Option.cpp

#include "Option.hpp"

extern "C" {
#include <libavutil/error.h>
#include <libavutil/mem.h>
}

#include <sstream>
#include <stdexcept>

namespace avtranscoder
{

Option::Option(AVOption& avOption, void* avContext)
    : _avOption(&avOption)
    , _avContext(avContext)
    , _childOptions()
    , _defaultChildIndex(0)
{
    _type = getTypeFromAVOption(getUnit(), _avOption->type);
}

EOptionBaseType Option::getTypeFromAVOption(const std::string& unit, const AVOptionType avType)
{
    if(!unit.empty() && avType == AV_OPT_TYPE_FLAGS)
        return eOptionBaseTypeGroup;
    else if(!unit.empty() && (avType == AV_OPT_TYPE_INT || avType == AV_OPT_TYPE_INT64))
        return eOptionBaseTypeChoice;
    else if(!unit.empty() && avType == AV_OPT_TYPE_CONST)
        return eOptionBaseTypeChild;

    switch(avType)
    {
        case AV_OPT_TYPE_FLAGS:
        {
            return eOptionBaseTypeBool;
        }
        case AV_OPT_TYPE_INT:
        case AV_OPT_TYPE_INT64:
        {
            return eOptionBaseTypeInt;
        }
        case AV_OPT_TYPE_DOUBLE:
        case AV_OPT_TYPE_FLOAT:
        {
            return eOptionBaseTypeDouble;
        }
        case AV_OPT_TYPE_STRING:
        case AV_OPT_TYPE_BINARY:
        {
            return eOptionBaseTypeString;
        }
        case AV_OPT_TYPE_RATIONAL:
        {
            return eOptionBaseTypeRatio;
        }
        default:
        {
            return eOptionBaseTypeUnknown;
        }
    }
    return eOptionBaseTypeUnknown;
}

EOptionBaseType Option::getType() const
{
    return _type;
}

bool Option::getDefaultBool() const
{
    return _avOption->default_val.i64;
}

int Option::getDefaultInt() const
{
    return _avOption->default_val.i64;
}

double Option::getDefaultDouble() const
{
    return _avOption->default_val.dbl;
}

std::string Option::getDefaultString() const
{
    return std::string(_avOption->default_val.str ? _avOption->default_val.str : "");
}

std::pair<int, int> Option::getDefaultRatio() const
{
    return std::make_pair(_avOption->default_val.q.num, _avOption->default_val.q.den);
}

bool Option::getBool() const
{
    int64_t out_val;
    int error = av_opt_get_int(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, &out_val);
    checkFFmpegGetOption(error);

    return out_val ? true : false;
}

int Option::getInt() const
{
    int64_t out_val;
    int error = av_opt_get_int(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, &out_val);
    checkFFmpegGetOption(error);

    return out_val;
}

double Option::getDouble() const
{
    double out_val;
    int error = av_opt_get_double(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, &out_val);
    checkFFmpegGetOption(error);

    return out_val;
}

std::string Option::getString() const
{
    void* out_val = av_malloc(128);
    int error = av_opt_get(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, (uint8_t**)&out_val);

    std::string strValue(out_val ? reinterpret_cast<const char*>(out_val) : "");

    av_free(out_val);

    checkFFmpegGetOption(error);

    return strValue;
}

std::pair<int, int> Option::getRatio() const
{
    Rational out_val;
    int error = av_opt_get_q(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, &out_val);
    checkFFmpegGetOption(error);

    return std::make_pair(out_val.num, out_val.den);
}

void Option::setFlag(const std::string& flag, const bool enable)
{
    int64_t optVal;
    int error = av_opt_get_int(_avContext, getName().c_str(), AV_OPT_SEARCH_CHILDREN, &optVal);
    checkFFmpegGetOption(error);

    if(enable)
        optVal = optVal | _avOption->default_val.i64;
    else
        optVal = optVal & ~_avOption->default_val.i64;

    error = av_opt_set_int(_avContext, getName().c_str(), optVal, AV_OPT_SEARCH_CHILDREN);
    checkFFmpegSetOption(error, flag);
}

void Option::setBool(const bool value)
{
    int error = av_opt_set_int(_avContext, getName().c_str(), value, AV_OPT_SEARCH_CHILDREN);

    std::ostringstream os;
    os << (value ? "true" : "false");
    checkFFmpegSetOption(error, os.str());
}

void Option::setInt(const int value)
{
    int error = av_opt_set_int(_avContext, getName().c_str(), value, AV_OPT_SEARCH_CHILDREN);

