| // 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. |
| |
| #ifndef MEDIA_GPU_H264_DECODER_H_ |
| #define MEDIA_GPU_H264_DECODER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "media/base/limits.h" |
| #include "media/filters/h264_parser.h" |
| #include "media/gpu/accelerated_video_decoder.h" |
| #include "media/gpu/h264_dpb.h" |
| #include "media/gpu/media_gpu_export.h" |
| #include "ui/gfx/geometry/size.h" |
| |
| namespace media { |
| |
| // Clients of this class are expected to pass H264 Annex-B byte stream |
| // and are expected to provide an implementation of H264Accelerator for |
| // offloading final steps of the decoding process. |
| // |
| // This class must be created, called and destroyed on a single thread, and |
| // does nothing internally on any other thread. |
| class MEDIA_GPU_EXPORT H264Decoder : public AcceleratedVideoDecoder { |
| public: |
| class MEDIA_GPU_EXPORT H264Accelerator { |
| public: |
| H264Accelerator(); |
| virtual ~H264Accelerator(); |
| |
| // Create a new H264Picture that the decoder client can use for decoding |
| // and pass back to this accelerator for decoding or reference. |
| // When the picture is no longer needed by decoder, it will just drop |
| // its reference to it, and it may do so at any time. |
| // Note that this may return nullptr if accelerator is not able to provide |
| // any new pictures at given time. The decoder is expected to handle |
| // this situation as normal and return from Decode() with kRanOutOfSurfaces. |
| virtual scoped_refptr<H264Picture> CreateH264Picture() = 0; |
| |
| // Submit metadata for the current frame, providing the current |sps| and |
| // |pps| for it, |dpb| has to contain all the pictures in DPB for current |
| // frame, and |ref_pic_p0/b0/b1| as specified in the H264 spec. Note that |
| // depending on the frame type, either p0, or b0 and b1 are used. |pic| |
| // contains information about the picture for the current frame. |
| // Note that this does not run decode in the accelerator and the decoder |
| // is expected to follow this call with one or more SubmitSlice() calls |
| // before calling SubmitDecode(). |
| // Return true if successful. |
| virtual bool SubmitFrameMetadata(const H264SPS* sps, |
| const H264PPS* pps, |
| const H264DPB& dpb, |
| const H264Picture::Vector& ref_pic_listp0, |
| const H264Picture::Vector& ref_pic_listb0, |
| const H264Picture::Vector& ref_pic_listb1, |
| const scoped_refptr<H264Picture>& pic) = 0; |
| |
| // Submit one slice for the current frame, passing the current |pps| and |
| // |pic| (same as in SubmitFrameMetadata()), the parsed header for the |
| // current slice in |slice_hdr|, and the reordered |ref_pic_listX|, |
| // as per H264 spec. |
| // |data| pointing to the full slice (including the unparsed header| of |
| // |size| in bytes. |
| // This must be called one or more times per frame, before SubmitDecode(). |
| // Note that |data| does not have to remain valid after this call returns. |
| // Return true if successful. |
| virtual bool SubmitSlice(const H264PPS* pps, |
| const H264SliceHeader* slice_hdr, |
| const H264Picture::Vector& ref_pic_list0, |
| const H264Picture::Vector& ref_pic_list1, |
| const scoped_refptr<H264Picture>& pic, |
| const uint8_t* data, |
| size_t size) = 0; |
| |
| // Execute the decode in hardware for |pic|, using all the slices and |
| // metadata submitted via SubmitFrameMetadata() and SubmitSlice() since |
| // the previous call to SubmitDecode(). |
| // Return true if successful. |
| virtual bool SubmitDecode(const scoped_refptr<H264Picture>& pic) = 0; |
| |
| // Schedule output (display) of |pic|. Note that returning from this |
| // method does not mean that |pic| has already been outputted (displayed), |
| // but guarantees that all pictures will be outputted in the same order |
| // as this method was called for them. Decoder may drop its reference |
| // to |pic| after calling this method. |
| // Return true if successful. |
| virtual bool OutputPicture(const scoped_refptr<H264Picture>& pic) = 0; |
| |
| // Reset any current state that may be cached in the accelerator, dropping |
| // any cached parameters/slices that have not been committed yet. |
| virtual void Reset() = 0; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(H264Accelerator); |
| }; |
| |
| H264Decoder(H264Accelerator* accelerator); |
| ~H264Decoder() override; |
| |
| // AcceleratedVideoDecoder implementation. |
| bool Flush() override WARN_UNUSED_RESULT; |
| void Reset() override; |
| void SetStream(const uint8_t* ptr, size_t size) override; |
| DecodeResult Decode() override WARN_UNUSED_RESULT; |
| gfx::Size GetPicSize() const override; |
