filter/Filter: clarify that the FilterPCM() return value may be empty

And adjust TwoFilter accordingly.
This commit is contained in:
Max Kellermann 2024-11-05 12:24:26 +01:00
parent b7b4c6b4ea
commit d7ae512b5e
2 changed files with 9 additions and 2 deletions

View File

@ -43,7 +43,7 @@ public:
* @param src the input buffer
* @return the output buffer (will be invalidated by deleting
* this object or any call to Reset(), FilterPCM() or
* Flush())
* Flush()); may be empty if no output is currently available
*/
virtual std::span<const std::byte> FilterPCM(std::span<const std::byte> src) = 0;

View File

@ -10,7 +10,14 @@
std::span<const std::byte>
TwoFilters::FilterPCM(std::span<const std::byte> src)
{
return second->FilterPCM(first->FilterPCM(src));
if (const auto dest = first->FilterPCM(src); dest.empty()) [[unlikely]]
/* no output from the first filter; pass the empty
buffer on, do not call the second filter */
return dest;
else
/* pass output from the first filter to the second
filter and return its result */
return second->FilterPCM(dest);
}
std::span<const std::byte>