Add VAVDA, the VAAPI Video Decode Accelerator for Intel CPUs.

content/common/gpu/media/vaapi_h264_decoder.h

+// 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 <queue>
+
+#include <GL/glx.h>
+
+#include "base/callback_forward.h"
+#include "base/lazy_instance.h"
+#include "base/memory/linked_ptr.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/gpu/media/h264_dpb.h"
+#include "content/common/gpu/media/h264_parser.h"
+#include "media/base/video_decoder_config.h"
+#include "media/base/limits.h"
+#include "third_party/libva/va/va.h"
+
+namespace content {
+
+// An H264 decoder for use for VA-API-specific decoding. Provides features not
+// supported by 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 pictures via client-provided |OutputPicCB|.
+//
+// If used in multi-threaded environment, some of the functions have to be
+// called on the child thread, i.e. the main thread of the GPU process
+// (the one that has the GLX context passed to Initialize() set as current).
+// This is essential so that the GLX calls can work properly.
+// Decoder thread, on the other hand, does not require a GLX context and should
+// be the same as the one on which Decode*() functions are called.
+class VaapiH264Decoder {
+ public:
+  // Callback invoked on the client when a picture is to be displayed.
+  // Callee has to call PutPicToTexture() for the given picture before
+  // displaying it, to ensure the contents have been synced properly.
+  // Arguments: input buffer id, output buffer id (both provided by the client
+  // at the time of Decode() and AssignPictureBuffer() calls).
+  typedef base::Callback<void(int32, int32)> OutputPicCB;
+
+  // 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.
+    kReadyToDecode,  // Successfully initialized.
+    kDecodedFrame,  // Successfully decoded a frame.
+    kNeedMoreStreamData,  // Need more stream data to decode the next frame.
+    kNoOutputAvailable,  // Waiting for the client to free up output surfaces.
+  };
+
+  VaapiH264Decoder();
+  // Should be called on the GLX thread, for the surface cleanup to work
+  // properly.
+  ~VaapiH264Decoder();
+
+  // Initializes and sets up libva connection and GL/X11 resources.
+  // Must be called on the GLX thread with |glx_context| being current and
+  // with decoder thread not yet running.
+  // |output_pic_cb| will be called to notify when a picture can be displayed.
+  bool Initialize(media::VideoCodecProfile profile,
+                  Display* x_display,
+                  GLXContext glx_context,
+                  const OutputPicCB& output_pic_cb);
+  void Destroy();
+
+  // Notify the decoder that this output buffer has been consumed and
+  // can be reused (overwritten).
+  // Must be run on the decoder thread.
+  void ReusePictureBuffer(int32 picture_buffer_id);
+
+  // Give a new picture buffer (texture) to decoder for use.
+  // Must be run on the GLX thread with decoder thread not yet running.
+  bool AssignPictureBuffer(int32 picture_buffer_id, uint32 texture_id);
+
+  // Sync the data so that the texture for given |picture_buffer_id| can
+  // be displayed.
+  // Must be run on the GLX thread.
+  bool PutPicToTexture(int32 picture_buffer_id);
+
+  // Have the decoder flush its state and trigger output of all previously
+  // decoded pictures via OutputPicCB.
+  // Returns false if any of the resulting invocations of the callback fail.
+  bool Flush();
+
+  // Called while decoding.
+  // Stop decoding, discarding all remaining input/output, but do not flush
+  // state, so the playback of the same stream can be resumed (possibly from
+  // another location).
+  void Reset();
+
+  // Set current stream data pointer to |ptr| and |size|.
+  // Must be run on decoder thread.
+  void SetStream(uint8* ptr, size_t size);
+
+  // Start parsing stream to detect picture sizes. Does not produce any
+  // decoded pictures and can be called without providing output textures.
+  // Also to be used after Reset() to find a suitable location in the
+  // stream to resume playback from.
+  DecResult DecodeInitial(int32 input_id);
+
+  // Runs until a frame is decoded or end of provided stream data buffer
+  // is reached. Decoded pictures will be returned asynchronously via
+  // OutputPicCB.
+  DecResult DecodeOneFrame(int32 input_id);
+
+  // Return dimensions for output buffer (texture) allocation.
+  // Valid only after a successful DecodeInitial().
+  int pic_height() { return pic_height_; }
+  int pic_width() { return pic_width_; }
+
+  // Return the number of output pictures required for decoding.
+  // Valid after a successful DecodeInitial().
+  static size_t GetRequiredNumOfPictures();
+
+ private:
+  // We need to keep at least 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.
+  enum { kNumReqPictures = H264DPB::kDPBMaxSize +
+      media::limits::kMaxVideoFrames + 2 };

[Ami GONE FROM CHROMIUM, 2012/05/03 23:22:53]

Why 2 and not 1?  (comment needs to match)

[Pawel Osciak, 2012/05/06 17:49:19]

Done.