| size_t GetRequiredNumOfPictures() const override; |
| |
| 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 = 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); |
| // Process current slice header to discover if we need to start a new picture, |
| // finishing up the current one. |
| bool PreprocessCurrentSlice(); |
| // Process current slice as a slice of the current picture. |
| bool ProcessCurrentSlice(); |
| |
| // Return true if we need to start a new picture. |
| bool IsNewPrimaryCodedPicture(const H264SliceHeader* slice_hdr) const; |
| |
| // Initialize the current picture according to data in |slice_hdr|. |
| bool InitCurrPicture(const H264SliceHeader* slice_hdr); |
| |
| // Initialize |pic| as a "non-existing" picture (see spec) with |frame_num|, |
| // to be used for frame gap concealment. |
| bool InitNonexistingPicture(scoped_refptr<H264Picture> pic, int frame_num); |
| |
| // Calculate picture order counts for |pic| on initialization |
| // of a new frame (see spec). |
| bool CalculatePicOrderCounts(scoped_refptr<H264Picture> pic); |
| |
| // Update PicNum values in pictures stored in DPB on creation of |
| // a picture with |frame_num|. |
| void UpdatePicNums(int frame_num); |
| |
| bool UpdateMaxNumReorderFrames(const H264SPS* sps); |
| |
| // Prepare reference picture lists for the current frame. |
| void PrepareRefPicLists(const H264SliceHeader* slice_hdr); |
| // Prepare reference picture lists for the given slice. |
| bool ModifyReferencePicLists(const H264SliceHeader* slice_hdr, |
| H264Picture::Vector* ref_pic_list0, |
| H264Picture::Vector* ref_pic_list1); |
| |
| // Construct initial reference picture lists for use in decoding of |
| // P and B pictures (see 8.2.4 in spec). |
| void ConstructReferencePicListsP(const H264SliceHeader* slice_hdr); |
| void ConstructReferencePicListsB(const H264SliceHeader* slice_hdr); |
| |
| // Helper functions for reference list construction, per spec. |
| int PicNumF(const scoped_refptr<H264Picture>& pic); |
| int LongTermPicNumF(const scoped_refptr<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(const H264SliceHeader* slice_hdr, |
| int list, |
| H264Picture::Vector* ref_pic_listx); |
| |
| // 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(scoped_refptr<H264Picture> pic); |
| bool ReferencePictureMarking(scoped_refptr<H264Picture> pic); |
| bool SlidingWindowPictureMarking(); |
| |
| // Handle a gap in frame_num in the stream up to |frame_num|, by creating |
| // "non-existing" pictures (see spec). |
| bool HandleFrameNumGap(int frame_num); |
| |
| // Start processing a new frame. |
| bool StartNewFrame(const H264SliceHeader* slice_hdr); |
| |
| // All data for a frame received, process it and decode. |
| bool FinishPrevFrameIfPresent(); |
| |
| // Called after we are done processing |pic|. Performs all operations to be |
| // done after decoding, including DPB management, reference picture marking |
| // and memory management operations. |
| // This will also output pictures if any have become ready to be outputted |
| // after processing |pic|. |
| bool FinishPicture(scoped_refptr<H264Picture> pic); |
| |
| // 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(); |
| |
| // Commits all pending data for HW decoder and starts HW decoder. |
| bool DecodePicture(); |
| |
| // Notifies client that a picture is ready for output. |
| void OutputPic(scoped_refptr<H264Picture> pic); |
| |
| // Output all pictures in DPB that have not been outputted yet. |
| bool OutputAllRemainingPics(); |
| |
| // Decoder state. |
| State state_; |
| |
| // Parser in use. |
| H264Parser parser_; |
| |
| // DPB in use. |
| H264DPB dpb_; |
| |
| // Picture currently being processed/decoded. |
| scoped_refptr<H264Picture> curr_pic_; |
| |
| // Reference picture lists, constructed for each frame. |
| H264Picture::Vector ref_pic_list_p0_; |
| H264Picture::Vector ref_pic_list_b0_; |
| H264Picture::Vector ref_pic_list_b1_; |
| |
| // Global state values, needed in decoding. See spec. |
| int max_frame_num_; |
| int max_pic_num_; |
| int max_long_term_frame_idx_; |
| size_t max_num_reorder_frames_; |
| |
| int prev_frame_num_; |
| int prev_ref_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_; |
| |
| // Current NALU and slice header being processed. |
| std::unique_ptr<H264NALU> curr_nalu_; |
| std::unique_ptr<H264SliceHeader> curr_slice_hdr_; |
| |
| // Output picture size. |
| gfx::Size pic_size_; |
| |
| // PicOrderCount of the previously outputted frame. |
| int last_output_poc_; |
| |
| H264Accelerator* accelerator_; |
| |
| DISALLOW_COPY_AND_ASSIGN(H264Decoder); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_GPU_H264_DECODER_H_ |