PPB_VideoEncoder Struct Reference

Data Fields

PP_Resource(* Create )(PP_Instance instance)
PP_Bool(* IsVideoEncoder )(PP_Resource resource)
int32_t(* GetSupportedProfiles )(PP_Resource video_encoder, struct PP_ArrayOutput output, struct PP_CompletionCallback callback)
int32_t(* Initialize )(PP_Resource video_encoder, PP_VideoFrame_Format input_format, const struct PP_Size *input_visible_size, PP_VideoProfile output_profile, uint32_t initial_bitrate, PP_HardwareAcceleration acceleration, struct PP_CompletionCallback callback)
int32_t(* GetFramesRequired )(PP_Resource video_encoder)
int32_t(* GetFrameCodedSize )(PP_Resource video_encoder, struct PP_Size *coded_size)
int32_t(* GetVideoFrame )(PP_Resource video_encoder, PP_Resource *video_frame, struct PP_CompletionCallback callback)
int32_t(* Encode )(PP_Resource video_encoder, PP_Resource video_frame, PP_Bool force_keyframe, struct PP_CompletionCallback callback)
int32_t(* GetBitstreamBuffer )(PP_Resource video_encoder, struct PP_BitstreamBuffer *bitstream_buffer, struct PP_CompletionCallback callback)
void(* RecycleBitstreamBuffer )(PP_Resource video_encoder, const struct PP_BitstreamBuffer *bitstream_buffer)
void(* RequestEncodingParametersChange )(PP_Resource video_encoder, uint32_t bitrate, uint32_t framerate)
void(* Close )(PP_Resource video_encoder)

Detailed Description

Video encoder interface.

Typical usage:

  • Call Create() to create a new video encoder resource.
  • Call GetSupportedFormats() to determine which codecs and profiles are available.
  • Call Initialize() to initialize the encoder for a supported profile.
  • Call GetVideoFrame() to get a blank frame and fill it in, or get a video frame from another resource, e.g. PPB_MediaStreamVideoTrack.
  • Call Encode() to push the video frame to the encoder. If an external frame is pushed, wait for completion to recycle the frame.
  • Call GetBitstreamBuffer() continuously (waiting for each previous call to complete) to pull encoded pictures from the encoder.
  • Call RecycleBitstreamBuffer() after consuming the data in the bitstream buffer.
  • To destroy the encoder, the plugin should release all of its references to it. Any pending callbacks will abort before the encoder is destroyed.

Available video codecs vary by platform. All: vp8 (software). ChromeOS, depending on your device: h264 (hardware), vp8 (hardware)


Field Documentation

void(* PPB_VideoEncoder::Close)(PP_Resource video_encoder)

Closes the video encoder, and cancels any pending encodes.

Any pending callbacks will still run, reporting PP_ERROR_ABORTED . It is not valid to call any encoder functions after a call to this method. Note: Destroying the video encoder closes it implicitly, so you are not required to call Close().

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.

Creates a new video encoder resource.

Parameters:
[in]instanceA PP_Instance identifying the instance with the video encoder.
Returns:
A PP_Resource corresponding to a video encoder if successful or 0 otherwise.
int32_t(* PPB_VideoEncoder::Encode)(PP_Resource video_encoder, PP_Resource video_frame, PP_Bool force_keyframe, struct PP_CompletionCallback callback)

Encodes a video frame.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]video_frameThe PPB_VideoFrame to be encoded.
[in]force_keyframeA PP_Bool> specifying whether the encoder should emit a key frame for this video frame.
[in]callbackA PP_CompletionCallback to be called upon completion. Plugins that pass PPB_VideoFrame resources owned by other resources should wait for completion before reusing them.
Returns:
An int32_t containing an error code from pp_errors.h. Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
int32_t(* PPB_VideoEncoder::GetBitstreamBuffer)(PP_Resource video_encoder, struct PP_BitstreamBuffer *bitstream_buffer, struct PP_CompletionCallback callback)

Gets the next encoded bitstream buffer from the encoder.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[out]bitstream_bufferA PP_BitstreamBuffer containing encoded video data.
[in]callbackA PP_CompletionCallback to be called upon completion. The plugin can call GetBitstreamBuffer from the callback in order to continuously "pull" bitstream buffers from the encoder.
Returns:
An int32_t containing an error code from pp_errors.h. Returns PP_ERROR_FAILED if Initialize() has not successfully completed. Returns PP_ERROR_INPROGRESS if a prior call to GetBitstreamBuffer() has not completed.
int32_t(* PPB_VideoEncoder::GetFrameCodedSize)(PP_Resource video_encoder, struct PP_Size *coded_size)

Gets the coded size of the video frames required by the encoder.

