AVOption first try

Originally committed as revision 4563 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 162 insertions, 0 deletions

diff --git a/libavcodec/opt.c b/libavcodec/opt.c
new file mode 100644
index 0000000000..4d49570930
--- /dev/null
+++ b/libavcodec/opt.c
@@ -0,0 +1,162 @@
+/*
+ * AVOptions
+ * Copyright (c) 2005 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 opt.c
+ * AVOptions
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+ 
+#include "avcodec.h"
+ 
+static double av_parse_num(const char *name, char **tail){
+    double d;
+    d= strtod(name, tail);
+    if(*tail>name && (**tail=='/' || **tail==':'))
+        d/=strtod((*tail)+1, tail);
+    return d;
+}
+
+//FIXME order them and do a bin search
+static AVOption *find_opt(void *v, const char *name){
+    AVClass *c= *(AVClass**)v; //FIXME silly way of storing AVClass
+    AVOption *o= c->option;
+    
+    for(;o && o->name; o++){
+        if(!strcmp(o->name, name))
+            return o;
+    }
+    return NULL;
+}
+
+static int av_set_number(void *obj, const char *name, double num, int den, int64_t intnum){
+    AVOption *o= find_opt(obj, name);
+    void *dst;
+    if(!o || o->offset<=0) 
+        return -1;
+    
+    if(o->max*den < num*intnum || o->min*den > num*intnum)
+        return -1;
+        
+    dst= ((uint8_t*)obj) + o->offset;
+
+    switch(o->type){
+    case FF_OPT_TYPE_INT:
+        *(int*)dst= lrintf(num/den)*intnum;
+        break;
+    case FF_OPT_TYPE_INT64:
+        *(int64_t*)dst= lrintf(num/den)*intnum;
+        break;
+    case FF_OPT_TYPE_FLOAT:
+        *(float*)dst= num*intnum/den;
+        break;
+    case FF_OPT_TYPE_DOUBLE:
+        *(double*)dst= num*intnum/den;
+        break;
+    case FF_OPT_TYPE_RATIONAL:
+        if((int)num == num)
+            *(AVRational*)dst= (AVRational){num*intnum, den};
+        else
+            *(AVRational*)dst= av_d2q(num*intnum/den, 1<<24);
+    default:
+        return -1;
+    }
+    return 0;
+}
+
+//FIXME use eval.c maybe?
+int av_set_string(void *obj, const char *name, const char *val){
+    AVOption *o= find_opt(obj, name);
+    if(!o || !val || o->offset<=0) 
+        return -1;
+    if(o->type != FF_OPT_TYPE_STRING){
+        double d=0, tmp_d;
+        for(;;){
+            int i;
+            char buf[256], *tail;
+
+            for(i=0; i<sizeof(buf)-1 && val[i] && val[i]!='+'; i++)
+                buf[i]= val[i];
+            buf[i]=0;
+            val+= i;
+            
+            tmp_d= av_parse_num(buf, &tail);
+            if(tail > buf)
+                d+= tmp_d;
+            else{
+                AVOption *o_named= find_opt(obj, buf);
+                if(o_named && o_named->type == FF_OPT_TYPE_CONST) 
+                    d+= o_named->default_val;
+                else if(!strcmp(buf, "default")) d+= o->default_val;
+                else if(!strcmp(buf, "max"    )) d+= o->max;
+                else if(!strcmp(buf, "min"    )) d+= o->min;
+                else return -1;
+            }
+
+            if(*val == '+') val++;
+            if(!*val)
+                return av_set_number(obj, name, d, 1, 1);
+        }
+        return -1;
+    }
+    
+    memcpy(((uint8_t*)obj) + o->offset, val, sizeof(val));
+    return 0;
+}
+
+int av_set_double(void *obj, const char *name, double n){
+    return av_set_number(obj, name, n, 1, 1);
+}
+
+int av_set_q(void *obj, const char *name, AVRational n){
+    return av_set_number(obj, name, n.num, n.den, 1);
+}
+
+int av_set_int(void *obj, const char *name, int64_t n){
+    return av_set_number(obj, name, 1, 1, n);
+}
+
+const char *av_get_string(void *obj, const char *name){
+    AVOption *o= find_opt(obj, name);
+    if(!o || o->offset<=0)
+        return NULL;
+    if(o->type != FF_OPT_TYPE_STRING) //FIXME convert to string? but what about free()?
+        return NULL;
+
+    return (const char*)(((uint8_t*)obj) + o->offset);
+}
+
+double av_get_double(void *obj, const char *name){
+    AVOption *o= find_opt(obj, name);
+    void *dst;
+    if(!o || o->offset<=0)
+        return NAN;
+
+    dst= ((uint8_t*)obj) + o->offset;
+
+    switch(o->type){
+    case FF_OPT_TYPE_INT:       return *(int*)dst;
+    case FF_OPT_TYPE_INT64:     return *(int64_t*)dst; //FIXME maybe write a av_get_int64() ?
+    case FF_OPT_TYPE_FLOAT:     return *(float*)dst;
+    case FF_OPT_TYPE_DOUBLE:    return *(double*)dst;
+    case FF_OPT_TYPE_RATIONAL:  return av_q2d(*(AVRational*)dst); //FIXME maybe write a av_get_q() ?
+    default:                    return NAN;
+    }
+}