--- /dev/null
+/* putvlc.c, generation of variable length codes */
+
+/* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */
+
+/*
+ * Disclaimer of Warranty
+ *
+ * These software programs are available to the user without any license fee or
+ * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims
+ * any and all warranties, whether express, implied, or statuary, including any
+ * implied warranties or merchantability or of fitness for a particular
+ * purpose. In no event shall the copyright-holder be liable for any
+ * incidental, punitive, or consequential damages of any kind whatsoever
+ * arising from the use of these programs.
+ *
+ * This disclaimer of warranty extends to the user of these programs and user's
+ * customers, employees, agents, transferees, successors, and assigns.
+ *
+ * The MPEG Software Simulation Group does not represent or warrant that the
+ * programs furnished hereunder are free of infringement of any third-party
+ * patents.
+ *
+ * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware,
+ * are subject to royalty fees to patent holders. Many of these patents are
+ * general enough such that they are unavoidable regardless of implementation
+ * design.
+ *
+ */
+
+#include <stdio.h>
+
+#include "config.h"
+#include "global.h"
+#include "vlc.h"
+
+/* generate variable length code for DC coefficient (7.2.1) */
+static void putDC(slice_engine_t *engine, sVLCtable *tab, int val)
+{
+ int absval, size;
+
+ absval = (val < 0) ? -val : val;
+
+ if(absval > dctsatlim)
+ {
+/* should never happen */
+ sprintf(errortext,"DC value out of range (%d)\n",val);
+ error(errortext);
+ }
+
+/* compute dct_dc_size */
+ size = 0;
+
+ while(absval)
+ {
+ absval >>= 1;
+ size++;
+ }
+
+//printf("putDC %x %d %d\n", tab[size].code, tab[size].len, size);
+//slice_testbits(engine);
+/* generate VLC for dct_dc_size (Table B-12 or B-13) */
+ slice_putbits(engine, tab[size].code, tab[size].len);
+//slice_testbits(engine);
+
+/* append fixed length code (dc_dct_differential) */
+ if(size != 0)
+ {
+ if(val >= 0)
+ absval = val;
+ else
+ absval = val + (1 << size) - 1;
+ slice_putbits(engine, absval, size);
+ }
+//slice_testbits(engine);
+}
+
+/* generate variable length code for luminance DC coefficient */
+void putDClum(slice_engine_t *engine, int val)
+{
+ putDC(engine, DClumtab, val);
+}
+
+/* generate variable length code for chrominance DC coefficient */
+void putDCchrom(slice_engine_t *engine, int val)
+{
+ putDC(engine, DCchromtab, val);
+}
+
+/* generate variable length code for other DCT coefficients (7.2.2) */
+void putAC(slice_engine_t *engine, int run, int signed_level, int vlcformat)
+{
+ int level, len;
+ VLCtable *ptab;
+
+ level = (signed_level < 0) ? -signed_level : signed_level; /* abs(signed_level) */
+
+/* make sure run and level are valid */
+ if(run < 0 || run > 63 || level == 0 || level > dctsatlim)
+ {
+ sprintf(errortext,"AC value out of range (run=%d, signed_level=%d)\n",
+ run,signed_level);
+ error(errortext);
+ }
+
+ len = 0;
+
+ if(run < 2 && level < 41)
+ {
+/* vlcformat selects either of Table B-14 / B-15 */
+ if(vlcformat)
+ ptab = &dct_code_tab1a[run][level - 1];
+ else
+ ptab = &dct_code_tab1[run][level - 1];
+
+ len = ptab->len;
+ }
+ else
+ if(run < 32 && level < 6)
+ {
+/* vlcformat selects either of Table B-14 / B-15 */
+ if(vlcformat)
+ ptab = &dct_code_tab2a[run - 2][level - 1];
+ else
+ ptab = &dct_code_tab2[run - 2][level - 1];
+
+ len = ptab->len;
+ }
+
+ if(len != 0) /* a VLC code exists */
+ {
+ slice_putbits(engine, ptab->code, len);
+ slice_putbits(engine, signed_level < 0, 1); /* sign */
+ }
+ else
+ {
+/* no VLC for this (run, level) combination: use escape coding (7.2.2.3) */
+ slice_putbits(engine, 1l, 6); /* Escape */
+ slice_putbits(engine, run, 6); /* 6 bit code for run */
+ if(mpeg1)
+ {
+/* ISO/IEC 11172-2 uses a 8 or 16 bit code */
+ if (signed_level > 127)
+ slice_putbits(engine, 0, 8);
+ if (signed_level < -127)
+ slice_putbits(engine, 128, 8);
+ slice_putbits(engine, signed_level, 8);
+ }
+ else
+ {
+/* ISO/IEC 13818-2 uses a 12 bit code, Table B-16 */
+ slice_putbits(engine, signed_level, 12);
+ }
+ }
+}
+
+/* generate variable length code for first coefficient
+ * of a non-intra block (7.2.2.2) */
+void putACfirst(slice_engine_t *engine, int run, int val)
+{
+ if(run == 0 && (val == 1 || val == -1)) /* these are treated differently */
+ slice_putbits(engine, 2 | (val < 0), 2); /* generate '1s' (s=sign), (Table B-14, line 2) */
+ else
+ putAC(engine, run, val, 0); /* no difference for all others */
+}
+
+/* generate variable length code for macroblock_address_increment (6.3.16) */
+void putaddrinc(slice_engine_t *engine, int addrinc)
+{
+ while(addrinc > 33)
+ {
+ slice_putbits(engine, 0x08, 11); /* macroblock_escape */
+ addrinc -= 33;
+ }
+
+//printf("putaddrinc %d %d\n", addrinctab[addrinc - 1].code, addrinctab[addrinc - 1].len);
+//sleep(1);
+ slice_putbits(engine,
+ addrinctab[addrinc - 1].code,
+ addrinctab[addrinc - 1].len);
+}
+
+/* generate variable length code for macroblock_type (6.3.16.1) */
+void putmbtype(slice_engine_t *engine, int pict_type, int mb_type)
+{
+ slice_putbits(engine,
+ mbtypetab[pict_type - 1][mb_type].code,
+ mbtypetab[pict_type - 1][mb_type].len);
+}
+
+/* generate variable length code for motion_code (6.3.16.3) */
+void putmotioncode(slice_engine_t *engine, int motion_code)
+{
+ int abscode;
+
+ abscode = (motion_code >= 0) ? motion_code : -motion_code; /* abs(motion_code) */
+ slice_putbits(engine,
+ motionvectab[abscode].code,
+ motionvectab[abscode].len);
+ if(motion_code!=0)
+ slice_putbits(engine,
+ motion_code < 0,
+ 1); /* sign, 0=positive, 1=negative */
+}
+
+/* generate variable length code for dmvector[t] (6.3.16.3), Table B-11 */
+void putdmv(slice_engine_t *engine, int dmv)
+{
+ if(dmv == 0)
+ slice_putbits(engine, 0, 1);
+ else if (dmv>0)
+ slice_putbits(engine, 2, 2);
+ else
+ slice_putbits(engine, 3, 2);
+}
+
+/* generate variable length code for coded_block_pattern (6.3.16.4)
+ *
+ * 4:2:2, 4:4:4 not implemented
+ */
+void putcbp(slice_engine_t *engine, int cbp)
+{
+ slice_putbits(engine, cbptable[cbp].code, cbptable[cbp].len);
+}
projects / goodguy / history.git / blobdiff