Add m-esr52 at 52.6.0

1 files changed, 847 insertions, 0 deletions

diff --git a/media/libav/libavutil/opt.c b/media/libav/libavutil/opt.c
new file mode 100644
index 000000000..059c525c3
--- /dev/null
+++ b/media/libav/libavutil/opt.c
@@ -0,0 +1,847 @@
+/*
+ * AVOptions
+ * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 "avstring.h"
+#include "common.h"
+#include "opt.h"
+#include "eval.h"
+#include "dict.h"
+#include "log.h"
+#include "mathematics.h"
+
+const AVOption *av_opt_next(void *obj, const AVOption *last)
+{
+    AVClass *class = *(AVClass**)obj;
+    if (!last && class->option && class->option[0].name)
+        return class->option;
+    if (last && last[1].name)
+        return ++last;
+    return NULL;
+}
+
+static int read_number(const AVOption *o, void *dst, double *num, int *den, int64_t *intnum)
+{
+    switch (o->type) {
+    case AV_OPT_TYPE_FLAGS:     *intnum = *(unsigned int*)dst;return 0;
+    case AV_OPT_TYPE_INT:       *intnum = *(int         *)dst;return 0;
+    case AV_OPT_TYPE_INT64:     *intnum = *(int64_t     *)dst;return 0;
+    case AV_OPT_TYPE_FLOAT:     *num    = *(float       *)dst;return 0;
+    case AV_OPT_TYPE_DOUBLE:    *num    = *(double      *)dst;return 0;
+    case AV_OPT_TYPE_RATIONAL:  *intnum = ((AVRational*)dst)->num;
+                                *den    = ((AVRational*)dst)->den;
+                                                        return 0;
+    }
+    return AVERROR(EINVAL);
+}
+
+static int write_number(void *obj, const AVOption *o, void *dst, double num, int den, int64_t intnum)
+{
+    if (o->type != AV_OPT_TYPE_FLAGS &&
+        (o->max * den < num * intnum || o->min * den > num * intnum)) {
+        av_log(obj, AV_LOG_ERROR, "Value %f for parameter '%s' out of range\n",
+               num*intnum/den, o->name);
+        return AVERROR(ERANGE);
+    }
+
+    switch (o->type) {
+    case AV_OPT_TYPE_FLAGS:
+    case AV_OPT_TYPE_INT:   *(int       *)dst= llrint(num/den)*intnum; break;
+    case AV_OPT_TYPE_INT64: *(int64_t   *)dst= llrint(num/den)*intnum; break;
+    case AV_OPT_TYPE_FLOAT: *(float     *)dst= num*intnum/den;         break;
+    case AV_OPT_TYPE_DOUBLE:*(double    *)dst= num*intnum/den;         break;
+    case AV_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 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;
+}
+
+static int set_string_binary(void *obj, const AVOption *o, const char *val, uint8_t **dst)
+{
+    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);
+    if (!ptr)
+        return AVERROR(ENOMEM);
+    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;
+}
+
+static int set_string(void *obj, const AVOption *o, const char *val, uint8_t **dst)
+{
+    av_freep(dst);
+    *dst = av_strdup(val);
+    return 0;
+}
+
+#define DEFAULT_NUMVAL(opt) ((opt->type == AV_OPT_TYPE_INT64 || \
+                              opt->type == AV_OPT_TYPE_CONST || \
+                              opt->type == AV_OPT_TYPE_FLAGS || \
+                              opt->type == AV_OPT_TYPE_INT) ? \
+                             opt->default_val.i64 : opt->default_val.dbl)
+
+static int set_string_number(void *obj, void *target_obj, const AVOption *o, const char *val, void *dst)
+{
+    int ret = 0, notfirst = 0;
+    for (;;) {
+        int i, den = 1;
+        char buf[256];
+        int cmd = 0;
+        double d, num = 1;
+        int64_t intnum = 1;
+
+        i = 0;
+        if (*val == '+' || *val == '-') {
+            if (o->type == AV_OPT_TYPE_FLAGS)
+                cmd = *(val++);
+            else if (!notfirst)
+                buf[i++] = *val;
+        }
+
+        for (; i < sizeof(buf) - 1 && val[i] && val[i] != '+' && val[i] != '-'; i++)
+            buf[i] = val[i];
+        buf[i] = 0;
+
+        {
+            const AVOption *o_named = av_opt_find(target_obj, buf, o->unit, 0, 0);
+            if (o_named && o_named->type == AV_OPT_TYPE_CONST)
