/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "FFmpegLibWrapper.h"

#include "FFmpegLog.h"

#include "mozilla/PodOperations.h"

#ifdef MOZ_FFMPEG

#include "mozilla/StaticPrefs.h"

#endif

#include "mozilla/Types.h"

#include "PlatformDecoderModule.h"

#include "prlink.h"

#define AV_LOG_DEBUG    48

#define AV_LOG_INFO     32

namespace mozilla

{

FFmpegLibWrapper::LinkResult

FFmpegLibWrapper::Link()

{

  if (!mAVCodecLib || !mAVUtilLib) {

    Unlink();

    return LinkResult::NoProvidedLib;

  }

  avcodec_version =

    (decltype(avcodec_version))PR_FindSymbol(mAVCodecLib, "avcodec_version");

  if (!avcodec_version) {

    Unlink();

    return LinkResult::NoAVCodecVersion;

  }

  uint32_t version = avcodec_version();

  uint32_t macro = (version >> 16) & 0xFFu;

  mVersion = static_cast<int>(macro);

  uint32_t micro = version & 0xFFu;

  // A micro version >= 100 indicates that it's FFmpeg (as opposed to LibAV).

  bool isFFMpeg = micro >= 100;

  if (!isFFMpeg) {

    if (macro == 57) {

      // Due to current AVCodecContext binary incompatibility we can only

      // support FFmpeg 57 at this stage.

      Unlink();

      return LinkResult::CannotUseLibAV57;

    }

#ifdef MOZ_FFMPEG

    if (version < (54u << 16 | 35u << 8 | 1u) &&

        !StaticPrefs::MediaLibavcodecAllowObsolete()) {

      // Refuse any libavcodec version prior to 54.35.1.

      // (Unless media.libavcodec.allow-obsolete==true)

      Unlink();

      return LinkResult::BlockedOldLibAVVersion;

    }

#endif

  }

  enum {

    AV_FUNC_AVUTIL_MASK = 1 << 8,

    AV_FUNC_53 = 1 << 0,

    AV_FUNC_54 = 1 << 1,

    AV_FUNC_55 = 1 << 2,

    AV_FUNC_56 = 1 << 3,

    AV_FUNC_57 = 1 << 4,

    AV_FUNC_58 = 1 << 5,

    AV_FUNC_AVUTIL_53 = AV_FUNC_53 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVUTIL_54 = AV_FUNC_54 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVUTIL_55 = AV_FUNC_55 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVUTIL_56 = AV_FUNC_56 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVUTIL_57 = AV_FUNC_57 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVUTIL_58 = AV_FUNC_58 | AV_FUNC_AVUTIL_MASK,

    AV_FUNC_AVCODEC_ALL = AV_FUNC_53 | AV_FUNC_54 | AV_FUNC_55 | AV_FUNC_56 | AV_FUNC_57 | AV_FUNC_58,

    AV_FUNC_AVUTIL_ALL = AV_FUNC_AVCODEC_ALL | AV_FUNC_AVUTIL_MASK

  };

  switch (macro) {

    case 53:

      version = AV_FUNC_53;

      break;

    case 54:

      version = AV_FUNC_54;

      break;

    case 55:

      version = AV_FUNC_55;

      break;

    case 56:

      version = AV_FUNC_56;

      break;

    case 57:

      version = AV_FUNC_57;

      break;

    case 58:

      version = AV_FUNC_58;

      break;

    default:

      FFMPEG_LOG("Unknown avcodec version");

      Unlink();

      return isFFMpeg

             ? ((macro > 57)

                ? LinkResult::UnknownFutureFFMpegVersion

                : LinkResult::UnknownOlderFFMpegVersion)

             // All LibAV versions<54.35.1 are blocked, therefore we must be

             // dealing with a later one.

