Hi,
2014-08-31 23:18 GMT+02:00 Justin Ruggles <[email protected]>:
> That seems wrong. shouldn't that be s->predictor_buf[i]
Indeed. Fortunately, it was in dead code ("TODO: determine when this
will actually help. for now it's not used.")
Patch updated (and rebased on top of HEAD).
--
Christophe
From 6ebedccf8de4b71ef951e40ac9470b0694134dcc Mon Sep 17 00:00:00 2001
From: Christophe Gisquet <[email protected]>
Date: Sun, 17 Aug 2014 17:09:13 +0000
Subject: [PATCH 1/3] alacenc: increase predictor buffer
This change is almost cosmetical only, and reduces the changes needed to
fix the 24bps case.
---
libavcodec/alacenc.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c
index 401f26f..117813c 100644
--- a/libavcodec/alacenc.c
+++ b/libavcodec/alacenc.c
@@ -66,7 +66,7 @@ typedef struct AlacEncodeContext {
int write_sample_size;
int extra_bits;
int32_t sample_buf[2][DEFAULT_FRAME_SIZE];
- int32_t predictor_buf[DEFAULT_FRAME_SIZE];
+ int32_t predictor_buf[2][DEFAULT_FRAME_SIZE];
int interlacing_shift;
int interlacing_leftweight;
PutBitContext pbctx;
@@ -253,13 +253,14 @@ static void alac_linear_predictor(AlacEncodeContext *s, int ch)
{
int i;
AlacLPCContext lpc = s->lpc[ch];
+ int32_t *residual = s->predictor_buf[ch];
if (lpc.lpc_order == 31) {
- s->predictor_buf[0] = s->sample_buf[ch][0];
+ residual[0] = s->sample_buf[ch][0];
for (i = 1; i < s->frame_size; i++) {
- s->predictor_buf[i] = s->sample_buf[ch][i ] -
- s->sample_buf[ch][i - 1];
+ residual[i] = s->sample_buf[ch][i ] -
+ s->sample_buf[ch][i - 1];
}
return;
@@ -269,7 +270,6 @@ static void alac_linear_predictor(AlacEncodeContext *s, int ch)
if (lpc.lpc_order > 0) {
int32_t *samples = s->sample_buf[ch];
- int32_t *residual = s->predictor_buf;
// generate warm-up samples
residual[0] = samples[0];
@@ -313,11 +313,11 @@ static void alac_linear_predictor(AlacEncodeContext *s, int ch)
}
}
-static void alac_entropy_coder(AlacEncodeContext *s)
+static void alac_entropy_coder(AlacEncodeContext *s, int ch)
{
unsigned int history = s->rc.initial_history;
int sign_modifier = 0, i, k;
- int32_t *samples = s->predictor_buf;
+ int32_t *samples = s->predictor_buf[ch];
for (i = 0; i < s->frame_size;) {
int x;
@@ -432,10 +432,11 @@ static void write_element(AlacEncodeContext *s,
// TODO: determine when this will actually help. for now it's not used.
if (prediction_type == 15) {
// 2nd pass 1st order filter
+ int32_t *residual = s->predictor_buf[i];
for (j = s->frame_size - 1; j > 0; j--)
- s->predictor_buf[j] -= s->predictor_buf[j - 1];
+ residual[j] -= residual[j - 1];
}
- alac_entropy_coder(s);
+ alac_entropy_coder(s, i);
}
}
}
--
1.9.2.msysgit.0
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