Migration from Native Client to WebAssembly

This section provides an extension to https://developer.chrome.com/docs/native-client/migration/ article, which describes interface mapping from Google PPAPI interfaces to WebAssembly.

Emscripten SDK, modified by Samsung, provides additional functionalities that were available in Native Client - Player, Sockets and Video Decoder APIs.

This topic lists all the Samsung-specific PPAPIs and their corresponding WASM APIs, for ease of reference when planning your WebAssembly application project.

Samsung-specific PPAPIs vs. WASM

The following table contains all the Samsung specific PPAPIs and their WebAssembly (WASM) equivalents in the Samsung Emscripten SDK.

	PPAPI	WASM
Player	NaCl Player	WASM Player
Sockets	POSIX API (through nacl_io)	POSIX API
Video Decoder	`pp::VideoDecoder`	Part of WASM Player functionality. WASM Player needs to be initialized with the `RenderingMode::kVideoTexture` parameter, which indicates that you want to return decoded frames to application as GL Texture instead of presenting them on a screen.

Table 1. Samsung PPAPIs and Their WASM Equivalents

Data Source Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::ESDataSource functionalities.

PPAPI	Corresponding WASM API
`Samsung::NaClPlayer::ESDataSource::AddStream`	`samsung::wasm::ElementaryMediaStreamSource::AddTrack`
`Samsung::NaClPlayer::ESDataSource::SetDuration`	`samsung::wasm::ElementaryMediaStreamSource::SetDuration`
`Samsung::NaClPlayer::ESDataSource::SetEndOfStream`	`samsung::wasm::ElementaryMediaTrack::AppendEndOfTrack`

Table 2. Data Source Methods

Elementary Stream Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::ElementaryStream functionalities.

PPAPI	Corresponding WASM API
`Samsung::NaClPlayer::ElementaryStream::GetStreamType`	`samsung::wasm::ElementaryMediaTrack::GetType`
`Samsung::NaClPlayer::ElementaryStream::InitializeDone`	`samsung::wasm::ElementaryMediaStreamSource::AddTrack`
`Samsung::NaClPlayer::ElementaryStream::AppendPacket`	`samsung::wasm::ElementaryMediaTrack::AppendPacketAsync`
`Samsung::NaClPlayer::ElementaryStream::AppendEncryptedPacket`	`samsung::wasm::ElementaryMediaTrack::AppendEncryptedPacketAsync`
`Samsung::NaClPlayer::ElementaryStream::AppendTrustZonePacket`	No corresponding WASM API available
`Samsung::NaClPlayer::ElementaryStream::Flush`	`samsung::wasm::ElementaryMediaStreamSource::Flush`
`Samsung::NaClPlayer::ElementaryStream::SetDRMInitData`	`samsung::wasm::MediaKey::SetupEncryption`

Table 3. Elementary Stream Methods

Audio Elementary Stream Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::AudioElementaryStream functionalities.

PPAPI	Corresponding WASM API
`Samsung::NaClPlayer::AudioElementaryStream::GetAudioCodecType`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::AudioElementaryStream::SetAudioCodecType`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::AudioElementaryStream::GetAudioCodecProfile`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::AudioElementaryStream::SetAudioCodecProfile`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::AudioElementaryStream::GetSampleFormat`	`samsung::wasm::ElementaryAudioTrackConfig::sample_format`
`Samsung::NaClPlayer::AudioElementaryStream::SetSampleFormat`	`samsung::wasm::ElementaryAudioTrackConfig::sample_format`
`Samsung::NaClPlayer::AudioElementaryStream::SetBitsPerChannel`	No corresponding WASM API available
`Samsung::NaClPlayer::AudioElementaryStream::GetBitsPerChannel`	No corresponding WASM API available
`Samsung::NaClPlayer::AudioElementaryStream::GetSamplesPerSecond`	`samsung::wasm::ElementaryAudioTrackConfig::samples_per_second`
`Samsung::NaClPlayer::AudioElementaryStream::GetBitsPerChannel`	`samsung::wasm::ElementaryAudioTrackConfig::samples_per_second`
`Samsung::NaClPlayer::AudioElementaryStream::SetCodecExtraData`	`samsung::wasm::ElementaryMediaTrackConfig::extradata`

Table 4. Audio Elementary Stream Methods

Video Elementary Stream Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::VideoElementaryStream functionalities.

