From 00fbd7bb4b64d6078b79c1e35d5b1d3bb325a405 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Sat, 12 Apr 2008 04:20:30 +0000
Subject: special optimized case for 16bit stereo
Not having to loop for every sample byte (depending on a variable
unknown at compile time) saves a lot of CPU cycles. We could consider
reimplementing this function with liboil...
git-svn-id: https://svn.musicpd.org/mpd/trunk@7330 09075e82-0dd4-0310-85a5-a0d7c8717e4f
---
src/inputPlugins/flac_plugin.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
(limited to 'src/inputPlugins')
diff --git a/src/inputPlugins/flac_plugin.c b/src/inputPlugins/flac_plugin.c
index 8f4c96884..b52704959 100644
--- a/src/inputPlugins/flac_plugin.c
+++ b/src/inputPlugins/flac_plugin.c
@@ -206,6 +206,18 @@ static void flacMetadata(const flac_decoder * dec,
flac_metadata_common_cb(block, (FlacData *) vdata);
}
+static void flac_convert_stereo16(unsigned char *dest,
+ const FLAC__int32 * const buf[],
+ unsigned int position, unsigned int end)
+{
+ for (; position < end; ++position) {
+ *(uint16_t*)dest = buf[0][position];
+ dest += 2;
+ *(uint16_t*)dest = buf[1][position];
+ dest += 2;
+ }
+}
+
static void flac_convert(unsigned char *dest,
unsigned int num_channels,
unsigned int bytes_per_sample,
@@ -266,9 +278,14 @@ static FLAC__StreamDecoderWriteStatus flacWrite(const flac_decoder *dec,
if (num_samples > max_samples)
num_samples = max_samples;
- flac_convert(data->chunk + data->chunk_length,
- num_channels, bytes_per_sample, buf,
- c_samp, c_samp + num_samples);
+ if (bytes_per_sample == 2)
+ flac_convert_stereo16(data->chunk + data->chunk_length,
+ buf, c_samp,
+ c_samp + num_samples);
+ else
+ flac_convert(data->chunk + data->chunk_length,
+ num_channels, bytes_per_sample, buf,
+ c_samp, c_samp + num_samples);
data->chunk_length = num_samples;
if (flacSendChunk(data) < 0) {
--
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