Move AVOptions from libavcodec to libavutil

Originally committed as revision 25210 to svn://svn.ffmpeg.org/ffmpeg/trunk

4 files changed, 656 insertions, 0 deletions

diff --git a/libavutil/Makefile b/libavutil/Makefile
index 22b5452f55..f9178e87d9 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -49,6 +49,7 @@ OBJS = adler32.o                                                        \
        mathematics.o                                                    \
        md5.o                                                            \
        mem.o                                                            \
+       opt.o                                                            \
        pixdesc.o                                                        \
        random_seed.o                                                    \
        rational.o                                                       \
diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index 758b012591..88fc092977 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -78,6 +78,13 @@ enum AVMediaType {
     AVMEDIA_TYPE_NB
 };
 
+#define FF_LAMBDA_SHIFT 7
+#define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
+#define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
+#define FF_LAMBDA_MAX (256*128-1)
+
+#define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
+
 #include "common.h"
 #include "error.h"
 #include "mathematics.h"
diff --git a/libavutil/opt.c b/libavutil/opt.c
new file mode 100644
index 0000000000..ba48a904c0
--- /dev/null
+++ b/libavutil/opt.c
@@ -0,0 +1,441 @@
+/*
+ * AVOptions
+ * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * AVOptions
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "avutil.h"
+#include "opt.h"
+#include "libavutil/eval.h"
+
+//FIXME order them and do a bin search
+const AVOption *av_find_opt(void *v, const char *name, const char *unit, int mask, int flags){
+    AVClass *c= *(AVClass**)v; //FIXME silly way of storing AVClass
+    const AVOption *o= c->option;
+
+    for(;o && o->name; o++){
+        if(!strcmp(o->name, name) && (!unit || (o->unit && !strcmp(o->unit, unit))) && (o->flags & mask) == flags )
+            return o;
+    }
+    return NULL;
+}
+
+const AVOption *av_next_option(void *obj, const AVOption *last){
+    if(last && last[1].name) return ++last;
+    else if(last)            return NULL;
+    else                     return (*(AVClass**)obj)->option;
+}
+
+static int av_set_number2(void *obj, const char *name, double num, int den, int64_t intnum, const AVOption **o_out){
+    const AVOption *o= av_find_opt(obj, name, NULL, 0, 0);
+    void *dst;
+    if(o_out)
+        *o_out= o;
+    if(!o || o->offset<=0)
+        return AVERROR(ENOENT);
+
+    if(o->max*den < num*intnum || o->min*den > num*intnum) {
+        av_log(obj, AV_LOG_ERROR, "Value %lf for parameter '%s' out of range\n", num, name);
+        return AVERROR(ERANGE);
+    }
+
+    dst= ((uint8_t*)obj) + o->offset;
+
+    switch(o->type){
+    case FF_OPT_TYPE_FLAGS:
+    case FF_OPT_TYPE_INT:   *(int       *)dst= llrint(num/den)*intnum; break;
+    case FF_OPT_TYPE_INT64: *(int64_t   *)dst= llrint(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);
+        break;
+    default:
+        return AVERROR(EINVAL);
+    }
+    return 0;
+}
+
+static const AVOption *av_set_number(void *obj, const char *name, double num, int den, int64_t intnum){
+    const AVOption *o = NULL;
+    if (av_set_number2(obj, name, num, den, intnum, &o) < 0)
+        return NULL;
+    else
+        return o;
+}
+
+static const double const_values[]={
+    M_PI,
+    M_E,
+    FF_QP2LAMBDA,
+    0
+};
+
+static const char * const const_names[]={
+    "PI",
+    "E",
+    "QP2LAMBDA",
+    0
+};
+
+static int hexchar2int(char c) {
+    if (c >= '0' && c <= '9') return c - '0';
+    if (c >= 'a' && c <= 'f') return c - 'a' + 10;
+    if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+    return -1;
+}
+
+int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out){
+    int ret;
+    const AVOption *o= av_find_opt(obj, name, NULL, 0, 0);
+    if (o_out)
+        *o_out = o;
+    if(!o)
+        return AVERROR(ENOENT);
+    if(!val || o->offset<=0)
+        return AVERROR(EINVAL);
+
+    if(o->type == FF_OPT_TYPE_BINARY){
+        uint8_t **dst = (uint8_t **)(((uint8_t*)obj) + o->offset);
+        int *lendst = (int *)(dst + 1);
+        uint8_t *bin, *ptr;
+        int len = strlen(val);
+        av_freep(dst);
+        *lendst = 0;
+        if (len & 1) return AVERROR(EINVAL);
