Merge pull request #235 from mozilla/misc-prealloc

Preallocate vector storage when the size is known

Author: baumanj

mp4parse/src/fallible.rs

@@ -256,7 +256,7 @@ impl<T> TryVec<T> {
         Ok(())
     }
 
-    fn reserve(&mut self, additional: usize) -> Result<()> {
+    pub fn reserve(&mut self, additional: usize) -> Result<()> {
         #[cfg(feature = "mp4parse_fallible")]
         {
             let available = self

mp4parse/src/lib.rs

@@ -2059,10 +2059,11 @@ fn read_tkhd<T: Read>(src: &mut BMFFBox<T>) -> Result<TrackHeaderBox> {
 }
 
 /// Parse a elst box.
+/// See ISO 14496-12:2015 § 8.6.6
 fn read_elst<T: Read>(src: &mut BMFFBox<T>) -> Result<EditListBox> {
     let (version, _) = read_fullbox_extra(src)?;
     let edit_count = be_u32_with_limit(src)?;
-    let mut edits = TryVec::new();
+    let mut edits = TryVec::with_capacity(edit_count.to_usize())?;
     for _ in 0..edit_count {
         let (segment_duration, media_time) = match version {
             1 => {
@@ -2134,10 +2135,11 @@ fn read_mdhd<T: Read>(src: &mut BMFFBox<T>) -> Result<MediaHeaderBox> {
 }
 
 /// Parse a stco box.
+/// See ISO 14496-12:2015 § 8.7.5
 fn read_stco<T: Read>(src: &mut BMFFBox<T>) -> Result<ChunkOffsetBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let offset_count = be_u32_with_limit(src)?;
-    let mut offsets = TryVec::new();
+    let mut offsets = TryVec::with_capacity(offset_count.to_usize())?;
     for _ in 0..offset_count {
         offsets.push(be_u32(src)?.into())?;
     }
@@ -2149,10 +2151,11 @@ fn read_stco<T: Read>(src: &mut BMFFBox<T>) -> Result<ChunkOffsetBox> {
 }
 
 /// Parse a co64 box.
+/// See ISO 14496-12:2015 § 8.7.5
 fn read_co64<T: Read>(src: &mut BMFFBox<T>) -> Result<ChunkOffsetBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let offset_count = be_u32_with_limit(src)?;
-    let mut offsets = TryVec::new();
+    let mut offsets = TryVec::with_capacity(offset_count.to_usize())?;
     for _ in 0..offset_count {
         offsets.push(be_u64(src)?)?;
     }
@@ -2164,10 +2167,11 @@ fn read_co64<T: Read>(src: &mut BMFFBox<T>) -> Result<ChunkOffsetBox> {
 }
 
 /// Parse a stss box.
+/// See ISO 14496-12:2015 § 8.6.2
 fn read_stss<T: Read>(src: &mut BMFFBox<T>) -> Result<SyncSampleBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let sample_count = be_u32_with_limit(src)?;
-    let mut samples = TryVec::new();
+    let mut samples = TryVec::with_capacity(sample_count.to_usize())?;
     for _ in 0..sample_count {
         samples.push(be_u32(src)?)?;
     }
@@ -2179,10 +2183,11 @@ fn read_stss<T: Read>(src: &mut BMFFBox<T>) -> Result<SyncSampleBox> {
 }
 
 /// Parse a stsc box.
+/// See ISO 14496-12:2015 § 8.7.4
 fn read_stsc<T: Read>(src: &mut BMFFBox<T>) -> Result<SampleToChunkBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let sample_count = be_u32_with_limit(src)?;
-    let mut samples = TryVec::new();
+    let mut samples = TryVec::with_capacity(sample_count.to_usize())?;
     for _ in 0..sample_count {
         let first_chunk = be_u32(src)?;
         let samples_per_chunk = be_u32_with_limit(src)?;
@@ -2200,16 +2205,23 @@ fn read_stsc<T: Read>(src: &mut BMFFBox<T>) -> Result<SampleToChunkBox> {
     Ok(SampleToChunkBox { samples })
 }
 
