.as_ptr(),
+                <*const _>::cast_mut(pattern),
+            )
+        }
+    }
+
+    /// The number of subsamples that make up the buffer's contents.
+    #[doc(alias = "AMediaCodecCryptoInfo_getNumSubSamples")]
+    pub fn num_sub_samples(&self) -> usize {
+        unsafe { ffi::AMediaCodecCryptoInfo_getNumSubSamples(self.inner.as_ptr()) }
+    }
+
+    /// A 16-byte opaque key.
+    #[doc(alias = "AMediaCodecCryptoInfo_getKey")]
+    pub fn key(&self) -> Result<[u8; 16]> {
+        let mut key = [0u8; 16];
+        let status =
+            unsafe { ffi::AMediaCodecCryptoInfo_getKey(self.inner.as_ptr(), key.as_mut_ptr()) };
+        MediaError::from_status(status).map(|()| key)
+    }
+
+    /// A 16-byte initialization vector.
+    #[doc(alias = "AMediaCodecCryptoInfo_getIV")]
+    pub fn iv(&self) -> Result<[u8; 16]> {
+        let mut iv = [0u8; 16];
+        let status =
+            unsafe { ffi::AMediaCodecCryptoInfo_getIV(self.inner.as_ptr(), iv.as_mut_ptr()) };
+        MediaError::from_status(status).map(|()| iv)
+    }
+
+    /// The type of encryption that has been applied,
+    /// one of AMEDIACODECRYPTOINFO_MODE_CLEAR or AMEDIACODECRYPTOINFO_MODE_AES_CTR.
+    #[doc(alias = "AMediaCodecCryptoInfo_getMode")]
+    pub fn mode(&self) -> ffi::cryptoinfo_mode_t {
+        unsafe { ffi::AMediaCodecCryptoInfo_getMode(self.inner.as_ptr()) }
+    }
+
+    /// The number of leading unencrypted bytes in each subsample.
+    #[doc(alias = "AMediaCodecCryptoInfo_getClearBytes")]
+    pub fn clear_bytes(&self) -> Result<usize> {
+        let mut clear_bytes = MaybeUninit::uninit();
+
+        let status = unsafe {
+            ffi::AMediaCodecCryptoInfo_getClearBytes(self.inner.as_ptr(), clear_bytes.as_mut_ptr())
+        };
+        MediaError::from_status(status).map(|()| unsafe { clear_bytes.assume_init() })
+    }
+
+    /// The number of trailing encrypted bytes in each subsample.
+    #[doc(alias = "AMediaCodecCryptoInfo_getEncryptedBytes")]
+    pub fn encrypted_bytes(&self) -> Result<usize> {
+        let mut encrypted_bytes = MaybeUninit::uninit();
+        let status = unsafe {
+            ffi::AMediaCodecCryptoInfo_getEncryptedBytes(
+                self.inner.as_ptr(),
+                encrypted_bytes.as_mut_ptr(),
+            )
+        };
+        MediaError::from_status(status).map(|()| unsafe { encrypted_bytes.assume_init() })
+    }
+}
+
+impl Drop for MediaCodecCryptoInfo {
+    /// Delete a [`MediaCodecCryptoInfo`] created previously with [`MediaCodecCryptoInfo::new()`], or
+    /// obtained from [`super::media_extractor::MediaExtractor`].
+    #[doc(alias = "AMediaCodecCryptoInfo_delete")]
+    fn drop(&mut self) {
+        let status = unsafe { ffi::AMediaCodecCryptoInfo_delete(self.inner.as_ptr()) };
+        MediaError::from_status(status).unwrap()
+    }
+}

ndk/src/media/mod.rs

@@ -5,4 +5,5 @@
 
 pub mod image_reader;
 pub mod media_codec;
+pub mod media_codec_crypto;
 pub mod media_format;