FFmpegFunctions.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  FFmpegFunctions.cpp
 
  Dmitry Vedenko
 
**********************************************************************/
 
#include "FFmpegFunctions.h"
 
#include <wx/string.h>
#include <wx/dynlib.h>
#include <wx/log.h>
#include <wx/utils.h>
 
#if defined(__WXMSW__)
#  include <wx/buffer.h>
#  include <wx/msw/registry.h>
 
#  define WIN32_LEAN_AND_MEAN
#  include <windows.h>
#  include <psapi.h>
#else
#  include <dlfcn.h>
#endif
 
#include "Prefs.h"
#include "FileNames.h"
 
#include "impl/avutil/AVUtilFunctionsLoader.h"
#include "impl/avcodec/AVCodecFunctionsLoader.h"
#include "impl/avformat/AVFormatFunctionsLoader.h"
 
#include "impl/FFmpegAPIResolver.h"
#include "impl/FFmpegLog.h"
 
void* GetSymbolFromProcess(const char* name)
{
#if defined(__WXMSW__)
   std::vector<HMODULE> handles(256);
 
   DWORD neededMemory;
 
   if (!EnumProcessModules(
          GetCurrentProcess(), handles.data(), sizeof(HMODULE) * handles.size(),
          &neededMemory))
   {
      return nullptr;
   }
 
   const int modulesCount = neededMemory / sizeof(HMODULE);
 
   if (modulesCount > handles.size())
   {
      handles.resize(modulesCount);
 
      if (!EnumProcessModules(
             GetCurrentProcess(), handles.data(),
             sizeof(HMODULE) * handles.size(), &neededMemory))
      {
         return nullptr;
      }
   }
 
   for (HMODULE handle : handles)
   {
      void* addr = GetProcAddress(handle, name);
 
      if (addr != nullptr)
         return addr;
   }
 
   return nullptr;
#else
   return dlsym(RTLD_DEFAULT, name);
#endif
}
 
struct EnvSetter final
{
   static const wxString VariableName;
   static const wxString Separator;
 
   explicit EnvSetter(bool fromUserPathOnly)
   {
      ValueExisted = wxGetEnv(VariableName, &OldValue);
 
      wxString value;
 
      for (const wxString& path : FFmpegFunctions::GetSearchPaths(fromUserPathOnly))
      {
         if (!value.empty())
            value += Separator;
 
         value += path;
      }
 
      wxSetEnv(VariableName, value);
   };
 
   ~EnvSetter()
   {
      if (ValueExisted)
         wxSetEnv(VariableName, OldValue);
      else
         wxUnsetEnv(VariableName);
   }
 
   wxString OldValue;
   bool ValueExisted;
};
 
#if defined(__WXMSW__)
const wxString EnvSetter::VariableName("PATH");
const wxString EnvSetter::Separator(";");
#elif defined(__WXMAC__)
const wxString EnvSetter::VariableName("DYLD_LIBRARY_PATH");
const wxString EnvSetter::Separator(":");
#else
const wxString EnvSetter::VariableName("LD_LIBRARY_PATH");
const wxString EnvSetter::Separator(":");
#endif
 
std::vector<wxString> BuildAVFormatPaths(int version)
{
   return {
#if defined(__WXMSW__)
      wxString::Format("avformat-%d.dll", version),
#elif defined(__WXMAC__)
      wxString::Format("libavformat.%d.dylib", version),
      wxString::Format("ffmpeg.%d.64bit.dylib", version),
#elif defined(__OpenBSD__)
      wxString::Format("libavformat.so"),
#else
      wxString::Format("libavformat.so.%d", version),
#endif
};
}
 
struct FFmpegFunctions::Private final
{
   std::shared_ptr<wxDynamicLibrary> AVFormatLibrary;
   std::shared_ptr<wxDynamicLibrary> AVCodecLibrary;
   std::shared_ptr<wxDynamicLibrary> AVUtilLibrary;
 
   std::unique_ptr<FFmpegLog> FFmpegLogCallbackSetter;
 
