| // Copyright 2014 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_VIDEO_H264_POC_H_ |
| #define MEDIA_VIDEO_H264_POC_H_ |
| |
| #include <stdint.h> |
| |
| #include "base/macros.h" |
| |
| namespace media { |
| |
| struct H264SPS; |
| struct H264SliceHeader; |
| |
| class MEDIA_EXPORT H264POC { |
| public: |
| H264POC(); |
| ~H264POC(); |
| |
| // Returns the picture order count for a slice. |
| base::Optional<int32_t> ComputePicOrderCnt(const H264SPS* sps, |
| const H264SliceHeader& slice_hdr); |
| |
| // As specified, the POC of a frame with MMCO5 changes (to zero) after |
| // decoding. We instead return 0 immediately, and flag that this has occurred |
| // by returning true here until ComputePicOrderCnt() is called again. |
| // |
| // Frames with MMCO5 do not reorder relative to frames earlier in decode |
| // order, but may reorder relative to frames later in decode order (just like |
| // IDRs). |
| bool IsPendingMMCO5() { return pending_mmco5_; } |
| |
| // Reset computation state. It's best (although not strictly required) to call |
| // this after a seek. |
| void Reset(); |
| |
| private: |
| int32_t ref_pic_order_cnt_msb_; |
| int32_t ref_pic_order_cnt_lsb_; |
| int32_t prev_frame_num_; |
| int32_t prev_frame_num_offset_; |
| bool pending_mmco5_; |
| |
| DISALLOW_COPY_AND_ASSIGN(H264POC); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_VIDEO_H264_POC_H_ |