PPAPI	Corresponding WASM API
`Samsung::NaClPlayer::VideoElementaryStream::GetVideoCodecType`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::VideoElementaryStream::SetVideoCodecType`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::VideoElementaryStream::GetVideoCodecProfile`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::VideoElementaryStream::SetVideoCodecProfile`	`samsung::wasm::ElementaryMediaTrackConfig::mime_type`
`Samsung::NaClPlayer::VideoElementaryStream::GetVideoFrameFormat`	No corresponding WASM API available
`Samsung::NaClPlayer::VideoElementaryStream::SetVideoFrameFormat`	No corresponding WASM API available
`Samsung::NaClPlayer::VideoElementaryStream::GetVideoFrameSize`	`samsung::wasm::ElementaryVideoTrackConfig::width` `samsung::wasm::ElementaryVideoTrackConfig::height`
`Samsung::NaClPlayer::VideoElementaryStream::SetVideoFrameSize`	`samsung::wasm::ElementaryVideoTrackConfig::width` `samsung::wasm::ElementaryVideoTrackConfig::height`
`Samsung::NaClPlayer::VideoElementaryStream::GetFrameRate`	`samsung::wasm::ElementaryVideoTrackConfig::framerate_num` `samsung::wasm::ElementaryVideoTrackConfig::framerate_den`
`Samsung::NaClPlayer::VideoElementaryStream::SetFrameRate`	`samsung::wasm::ElementaryVideoTrackConfig::framerate_num` `samsung::wasm::ElementaryVideoTrackConfig::framerate_den`
`Samsung::NaClPlayer::VideoElementaryStream::SetCodecExtraData`	`samsung::wasm::ElementaryMediaTrackConfig::extradata`

Table 5. Video Elementary Stream Methods

Media Player Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::MediaPlayer functionalities.

PPAPI	Corresponding WASM API
`Samsung::NaClPlayer::MediaPlayer::MediaPlayer`	`samsung::wasm::HtmlMediaElement`
`Samsung::NaClPlayer::MediaPlayer::SetMediaEventsListener`	`samsung::html::HtmlMediaElement::SetListener`
`Samsung::NaClPlayer::MediaPlayer::SetSubtitleListener`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SetBufferingListener`	`samsung::html::HtmlMediaElement::SetListener`
`Samsung::NaClPlayer::MediaPlayer::SetDRMListener`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::BindToDisplay`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::AttachDataSource`	`samsung::html::HTMLMediaElement::SetSrc`
`Samsung::NaClPlayer::MediaPlayer::Play`	`samsung::html::HTMLMediaElement::Play`
`Samsung::NaClPlayer::MediaPlayer::Pause`	`samsung::html::HTMLMediaElement::Pause`
`Samsung::NaClPlayer::MediaPlayer::Stop`	`samsung::html::HTMLMediaElement::~HTMLMediaElement`
`Samsung::NaClPlayer::MediaPlayer::Seek`	`samsung::html::HTMLMediaElement::SetCurrentTime`
`Samsung::NaClPlayer::MediaPlayer::SetPlaybackRate`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetDuration`	`samsung::html::HTMLMediaElement::GetDuration`
`Samsung::NaClPlayer::MediaPlayer::GetCurrentTime`	`samsung::html::HTMLMediaElement::GetCurrentTime`
`Samsung::NaClPlayer::MediaPlayer::GetPlayerState`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetCurrentVideoTrackInfo`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetVideoTracksList`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetCurrentAudioTrackInfo`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetAudioTracksList`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetCurrentTextTrackInfo`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::GetTextTracksList`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SelectTrack`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::AddExternalSubtitles`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SetSubtitlesDelay`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SetDisplayRect`	Customized with video-tag parameters in JavaScript
`Samsung::NaClPlayer::MediaPlayer::SetDisplayMode`	Customized with video-tag parameters in JavaScript
`Samsung::NaClPlayer::MediaPlayer::SetVr360Mode`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SetVr360Rotation`	No corresponding WASM API available
`Samsung::NaClPlayer::MediaPlayer::SetDRMSpecificData`	`samsung::wasm::MediaKey::SetupEncryption`

Table 6. Media Player Methods

URL Data Source Functionalities

The following table shows how the WASM Player supports the Samsung::NaClPlayer::URLDataSource functionalities.

PPAPI	WASM (Emscripten)
`Samsung::NaClPlayer::URLDataSource`	Available using `video` tag with `url src` element.

Table 7. URL Data Source Methods

Video Decoder Functionalities

The following table shows how the WASM Player supports the pp::VideoDecoder functionalities.

PPAPI	WASM (Emscripten)
`pp::VideoDecoder::Create`	`samsung::wasm::ElementaryMediaStreamSource::AddTrack`
`pp::VideoDecoder::Initialize`	`samsung::wasm::ElementaryMediaStreamSource::AddTrack`
`pp::VideoDecoder::Decode`	`samsung::html::HtmlMediaElement::Play`
`pp::VideoDecoder::GetPicture`	`samsung::wasm::ElementaryMediaTrack::FillTextureWithNextFrame`
`pp::VideoDecoder::RecyclePicture`	`samsung::wasm::ElementaryMediaTrack::RecycleTexture`
`pp::VideoDecoder::Flush`	`samsung::wasm::ElementaryMediaStreamSource::Flush`
`pp::VideoDecoder::Reset`	`samsung::wasm::ElementaryMediaStreamSource::RemoveTrack` `samsung::wasm::ElementaryMediaStreamSource::AddTrack`

Table 8. Video Decoder Methods