    std::ostringstream os;
    os << value;
    checkFFmpegSetOption(error, os.str());
}

void Option::setDouble(const double value)
{
    int error = av_opt_set_double(_avContext, getName().c_str(), value, AV_OPT_SEARCH_CHILDREN);

    std::ostringstream os;
    os << value;
    checkFFmpegSetOption(error, os.str());
}

void Option::setString(const std::string& value)
{
    int error = av_opt_set(_avContext, getName().c_str(), value.c_str(), AV_OPT_SEARCH_CHILDREN);
    checkFFmpegSetOption(error, value);
}

void Option::setRatio(const int num, const int den)
{
    Rational ratio;
    ratio.num = num;
    ratio.den = den;
    int error = av_opt_set_q(_avContext, getName().c_str(), ratio, AV_OPT_SEARCH_CHILDREN);

    std::ostringstream os;
    os << num << "/" << den;
    checkFFmpegSetOption(error, os.str());
}

void Option::appendChild(const Option& child)
{
    _childOptions.push_back(child);
}

void Option::checkFFmpegGetOption(const int ffmpegReturnCode) const
{
    if(ffmpegReturnCode)
    {
        throw std::runtime_error("unknown key " + getName() + ": " + getDescriptionFromErrorCode(ffmpegReturnCode));
    }
}

void Option::checkFFmpegSetOption(const int ffmpegReturnCode, const std::string& optionValue)
{
    if(ffmpegReturnCode)
    {
        throw std::runtime_error("setting " + getName() + " parameter to " + optionValue + ": " +
                                 getDescriptionFromErrorCode(ffmpegReturnCode));
    }
}

void loadOptions(OptionMap& outOptions, void* av_class, int req_flags)
{
    if(!av_class)
        return;

    // Use multimap because it is possible to have several parent options with the same unit
    std::multimap<std::string, std::string> optionUnitToParentName;
    std::vector<Option> childOptions;

    const AVOption* avOption = NULL;

// iterate on options
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(51, 12, 0)
    while((avOption = av_next_option(av_class, avOption)))
#else
    while((avOption = av_opt_next(av_class, avOption)))
#endif
    {
        if(!avOption || !avOption->name || (avOption->flags & req_flags) != req_flags)
        {
            continue;
        }

        Option option(*const_cast<AVOption*>(avOption), av_class);

        if(option.getType() == eOptionBaseTypeChild)
        {
            childOptions.push_back(option);
        }
        else
        {
            outOptions.insert(std::make_pair(option.getName(), option));
            if(! option.getUnit().empty())
            {
                optionUnitToParentName.insert(std::make_pair(option.getUnit(), option.getName()));
            }
        }
    }

    // iterate on child options
    for(std::vector<Option>::iterator itChild = childOptions.begin(); itChild != childOptions.end(); ++itChild)
    {
        bool parentFound = false;
        for(std::multimap<std::string, std::string>::iterator itUnitToParents = optionUnitToParentName.begin();
            itUnitToParents != optionUnitToParentName.end(); ++itUnitToParents)
        {
            const std::string parentUnit = itUnitToParents->first;
            if(parentUnit == itChild->getUnit())
            {
                // Get all the parent options with the same unit
                std::pair<std::multimap<std::string, std::string>::iterator, std::multimap<std::string, std::string>::iterator> parentOptions = optionUnitToParentName.equal_range(parentUnit);
                for(std::multimap<std::string, std::string>::iterator itParent = parentOptions.first; itParent != parentOptions.second; ++itParent)
                {
                    const std::string parentName = itParent->second;
                    Option& parentOption = outOptions.at(parentName);
                    parentOption.appendChild(*itChild);

                    // child of a Choice
                    if(parentOption.getType() == eOptionBaseTypeChoice)
                    {
                        if(itChild->getDefaultInt() == parentOption.getDefaultInt())
                            parentOption.setDefaultChildIndex(parentOption.getChilds().size() - 1);
                    }

                    parentFound = true;
                }

                if(parentFound)
                    break;
            }
        }

        if(!parentFound)
        {
            LOG_WARN("Can't find a choice option for " << itChild->getName())
        }
    }
}

void loadOptions(OptionArray& outOptions, void* av_class, int req_flags)
{
    OptionMap optionMap;
    loadOptions(optionMap, av_class, req_flags);

    for(OptionMap::iterator it = optionMap.begin(); it != optionMap.end(); ++it)
        outOptions.push_back(it->second);
}
}