   AVFormatFactories FormatFactories;
   AVCodecFactories  CodecFactories;
   AVUtilFactories   UtilFactories;
 
   std::shared_ptr<wxDynamicLibrary> LibraryWithSymbol(const char* symbol, bool fromUserPathOnly) const
   {
      if (AVFormatLibrary->HasSymbol(symbol))
         return AVFormatLibrary;
 
      void* addr = GetSymbolFromProcess(symbol);
 
      if (addr == nullptr)
         return nullptr;
 
      const wxString path = FileNames::PathFromAddr(addr);
 
      if (path.empty())
         return nullptr;
 
      return LoadLibrary(wxFileNameFromPath(path), fromUserPathOnly);
   }
 
   bool Load(FFmpegFunctions& functions, const wxString& path, bool fromUserPathOnly)
   {
      // We start by loading AVFormat
      AVFormatLibrary = LoadLibrary(path, fromUserPathOnly);
 
      if (AVFormatLibrary == nullptr)
         return false;
 
      if ((AVCodecLibrary = LibraryWithSymbol("avcodec_version", fromUserPathOnly)) == nullptr)
         return false;
 
      if ((AVUtilLibrary = LibraryWithSymbol("avutil_version", fromUserPathOnly)) == nullptr)
         return false;
 
      if (
         !LoadAVFormatFunctions(*AVFormatLibrary, functions) ||
         !LoadAVCodecFunctions(*AVCodecLibrary, functions) ||
         !LoadAVUtilFunctions(*AVUtilLibrary, functions))
         return false;
 
      if (!FFmpegAPIResolver::Get().GetAVFormatFactories(
             functions.AVFormatVersion.Major, FormatFactories))
         return false;
 
      if (!FFmpegAPIResolver::Get().GetAVCodecFactories(
             functions.AVCodecVersion.Major, CodecFactories))
         return false;
 
      AVCodecIDResolver codecResolvers;
 
      if (!FFmpegAPIResolver::Get().GetAVCodecIDResolver(
             functions.AVCodecVersion.Major, codecResolvers))
         return false;
 
      functions.GetAVCodecID = codecResolvers.GetAVCodecID;
      functions.GetAudacityCodecID = codecResolvers.GetAudacityCodecID;
 
      if (!FFmpegAPIResolver::Get().GetAVUtilFactories(
             functions.AVUtilVersion.Major, UtilFactories))
         return false;
 
      wxLogInfo("FFmpeg libraries loaded successfully from: %s",
         FileNames::PathFromAddr(AVFormatLibrary->GetSymbol("avformat_version")));
 
      if (functions.avcodec_register_all)
         functions.avcodec_register_all();
 
      if (functions.av_register_all)
         functions.av_register_all();
 
      FFmpegLogCallbackSetter =
         UtilFactories.CreateLogCallbackSetter(functions);
 
      return true;
   }
 
   std::shared_ptr<wxDynamicLibrary> LoadLibrary(const wxString& libraryName, bool fromUserPathOnly) const
   {
#if defined(__WXMAC__)
      // On macOS dyld reads environment only when application starts.
      // Let's emulate the process manually
      for (const wxString& path : FFmpegFunctions::GetSearchPaths(fromUserPathOnly))
      {
         const wxString fullName = wxFileName(path, libraryName).GetFullPath();
 
         if (!wxFileExists(fullName))
            continue;
 
         auto library = std::make_shared<wxDynamicLibrary>(fullName);
 
         if (library->IsLoaded())
            return library;
      }
#endif
      auto library = std::make_shared<wxDynamicLibrary> (libraryName);
 
      if (library->IsLoaded())
         return library;
 
      return {};
   }
};
 
FFmpegFunctions::FFmpegFunctions()
    : mPrivate(std::make_unique<Private>())
{
}
 
FFmpegFunctions::~FFmpegFunctions()
{
}
 
std::shared_ptr<FFmpegFunctions> FFmpegFunctions::Load(bool fromUserPathOnly)
{
   static std::weak_ptr<FFmpegFunctions> weakFunctions;
 
   auto functions = weakFunctions.lock();
 
   if (functions)
      return functions;
 
   std::shared_ptr<FFmpegFunctions> ffmpeg =
      std::make_shared<FFmpegFunctions>();
 
   const auto supportedVersions =
      FFmpegAPIResolver::Get().GetSuportedAVFormatVersions();
 
