mirror of
https://github.com/RGBCube/serenity
synced 2025-07-27 13:27:35 +00:00
LibAudio: Optimize FlacLoader by avoiding allocations
- Pre-allocate and reuse sample decompression buffers. In many FLAC files, the amount of samples per frame is either constant or the largest frame will be hit within the first couple of frames. Also, during audio output, we need to move and combine the samples from the decompression buffers into the final output buffers anyways. Avoiding the reallocation of these large buffers provides an improvement from 16x to 18x decode speed on strongly compressed but otherwise usual input. - Leave a FIXME for a similar improvement that can be made in the residual decoder. - Pre-allocate audio chunks if frame size is known. - Use reasonable inline capacities in several places where we know the maximum or usual capacity needed.
This commit is contained in:
parent
60ac254df6
commit
111fd1e5fe
3 changed files with 69 additions and 46 deletions
|
@ -69,11 +69,11 @@ private:
|
|||
// Helper of next_frame that fetches a sub frame's header
|
||||
ErrorOr<FlacSubframeHeader, LoaderError> next_subframe_header(BigEndianInputBitStream& bit_input, u8 channel_index);
|
||||
// Helper of next_frame that decompresses a subframe
|
||||
ErrorOr<Vector<i64>, LoaderError> parse_subframe(FlacSubframeHeader& subframe_header, BigEndianInputBitStream& bit_input);
|
||||
ErrorOr<void, LoaderError> parse_subframe(Vector<i64>& samples, FlacSubframeHeader& subframe_header, BigEndianInputBitStream& bit_input);
|
||||
// Subframe-internal data decoders (heavy lifting)
|
||||
ErrorOr<Vector<i64>, LoaderError> decode_fixed_lpc(FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
ErrorOr<Vector<i64>, LoaderError> decode_verbatim(FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
ErrorOr<Vector<i64>, LoaderError> decode_custom_lpc(FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
ErrorOr<void, LoaderError> decode_custom_lpc(Vector<i64>& decoded, FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
MaybeLoaderError decode_residual(Vector<i64>& decoded, FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
// decode a single rice partition that has its own rice parameter
|
||||
ALWAYS_INLINE ErrorOr<Vector<i64>, LoaderError> decode_rice_partition(u8 partition_type, u32 partitions, u32 partition_index, FlacSubframeHeader& subframe, BigEndianInputBitStream& bit_input);
|
||||
|
@ -110,6 +110,10 @@ private:
|
|||
Optional<FlacFrameHeader> m_current_frame;
|
||||
u64 m_current_sample_or_frame { 0 };
|
||||
SeekTable m_seektable;
|
||||
|
||||
// Keep around a few temporary buffers whose allocated space can be reused.
|
||||
// This is an empirical optimization since allocations and deallocations take a lot of time in the decoder.
|
||||
mutable Vector<Vector<i64>, 2> m_subframe_buffers;
|
||||
};
|
||||
|
||||
}
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue