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authorReimar Döffinger <Reimar.Doeffinger@gmx.de>2014-11-22 20:05:08 +0100
committerReimar Döffinger <Reimar.Doeffinger@gmx.de>2014-12-17 04:27:09 +0100
commit254da44bf97e4d5d919a5363f476f936f3c06ccd (patch)
tree2a77e0963fee4e972b41556b54099f94c94b8cd2 /libavcodec/flacenc.c
parentabbcc68e5cefc09265d2665e507f69907cd5b8ca (diff)
downloadffmpeg-254da44bf97e4d5d919a5363f476f936f3c06ccd.tar.gz
flacenc: calculate lower sum levels in-place.
Should improve cache usage and reduces stack usage. Also reduces number of copies in case many levels have the same number of bits. Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Diffstat (limited to 'libavcodec/flacenc.c')
-rw-r--r--libavcodec/flacenc.c34
1 files changed, 19 insertions, 15 deletions
diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c
index e66ef3db5e..97867823d9 100644
--- a/libavcodec/flacenc.c
+++ b/libavcodec/flacenc.c
@@ -609,10 +609,10 @@ static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
}
-static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
- uint64_t sums[][MAX_PARTITIONS])
+static void calc_sum_top(int pmax, uint32_t *data, int n, int pred_order,
+ uint64_t sums[MAX_PARTITIONS])
{
- int i, j;
+ int i;
int parts;
uint32_t *res, *res_end;
@@ -624,17 +624,18 @@ static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
uint64_t sum = 0;
while (res < res_end)
sum += *(res++);
- sums[pmax][i] = sum;
+ sums[i] = sum;
res_end += n >> pmax;
}
- /* sums for lower levels */
- for (i = pmax - 1; i >= pmin; i--) {
- parts = (1 << i);
- for (j = 0; j < parts; j++)
- sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
- }
}
+static void calc_sum_next(int level, uint64_t sums[MAX_PARTITIONS])
+{
+ int i;
+ int parts = (1 << level);
+ for (i = 0; i < parts; i++)
+ sums[i] = sums[2*i] + sums[2*i+1];
+}
static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
int32_t *data, int n, int pred_order)
@@ -644,7 +645,7 @@ static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
int opt_porder;
RiceContext tmp_rc;
uint32_t *udata;
- uint64_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
+ uint64_t sums[MAX_PARTITIONS];
av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
@@ -656,16 +657,19 @@ static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
for (i = 0; i < n; i++)
udata[i] = (2*data[i]) ^ (data[i]>>31);
- calc_sums(pmin, pmax, udata, n, pred_order, sums);
+ calc_sum_top(pmax, udata, n, pred_order, sums);
opt_porder = pmin;
bits[pmin] = UINT32_MAX;
- for (i = pmin; i <= pmax; i++) {
- bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
- if (bits[i] <= bits[opt_porder]) {
+ for (i = pmax; ; ) {
+ bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums, n, pred_order);
+ if (bits[i] < bits[opt_porder]) {
opt_porder = i;
*rc = tmp_rc;
}
+ if (i == pmin)
+ break;
+ calc_sum_next(--i, sums);
}
av_freep(&udata);