#if !defined(__WXMAC__)
   EnvSetter envSetter(fromUserPathOnly);
#endif
 
   for (int version : supportedVersions)
   {
      for (const wxString& path : BuildAVFormatPaths(version))
      {
         if (ffmpeg->mPrivate->Load(*ffmpeg, path, fromUserPathOnly))
         {
            weakFunctions = ffmpeg;
            return ffmpeg;
         }
      }
   }
 
   return {};
}
 
StringSetting AVFormatPath { L"/FFmpeg/FFmpegLibPath", L"" };
 
std::vector<wxString> FFmpegFunctions::GetSearchPaths(bool fromUserPathOnly)
{
   std::vector<wxString> paths;
 
   const wxString userAVFormatFullPath = AVFormatPath.Read();
 
   if (!userAVFormatFullPath.empty())
   {
      // For some directories, wxPathOnly will fail.
      // For example, if path is `c:\ffmpeg-4.4`
      // wxPathOnly will return `c:\`
      if (wxDirExists(userAVFormatFullPath))
         paths.emplace_back(userAVFormatFullPath);
      else
         paths.emplace_back(wxPathOnly(userAVFormatFullPath));
   }
 
   if (fromUserPathOnly)
      return paths;
 
#if defined(__WXMSW__)
   wxRegKey reg(wxT("HKEY_LOCAL_MACHINE\\Software\\FFmpeg for Audacity"));
   wxString path;
 
   if (reg.Exists())
      reg.QueryValue(wxT("InstallPath"), path);
 
   if (!path.empty())
      paths.emplace_back(path);
 
#elif defined(__WXMAC__)
   paths.emplace_back(wxT("/Library/Application Support/audacity/libs"));
   paths.emplace_back(wxT("/usr/local/lib/audacity"));
   // x86_64 Homebrew
   paths.emplace_back(wxT("/usr/local/lib"));
   // ARM64 Homebrew
   paths.emplace_back(wxT("/opt/homebrew/lib"));
#endif
 
   return paths;
}
 
std::unique_ptr<AVIOContextWrapper> FFmpegFunctions::CreateAVIOContext() const
{
   return mPrivate->FormatFactories.CreateAVIOContextWrapper(*this);
}
 
std::unique_ptr<AVFormatContextWrapper>
FFmpegFunctions::CreateAVFormatContext() const
{
   return mPrivate->FormatFactories.CreateAVFormatContextWrapper(*this);
}
 
std::unique_ptr<AVStreamWrapper>
FFmpegFunctions::CreateAVStreamWrapper(AVStream* stream, bool forEncoding) const
{
   return mPrivate->FormatFactories.CreateAVStreamWrapper(*this, stream, forEncoding);
}
 
std::unique_ptr<AVPacketWrapper> FFmpegFunctions::CreateAVPacketWrapper() const
{
   return mPrivate->CodecFactories.CreateAVPacketWrapper(*this);
}
 
std::unique_ptr<AVFrameWrapper> FFmpegFunctions::CreateAVFrameWrapper() const
{
   return mPrivate->UtilFactories.CreateAVFrameWrapper(*this);
}
 
std::unique_ptr<AVInputFormatWrapper>
FFmpegFunctions::CreateAVInputFormatWrapper(
   AVInputFormat* inputFormat) const
{
   return mPrivate->FormatFactories.CreateAVInputFormatWrapper(inputFormat);
}
 
std::unique_ptr<AVOutputFormatWrapper> FFmpegFunctions::GuessOutputFormat(
   const char* short_name, const char* filename, const char* mime_type)
{
   AVOutputFormat* outputFormat =
      av_guess_format(short_name, filename, mime_type);
 
   return mPrivate->FormatFactories.CreateAVOutputFormatWrapper(outputFormat);
}
 
std::unique_ptr<AVChannelLayoutWrapper>
FFmpegFunctions::CreateDefaultChannelLayout(int channelsCount) const
{
   return mPrivate->UtilFactories.CreateDefaultChannelLayout(
      *this, channelsCount);
}
 
std::unique_ptr<AVChannelLayoutWrapper>
FFmpegFunctions::CreateLegacyChannelLayout(
   uint64_t layout, int channelsCount) const
{
   return mPrivate->UtilFactories.CreateLegacyChannelLayout(
      *this, layout, channelsCount);
}
 
std::unique_ptr<AVChannelLayoutWrapper>
FFmpegFunctions::CreateAVChannelLayout(const AVChannelLayout* layout) const
{
   return mPrivate->UtilFactories.CreateAVChannelLayout(*this, layout);
}
 
