Hi,
2014-08-17 19:09 GMT+02:00 Christophe Gisquet <christophe.gisq...@gmail.com>:
> The raw coded bits are extracted prior to decorrelation, as is correctly
> performed by the decoder, and not after.
Forgot to mention it fixes ticket #2768 (haven't checked 2497 yet), so
commit message amended.
--
Christophe
From d7ce32fdc0437d79146bd37a8a732d07eb0774ed Mon Sep 17 00:00:00 2001
From: Christophe Gisquet <christophe.gisq...@gmail.com>
Date: Sun, 17 Aug 2014 18:56:45 +0200
Subject: [PATCH 2/2] alacenc: fix extra bits extraction
The raw coded bits are extracted prior to decorrelation, as is correctly
performed by the decoder, and not after.
Fixes ticket #2768.
---
libavcodec/alacenc.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c
index 6345253..b9ad899 100644
--- a/libavcodec/alacenc.c
+++ b/libavcodec/alacenc.c
@@ -394,6 +394,19 @@ static void write_element(AlacEncodeContext *s,
init_sample_buffers(s, channels, samples);
write_element_header(s, element, instance);
+ // extract extra bits if needed
+ if (s->extra_bits) {
+ uint32_t mask = (1 << s->extra_bits) - 1;
+ for (j = 0; j < channels; j++) {
+ int32_t *extra = s->predictor_buf[j];
+ int32_t *smp = s->sample_buf[j];
+ for (i = 0; i < s->frame_size; i++) {
+ extra[i] = smp[i] & mask;
+ smp[i] >>= s->extra_bits;
+ }
+ }
+ }
+
if (channels == 2)
alac_stereo_decorrelation(s);
else
@@ -419,8 +432,7 @@ static void write_element(AlacEncodeContext *s,
uint32_t mask = (1 << s->extra_bits) - 1;
for (i = 0; i < s->frame_size; i++) {
for (j = 0; j < channels; j++) {
- put_bits(pb, s->extra_bits, s->sample_buf[j][i] & mask);
- s->sample_buf[j][i] >>= s->extra_bits;
+ put_bits(pb, s->extra_bits, s->predictor_buf[j][i] & mask);
}
}
}
--
1.9.2.msysgit.0
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