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authorMichael Niedermayer2003-04-04 14:42:28 +0000
committerMichael Niedermayer2003-04-04 14:42:28 +0000
commit0da71265d84b587c7159cd82708ca60ad050dd4c (patch)
treefc97766fbbea1ab3af9df1aa9e4f37f8b0aca02d /libavcodec/golomb.h
parent6aafe463e5d1483b95ad259334c45d2741c92fb2 (diff)
H264 decoder & demuxer
Originally committed as revision 1732 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/golomb.h')
-rw-r--r--libavcodec/golomb.h215
1 files changed, 215 insertions, 0 deletions
diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
new file mode 100644
index 0000000000..552c01730e
--- /dev/null
+++ b/libavcodec/golomb.h
@@ -0,0 +1,215 @@
+/*
+ * exp golomb vlc stuff
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file golomb.h
+ * @brief
+ * exp golomb vlc stuff
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+extern const uint8_t ff_golomb_vlc_len[512];
+extern const uint8_t ff_ue_golomb_vlc_code[512];
+extern const int8_t ff_se_golomb_vlc_code[512];
+extern const uint8_t ff_ue_golomb_len[256];
+
+
+ /**
+ * read unsigned exp golomb code.
+ */
+static inline int get_ue_golomb(GetBitContext *gb){
+ unsigned int buf;
+ int log;
+
+ OPEN_READER(re, gb);
+ UPDATE_CACHE(re, gb);
+ buf=GET_CACHE(re, gb);
+
+ if(buf >= (1<<27)){
+ buf >>= 32 - 9;
+ LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
+ CLOSE_READER(re, gb);
+
+ return ff_ue_golomb_vlc_code[buf];
+ }else{
+ log= 2*av_log2(buf) - 31;
+ buf>>= log;
+ buf--;
+ LAST_SKIP_BITS(re, gb, 32 - log);
+ CLOSE_READER(re, gb);
+
+ return buf;
+ }
+}
+
+/**
+ * read unsigned truncated exp golomb code.
+ */
+static inline int get_te0_golomb(GetBitContext *gb, int range){
+ assert(range >= 1);
+
+ if(range==1) return 0;
+ else if(range==2) return get_bits1(gb);
+ else return get_ue_golomb(gb);
+}
+
+/**
+ * read unsigned truncated exp golomb code.
+ */
+static inline int get_te_golomb(GetBitContext *gb, int range){
+ assert(range >= 1);
+
+ if(range==2) return get_bits1(gb);
+ else return get_ue_golomb(gb);
+}
+
+
+/**
+ * read signed exp golomb code.
+ */
+static inline int get_se_golomb(GetBitContext *gb){
+ unsigned int buf;
+ int log;
+
+ OPEN_READER(re, gb);
+ UPDATE_CACHE(re, gb);
+ buf=GET_CACHE(re, gb);
+
+ if(buf >= (1<<27)){
+ buf >>= 32 - 9;
+ LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
+ CLOSE_READER(re, gb);
+
+ return ff_se_golomb_vlc_code[buf];
+ }else{
+ log= 2*av_log2(buf) - 31;
+ buf>>= log;
+
+ LAST_SKIP_BITS(re, gb, 32 - log);
+ CLOSE_READER(re, gb);
+
+ if(buf&1) buf= -(buf>>1);
+ else buf= (buf>>1);
+
+ return buf;
+ }
+}
+
+#ifdef TRACE
+
+static inline int get_ue(GetBitContext *s, char *file, char *func, int line){
+ int show= show_bits(s, 24);
+ int pos= get_bits_count(s);
+ int i= get_ue_golomb(s);
+ int len= get_bits_count(s) - pos;
+ int bits= show>>(24-len);
+
+ print_bin(bits, len);
+
+ printf("%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
+
+ return i;
+}
+
+static inline int get_se(GetBitContext *s, char *file, char *func, int line){
+ int show= show_bits(s, 24);
+ int pos= get_bits_count(s);
+ int i= get_se_golomb(s);
+ int len= get_bits_count(s) - pos;
+ int bits= show>>(24-len);
+
+ print_bin(bits, len);
+
+ printf("%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
+
+ return i;
+}
+
+static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){
+ int show= show_bits(s, 24);
+ int pos= get_bits_count(s);
+ int i= get_te0_golomb(s, r);
+ int len= get_bits_count(s) - pos;
+ int bits= show>>(24-len);
+
+ print_bin(bits, len);
+
+ printf("%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
+
+ return i;
+}
+
+#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+
+#endif
+
+/**
+ * write unsigned exp golomb code.
+ */
+static inline void set_ue_golomb(PutBitContext *pb, int i){
+ int e;
+
+ assert(i>=0);
+
+#if 0
+ if(i=0){
+ put_bits(pb, 1, 1);
+ return;
+ }
+#endif
+ if(i<256)
+ put_bits(pb, ff_ue_golomb_len[i], i+1);
+ else{
+ e= av_log2(i+1);
+
+ put_bits(pb, 2*e+1, i+1);
+ }
+}
+
+/**
+ * write truncated unsigned exp golomb code.
+ */
+static inline void set_te_golomb(PutBitContext *pb, int i, int range){
+ assert(range >= 1);
+ assert(i<=range);
+
+ if(range==2) put_bits(pb, 1, i);
+ else set_ue_golomb(pb, i);
+}
+
+/**
+ * write signed exp golomb code.
+ */
+static inline void set_se_golomb(PutBitContext *pb, int i){
+#if 0
+ if(i<=0) i= -2*i;
+ else i= 2*i-1;
+#elif 1
+ i= 2*i-1;
+ if(i<0) i^= -1; //FIXME check if gcc does the right thing
+#else
+ i= 2*i-1;
+ i^= (i>>31);
+#endif
+ set_ue_golomb(pb, i);
+}