             : LinkResult::UnknownFutureLibAVVersion;

  }

#define AV_FUNC_OPTION(func, ver)                                              \

  if ((ver) & version) {                                                       \

    if (!(func = (decltype(func))PR_FindSymbol(((ver) & AV_FUNC_AVUTIL_MASK) ? mAVUtilLib : mAVCodecLib, #func))) { \

      FFMPEG_LOG("Couldn't load function " # func);                            \

    }                                                                          \

  } else {                                                                     \

    func = (decltype(func))nullptr;                                            \

  }

#define AV_FUNC(func, ver)                                                     \

  AV_FUNC_OPTION(func, ver)                                                    \

  if ((ver) & version && !func) {                                              \

    Unlink();                                                                  \

    return isFFMpeg ? LinkResult::MissingFFMpegFunction                        \

                    : LinkResult::MissingLibAVFunction;                        \

  }

  AV_FUNC(av_lockmgr_register, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_alloc_context3, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_close, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_decode_audio4, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_decode_video2, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_find_decoder, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_flush_buffers, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_open2, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_register_all, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(av_init_packet, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(av_parser_init, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(av_parser_close, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(av_parser_parse2, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(avcodec_alloc_frame, (AV_FUNC_53 | AV_FUNC_54))

  AV_FUNC(avcodec_get_frame_defaults, (AV_FUNC_53 | AV_FUNC_54))

  AV_FUNC(avcodec_free_frame, AV_FUNC_54)

  AV_FUNC_OPTION(av_rdft_init, AV_FUNC_AVCODEC_ALL)

  AV_FUNC_OPTION(av_rdft_calc, AV_FUNC_AVCODEC_ALL)

  AV_FUNC_OPTION(av_rdft_end, AV_FUNC_AVCODEC_ALL)

  AV_FUNC(av_log_set_level, AV_FUNC_AVUTIL_ALL)

  AV_FUNC(av_malloc, AV_FUNC_AVUTIL_ALL)

  AV_FUNC(av_freep, AV_FUNC_AVUTIL_ALL)

  AV_FUNC(av_frame_alloc, (AV_FUNC_AVUTIL_55 | AV_FUNC_AVUTIL_56 | AV_FUNC_AVUTIL_57 | AV_FUNC_AVUTIL_58))

  AV_FUNC(av_frame_free, (AV_FUNC_AVUTIL_55 | AV_FUNC_AVUTIL_56 | AV_FUNC_AVUTIL_57 | AV_FUNC_AVUTIL_58))

  AV_FUNC(av_frame_unref, (AV_FUNC_AVUTIL_55 | AV_FUNC_AVUTIL_56 | AV_FUNC_AVUTIL_57 | AV_FUNC_AVUTIL_58))

  AV_FUNC_OPTION(av_frame_get_colorspace, AV_FUNC_AVUTIL_ALL)

#undef AV_FUNC

#undef AV_FUNC_OPTION

  avcodec_register_all();

  if (MOZ_LOG_TEST(sPDMLog, LogLevel::Debug)) {

    av_log_set_level(AV_LOG_DEBUG);

  } else if (MOZ_LOG_TEST(sPDMLog, LogLevel::Info)) {

    av_log_set_level(AV_LOG_INFO);

  } else {

    av_log_set_level(0);

  }

  return LinkResult::Success;

}

void

FFmpegLibWrapper::Unlink()

{

  if (av_lockmgr_register) {

    // Registering a null lockmgr cause the destruction of libav* global mutexes

    // as the default lockmgr that allocated them will be deregistered.

    // This prevents ASAN and valgrind to report sizeof(pthread_mutex_t) leaks.

    av_lockmgr_register(nullptr);

  }

  if (mAVUtilLib && mAVUtilLib != mAVCodecLib) {

    PR_UnloadLibrary(mAVUtilLib);

  }

  if (mAVCodecLib) {

    PR_UnloadLibrary(mAVCodecLib);

  }

  PodZero(this);

}

} // namespace mozilla