virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
Code Issues Releases Activity

Implement revert_inter_ch_decorr() and revert_acfilter()

Browse Source
This commit is contained in:
Mashiat Sarker Shakkhar 2011-12-23 13:17:28 +06:00
parent 10406b95ad
commit 7409210647
1 changed files with 35 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
libavcodec/wmalosslessdec.c
View File

@ -232,6 +232,7 @@ typedef struct WmallDecodeCtx {
int8_t acfilter_order;
int8_t acfilter_scaling;
int acfilter_coeffs[16];
int acfilter_prevvalues[16];
int8_t mclms_order;
int8_t mclms_scaling;
@ -1006,7 +1007,41 @@ static void revert_cdlms(WmallDecodeCtx *s, int ch, int coef_begin, int coef_end
}
}
static void revert_inter_ch_decorr(WmallDecodeCtx *s, int tile_size)
{
int icoef;
if (s->num_channels != 2)
return;
else {
for (icoef = 0; icoef < tile_size; icoef++) {
s->channel_residues[0][icoef] -= s->channel_residues[1][icoef] >> 1;
s->channel_residues[1][icoef] += s->channel_residues[0][icoef];
}
}
}
static void revert_acfilter(WmallDecodeCtx *s, int tile_size)
{
int ich, icoef;
int pred = 0, itap;
int **ch_coeffs = s->channel_residues;
int *filter_coeffs = s->acfilter_coeffs;
int *prevvalues = s->acfilter_prevvalues;
int scaling = s->acfilter_scaling;
int order = s->acfilter_order;
for (ich = 0; ich < s->num_channels; ich++) {
for (icoef = 0; icoef < tile_size; icoef++) {
for (itap = 0; itap < order; itap++)
pred += filter_coeffs[itap] * prevvalues[itap];
pred >>= scaling;
ch_coeffs[ich][icoef] += pred;
for (itap = 1; itap < order; itap++)
prevvalues[itap] = prevvalues[itap - 1];
prevvalues[0] = ch_coeffs[ich][icoef];
}
}
}
/**
*@brief Decode a single subframe (block).