Changeset 147 for libmpc/branches/r2d/libmpcenc/bitstream.c

Timestamp:

11/20/06 19:53:36 (17 years ago)

Author:

r2d

Message:

• added a first version of the seek table for sv8

File:

• libmpc/branches/r2d/libmpcenc/bitstream.c (modified) (2 diffs)

libmpc/branches/r2d/libmpcenc/bitstream.c

@@ -70 +70 @@
 }
 
+static void encodeGolomb(mpc_encoder_t * e, mpc_uint32_t nb, mpc_uint_t k)
+{
+        unsigned int l = (nb >> k) + 1;
+        nb &= (1 << k) - 1;
+
+        while( l > 32 ){
+                writeBits(e, 0, 32);
+                l -= 32;
+        }
+        writeBits(e, 1, l);
+        writeBits(e, nb, k);
+}
+
 void writeMagic(mpc_encoder_t * e)
 {
@@ -121 +134 @@
 }
 
+void writeSeekTable (mpc_encoder_t * e)
+{
+        mpc_uint32_t tmp1, tmp2, i, len;
+        mpc_uint32_t * table = e->seek_table;
+        mpc_uint8_t tmp[10];
+
+        // write the position to header
+        tmp1 = ftell(e->outputFile); // get the seek table position
+        tmp[0] = (mpc_uint8_t) (tmp1 >> 24);
+        tmp[1] = (mpc_uint8_t) (tmp1 >> 16);
+        tmp[2] = (mpc_uint8_t) (tmp1 >> 8);
+        tmp[3] = (mpc_uint8_t) tmp1;
+        fseek(e->outputFile, e->seek_ref + 3, SEEK_SET);
+        fwrite(tmp, sizeof(mpc_uint8_t), 4, e->outputFile);
+        fseek(e->outputFile, tmp1, SEEK_SET);
+
+        tmp1 = table[0];
+        tmp2 = table[1];
+
+        len = encodeSize(tmp1 - e->seek_ref, tmp, MPC_FALSE);
+        for( i = 0; i < len; i++)
+                writeBits ( e, tmp[i], 8 );
+        len = encodeSize(tmp2 - e->seek_ref, tmp, MPC_FALSE);
+        for( i = 0; i < len; i++)
+                writeBits ( e, tmp[i], 8 );
+
+        for( i = 2; i < e->seek_pos; i++){
+                int code = table[i] - 2 * tmp2 + tmp1;
+                tmp1 = tmp2;
+                tmp2 = table[i];
+                if (code >= 0) {
+                        writeBits(e, 0, 1);
+                        encodeGolomb(e, code, 10);
+                } else {
+                        writeBits(e, 1, 1);
+                        encodeGolomb(e, -code, 10);
+                }
+        }
+}
+
 /* end of bitstream.c */