Coded size is the logical size of the input frames, in pixels. The encoder may have hardware alignment requirements that make this different from |input_visible_size|, as requested in the call to Initialize().

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]coded_sizeA PP_Size to hold the coded size.
Returns:
An int32_t containing a result code from pp_errors.h. Returns PP_ERROR_FAILED if Initialize() has not successfully completed.

Gets the number of input video frames that the encoder may hold while encoding.

If the plugin is providing the video frames, it should have at least this many available.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
Returns:
An int32_t containing the number of frames required, or an error code from pp_errors.h. Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
int32_t(* PPB_VideoEncoder::GetSupportedProfiles)(PP_Resource video_encoder, struct PP_ArrayOutput output, struct PP_CompletionCallback callback)

Gets an array of supported video encoder profiles.

These can be used to choose a profile before calling Initialize().

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]outputA PP_ArrayOutput to receive the supported PP_VideoProfileDescription structs.
[in]callbackA PP_CompletionCallback to be called upon completion.
Returns:
If >= 0, the number of supported profiles returned, otherwise an error code from pp_errors.h.
int32_t(* PPB_VideoEncoder::GetVideoFrame)(PP_Resource video_encoder, PP_Resource *video_frame, struct PP_CompletionCallback callback)

Gets a blank video frame which can be filled with video data and passed to the encoder.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[out]video_frameA blank PPB_VideoFrame resource.
[in]callbackA PP_CompletionCallback to be called upon completion.
Returns:
An int32_t containing an error code from pp_errors.h. Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
int32_t(* PPB_VideoEncoder::Initialize)(PP_Resource video_encoder, PP_VideoFrame_Format input_format, const struct PP_Size *input_visible_size, PP_VideoProfile output_profile, uint32_t initial_bitrate, PP_HardwareAcceleration acceleration, struct PP_CompletionCallback callback)

Initializes a video encoder resource.

The plugin should call Initialize() successfully before calling any of the functions below.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]input_formatThe PP_VideoFrame_Format of the frames which will be encoded.
[in]input_visible_sizeA PP_Size specifying the dimensions of the visible part of the input frames.
[in]output_profileA PP_VideoProfile specifying the codec profile of the encoded output stream.
[in]accelerationA PP_HardwareAcceleration specifying whether to use a hardware accelerated or a software implementation.
[in]callbackA PP_CompletionCallback to be called upon completion.
Returns:
An int32_t containing an error code from pp_errors.h. Returns PP_ERROR_NOTSUPPORTED if video encoding is not available, or the requested codec profile is not supported.

Determines if the given resource is a video encoder.

Parameters:
[in]resourceA PP_Resource identifying a resource.
Returns:
PP_TRUE if the resource is a PPB_VideoEncoder, PP_FALSE if the resource is invalid or some other type.
void(* PPB_VideoEncoder::RecycleBitstreamBuffer)(PP_Resource video_encoder, const struct PP_BitstreamBuffer *bitstream_buffer)

Recycles a bitstream buffer back to the encoder.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]bitstream_bufferA PP_BitstreamBuffer that is no longer needed by the plugin.
void(* PPB_VideoEncoder::RequestEncodingParametersChange)(PP_Resource video_encoder, uint32_t bitrate, uint32_t framerate)

Requests a change to encoding parameters.

This is only a request, fulfilled on a best-effort basis.

Parameters:
[in]video_encoderA PP_Resource identifying the video encoder.
[in]bitrateThe requested new bitrate, in bits per second.
[in]framerateThe requested new framerate, in frames per second.

The documentation for this struct was generated from the following file: