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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef CONTENT_COMMON_GPU_MEDIA_H264_DECODER_H_ | |
6 #define CONTENT_COMMON_GPU_MEDIA_H264_DECODER_H_ | |
7 | |
8 #include <vector> | |
9 | |
10 #include "base/memory/ref_counted.h" | |
11 #include "base/memory/scoped_ptr.h" | |
12 #include "base/message_loop/message_loop_proxy.h" | |
13 #include "content/common/content_export.h" | |
14 #include "content/common/gpu/media/accelerated_video_decoder.h" | |
15 #include "content/common/gpu/media/h264_dpb.h" | |
16 #include "media/base/limits.h" | |
17 #include "media/filters/h264_parser.h" | |
18 #include "ui/gfx/geometry/size.h" | |
19 | |
20 namespace content { | |
21 | |
22 // Clients of this class are expected to pass H264 Annex-B byte stream | |
23 // and are expected to provide an implementation of H264Accelerator for | |
24 // offloading final steps of the decoding process. | |
25 // | |
26 // This class must be created, called and destroyed on a single thread, and | |
27 // does nothing internally on any other thread. | |
28 class CONTENT_EXPORT H264Decoder : public AcceleratedVideoDecoder { | |
29 public: | |
30 class CONTENT_EXPORT H264Accelerator { | |
31 public: | |
32 H264Accelerator(); | |
33 virtual ~H264Accelerator(); | |
34 | |
35 // Create a new H264Picture that the decoder client can use for decoding | |
36 // and pass back to this accelerator for decoding or reference. | |
37 // When the picture is no longer needed by decoder, it will just drop | |
38 // its reference to it, and it may do so at any time. | |
39 // Note that this may return nullptr if accelerator is not able to provide | |
40 // any new pictures at given time. The decoder is expected to handle | |
41 // this situation as normal and return from Decode() with kRanOutOfSurfaces. | |
42 virtual scoped_refptr<H264Picture> CreateH264Picture() = 0; | |
43 | |
44 // Submit metadata for the current frame, providing the current |sps| and | |
45 // |pps| for it, |dpb| has to contain all the pictures in DPB for current | |
46 // frame, and |ref_pic_p0/b0/b1| as specified in the H264 spec. Note that | |
47 // depending on the frame type, either p0, or b0 and b1 are used. |pic| | |
48 // contains information about the picture for the current frame. | |
49 // Note that this does not run decode in the accelerator and the decoder | |
50 // is expected to follow this call with one or more SubmitSlice() calls | |
51 // before calling SubmitDecode(). | |
52 // Return true if successful. | |
53 virtual bool SubmitFrameMetadata(const media::H264SPS* sps, | |
54 const media::H264PPS* pps, | |
55 const H264DPB& dpb, | |
56 const H264Picture::Vector& ref_pic_listp0, | |
57 const H264Picture::Vector& ref_pic_listb0, | |
58 const H264Picture::Vector& ref_pic_listb1, | |
59 const scoped_refptr<H264Picture>& pic) = 0; | |
60 | |
61 // Submit one slice for the current frame, passing the current |pps| and | |
62 // |pic| (same as in SubmitFrameMetadata()), the parsed header for the | |
63 // current slice in |slice_hdr|, and the reordered |ref_pic_listX|, | |
64 // as per H264 spec. | |
65 // |data| pointing to the full slice (including the unparsed header| of | |
66 // |size| in bytes. | |
67 // This must be called one or more times per frame, before SubmitDecode(). | |
68 // Note that |data| does not have to remain valid after this call returns. | |
69 // Return true if successful. | |
70 virtual bool SubmitSlice(const media::H264PPS* pps, | |
71 const media::H264SliceHeader* slice_hdr, | |
72 const H264Picture::Vector& ref_pic_list0, | |
73 const H264Picture::Vector& ref_pic_list1, | |
74 const scoped_refptr<H264Picture>& pic, | |
75 const uint8_t* data, | |
76 size_t size) = 0; | |
77 | |
78 // Execute the decode in hardware for |pic|, using all the slices and | |
79 // metadata submitted via SubmitFrameMetadata() and SubmitSlice() since | |
80 // the previous call to SubmitDecode(). | |
81 // Return true if successful. | |
82 virtual bool SubmitDecode(const scoped_refptr<H264Picture>& pic) = 0; | |
83 | |
84 // Schedule output (display) of |pic|. Note that returning from this | |
85 // method does not mean that |pic| has already been outputted (displayed), | |
86 // but guarantees that all pictures will be outputted in the same order | |
87 // as this method was called for them. Decoder may drop its reference | |
88 // to |pic| after calling this method. | |
89 // Return true if successful. | |
90 virtual bool OutputPicture(const scoped_refptr<H264Picture>& pic) = 0; | |
91 | |
92 private: | |
93 DISALLOW_COPY_AND_ASSIGN(H264Accelerator); | |
94 }; | |
95 | |
96 H264Decoder(H264Accelerator* accelerator); | |
97 ~H264Decoder() override; | |
98 | |
99 // content::AcceleratedVideoDecoder implementation. | |
100 bool Flush() override WARN_UNUSED_RESULT; | |
101 void Reset() override; | |
102 void SetStream(const uint8_t* ptr, size_t size) override; | |
103 DecodeResult Decode() override WARN_UNUSED_RESULT; | |
104 gfx::Size GetPicSize() const override { return pic_size_; } | |
105 size_t GetRequiredNumOfPictures() const override; | |
106 | |
107 private: | |
108 // We need to keep at most kDPBMaxSize pictures in DPB for | |
109 // reference/to display later and an additional one for the one currently | |
110 // being decoded. We also ask for some additional ones since VDA needs | |
111 // to accumulate a few ready-to-output pictures before it actually starts | |
112 // displaying and giving them back. +2 instead of +1 because of subjective | |
113 // smoothness improvement during testing. | |
114 enum { | |
115 kPicsInPipeline = media::limits::kMaxVideoFrames + 2, | |
116 kMaxNumReqPictures = H264DPB::kDPBMaxSize + kPicsInPipeline, | |
117 }; | |
118 | |
119 // Internal state of the decoder. | |
120 enum State { | |
121 kNeedStreamMetadata, // After initialization, need an SPS. | |
122 kDecoding, // Ready to decode from any point. | |
123 kAfterReset, // After Reset(), need a resume point. | |
124 kError, // Error in decode, can't continue. | |
125 }; | |
126 | |
127 // Process H264 stream structures. | |
128 bool ProcessSPS(int sps_id, bool* need_new_buffers); | |
129 bool ProcessPPS(int pps_id); | |
130 bool PreprocessSlice(media::H264SliceHeader* slice_hdr); | |
131 bool ProcessSlice(media::H264SliceHeader* slice_hdr); | |
132 | |
133 // Initialize the current picture according to data in |slice_hdr|. | |
134 bool InitCurrPicture(media::H264SliceHeader* slice_hdr); | |
135 | |
136 // Calculate picture order counts for the new picture | |
137 // on initialization of a new frame (see spec). | |
138 bool CalculatePicOrderCounts(media::H264SliceHeader* slice_hdr); | |
139 | |
140 // Update PicNum values in pictures stored in DPB on creation of new | |
141 // frame (see spec). | |
142 void UpdatePicNums(); | |
143 | |
144 bool UpdateMaxNumReorderFrames(const media::H264SPS* sps); | |
145 | |
146 // Prepare reference picture lists for the current frame. | |
147 void PrepareRefPicLists(media::H264SliceHeader* slice_hdr); | |
148 // Prepare reference picture lists for the given slice. | |
149 bool ModifyReferencePicLists(media::H264SliceHeader* slice_hdr, | |
150 H264Picture::Vector* ref_pic_list0, | |
151 H264Picture::Vector* ref_pic_list1); | |
152 | |
153 // Construct initial reference picture lists for use in decoding of | |
154 // P and B pictures (see 8.2.4 in spec). | |
155 void ConstructReferencePicListsP(media::H264SliceHeader* slice_hdr); | |
156 void ConstructReferencePicListsB(media::H264SliceHeader* slice_hdr); | |
157 | |