+                d = DEFAULT_NUMVAL(o_named);
+            else if (!strcmp(buf, "default")) d = DEFAULT_NUMVAL(o);
+            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_expr_parse_and_eval(&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 == AV_OPT_TYPE_FLAGS) {
+            read_number(o, dst, NULL, NULL, &intnum);
+            if      (cmd == '+') d = intnum | (int64_t)d;
+            else if (cmd == '-') d = intnum &~(int64_t)d;
+        } else {
+            read_number(o, dst, &num, &den, &intnum);
+            if      (cmd == '+') d = notfirst*num*intnum/den + d;
+            else if (cmd == '-') d = notfirst*num*intnum/den - d;
+        }
+
+        if ((ret = write_number(obj, o, dst, d, 1, 1)) < 0)
+            return ret;
+        val += i;
+        if (!*val)
+            return 0;
+        notfirst = 1;
+    }
+
+    return 0;
+}
+
+int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
+{
+    void *dst, *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+    if (!val || o->flags & AV_OPT_FLAG_READONLY)
+        return AVERROR(EINVAL);
+
+    dst = ((uint8_t*)target_obj) + o->offset;
+    switch (o->type) {
+    case AV_OPT_TYPE_STRING:   return set_string(obj, o, val, dst);
+    case AV_OPT_TYPE_BINARY:   return set_string_binary(obj, o, val, dst);
+    case AV_OPT_TYPE_FLAGS:
+    case AV_OPT_TYPE_INT:
+    case AV_OPT_TYPE_INT64:
+    case AV_OPT_TYPE_FLOAT:
+    case AV_OPT_TYPE_DOUBLE:
+    case AV_OPT_TYPE_RATIONAL: return set_string_number(obj, target_obj, o, val, dst);
+    }
+
+    av_log(obj, AV_LOG_ERROR, "Invalid option type.\n");
+    return AVERROR(EINVAL);
+}
+
+#define OPT_EVAL_NUMBER(name, opttype, vartype)\
+    int av_opt_eval_ ## name(void *obj, const AVOption *o, const char *val, vartype *name ## _out)\
+    {\
+        if (!o || o->type != opttype || o->flags & AV_OPT_FLAG_READONLY)\
+            return AVERROR(EINVAL);\
+        return set_string_number(obj, obj, o, val, name ## _out);\
+    }
+
+OPT_EVAL_NUMBER(flags,  AV_OPT_TYPE_FLAGS,    int)
+OPT_EVAL_NUMBER(int,    AV_OPT_TYPE_INT,      int)
+OPT_EVAL_NUMBER(int64,  AV_OPT_TYPE_INT64,    int64_t)
+OPT_EVAL_NUMBER(float,  AV_OPT_TYPE_FLOAT,    float)
+OPT_EVAL_NUMBER(double, AV_OPT_TYPE_DOUBLE,   double)
+OPT_EVAL_NUMBER(q,      AV_OPT_TYPE_RATIONAL, AVRational)
+
+static int set_number(void *obj, const char *name, double num, int den, int64_t intnum,
+                                  int search_flags)
+{
+    void *dst, *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+
+    if (o->flags & AV_OPT_FLAG_READONLY)
+        return AVERROR(EINVAL);
+
+    dst = ((uint8_t*)target_obj) + o->offset;
+    return write_number(obj, o, dst, num, den, intnum);
+}
+
+int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
+{
+    return set_number(obj, name, 1, 1, val, search_flags);
+}
+
+int av_opt_set_double(void *obj, const char *name, double val, int search_flags)
+{
+    return set_number(obj, name, val, 1, 1, search_flags);
+}
+
+int av_opt_set_q(void *obj, const char *name, AVRational val, int search_flags)
+{
+    return set_number(obj, name, val.num, val.den, 1, search_flags);
+}
+
+int av_opt_set_bin(void *obj, const char *name, const uint8_t *val, int len, int search_flags)
+{
+    void *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+    uint8_t *ptr;
+    uint8_t **dst;
+    int *lendst;
+
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+
+    if (o->type != AV_OPT_TYPE_BINARY || o->flags & AV_OPT_FLAG_READONLY)
+        return AVERROR(EINVAL);
+
+    ptr = av_malloc(len);
+    if (!ptr)
+        return AVERROR(ENOMEM);
+
+    dst = (uint8_t **)(((uint8_t *)target_obj) + o->offset);
+    lendst = (int *)(dst + 1);
+
+    av_free(*dst);
+    *dst = ptr;
+    *lendst = len;
+    memcpy(ptr, val, len);
+
+    return 0;
+}
+
+int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags)
+{