std::unique_ptr<AVOutputFormatWrapper>
FFmpegFunctions::CreateAVOutputFormatWrapper(
   const AVOutputFormat* outputFormat) const
{
   return mPrivate->FormatFactories.CreateAVOutputFormatWrapper(outputFormat);
}
 
std::unique_ptr<AVCodecWrapper>
FFmpegFunctions::CreateDecoder(AVCodecIDFwd codecID) const
{
   AVCodec* codec = avcodec_find_decoder(codecID);
 
   if (codec == nullptr)
      return {};
 
   return mPrivate->CodecFactories.CreateAVCodecWrapper(codec);
}
 
std::unique_ptr<AVCodecWrapper>
FFmpegFunctions::CreateEncoder(AVCodecIDFwd codecID) const
{
   auto codec = avcodec_find_encoder(codecID);
 
   if (codec == nullptr)
      return {};
 
   return mPrivate->CodecFactories.CreateAVCodecWrapper(codec);
}
 
std::unique_ptr<AVCodecWrapper>
FFmpegFunctions::CreateEncoder(const char* name) const
{
   auto codec = avcodec_find_encoder_by_name(name);
 
   if (codec == nullptr)
      return {};
 
   return mPrivate->CodecFactories.CreateAVCodecWrapper(codec);
}
 
std::unique_ptr<AVCodecContextWrapper>
FFmpegFunctions::CreateAVCodecContextWrapper(AVCodecContext* context) const
{
   return mPrivate->CodecFactories.CreateAVCodecContextWrapper(
      *this, context);
}
 
std::unique_ptr<AVCodecContextWrapper>
FFmpegFunctions::CreateAVCodecContextWrapperFromCodec(
   std::unique_ptr<AVCodecWrapper> codec) const
{
   if (codec == nullptr)
      return {};
 
   return mPrivate->CodecFactories.CreateAVCodecContextWrapperFromCodec(
      *this, std::move(codec));
}
 
const std::vector<const AVOutputFormatWrapper*>&
FFmpegFunctions::GetOutputFormats() const
{
   if (mOutputFormats.empty())
      const_cast<FFmpegFunctions*>(this)->FillOuptutFormatsList();
 
   return mOutputFormatPointers;
}
 
const std::vector<const AVCodecWrapper*>& FFmpegFunctions::GetCodecs() const
{
   if (mCodecs.empty())
      const_cast<FFmpegFunctions*>(this)->FillCodecsList();
 
   return mCodecPointers;
}
 
void FFmpegFunctions::FillCodecsList()
{
   mCodecs.clear();
   mCodecPointers.clear();
 
   if (av_codec_iterate != nullptr)
   {
      const AVCodec* currentCodec = nullptr;
      void* i = 0;
 
      while ((currentCodec = av_codec_iterate(&i)))
      {
         mCodecs.emplace_back(
            mPrivate->CodecFactories.CreateAVCodecWrapper(currentCodec));
      }
   }
   else if (av_codec_next != nullptr)
   {
      AVCodec* currentCodec = nullptr;
 
      while ((currentCodec = av_codec_next(currentCodec)) != nullptr)
      {
         mCodecs.emplace_back(
            mPrivate->CodecFactories.CreateAVCodecWrapper(currentCodec));
      }
   }
 
   mCodecPointers.reserve(mCodecs.size());
 
   for (const auto& codec : mCodecs)
      mCodecPointers.emplace_back(codec.get());
}
 
void FFmpegFunctions::FillOuptutFormatsList()
{
   mOutputFormats.clear();
   mOutputFormatPointers.clear();
 
   if (av_muxer_iterate != nullptr)
   {
      const AVOutputFormat* currentFormat = nullptr;
      void* i = 0;
 
      while ((currentFormat = av_muxer_iterate(&i)))
      {
         mOutputFormats.emplace_back(
            mPrivate->FormatFactories.CreateAVOutputFormatWrapper(
               currentFormat));
      }
   }
   else if (av_oformat_next != nullptr)
   {
      AVOutputFormat* currentFormat = nullptr;
 
      while ((currentFormat = av_oformat_next(currentFormat)) != nullptr)
      {
         mOutputFormats.emplace_back(
            mPrivate->FormatFactories.CreateAVOutputFormatWrapper(currentFormat));
      }
   }
 
   mOutputFormatPointers.reserve(mOutputFormats.size());
 
   for (const auto& format : mOutputFormats)
      mOutputFormatPointers.emplace_back(format.get());
}