+        len /= 2;
+        ptr = bin = av_malloc(len);
+        while (*val) {
+            int a = hexchar2int(*val++);
+            int b = hexchar2int(*val++);
+            if (a < 0 || b < 0) {
+                av_free(bin);
+                return AVERROR(EINVAL);
+            }
+            *ptr++ = (a << 4) | b;
+        }
+        *dst = bin;
+        *lendst = len;
+        return 0;
+    }
+    if(o->type != FF_OPT_TYPE_STRING){
+        int notfirst=0;
+        for(;;){
+            int i;
+            char buf[256];
+            int cmd=0;
+            double d;
+
+            if(*val == '+' || *val == '-')
+                cmd= *(val++);
+
+            for(i=0; i<sizeof(buf)-1 && val[i] && val[i]!='+' && val[i]!='-'; i++)
+                buf[i]= val[i];
+            buf[i]=0;
+
+            {
+                const AVOption *o_named= av_find_opt(obj, buf, o->unit, 0, 0);
+                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 if(!strcmp(buf, "none"   )) d= 0;
+                else if(!strcmp(buf, "all"    )) d= ~0;
+                else {
+                    int res = av_parse_and_eval_expr(&d, buf, const_names, const_values, NULL, NULL, NULL, NULL, NULL, 0, obj);
+                    if (res < 0) {
+                        av_log(obj, AV_LOG_ERROR, "Unable to parse option value \"%s\"\n", val);
+                        return res;
+                    }
+                }
+            }
+            if(o->type == FF_OPT_TYPE_FLAGS){
+                if     (cmd=='+') d= av_get_int(obj, name, NULL) | (int64_t)d;
+                else if(cmd=='-') d= av_get_int(obj, name, NULL) &~(int64_t)d;
+            }else{
+                if     (cmd=='+') d= notfirst*av_get_double(obj, name, NULL) + d;
+                else if(cmd=='-') d= notfirst*av_get_double(obj, name, NULL) - d;
+            }
+
+            if ((ret = av_set_number2(obj, name, d, 1, 1, o_out)) < 0)
+                return ret;
+            val+= i;
+            if(!*val)
+                return 0;
+            notfirst=1;
+        }
+        return AVERROR(EINVAL);
+    }
+
+    if(alloc){
+        av_free(*(void**)(((uint8_t*)obj) + o->offset));
+        val= av_strdup(val);
+    }
+
+    memcpy(((uint8_t*)obj) + o->offset, &val, sizeof(val));
+    return 0;
+}
+
+const AVOption *av_set_double(void *obj, const char *name, double n){
+    return av_set_number(obj, name, n, 1, 1);
+}
+
+const AVOption *av_set_q(void *obj, const char *name, AVRational n){
+    return av_set_number(obj, name, n.num, n.den, 1);
+}
+
+const AVOption *av_set_int(void *obj, const char *name, int64_t n){
+    return av_set_number(obj, name, 1, 1, n);
+}
+
+/**
+ *
+ * @param buf a buffer which is used for returning non string values as strings, can be NULL
+ * @param buf_len allocated length in bytes of buf
+ */
+const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len){
+    const AVOption *o= av_find_opt(obj, name, NULL, 0, 0);
+    void *dst;
+    uint8_t *bin;
+    int len, i;
+    if(!o || o->offset<=0)
+        return NULL;
+    if(o->type != FF_OPT_TYPE_STRING && (!buf || !buf_len))
+        return NULL;
+
+    dst= ((uint8_t*)obj) + o->offset;
+    if(o_out) *o_out= o;
+
+    switch(o->type){
+    case FF_OPT_TYPE_FLAGS:     snprintf(buf, buf_len, "0x%08X",*(int    *)dst);break;
+    case FF_OPT_TYPE_INT:       snprintf(buf, buf_len, "%d" , *(int    *)dst);break;
+    case FF_OPT_TYPE_INT64:     snprintf(buf, buf_len, "%"PRId64, *(int64_t*)dst);break;
+    case FF_OPT_TYPE_FLOAT:     snprintf(buf, buf_len, "%f" , *(float  *)dst);break;
+    case FF_OPT_TYPE_DOUBLE:    snprintf(buf, buf_len, "%f" , *(double *)dst);break;
+    case FF_OPT_TYPE_RATIONAL:  snprintf(buf, buf_len, "%d/%d", ((AVRational*)dst)->num, ((AVRational*)dst)->den);break;
+    case FF_OPT_TYPE_STRING:    return *(void**)dst;
+    case FF_OPT_TYPE_BINARY:
+        len = *(int*)(((uint8_t *)dst) + sizeof(uint8_t *));
+        if(len >= (buf_len + 1)/2) return NULL;
+        bin = *(uint8_t**)dst;
+        for(i = 0; i < len; i++) snprintf(buf + i*2, 3, "%02X", bin[i]);
+        break;
+    default: return NULL;
+    }
+    return buf;
+}
+
+static int av_get_number(void *obj, const char *name, const AVOption **o_out, double *num, int *den, int64_t *intnum){
+    const AVOption *o= av_find_opt(obj, name, NULL, 0, 0);
+    void *dst;
+    if(!o || o->offset<=0)
+        goto error;
+
+    dst= ((uint8_t*)obj) + o->offset;
+
+    if(o_out) *o_out= o;
+
+    switch(o->type){