+    void *target_obj;
+    AVDictionary **dst;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+    if (o->flags & AV_OPT_FLAG_READONLY)
+        return AVERROR(EINVAL);
+
+    dst = (AVDictionary **)(((uint8_t *)target_obj) + o->offset);
+    av_dict_free(dst);
+    av_dict_copy(dst, val, 0);
+
+    return 0;
+}
+
+int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
+{
+    void *dst, *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+    uint8_t *bin, buf[128];
+    int len, i, ret;
+
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+
+    dst = (uint8_t*)target_obj + o->offset;
+
+    buf[0] = 0;
+    switch (o->type) {
+    case AV_OPT_TYPE_FLAGS:     ret = snprintf(buf, sizeof(buf), "0x%08X",  *(int    *)dst);break;
+    case AV_OPT_TYPE_INT:       ret = snprintf(buf, sizeof(buf), "%d" ,     *(int    *)dst);break;
+    case AV_OPT_TYPE_INT64:     ret = snprintf(buf, sizeof(buf), "%"PRId64, *(int64_t*)dst);break;
+    case AV_OPT_TYPE_FLOAT:     ret = snprintf(buf, sizeof(buf), "%f" ,     *(float  *)dst);break;
+    case AV_OPT_TYPE_DOUBLE:    ret = snprintf(buf, sizeof(buf), "%f" ,     *(double *)dst);break;
+    case AV_OPT_TYPE_RATIONAL:  ret = snprintf(buf, sizeof(buf), "%d/%d",   ((AVRational*)dst)->num, ((AVRational*)dst)->den);break;
+    case AV_OPT_TYPE_STRING:
+        if (*(uint8_t**)dst)
+            *out_val = av_strdup(*(uint8_t**)dst);
+        else
+            *out_val = av_strdup("");
+        return 0;
+    case AV_OPT_TYPE_BINARY:
+        len = *(int*)(((uint8_t *)dst) + sizeof(uint8_t *));
+        if ((uint64_t)len*2 + 1 > INT_MAX)
+            return AVERROR(EINVAL);
+        if (!(*out_val = av_malloc(len*2 + 1)))
+            return AVERROR(ENOMEM);
+        bin = *(uint8_t**)dst;
+        for (i = 0; i < len; i++)
+            snprintf(*out_val + i*2, 3, "%02X", bin[i]);
+        return 0;
+    default:
+        return AVERROR(EINVAL);
+    }
+
+    if (ret >= sizeof(buf))
+        return AVERROR(EINVAL);
+    *out_val = av_strdup(buf);
+    return 0;
+}
+
+static int get_number(void *obj, const char *name, double *num, int *den, int64_t *intnum,
+                      int search_flags)
+{
+    void *dst, *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+    if (!o || !target_obj)
+        goto error;
+
+    dst = ((uint8_t*)target_obj) + o->offset;
+
+    return read_number(o, dst, num, den, intnum);
+
+error:
+    *den=*intnum=0;
+    return -1;
+}
+
+int av_opt_get_int(void *obj, const char *name, int search_flags, int64_t *out_val)
+{
+    int64_t intnum = 1;
+    double     num = 1;
+    int   ret, den = 1;
+
+    if ((ret = get_number(obj, name, &num, &den, &intnum, search_flags)) < 0)
+        return ret;
+    *out_val = num*intnum/den;
+    return 0;
+}
+
+int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val)
+{
+    int64_t intnum = 1;
+    double     num = 1;
+    int   ret, den = 1;
+
+    if ((ret = get_number(obj, name, &num, &den, &intnum, search_flags)) < 0)
+        return ret;
+    *out_val = num*intnum/den;
+    return 0;
+}
+
+int av_opt_get_q(void *obj, const char *name, int search_flags, AVRational *out_val)
+{
+    int64_t intnum = 1;
+    double     num = 1;
+    int   ret, den = 1;
+
+    if ((ret = get_number(obj, name, &num, &den, &intnum, search_flags)) < 0)
+        return ret;
+
+    if (num == 1.0 && (int)intnum == intnum)
+        *out_val = (AVRational){intnum, den};
+    else
+        *out_val = av_d2q(num*intnum/den, 1<<24);
+    return 0;
+}
+
+int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val)
+{
+    void *target_obj;
+    AVDictionary *src;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+
+    if (!o || !target_obj)
+        return AVERROR_OPTION_NOT_FOUND;
+    if (o->type != AV_OPT_TYPE_DICT)
+        return AVERROR(EINVAL);
+
+    src = *(AVDictionary **)(((uint8_t *)target_obj) + o->offset);
+    av_dict_copy(out_val, src, 0);