+/// Parse a Composition Time to Sample Box
+/// See ISO 14496-12:2015 § 8.6.1.3
 fn read_ctts<T: Read>(src: &mut BMFFBox<T>) -> Result<CompositionOffsetBox> {
     let (version, _) = read_fullbox_extra(src)?;
 
-    let counts = u64::from(be_u32_with_limit(src)?);
+    let counts = be_u32_with_limit(src)?;
 
-    if src.bytes_left() < counts.checked_mul(8).expect("counts -> bytes overflow") {
+    if src.bytes_left()
+        < counts
+            .checked_mul(8)
+            .expect("counts -> bytes overflow")
+            .into()
+    {
         return Err(Error::InvalidData("insufficient data in 'ctts' box"));
     }
 
-    let mut offsets = TryVec::new();
+    let mut offsets = TryVec::with_capacity(counts.to_usize())?;
     for _ in 0..counts {
         let (sample_count, time_offset) = match version {
             // According to spec, Version0 shoule be used when version == 0;
@@ -2236,12 +2248,14 @@ fn read_ctts<T: Read>(src: &mut BMFFBox<T>) -> Result<CompositionOffsetBox> {
 }
 
 /// Parse a stsz box.
+/// See ISO 14496-12:2015 § 8.7.3.2
 fn read_stsz<T: Read>(src: &mut BMFFBox<T>) -> Result<SampleSizeBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let sample_size = be_u32(src)?;
     let sample_count = be_u32_with_limit(src)?;
     let mut sample_sizes = TryVec::new();
     if sample_size == 0 {
+        sample_sizes.reserve(sample_count.to_usize())?;
         for _ in 0..sample_count {
             sample_sizes.push(be_u32(src)?)?;
         }
@@ -2257,10 +2271,11 @@ fn read_stsz<T: Read>(src: &mut BMFFBox<T>) -> Result<SampleSizeBox> {
 }
 
 /// Parse a stts box.
+/// See ISO 14496-12:2015 § 8.6.1.2
 fn read_stts<T: Read>(src: &mut BMFFBox<T>) -> Result<TimeToSampleBox> {
     let (_, _) = read_fullbox_extra(src)?;
     let sample_count = be_u32_with_limit(src)?;
-    let mut samples = TryVec::new();
+    let mut samples = TryVec::with_capacity(sample_count.to_usize())?;
     for _ in 0..sample_count {
         let sample_count = be_u32_with_limit(src)?;
         let sample_delta = be_u32(src)?;
@@ -2715,6 +2730,7 @@ fn read_esds<T: Read>(src: &mut BMFFBox<T>) -> Result<ES_Descriptor> {
 }
 
 /// Parse `FLACSpecificBox`.
+/// See https://github.com/xiph/flac/blob/master/doc/isoflac.txt §  3.3.2
 fn read_dfla<T: Read>(src: &mut BMFFBox<T>) -> Result<FLACSpecificBox> {
     let (version, flags) = read_fullbox_extra(src)?;
     if version != 0 {

mp4parse_capi/src/lib.rs

@@ -1736,13 +1736,14 @@ fn get_pssh_info(
 
     pssh_data.clear();
     for pssh in &context.psshs {
-        let content_len = pssh.box_content.len();
-        if content_len > std::u32::MAX as usize {
-            return Err(Mp4parseStatus::Invalid);
-        }
+        let content_len = pssh
+            .box_content
+            .len()
+            .try_into()
+            .map_err(|_| Mp4parseStatus::Invalid)?;
         let mut data_len = TryVec::new();
         if data_len
-            .write_u32::<byteorder::NativeEndian>(content_len as u32)
+            .write_u32::<byteorder::NativeEndian>(content_len)
             .is_err()
         {
             return Err(Mp4parseStatus::Io);