support interleaved audio properly

Now NAAudioBuffer has step field which tells the distance to the next
sample in the channel. This can be used to work with interleaved audio
stored as native samples (instead of packed buffer like before).

1 files changed, 35 insertions, 10 deletions

diff --git a/nihav-core/src/frame.rs b/nihav-core/src/frame.rs
index 95bad26..145bd2a 100644
--- a/nihav-core/src/frame.rs
+++ b/nihav-core/src/frame.rs
@@ -197,6 +197,7 @@ pub struct NAAudioBuffer<T> {
     data:   NABufferRef<Vec<T>>,
     offs:   Vec<usize>,
     stride: usize,
+    step:   usize,
     chmap:  NAChannelMap,
     len:    usize,
 }
@@ -209,6 +210,8 @@ impl<T: Clone> NAAudioBuffer<T> {
     }
     /// Returns the distance between the start of one channel and the next one.
     pub fn get_stride(&self) -> usize { self.stride }
+    /// Returns the distance between the samples in one channel.
+    pub fn get_step(&self) -> usize { self.step }
     /// Returns audio format information.
     pub fn get_info(&self) -> NAAudioInfo { self.info }
     /// Returns channel map.
@@ -223,7 +226,7 @@ impl<T: Clone> NAAudioBuffer<T> {
         data.clone_from(self.data.as_ref());
         let mut offs: Vec<usize> = Vec::with_capacity(self.offs.len());
         offs.clone_from(&self.offs);
-        NAAudioBuffer { info: self.info, data: NABufferRef::new(data), offs, chmap: self.get_chmap().clone(), len: self.len, stride: self.stride }
+        NAAudioBuffer { info: self.info, data: NABufferRef::new(data), offs, chmap: self.get_chmap().clone(), len: self.len, stride: self.stride, step: self.step }
     }
     /// Return the length of frame in samples.
     pub fn get_length(&self) -> usize { self.len }
@@ -233,7 +236,7 @@ impl NAAudioBuffer<u8> {
     /// Constructs a new `NAAudioBuffer` instance.
     pub fn new_from_buf(info: NAAudioInfo, data: NABufferRef<Vec<u8>>, chmap: NAChannelMap) -> Self {
         let len = data.len();
-        NAAudioBuffer { info, data, chmap, offs: Vec::new(), len, stride: 0 }
+        NAAudioBuffer { info, data, chmap, offs: Vec::new(), len, stride: 0, step: 0 }
     }
 }
 
@@ -355,6 +358,17 @@ impl NABufferType {
             _ => 0,
         }
     }
+    /// Returns the distance between two samples in one channel.
+    pub fn get_audio_step(&self) -> usize {
+        match *self {
+            NABufferType::AudioU8(ref ab)     => ab.get_step(),
+            NABufferType::AudioI16(ref ab)    => ab.get_step(),
+            NABufferType::AudioI32(ref ab)    => ab.get_step(),
+            NABufferType::AudioF32(ref ab)    => ab.get_step(),
+            NABufferType::AudioPacked(ref ab) => ab.get_step(),
+            _ => 0,
+        }
+    }
     /// Returns reference to 8-bit (or packed) audio buffer.
     pub fn get_abuf_u8(&self) -> Option<NAAudioBuffer<u8>> {
         match *self {
@@ -562,18 +576,29 @@ pub fn alloc_video_buffer(vinfo: NAVideoInfo, align: u8) -> Result<NABufferType,
 #[allow(clippy::collapsible_if)]
 pub fn alloc_audio_buffer(ainfo: NAAudioInfo, nsamples: usize, chmap: NAChannelMap) -> Result<NABufferType, AllocatorError> {
     let mut offs: Vec<usize> = Vec::new();
-    if ainfo.format.is_planar() || (ainfo.channels == 1 && (ainfo.format.get_bits() % 8) == 0) {
+    if ainfo.format.is_planar() || ((ainfo.format.get_bits() % 8) == 0) {
         let len = nsamples.checked_mul(ainfo.channels as usize);
         if len == None { return Err(AllocatorError::TooLargeDimensions); }
         let length = len.unwrap();
-        let stride = nsamples;
-        for i in 0..ainfo.channels {
-            offs.push((i as usize) * stride);
+        let stride;
+        let step;
+        if ainfo.format.is_planar() {
+            stride = nsamples;
+            step   = 1;
+            for i in 0..ainfo.channels {
+                offs.push((i as usize) * stride);
+            }
+        } else {
+            stride = 1;
+            step   = ainfo.channels as usize;
+            for i in 0..ainfo.channels {
+                offs.push(i as usize);
+            }
         }
         if ainfo.format.is_float() {
             if ainfo.format.get_bits() == 32 {
                 let data: Vec<f32> = vec![0.0; length];
-                let buf: NAAudioBuffer<f32> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride };
+                let buf: NAAudioBuffer<f32> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride, step };
                 Ok(NABufferType::AudioF32(buf))
             } else {
                 Err(AllocatorError::TooLargeDimensions)
@@ -581,11 +606,11 @@ pub fn alloc_audio_buffer(ainfo: NAAudioInfo, nsamples: usize, chmap: NAChannelM
         } else {
             if ainfo.format.get_bits() == 8 && !ainfo.format.is_signed() {
                 let data: Vec<u8> = vec![0; length];
-                let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride };
+                let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride, step };
                 Ok(NABufferType::AudioU8(buf))
             } else if ainfo.format.get_bits() == 16 && ainfo.format.is_signed() {
                 let data: Vec<i16> = vec![0; length];
-                let buf: NAAudioBuffer<i16> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride };
+                let buf: NAAudioBuffer<i16> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride, step };
                 Ok(NABufferType::AudioI16(buf))
             } else {
                 Err(AllocatorError::TooLargeDimensions)
@@ -596,7 +621,7 @@ pub fn alloc_audio_buffer(ainfo: NAAudioInfo, nsamples: usize, chmap: NAChannelM
         if len == None { return Err(AllocatorError::TooLargeDimensions); }
         let length = ainfo.format.get_audio_size(len.unwrap() as u64);
         let data: Vec<u8> = vec![0; length];
-        let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride: 0 };
+        let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride: 0, step: 0 };
         Ok(NABufferType::AudioPacked(buf))
     }
 }