+
+    return 0;
+}
+
+int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name)
+{
+    const AVOption *field = av_opt_find(obj, field_name, NULL, 0, 0);
+    const AVOption *flag  = av_opt_find(obj, flag_name,
+                                        field ? field->unit : NULL, 0, 0);
+    int64_t res;
+
+    if (!field || !flag || flag->type != AV_OPT_TYPE_CONST ||
+        av_opt_get_int(obj, field_name, 0, &res) < 0)
+        return 0;
+    return res & flag->default_val.i64;
+}
+
+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_opt_next(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==AV_OPT_TYPE_CONST)
+            continue;
+        else if (unit && opt->type!=AV_OPT_TYPE_CONST)
+            continue;
+        else if (unit && opt->type==AV_OPT_TYPE_CONST && strcmp(unit, opt->unit))
+            continue;
+        else if (unit && opt->type == AV_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 AV_OPT_TYPE_FLAGS:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<flags>");
+                break;
+            case AV_OPT_TYPE_INT:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<int>");
+                break;
+            case AV_OPT_TYPE_INT64:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<int64>");
+                break;
+            case AV_OPT_TYPE_DOUBLE:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<double>");
+                break;
+            case AV_OPT_TYPE_FLOAT:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<float>");
+                break;
+            case AV_OPT_TYPE_STRING:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<string>");
+                break;
+            case AV_OPT_TYPE_RATIONAL:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<rational>");
+                break;
+            case AV_OPT_TYPE_BINARY:
+                av_log(av_log_obj, AV_LOG_INFO, "%-7s ", "<binary>");
+                break;
+            case AV_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' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_EXPORT)         ? 'X' : '.');
+        av_log(av_log_obj, AV_LOG_INFO, "%c", (opt->flags & AV_OPT_FLAG_READONLY)       ? 'R' : '.');
+
+        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 != AV_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;
+}
+
+void av_opt_set_defaults(void *s)
+{
+    const AVOption *opt = NULL;
+    while ((opt = av_opt_next(s, opt))) {
+        if (opt->flags & AV_OPT_FLAG_READONLY)
+            continue;
+
+        switch (opt->type) {
+            case AV_OPT_TYPE_CONST:
+                /* Nothing to be done here */
+            break;
+            case AV_OPT_TYPE_FLAGS:
+            case AV_OPT_TYPE_INT:
+            case AV_OPT_TYPE_INT64:
+                av_opt_set_int(s, opt->name, opt->default_val.i64, 0);
+            break;
+            case AV_OPT_TYPE_DOUBLE:
+            case AV_OPT_TYPE_FLOAT: {
+                double val;
+                val = opt->default_val.dbl;
+                av_opt_set_double(s, opt->name, val, 0);
+            }
+            break;
+            case AV_OPT_TYPE_RATIONAL: {
+                AVRational val;
+                val = av_d2q(opt->default_val.dbl, INT_MAX);
+                av_opt_set_q(s, opt->name, val, 0);
+            }
+            break;
+            case AV_OPT_TYPE_STRING:
+                av_opt_set(s, opt->name, opt->default_val.str, 0);
+                break;
+            case AV_OPT_TYPE_BINARY:
+            case AV_OPT_TYPE_DICT:
+                /* Cannot set defaults for these types */
+            break;
+            default:
+                av_log(s, AV_LOG_DEBUG, "AVOption type %d of option %s not implemented yet\n", opt->type, opt->name);
+        }
+    }
+}
+
+/**
+ * Store the value in the field in ctx that is named like key.
+ * ctx must be an AVClass context, storing is done using AVOptions.
