videolan/ffmpeg
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optimize & simplify

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Originally committed as revision 4026 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2005-03-09 23:48:17 +00:00
parent 7c653cc988
commit 42ebf67d89
1 changed files with 18 additions and 52 deletions
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70
libavcodec/loco.c
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@ -42,30 +42,9 @@ typedef struct RICEContext{
GetBitContext gb;
int save, run, run2; /* internal rice decoder state */
int sum, count; /* sum and count for getting rice parameter */
int lossy;
}RICEContext;
/* could use get_sr_golomb() but is behaves differently on numbers like Rice(2, -64) */
static inline int get_rice(GetBitContext *gb, int K)
{
int i;
int V = 0;
for(i = 0; !get_bits1(gb); i++);
V = i;
for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
if(V & 1) return (V + 1) >> 1;
return -(V >> 1);
}
static inline int get_u_rice(GetBitContext *gb, int K)
{
int i;
int V = 0;
for(i = 0; !get_bits1(gb); i++);
V = i;
for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
return V;
}
static int loco_get_rice_param(RICEContext *r)
{
int cnt = 0;
@ -81,8 +60,6 @@ static int loco_get_rice_param(RICEContext *r)
static inline void loco_update_rice_param(RICEContext *r, int val)
{
if (val < 0)
val = -val;
r->sum += val;
r->count++;
@ -95,15 +72,16 @@ static inline void loco_update_rice_param(RICEContext *r, int val)
static inline int loco_get_rice(RICEContext *r)
{
int v;
if (r->run > 0) { /* we have zero run */
r->run--;
loco_update_rice_param(r, 0);
return 0;
}
v = -get_rice(&r->gb, loco_get_rice_param(r));
v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
loco_update_rice_param(r, (v+1)>>1);
if (!v) {
if (r->save >= 0) {
r->run = get_u_rice(&r->gb, 2);
r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
if(r->run > 1)
r->save += r->run + 1;
else
@ -111,12 +89,15 @@ static inline int loco_get_rice(RICEContext *r)
}
else
r->run2++;
} else if (r->run2 > 0) {
if (r->run2 > 2)
r->save += r->run2;
else
r->save -= 3;
r->run2 = 0;
} else {
v = ((v>>1) + r->lossy) ^ -(v&1);
if (r->run2 > 0) {
if (r->run2 > 2)
r->save += r->run2;
else
r->save -= 3;
r->run2 = 0;
}
}
return v;
@ -125,19 +106,13 @@ static inline int loco_get_rice(RICEContext *r)
/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
static inline int loco_predict(uint8_t* data, int stride, int step)
{
int max_ab, min_ab;
int a, b, c;
a = data[-stride];
b = data[-step];
c = data[-stride - step];
max_ab = (a > b) ? a : b;
min_ab = (a < b) ? a : b;
if (c >= max_ab) return min_ab;
if (c <= min_ab) return max_ab;
return (a + b - c);
return mid_pred(a, a + b - c, b);
}
static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
@ -151,38 +126,27 @@ static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int heigh
rc.save = 0;
rc.run = 0;
rc.run2 = 0;
rc.lossy = l->lossy;
rc.sum = 8;
rc.count = 1;
/* restore top left pixel */
val = loco_get_rice(&rc);
loco_update_rice_param(&rc, val);
if (val < 0) val -= l->lossy;
if (val > 0) val += l->lossy;
data[0] = 128 + val;
/* restore top line */
for (i = 1; i < width; i++) {
val = loco_get_rice(&rc);
loco_update_rice_param(&rc, val);
if (val < 0) val -= l->lossy;
if (val > 0) val += l->lossy;
data[i * step] = data[i * step - step] + val;
}
data += stride;
for (j = 1; j < height; j++) {
/* restore left column */
val = loco_get_rice(&rc);
loco_update_rice_param(&rc, val);
if (val < 0) val -= l->lossy;
if (val > 0) val += l->lossy;
data[0] = data[-stride] + val;
/* restore all other pixels */
for (i = 1; i < width; i++) {
val = loco_get_rice(&rc);
loco_update_rice_param(&rc, val);
if (val < 0) val -= l->lossy;
if (val > 0) val += l->lossy;
data[i * step] = loco_predict(&data[i * step], stride, step) + val;
}
data += stride;
@ -302,6 +266,8 @@ static int decode_init(AVCodecContext *avctx){
av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
return -1;
}
if(avctx->debug & FF_DEBUG_PICT_INFO)
av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
return 0;
}