[FFmpeg-devel] [PATCH] mpegaudio: avoid unnecessary copy in high-precision mode
Mans Rullgard
mans
Tue May 5 19:18:42 CEST 2009
---
libavcodec/mpegaudiodec.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c
index 4d1129f..4c0d34a 100644
--- a/libavcodec/mpegaudiodec.c
+++ b/libavcodec/mpegaudiodec.c
@@ -846,31 +846,31 @@ void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
OUT_INT *samples, int incr,
int32_t sb_samples[SBLIMIT])
{
- int32_t tmp[32];
register MPA_INT *synth_buf;
register const MPA_INT *w, *w2, *p;
- int j, offset, v;
+ int j, offset;
OUT_INT *samples2;
#if FRAC_BITS <= 15
+ int32_t tmp[32];
int sum, sum2;
#else
int64_t sum, sum2;
#endif
- dct32(tmp, sb_samples);
-
offset = *synth_buf_offset;
synth_buf = synth_buf_ptr + offset;
- for(j=0;j<32;j++) {
- v = tmp[j];
#if FRAC_BITS <= 15
+ dct32(tmp, sb_samples);
+ for(j=0;j<32;j++) {
/* NOTE: can cause a loss in precision if very high amplitude
sound */
- v = av_clip_int16(v);
-#endif
- synth_buf[j] = v;
+ synth_buf[j] = av_clip_int16(tmp[j]);
}
+#else
+ dct32(synth_buf, sb_samples);
+#endif
+
/* copy to avoid wrap */
memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
--
1.6.2.3
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