+ *
+ * @param buf the string to parse, buf will be updated to point at the
+ * separator just after the parsed key/value pair
+ * @param key_val_sep a 0-terminated list of characters used to
+ * separate key from value
+ * @param pairs_sep a 0-terminated list of characters used to separate
+ * two pairs from each other
+ * @return 0 if the key/value pair has been successfully parsed and
+ * set, or a negative value corresponding to an AVERROR code in case
+ * of error:
+ * AVERROR(EINVAL) if the key/value pair cannot be parsed,
+ * the error code issued by av_opt_set() if the key/value pair
+ * cannot be set
+ */
+static int parse_key_value_pair(void *ctx, const char **buf,
+                                const char *key_val_sep, const char *pairs_sep)
+{
+    char *key = av_get_token(buf, key_val_sep);
+    char *val;
+    int ret;
+
+    if (!key)
+        return AVERROR(ENOMEM);
+
+    if (*key && strspn(*buf, key_val_sep)) {
+        (*buf)++;
+        val = av_get_token(buf, pairs_sep);
+        if (!val) {
+            av_freep(&key);
+            return AVERROR(ENOMEM);
+        }
+    } else {
+        av_log(ctx, AV_LOG_ERROR, "Missing key or no key/value separator found after key '%s'\n", key);
+        av_free(key);
+        return AVERROR(EINVAL);
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "Setting value '%s' for key '%s'\n", val, key);
+
+    ret = av_opt_set(ctx, key, val, AV_OPT_SEARCH_CHILDREN);
+    if (ret == AVERROR_OPTION_NOT_FOUND)
+        av_log(ctx, AV_LOG_ERROR, "Key '%s' not found.\n", key);
+
+    av_free(key);
+    av_free(val);
+    return ret;
+}
+
+int av_set_options_string(void *ctx, const char *opts,
+                          const char *key_val_sep, const char *pairs_sep)
+{
+    int ret, count = 0;
+
+    if (!opts)
+        return 0;
+
+    while (*opts) {
+        if ((ret = parse_key_value_pair(ctx, &opts, key_val_sep, pairs_sep)) < 0)
+            return ret;
+        count++;
+
+        if (*opts)
+            opts++;
+    }
+
+    return count;
+}
+
+void av_opt_free(void *obj)
+{
+    const AVOption *o = NULL;
+    while ((o = av_opt_next(obj, o))) {
+        switch (o->type) {
+        case AV_OPT_TYPE_STRING:
+        case AV_OPT_TYPE_BINARY:
+            av_freep((uint8_t *)obj + o->offset);
+            break;
+
+        case AV_OPT_TYPE_DICT:
+            av_dict_free((AVDictionary **)(((uint8_t *)obj) + o->offset));
+            break;
+
+        default:
+            break;
+        }
+    }
+}
+
+int av_opt_set_dict(void *obj, AVDictionary **options)
+{
+    AVDictionaryEntry *t = NULL;
+    AVDictionary    *tmp = NULL;
+    int ret = 0;
+
+    while ((t = av_dict_get(*options, "", t, AV_DICT_IGNORE_SUFFIX))) {
+        ret = av_opt_set(obj, t->key, t->value, 0);
+        if (ret == AVERROR_OPTION_NOT_FOUND)
+            av_dict_set(&tmp, t->key, t->value, 0);
+        else if (ret < 0) {
+            av_log(obj, AV_LOG_ERROR, "Error setting option %s to value %s.\n", t->key, t->value);
+            break;
+        }
+        ret = 0;
+    }
+    av_dict_free(options);
+    *options = tmp;
+    return ret;
+}
+
+const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
+                            int opt_flags, int search_flags)
+{
+    return av_opt_find2(obj, name, unit, opt_flags, search_flags, NULL);
+}
+
+const AVOption *av_opt_find2(void *obj, const char *name, const char *unit,
+                             int opt_flags, int search_flags, void **target_obj)
+{
+    const AVClass  *c = *(AVClass**)obj;
+    const AVOption *o = NULL;
+
+    if (!c)
+        return NULL;
+
+    if (search_flags & AV_OPT_SEARCH_CHILDREN) {
+        if (search_flags & AV_OPT_SEARCH_FAKE_OBJ) {
+            const AVClass *child = NULL;
+            while (child = av_opt_child_class_next(c, child))
+                if (o = av_opt_find2(&child, name, unit, opt_flags, search_flags, NULL))
+                    return o;
