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authorDavid Conrad <lessen42@gmail.com>2010-06-22 19:24:09 +0000
committerRonald S. Bultje <rsbultje@gmail.com>2010-06-22 19:24:09 +0000
commit3b636f21daa6996e20ef97131a1c3649c3043304 (patch)
tree8321dd9f0db957b5b61a6cb397693d3102108146 /libavcodec/vp56.h
parentc6ef6e14cfc472b8077f2d0805c092aeebc1c0f2 (diff)
downloadffmpeg-3b636f21daa6996e20ef97131a1c3649c3043304.tar.gz
Native VP8 decoder.
Patch by David Conrad <lessen42 gmail com> and myself. Originally committed as revision 23719 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/vp56.h')
-rw-r--r--libavcodec/vp56.h75
1 files changed, 75 insertions, 0 deletions
diff --git a/libavcodec/vp56.h b/libavcodec/vp56.h
index 0b6f2a870c..4eb414bbbe 100644
--- a/libavcodec/vp56.h
+++ b/libavcodec/vp56.h
@@ -237,6 +237,12 @@ static inline int vp56_rac_get(VP56RangeCoder *c)
return bit;
}
+// rounding is different than vp56_rac_get, is vp56_rac_get wrong?
+static inline int vp8_rac_get(VP56RangeCoder *c)
+{
+ return vp56_rac_get_prob(c, 128);
+}
+
static inline int vp56_rac_gets(VP56RangeCoder *c, int bits)
{
int value = 0;
@@ -248,12 +254,46 @@ static inline int vp56_rac_gets(VP56RangeCoder *c, int bits)
return value;
}
+static inline int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
+{
+ int value = 0;
+
+ while (bits--) {
+ value = (value << 1) | vp8_rac_get(c);
+ }
+
+ return value;
+}
+
+// fixme: add 1 bit to all the calls to this?
+static inline int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
+{
+ int v;
+
+ if (!vp8_rac_get(c))
+ return 0;
+
+ v = vp8_rac_get_uint(c, bits);
+
+ if (vp8_rac_get(c))
+ v = -v;
+
+ return v;
+}
+
+// P(7)
static inline int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
{
int v = vp56_rac_gets(c, 7) << 1;
return v + !v;
}
+static inline int vp8_rac_get_nn(VP56RangeCoder *c)
+{
+ int v = vp8_rac_get_uint(c, 7) << 1;
+ return v + !v;
+}
+
static inline int vp56_rac_get_tree(VP56RangeCoder *c,
const VP56Tree *tree,
const uint8_t *probs)
@@ -267,4 +307,39 @@ static inline int vp56_rac_get_tree(VP56RangeCoder *c,
return -tree->val;
}
+/**
+ * This is identical to vp8_rac_get_tree except for the possibility of starting
+ * on a node other than the root node, needed for coeff decode where this is
+ * used to save a bit after a 0 token (by disallowing EOB to immediately follow.)
+ */
+static inline int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
+ const uint8_t *probs, int i)
+{
+ do {
+ i = tree[i][vp56_rac_get_prob(c, probs[i])];
+ } while (i > 0);
+
+ return -i;
+}
+
+// how probabilities are associated with decisions is different I think
+// well, the new scheme fits in the old but this way has one fewer branches per decision
+static inline int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
+ const uint8_t *probs)
+{
+ return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
+}
+
+// DCTextra
+static inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
+{
+ int v = 0;
+
+ do {
+ v = (v<<1) + vp56_rac_get_prob(c, *prob++);
+ } while (*prob);
+
+ return v;
+}
+
#endif /* AVCODEC_VP56_H */