// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This file contains an implementation of a class that provides H264 decode
// support for use with VAAPI hardware video decode acceleration on Intel
// systems.
#ifndef CONTENT_COMMON_GPU_MEDIA_VAAPI_H264_DECODER_H_
#define CONTENT_COMMON_GPU_MEDIA_VAAPI_H264_DECODER_H_
#include <vector>
#include "base/callback_forward.h"
#include "base/memory/linked_ptr.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "content/common/gpu/media/h264_dpb.h"
#include "content/common/gpu/media/vaapi_wrapper.h"
#include "media/base/limits.h"
#include "media/filters/h264_parser.h"
namespace content {
// An H264 decoder that utilizes VA-API. Provides features not supported by
// the VA-API userspace library (libva), including stream parsing, reference
// picture management and other operations not supported by the HW codec.
//
// Provides functionality to allow plugging VAAPI HW acceleration into the
// VDA framework.
//
// Clients of this class are expected to pass H264 Annex-B byte stream and
// will receive decoded surfaces via client-provided |OutputPicCB|.
//
// This class must be created, called and destroyed on a single thread, and
// does nothing internally on any other thread.
class CONTENT_EXPORT VaapiH264Decoder {
public:
// Callback invoked on the client when a surface is to be displayed.
// Arguments: input buffer id provided at the time of Decode()
// and VASurface to output.
typedef base::Callback<
void(int32, const scoped_refptr<VASurface>&)> OutputPicCB;
enum VAVDAH264DecoderFailure {
FRAME_MBS_ONLY_FLAG_NOT_ONE = 0,
GAPS_IN_FRAME_NUM = 1,
MID_STREAM_RESOLUTION_CHANGE = 2,
INTERLACED_STREAM = 3,
VAAPI_ERROR = 4,
VAVDA_H264_DECODER_FAILURES_MAX,
};
// Callback to report errors for UMA purposes, not used to return errors
// to clients.
typedef base::Callback<void(VAVDAH264DecoderFailure error)>
ReportErrorToUmaCB;
// Decode result codes.
enum DecResult {
kDecodeError, // Error while decoding.
// TODO posciak: unsupported streams are currently treated as error
// in decoding; in future it could perhaps be possible to fall back
// to software decoding instead.
// kStreamError, // Error in stream.
kAllocateNewSurfaces, // Need a new set of surfaces to be allocated.
kRanOutOfStreamData, // Need more stream data to proceed.
kRanOutOfSurfaces, // Waiting for the client to free up output surfaces.
};
// |vaapi_wrapper| should be initialized.
// |output_pic_cb| notifies the client a surface is to be displayed.
// |report_error_to_uma_cb| called on errors for UMA purposes, not used
// to report errors to clients.
VaapiH264Decoder(VaapiWrapper* vaapi_wrapper,
const OutputPicCB& output_pic_cb,
const ReportErrorToUmaCB& report_error_to_uma_cb);
~VaapiH264Decoder();
// Have the decoder flush its state and trigger output of all previously
// decoded surfaces via OutputPicCB. Return false on failure.
bool Flush() WARN_UNUSED_RESULT;
// To be called during decoding.
// Stop (pause) decoding, discarding all remaining inputs and outputs,
// but do not flush decoder state, so that the playback can be resumed later,
// possibly from a different location.
void Reset();
// Set current stream data pointer to |ptr| and |size|. Output surfaces
// that are decoded from data in this stream chunk are to be returned along
// with the given |input_id|.
void SetStream(const uint8* ptr, size_t size, int32 input_id);
// Try to decode more of the stream, returning decoded frames asynchronously
// via output_pic_cb_. Return when more stream is needed, when we run out
// of free surfaces, when we need a new set of them, or when an error occurs.
DecResult Decode() WARN_UNUSED_RESULT;
// Return dimensions/required number of output surfaces that client should
// be ready to provide for the decoder to function properly.
// To be used after Decode() returns kNeedNewSurfaces.
gfx::Size GetPicSize() { return pic_size_; }
size_t GetRequiredNumOfPictures();
// To be used by the client to feed decoder with output surfaces.
void ReuseSurface(const scoped_refptr<VASurface>& va_surface);
private:
// We need to keep at most kDPBMaxSize pictures in DPB for
// reference/to display later and an additional one for the one currently
// being decoded. We also ask for some additional ones since VDA needs
// to accumulate a few ready-to-output pictures before it actually starts
// displaying and giving them back. +2 instead of +1 because of subjective
// smoothness improvement during testing.
enum {
kPicsInPipeline = media::limits::kMaxVideoFrames + 2,
kMaxNumReqPictures = H264DPB::kDPBMaxSize + kPicsInPipeline,
};
// Internal state of the decoder.
enum State {
kNeedStreamMetadata, // After initialization, need an SPS.
kDecoding, // Ready to decode from any point.
kAfterReset, // After Reset(), need a resume point.
kError, // Error in decode, can't continue.
};
// Process H264 stream structures.
bool ProcessSPS(int sps_id, bool* need_new_buffers);
bool ProcessPPS(int pps_id);
bool ProcessSlice(media::H264SliceHeader* slice_hdr);
// Initialize the current picture according to data in |slice_hdr|.
bool InitCurrPicture(media::H264SliceHeader* slice_hdr);
// Calculate picture order counts for the new picture
// on initialization of a new frame (see spec).
bool CalculatePicOrderCounts(media::H264SliceHeader* slice_hdr);
// Update PicNum values in pictures stored in DPB on creation of new
// frame (see spec).
void UpdatePicNums();
bool UpdateMaxNumReorderFrames(const media::H264SPS* sps);
// Prepare reference picture lists (ref_pic_list[01]_).
bool PrepareRefPicLists(media::H264SliceHeader* slice_hdr);
// Construct initial reference picture lists for use in decoding of
// P and B pictures (see 8.2.4 in spec).
void ConstructReferencePicListsP(media::H264SliceHeader* slice_hdr);
void ConstructReferencePicListsB(media::H264SliceHeader* slice_hdr);
// Helper functions for reference list construction, per spec.
int PicNumF(H264Picture *pic);
int LongTermPicNumF(H264Picture *pic);
// Perform the reference picture lists' modification (reordering), as
// specified in spec (8.2.4).
//
// |list| indicates list number and should be either 0 or 1.
bool ModifyReferencePicList(media::H264SliceHeader* slice_hdr, int list);
// Perform reference picture memory management operations (marking/unmarking
// of reference pictures, long term picture management, discarding, etc.).
// See 8.2.5 in spec.
bool HandleMemoryManagementOps();
void ReferencePictureMarking();
// Start processing a new frame.
bool StartNewFrame(media::H264SliceHeader* slice_hdr);
// All data for a frame received, process it and decode.
bool FinishPrevFrameIfPresent();
// Called after decoding, performs all operations to be done after decoding,
// including DPB management, reference picture marking and memory management
// operations.
// This will also output a picture if one is ready for output.
bool FinishPicture();
// Clear DPB contents and remove all surfaces in DPB from *in_use_ list.
// Cleared pictures will be made available for decode, unless they are
// at client waiting to be displayed.
void ClearDPB();
// These queue up data for HW decoder to be committed on running HW decode.
bool SendPPS();
bool SendIQMatrix();
bool SendVASliceParam(media::H264SliceHeader* slice_hdr);
bool SendSliceData(const uint8* ptr, size_t size);
bool QueueSlice(media::H264SliceHeader* slice_hdr);
// Helper methods for filling HW structures.
void FillVAPicture(VAPictureH264 *va_pic, H264Picture* pic);
int FillVARefFramesFromDPB(VAPictureH264 *va_pics, int num_pics);
// Commits all pending data for HW decoder and starts HW decoder.
bool DecodePicture();
// Notifies client that a picture is ready for output.
bool OutputPic(H264Picture* pic);
// Output all pictures in DPB that have not been outputted yet.
bool OutputAllRemainingPics();
// Represents a frame being decoded. Will always have a VASurface
// assigned to it, which will eventually contain decoded picture data.
class DecodeSurface;
// Assign an available surface to the given PicOrderCnt |poc|,
// removing it from the available surfaces pool. Return true if a surface
// has been found, false otherwise.
bool AssignSurfaceToPoC(int32 input_id, int poc);
// Indicate that a surface is no longer needed by decoder.
void UnassignSurfaceFromPoC(int poc);
// Return DecodeSurface assigned to |poc|.
DecodeSurface* DecodeSurfaceByPoC(int poc);
// Decoder state.
State state_;
// Parser in use.
media::H264Parser parser_;
// DPB in use.
H264DPB dpb_;
// Picture currently being processed/decoded.
scoped_ptr<H264Picture> curr_pic_;
// Reference picture lists, constructed for each picture before decoding.
// Those lists are not owners of the pointers (DPB is).
H264Picture::PtrVector ref_pic_list0_;
H264Picture::PtrVector ref_pic_list1_;
// Global state values, needed in decoding. See spec.
int max_pic_order_cnt_lsb_;
int max_frame_num_;
int max_pic_num_;
int max_long_term_frame_idx_;
size_t max_num_reorder_frames_;
int frame_num_;
int prev_frame_num_;
int prev_frame_num_offset_;
bool prev_has_memmgmnt5_;
// Values related to previously decoded reference picture.
bool prev_ref_has_memmgmnt5_;
int prev_ref_top_field_order_cnt_;
int prev_ref_pic_order_cnt_msb_;
int prev_ref_pic_order_cnt_lsb_;
H264Picture::Field prev_ref_field_;
// Currently active SPS and PPS.
int curr_sps_id_;
int curr_pps_id_;
// Output picture size.
gfx::Size pic_size_;
// Maps H.264 PicOrderCount to currently used DecodeSurfaces;
typedef std::map<int, linked_ptr<DecodeSurface> > DecSurfacesInUse;
DecSurfacesInUse decode_surfaces_in_use_;
// Unused VA surfaces returned by client, ready to be reused.
std::vector<scoped_refptr<VASurface> > available_va_surfaces_;
// The id of current input buffer, which will be associated with an
// output surface when a frame is successfully decoded.
int32 curr_input_id_;
VaapiWrapper* vaapi_wrapper_;
// Called by decoder when a surface should be outputted.
OutputPicCB output_pic_cb_;
// Called to report decoding error to UMA, not used to indicate errors
// to clients.
ReportErrorToUmaCB report_error_to_uma_cb_;
// PicOrderCount of the previously outputted frame.
int last_output_poc_;
DISALLOW_COPY_AND_ASSIGN(VaapiH264Decoder);
};
} // namespace content
#endif // CONTENT_COMMON_GPU_MEDIA_VAAPI_H264_DECODER_H_