+    case FF_OPT_TYPE_FLAGS:     *intnum= *(unsigned int*)dst;return 0;
+    case FF_OPT_TYPE_INT:       *intnum= *(int    *)dst;return 0;
+    case FF_OPT_TYPE_INT64:     *intnum= *(int64_t*)dst;return 0;
+    case FF_OPT_TYPE_FLOAT:     *num=    *(float  *)dst;return 0;
+    case FF_OPT_TYPE_DOUBLE:    *num=    *(double *)dst;return 0;
+    case FF_OPT_TYPE_RATIONAL:  *intnum= ((AVRational*)dst)->num;
+                                *den   = ((AVRational*)dst)->den;
+                                                        return 0;
+    }
+error:
+    *den=*intnum=0;
+    return -1;
+}
+
+double av_get_double(void *obj, const char *name, const AVOption **o_out){
+    int64_t intnum=1;
+    double num=1;
+    int den=1;
+
+    av_get_number(obj, name, o_out, &num, &den, &intnum);
+    return num*intnum/den;
+}
+
+AVRational av_get_q(void *obj, const char *name, const AVOption **o_out){
+    int64_t intnum=1;
+    double num=1;
+    int den=1;
+
+    av_get_number(obj, name, o_out, &num, &den, &intnum);
+    if(num == 1.0 && (int)intnum == intnum)
+        return (AVRational){intnum, den};
+    else
+        return av_d2q(num*intnum/den, 1<<24);
+}
+
+int64_t av_get_int(void *obj, const char *name, const AVOption **o_out){
+    int64_t intnum=1;
+    double num=1;
+    int den=1;
+
+    av_get_number(obj, name, o_out, &num, &den, &intnum);
+    return num*intnum/den;
+}
+
+static void opt_list(void *obj, void *av_log_obj, const char *unit,
+                     int req_flags, int rej_flags)
+{
+    const AVOption *opt=NULL;
+
+    while((opt= av_next_option(obj, opt))){
+        if (!(opt->flags & req_flags) || (opt->flags & rej_flags))
+            continue;
+
+        /* Don't print CONST's on level one.
+         * Don't print anything but CONST's on level two.
+         * Only print items from the requested unit.
+         */
+        if (!unit && opt->type==FF_OPT_TYPE_CONST)
+            continue;
+        else if (unit && opt->type!=FF_OPT_TYPE_CONST)
+            continue;
+        else if (unit && opt->type==FF_OPT_TYPE_CONST && strcmp(unit, opt->unit))
+            continue;
+        else if (unit && opt->type == FF_OPT_TYPE_CONST)
+            av_log(av_log_obj, AV_LOG_INFO, "   %-15s ", opt->name);
+        else
+            av_log(av_log_obj, AV_LOG_INFO, "-%-17s ", opt->name);
+
+        switch( opt->type )
+        {
+            case FF_OPT_TYPE_FLAGS:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<flags>" );
+                break;
+            case FF_OPT_TYPE_INT:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<int>" );
+                break;
+            case FF_OPT_TYPE_INT64:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<int64>" );
+                break;
+            case FF_OPT_TYPE_DOUBLE:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<double>" );
+                break;
+            case FF_OPT_TYPE_FLOAT:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<float>" );
+                break;
+            case FF_OPT_TYPE_STRING:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<string>" );
+                break;
+            case FF_OPT_TYPE_RATIONAL:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<rational>" );
+                break;
+            case FF_OPT_TYPE_BINARY:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "<binary>" );
+                break;
+            case FF_OPT_TYPE_CONST:
+            default:
+                av_log( av_log_obj, AV_LOG_INFO, "%-7s ", "" );
+                break;
+        }
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_ENCODING_PARAM) ? 'E' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_DECODING_PARAM) ? 'D' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_VIDEO_PARAM   ) ? 'V' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_AUDIO_PARAM   ) ? 'A' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_SUBTITLE_PARAM) ? 'S' : '.');
+
+        if(opt->help)
+            av_log(av_log_obj, AV_LOG_INFO, " %s", opt->help);
+        av_log(av_log_obj, AV_LOG_INFO, "\n");
+        if (opt->unit && opt->type != FF_OPT_TYPE_CONST) {
+            opt_list(obj, av_log_obj, opt->unit, req_flags, rej_flags);
+        }
+    }
+}
+
+int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags)
+{
+    if(!obj)
+        return -1;
+
+    av_log(av_log_obj, AV_LOG_INFO, "%s AVOptions:\n", (*(AVClass**)obj)->class_name);
+
+    opt_list(obj, av_log_obj, NULL, req_flags, rej_flags);
+
+    return 0;
+}
+
+/** Set the values of the AVCodecContext or AVFormatContext structure.
+ * They are set to the defaults specified in the according AVOption options
+ * array default_val field.
+ *
+ * @param s AVCodecContext or AVFormatContext for which the defaults will be set
+ */
+void av_opt_set_defaults2(void *s, int mask, int flags)
+{
+    const AVOption *opt = NULL;
+    while ((opt = av_next_option(s, opt)) != NULL) {
+        if((opt->flags & mask) != flags)
+            continue;
+        switch(opt->type) {
+            case FF_OPT_TYPE_CONST:
+                /* Nothing to be done here */
+            break;
+            case FF_OPT_TYPE_FLAGS:
+            case FF_OPT_TYPE_INT: {
+                int val;
+                val = opt->default_val;
+                av_set_int(s, opt->name, val);
+            }
+            break;
+            case FF_OPT_TYPE_INT64:
+                if((double)(opt->default_val+0.6) == opt->default_val)
+                    av_log(s, AV_LOG_DEBUG, "loss of precision in default of %s\n", opt->name);
+                av_set_int(s, opt->name, opt->default_val);
+            break;
+            case FF_OPT_TYPE_FLOAT: {
+                double val;
+                val = opt->default_val;
+                av_set_double(s, opt->name, val);
+            }
+            break;
+            case FF_OPT_TYPE_RATIONAL: {
+                AVRational val;
+                val = av_d2q(opt->default_val, INT_MAX);
+                av_set_q(s, opt->name, val);
+            }
+            break;
+            case FF_OPT_TYPE_STRING:
+            case FF_OPT_TYPE_BINARY:
+                /* Cannot set default for string as default_val is of type * double */
+            break;
+            default:
+                av_log(s, AV_LOG_DEBUG, "AVOption type %d of option %s not implemented yet\n", opt->type, opt->name);
+        }
+    }
+}
+
+void av_opt_set_defaults(void *s){
+    av_opt_set_defaults2(s, 0, 0);
+}
+
diff --git a/libavutil/opt.h b/libavutil/opt.h
new file mode 100644
index 0000000000..1006ab6e54
--- /dev/null
+++ b/libavutil/opt.h
@@ -0,0 +1,207 @@
+/*
+ * AVOptions
+ * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_OPT_H
+#define AVUTIL_OPT_H
+
+/**
+ * @file
+ * AVOptions
+ */
+
+#include "rational.h"
+#include "avutil.h"
+
+enum AVOptionType{
+    FF_OPT_TYPE_FLAGS,
+    FF_OPT_TYPE_INT,
+    FF_OPT_TYPE_INT64,
+    FF_OPT_TYPE_DOUBLE,
+    FF_OPT_TYPE_FLOAT,
+    FF_OPT_TYPE_STRING,
+    FF_OPT_TYPE_RATIONAL,
+    FF_OPT_TYPE_BINARY,  ///< offset must point to a pointer immediately followed by an int for the length
+    FF_OPT_TYPE_CONST=128,
+};
+
+/**
+ * AVOption
+ */
+typedef struct AVOption {
+    const char *name;
+
+    /**
+     * short English help text
+     * @todo What about other languages?
+     */
+    const char *help;
+
+    /**
+     * The offset relative to the context structure where the option
+     * value is stored. It should be 0 for named constants.
+     */
+    int offset;
+    enum AVOptionType type;
+
+    /**
+     * the default value for scalar options
+     */
+    double default_val;
+    double min;                 ///< minimum valid value for the option
+    double max;                 ///< maximum valid value for the option
+
+    int flags;
+#define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
+#define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
+#define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
+#define AV_OPT_FLAG_AUDIO_PARAM     8
+#define AV_OPT_FLAG_VIDEO_PARAM     16
+#define AV_OPT_FLAG_SUBTITLE_PARAM  32
+//FIXME think about enc-audio, ... style flags
+
+    /**
+     * The logical unit to which the option belongs. Non-constant
+     * options and corresponding named constants share the same
+     * unit. May be NULL.
+     */
+    const char *unit;
+} AVOption;
+
+/**
+ * AVOption2.
+ * THIS IS NOT PART OF THE API/ABI YET!
+ * This is identical to AVOption except that default_val was replaced by
+ * an union, it should be compatible with AVOption on normal platforms.
+ */
+typedef struct AVOption2 {
+    const char *name;
+
+    /**
+     * short English help text
+     * @todo What about other languages?
+     */
+    const char *help;
+
+    /**
+     * The offset relative to the context structure where the option
+     * value is stored. It should be 0 for named constants.
+     */
+    int offset;
+    enum AVOptionType type;
+
+    /**
+     * the default value for scalar options
+     */
+    union {
+        double dbl;
+        const char *str;
+    } default_val;
+
+    double min;                 ///< minimum valid value for the option
+    double max;                 ///< maximum valid value for the option
+
+    int flags;
+/*
+#define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
+#define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
+#define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
+#define AV_OPT_FLAG_AUDIO_PARAM     8
+#define AV_OPT_FLAG_VIDEO_PARAM     16
+#define AV_OPT_FLAG_SUBTITLE_PARAM  32
+*/
+//FIXME think about enc-audio, ... style flags
+
+    /**
+     * The logical unit to which the option belongs. Non-constant
+     * options and corresponding named constants share the same
+     * unit. May be NULL.
+     */
+    const char *unit;
+} AVOption2;
+
+
+/**
+ * Look for an option in obj. Look only for the options which
+ * have the flags set as specified in mask and flags (that is,
+ * for which it is the case that opt->flags & mask == flags).
+ *
+ * @param[in] obj a pointer to a struct whose first element is a
+ * pointer to an AVClass
+ * @param[in] name the name of the option to look for
+ * @param[in] unit the unit of the option to look for, or any if NULL
+ * @return a pointer to the option found, or NULL if no option
+ * has been found
+ */
+const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
+
+/**
+ * Set the field of obj with the given name to value.
+ *
+ * @param[in] obj A struct whose first element is a pointer to an
+ * AVClass.
+ * @param[in] name the name of the field to set
+ * @param[in] val The value to set. If the field is not of a string
+ * type, then the given string is parsed.
+ * SI postfixes and some named scalars are supported.
+ * If the field is of a numeric type, it has to be a numeric or named
+ * scalar. Behavior with more than one scalar and +- infix operators
+ * is undefined.
+ * If the field is of a flags type, it has to be a sequence of numeric
+ * scalars or named flags separated by '+' or '-'. Prefixing a flag
+ * with '+' causes it to be set without affecting the other flags;
+ * similarly, '-' unsets a flag.
+ * @param[out] o_out if non-NULL put here a pointer to the AVOption
+ * found
+ * @param alloc when 1 then the old value will be av_freed() and the
+ *                     new av_strduped()
+ *              when 0 then no av_free() nor av_strdup() will be used
+ * @return 0 if the value has been set, or an AVERROR code in case of
+ * error:
+ * AVERROR(ENOENT) if no matching option exists
+ * AVERROR(ERANGE) if the value is out of range
+ * AVERROR(EINVAL) if the value is not valid
+ */
+int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
+
+const AVOption *av_set_double(void *obj, const char *name, double n);
+const AVOption *av_set_q(void *obj, const char *name, AVRational n);
+const AVOption *av_set_int(void *obj, const char *name, int64_t n);
+double av_get_double(void *obj, const char *name, const AVOption **o_out);
+AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
+int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
+const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
+const AVOption *av_next_option(void *obj, const AVOption *last);
+
+/**
+ * Show the obj options.
+ *
+ * @param req_flags requested flags for the options to show. Show only the
+ * options for which it is opt->flags & req_flags.
+ * @param rej_flags rejected flags for the options to show. Show only the
+ * options for which it is !(opt->flags & req_flags).
+ * @param av_log_obj log context to use for showing the options
+ */
+int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
+
+void av_opt_set_defaults(void *s);
+void av_opt_set_defaults2(void *s, int mask, int flags);
+
+#endif /* AVUTIL_OPT_H */