158 // Helper functions for reference list construction, per spec. | |
159 int PicNumF(const scoped_refptr<H264Picture>& pic); | |
160 int LongTermPicNumF(const scoped_refptr<H264Picture>& pic); | |
161 | |
162 // Perform the reference picture lists' modification (reordering), as | |
163 // specified in spec (8.2.4). | |
164 // | |
165 // |list| indicates list number and should be either 0 or 1. | |
166 bool ModifyReferencePicList(media::H264SliceHeader* slice_hdr, | |
167 int list, | |
168 H264Picture::Vector* ref_pic_listx); | |
169 | |
170 // Perform reference picture memory management operations (marking/unmarking | |
171 // of reference pictures, long term picture management, discarding, etc.). | |
172 // See 8.2.5 in spec. | |
173 bool HandleMemoryManagementOps(); | |
174 void ReferencePictureMarking(); | |
175 | |
176 // Start processing a new frame. | |
177 bool StartNewFrame(media::H264SliceHeader* slice_hdr); | |
178 | |
179 // All data for a frame received, process it and decode. | |
180 bool FinishPrevFrameIfPresent(); | |
181 | |
182 // Called after decoding, performs all operations to be done after decoding, | |
183 // including DPB management, reference picture marking and memory management | |
184 // operations. | |
185 // This will also output a picture if one is ready for output. | |
186 bool FinishPicture(); | |
187 | |
188 // Clear DPB contents and remove all surfaces in DPB from *in_use_ list. | |
189 // Cleared pictures will be made available for decode, unless they are | |
190 // at client waiting to be displayed. | |
191 void ClearDPB(); | |
192 | |
193 // Commits all pending data for HW decoder and starts HW decoder. | |
194 bool DecodePicture(); | |
195 | |
196 // Notifies client that a picture is ready for output. | |
197 void OutputPic(scoped_refptr<H264Picture> pic); | |
198 | |
199 // Output all pictures in DPB that have not been outputted yet. | |
200 bool OutputAllRemainingPics(); | |
201 | |
202 // Decoder state. | |
203 State state_; | |
204 | |
205 // Parser in use. | |
206 media::H264Parser parser_; | |
207 | |
208 // DPB in use. | |
209 H264DPB dpb_; | |
210 | |
211 // Picture currently being processed/decoded. | |
212 scoped_refptr<H264Picture> curr_pic_; | |
213 | |
214 // Reference picture lists, constructed for each frame. | |
215 H264Picture::Vector ref_pic_list_p0_; | |
216 H264Picture::Vector ref_pic_list_b0_; | |
217 H264Picture::Vector ref_pic_list_b1_; | |
218 | |
219 // Global state values, needed in decoding. See spec. | |
220 int max_pic_order_cnt_lsb_; | |
221 int max_frame_num_; | |
222 int max_pic_num_; | |
223 int max_long_term_frame_idx_; | |
224 size_t max_num_reorder_frames_; | |
225 | |
226 int frame_num_; | |
227 int prev_frame_num_; | |
228 int prev_frame_num_offset_; | |
229 bool prev_has_memmgmnt5_; | |
230 | |
231 // Values related to previously decoded reference picture. | |
232 bool prev_ref_has_memmgmnt5_; | |
233 int prev_ref_top_field_order_cnt_; | |
234 int prev_ref_pic_order_cnt_msb_; | |
235 int prev_ref_pic_order_cnt_lsb_; | |
236 H264Picture::Field prev_ref_field_; | |
237 | |
238 // Currently active SPS and PPS. | |
239 int curr_sps_id_; | |
240 int curr_pps_id_; | |
241 | |
242 // Current NALU and slice header being processed. | |
243 scoped_ptr<media::H264NALU> curr_nalu_; | |
244 scoped_ptr<media::H264SliceHeader> curr_slice_hdr_; | |
245 | |
246 // Output picture size. | |
247 gfx::Size pic_size_; | |
248 | |
249 // PicOrderCount of the previously outputted frame. | |
250 int last_output_poc_; | |
251 | |
252 H264Accelerator* accelerator_; | |
253 | |
254 DISALLOW_COPY_AND_ASSIGN(H264Decoder); | |
255 }; | |
256 | |
257 } // namespace content | |
258 | |
259 #endif // CONTENT_COMMON_GPU_MEDIA_H264_DECODER_H_ | |
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