+
+  // Internal state of the decoder.
+  enum State {
+    kUninitialized,  // Initialize() not yet called.
+    kInitialized,  // Initialize() called, pictures requested.
+    kDecoding,  // DecodeInitial() successful, output surfaces allocated.
+    kAfterReset,  // After Reset() during decoding.
+    kError,  // Error in kDecoding state.
+  };
+
+  // Get usable framebuffer configuration for use in binding textures
+  // or return false on failure.
+  bool InitializeFBConfig();
+
+  // Process H264 stream structures.
+  bool ProcessSPS(int sps_id);
+  bool ProcessPPS(int pps_id);
+  bool ProcessSlice(H264SliceHeader* slice_hdr);
+
+  // Initialize the current picture according to data in |slice_hdr|.
+  bool InitCurrPicture(H264SliceHeader* slice_hdr);
+
+  // Calculate picture order counts for the new picture
+  // on initialization of a new frame (see spec).
+  bool CalculatePicOrderCounts(H264SliceHeader* slice_hdr);
+
+  // Update PicNum values in pictures stored in DPB on creation of new
+  // frame (see spec).
+  void UpdatePicNums();
+
+  // Construct initial reference picture lists for use in decoding of
+  // P and B pictures (see 8.2.4 in spec).
+  void ConstructReferencePicListsP(H264SliceHeader* slice_hdr);
+  void ConstructReferencePicListsB(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(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(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();
+
+  // Convert VideoCodecProfile to VAProfile and set it as active.
+  bool SetProfile(media::VideoCodecProfile profile);
+
+  // Vaapi-related functions.
+
+  // Allocates VASurfaces and creates a VAContext for them.
+  bool CreateVASurfaces();
+
+  // Destroys allocated VASurfaces and related VAContext.
+  void DestroyVASurfaces();
+
+  // These queue up data for HW decoder to be committed on running HW decode.
+  bool SendPPS();
+  bool SendIQMatrix();
+  bool SendVASliceParam(H264SliceHeader* slice_hdr);
+  bool SendSliceData(const uint8* ptr, size_t size);
+  bool QueueSlice(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);
+
+  State state_;
+
+  // A frame has been sent to hardware as the result of the last
+  // DecodeOneFrame() call.
+  bool frame_ready_at_hw_;
+
+  // Parser in use.
+  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_;
+
+  int frame_num_;
+  int prev_frame_num_;
+  int prev_frame_num_offset_;
+
+  // 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.
+  int pic_width_;
+  int pic_height_;
+
+  // Data queued up for HW decoder, to be commited on next HW decode.
+  std::queue<VABufferID> pending_slice_bufs_;
+  std::queue<VABufferID> pending_va_bufs_;
+
+  // Manages binding of a client-provided output buffer (texture) to VASurface.
+  class DecodeSurface;
+
+  // Maps output_buffer_id to a decode surface. Used to look up surfaces
+  // on requests from the client.
+  typedef std::map<int32, linked_ptr<DecodeSurface> > DecodeSurfaces;
+  DecodeSurfaces decode_surfaces_;
+
+  // Number of decode surface currently available for decoding.
+  int num_available_decode_surfaces_;
+
+  // Maps decode surfaces to PicOrderCount, used to look up output buffers
+  // when a decision to output a picture has been made.
+  typedef std::map<int, DecodeSurface*> POCToDecodeSurfaces;
+  POCToDecodeSurfaces poc_to_decode_surfaces_;
+
+  // Find an available surface and assign it to given PicOrderCnt |poc|,
+  // removing it from the available surfaces pool. Return true if a surface
+  // has been found, false otherwise.
+  bool AssignSurfaceToPoC(int poc);
+
+  // Unassign a surface from |poc| and return a pointer to it, or NULL if there
+  // is no surface associated with given |poc|. Note that this does not make
+  // the surface available for reuse - as this can only happen after client
+  // returns the surface via ReusePictureBuffer() - but only removes its
+  // association with given |poc|.
+  DecodeSurface* UnassignSurfaceFromPoC(int poc);
+
+  // The id of current input buffer, which will be associated with an
+  // output picture if a frame is decoded successfully.
+  int32 curr_input_id_;
+
+  // X/GLX handles.
+  Display* x_display_;
+  GLXContext parent_glx_context_;
+  GLXFBConfig fb_config_;
+
+  // VA handles.
+  VADisplay va_display_;
+  VAConfigID va_config_id_;
+  VAContextID va_context_id_;
+  VAProfile profile_;
+
+  // Allocated VASurfaces.
+  VASurfaceID va_surface_ids_[kNumReqPictures];
+
+  // Called by decoder when a picture should be outputted.
+  OutputPicCB output_pic_cb_;
+
+  DISALLOW_COPY_AND_ASSIGN(VaapiH264Decoder);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_VAAPI_H264_DECODER_H_
+