av1: parser: advance the parser when an OBU is dropped
If we drop an OBU, we must advance the parser to the next OBU, otherwise we will
be stuck in an infinite loop.
diff --git a/src/codec/av1/parser.rs b/src/codec/av1/parser.rs
index e9b1a39..efc44c7 100644
--- a/src/codec/av1/parser.rs
+++ b/src/codec/av1/parser.rs
@@ -51,6 +51,14 @@
pub const GM_ABS_TRANS_BITS: u32 = 12;
pub const GM_TRANS_PREC_BITS: u32 = 6;
+pub enum ParsedObu<'a> {
+ /// We should process the OBU normally.
+ Process(Obu<'a>),
+ /// We should drop this OBU and advance to the next one. The u32 is how much
+ /// we should advance.
+ Drop(u32),
+}
+
#[derive(N, Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
pub enum ObuType {
#[default]
@@ -1482,7 +1490,7 @@
/// format.
///
/// `None` may eventually be returned if the OBU is to be dropped.
- pub fn parse_obu<'a>(&mut self, data: &'a [u8]) -> anyhow::Result<Option<Obu<'a>>> {
+ pub fn parse_obu<'a>(&mut self, data: &'a [u8]) -> anyhow::Result<ParsedObu<'a>> {
if data.is_empty() {
return Err(anyhow!("Empty data"));
}
@@ -1508,7 +1516,7 @@
let obu_length = reader.current_annexb_obu_length(annexb_state)?;
match obu_length {
Some(length) => length,
- None => return Ok(None),
+ None => return Ok(ParsedObu::Drop(reader.consumed(0))),
}
} else {
0
@@ -1560,9 +1568,9 @@
&& header.extension_flag
{
log::debug!("Dropping obu as per drop_obu() in the specification",);
- Ok(None)
+ Ok(ParsedObu::Drop(reader.consumed(0)))
} else {
- Ok(Some(Obu {
+ Ok(ParsedObu::Process(Obu {
header,
data: Cow::from(&data[..start_offset + obu_size]),
start_offset,
@@ -3738,7 +3746,7 @@
#[cfg(test)]
mod tests {
- use crate::codec::av1::parser::{Parser, StreamFormat};
+ use crate::codec::av1::parser::{ParsedObu, Parser, StreamFormat};
use crate::utils::IvfIterator;
use super::ObuType;
@@ -3767,9 +3775,12 @@
while let Ok(obu) = parser.parse_obu(&packet[consumed..]) {
let obu = match obu {
- Some(obu) => obu,
+ ParsedObu::Process(obu) => obu,
// This OBU should be dropped.
- None => continue,
+ ParsedObu::Drop(length) => {
+ consumed += usize::try_from(length).unwrap();
+ continue;
+ }
};
consumed += obu.data.len();
num_obus += 1;
@@ -3813,9 +3824,12 @@
while let Ok(obu) = parser.parse_obu(&packet[consumed..]) {
let obu = match obu {
- Some(obu) => obu,
+ ParsedObu::Process(obu) => obu,
// This OBU should be dropped.
- None => continue,
+ ParsedObu::Drop(length) => {
+ consumed += usize::try_from(length).unwrap();
+ continue;
+ }
};
assert!(matches!(parser.stream_format, StreamFormat::LowOverhead));
consumed += obu.data.len();
@@ -3831,9 +3845,12 @@
while let Ok(obu) = parser.parse_obu(&packet[consumed..]) {
let obu = match obu {
- Some(obu) => obu,
+ ParsedObu::Process(obu) => obu,
// This OBU should be dropped.
- None => continue,
+ ParsedObu::Drop(length) => {
+ consumed += usize::try_from(length).unwrap();
+ continue;
+ }
};
assert!(matches!(parser.stream_format, StreamFormat::AnnexB { .. }));
consumed += obu.data.len();
@@ -3866,9 +3883,12 @@
while let Ok(obu) = parser.parse_obu(&packet[consumed..]) {
let obu = match obu {
- Some(obu) => obu,
+ ParsedObu::Process(obu) => obu,
// This OBU should be dropped.
- None => continue,
+ ParsedObu::Drop(length) => {
+ consumed += usize::try_from(length).unwrap();
+ continue;
+ }
};
let data_len = obu.data.len();