+        } else {
+            void *child = NULL;
+            while (child = av_opt_child_next(obj, child))
+                if (o = av_opt_find2(child, name, unit, opt_flags, search_flags, target_obj))
+                    return o;
+        }
+    }
+
+    while (o = av_opt_next(obj, o)) {
+        if (!strcmp(o->name, name) && (o->flags & opt_flags) == opt_flags &&
+            ((!unit && o->type != AV_OPT_TYPE_CONST) ||
+             (unit  && o->unit && !strcmp(o->unit, unit)))) {
+            if (target_obj) {
+                if (!(search_flags & AV_OPT_SEARCH_FAKE_OBJ))
+                    *target_obj = obj;
+                else
+                    *target_obj = NULL;
+            }
+            return o;
+        }
+    }
+    return NULL;
+}
+
+void *av_opt_child_next(void *obj, void *prev)
+{
+    const AVClass *c = *(AVClass**)obj;
+    if (c->child_next)
+        return c->child_next(obj, prev);
+    return NULL;
+}
+
+const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev)
+{
+    if (parent->child_class_next)
+        return parent->child_class_next(prev);
+    return NULL;
+}
+
+#ifdef TEST
+
+typedef struct TestContext
+{
+    const AVClass *class;
+    int num;
+    int toggle;
+    char *string;
+    int flags;
+    AVRational rational;
+} TestContext;
+
+#define OFFSET(x) offsetof(TestContext, x)
+
+#define TEST_FLAG_COOL 01
+#define TEST_FLAG_LAME 02
+#define TEST_FLAG_MU   04
+
+static const AVOption test_options[]= {
+{"num",      "set num",        OFFSET(num),      AV_OPT_TYPE_INT,      {.i64 = 0},       0,        100                 },
+{"toggle",   "set toggle",     OFFSET(toggle),   AV_OPT_TYPE_INT,      {.i64 = 0},       0,        1                   },
+{"rational", "set rational",   OFFSET(rational), AV_OPT_TYPE_RATIONAL, {.dbl = 0},  0,        10                  },
+{"string",   "set string",     OFFSET(string),   AV_OPT_TYPE_STRING,   {0},              CHAR_MIN, CHAR_MAX            },
+{"flags",    "set flags",      OFFSET(flags),    AV_OPT_TYPE_FLAGS,    {.i64 = 0},       0,        INT_MAX, 0, "flags" },
+{"cool",     "set cool flag ", 0,                AV_OPT_TYPE_CONST,    {.i64 = TEST_FLAG_COOL}, INT_MIN,  INT_MAX, 0, "flags" },
+{"lame",     "set lame flag ", 0,                AV_OPT_TYPE_CONST,    {.i64 = TEST_FLAG_LAME}, INT_MIN,  INT_MAX, 0, "flags" },
+{"mu",       "set mu flag ",   0,                AV_OPT_TYPE_CONST,    {.i64 = TEST_FLAG_MU},   INT_MIN,  INT_MAX, 0, "flags" },
+{NULL},
+};
+
+static const char *test_get_name(void *ctx)
+{
+    return "test";
+}
+
+static const AVClass test_class = {
+    "TestContext",
+    test_get_name,
+    test_options
+};
+
+int main(void)
+{
+    int i;
+
+    printf("\nTesting av_set_options_string()\n");
+    {
+        TestContext test_ctx;
+        const char *options[] = {
+            "",
+            ":",
+            "=",
+            "foo=:",
+            ":=foo",
+            "=foo",
+            "foo=",
+            "foo",
+            "foo=val",
+            "foo==val",
+            "toggle=:",
+            "string=:",
+            "toggle=1 : foo",
+            "toggle=100",
+            "toggle==1",
+            "flags=+mu-lame : num=42: toggle=0",
+            "num=42 : string=blahblah",
+            "rational=0 : rational=1/2 : rational=1/-1",
+            "rational=-1/0",
+        };
+
+        test_ctx.class = &test_class;
+        av_opt_set_defaults(&test_ctx);
+        test_ctx.string = av_strdup("default");
+
+        av_log_set_level(AV_LOG_DEBUG);
+
+        for (i=0; i < FF_ARRAY_ELEMS(options); i++) {
+            av_log(&test_ctx, AV_LOG_DEBUG, "Setting options string '%s'\n", options[i]);
+            if (av_set_options_string(&test_ctx, options[i], "=", ":") < 0)
+                av_log(&test_ctx, AV_LOG_ERROR, "Error setting options string: '%s'\n", options[i]);
+            printf("\n");
+        }
+    }
+
+    return 0;
+}
+
+#endif