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Diffstat (limited to 'chromium/media/filters/h264_parser.h')
| -rw-r--r-- | chromium/media/filters/h264_parser.h | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/chromium/media/filters/h264_parser.h b/chromium/media/filters/h264_parser.h new file mode 100644 index 00000000000..3a60dcea650 --- /dev/null +++ b/chromium/media/filters/h264_parser.h @@ -0,0 +1,410 @@ +// 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. +// +// This file contains an implementation of an H264 Annex-B video stream parser. + +#ifndef MEDIA_FILTERS_H264_PARSER_H_ +#define MEDIA_FILTERS_H264_PARSER_H_ + +#include <sys/types.h> + +#include <map> + +#include "base/basictypes.h" +#include "media/base/media_export.h" +#include "media/filters/h264_bit_reader.h" + +namespace media { + +// For explanations of each struct and its members, see H.264 specification +// at http://www.itu.int/rec/T-REC-H.264. +struct MEDIA_EXPORT H264NALU { + H264NALU(); + + enum Type { + kUnspecified = 0, + kNonIDRSlice = 1, + kSliceDataA = 2, + kSliceDataB = 3, + kSliceDataC = 4, + kIDRSlice = 5, + kSEIMessage = 6, + kSPS = 7, + kPPS = 8, + kAUD = 9, + kEOSeq = 10, + kEOStream = 11, + kFiller = 12, + kSPSExt = 13, + kReserved14 = 14, + kReserved15 = 15, + kReserved16 = 16, + kReserved17 = 17, + kReserved18 = 18, + kCodedSliceAux = 19, + kCodedSliceExtension = 20, + }; + + // After (without) start code; we don't own the underlying memory + // and a shallow copy should be made when copying this struct. + const uint8* data; + off_t size; // From after start code to start code of next NALU (or EOS). + + int nal_ref_idc; + int nal_unit_type; +}; + +enum { + kH264ScalingList4x4Length = 16, + kH264ScalingList8x8Length = 64, +}; + +struct MEDIA_EXPORT H264SPS { + H264SPS(); + + int profile_idc; + bool constraint_set0_flag; + bool constraint_set1_flag; + bool constraint_set2_flag; + bool constraint_set3_flag; + bool constraint_set4_flag; + bool constraint_set5_flag; + int level_idc; + int seq_parameter_set_id; + + int chroma_format_idc; + bool separate_colour_plane_flag; + int bit_depth_luma_minus8; + int bit_depth_chroma_minus8; + bool qpprime_y_zero_transform_bypass_flag; + + bool seq_scaling_matrix_present_flag; + int scaling_list4x4[6][kH264ScalingList4x4Length]; + int scaling_list8x8[6][kH264ScalingList8x8Length]; + + int log2_max_frame_num_minus4; + int pic_order_cnt_type; + int log2_max_pic_order_cnt_lsb_minus4; + bool delta_pic_order_always_zero_flag; + int offset_for_non_ref_pic; + int offset_for_top_to_bottom_field; + int num_ref_frames_in_pic_order_cnt_cycle; + int expected_delta_per_pic_order_cnt_cycle; // calculated + int offset_for_ref_frame[255]; + int max_num_ref_frames; + bool gaps_in_frame_num_value_allowed_flag; + int pic_width_in_mbs_minus1; + int pic_height_in_map_units_minus1; + bool frame_mbs_only_flag; + bool mb_adaptive_frame_field_flag; + bool direct_8x8_inference_flag; + bool frame_cropping_flag; + int frame_crop_left_offset; + int frame_crop_right_offset; + int frame_crop_top_offset; + int frame_crop_bottom_offset; + + bool vui_parameters_present_flag; + int sar_width; // Set to 0 when not specified. + int sar_height; // Set to 0 when not specified. + bool bitstream_restriction_flag; + int max_num_reorder_frames; + int max_dec_frame_buffering; + + int chroma_array_type; +}; + +struct MEDIA_EXPORT H264PPS { + H264PPS(); + + int pic_parameter_set_id; + int seq_parameter_set_id; + bool entropy_coding_mode_flag; + bool bottom_field_pic_order_in_frame_present_flag; + int num_slice_groups_minus1; + // TODO(posciak): Slice groups not implemented, could be added at some point. + int num_ref_idx_l0_default_active_minus1; + int num_ref_idx_l1_default_active_minus1; + bool weighted_pred_flag; + int weighted_bipred_idc; + int pic_init_qp_minus26; + int pic_init_qs_minus26; + int chroma_qp_index_offset; + bool deblocking_filter_control_present_flag; + bool constrained_intra_pred_flag; + bool redundant_pic_cnt_present_flag; + bool transform_8x8_mode_flag; + + bool pic_scaling_matrix_present_flag; + int scaling_list4x4[6][kH264ScalingList4x4Length]; + int scaling_list8x8[6][kH264ScalingList8x8Length]; + + int second_chroma_qp_index_offset; +}; + +struct MEDIA_EXPORT H264ModificationOfPicNum { + int modification_of_pic_nums_idc; + union { + int abs_diff_pic_num_minus1; + int long_term_pic_num; + }; +}; + +struct MEDIA_EXPORT H264WeightingFactors { + bool luma_weight_flag; + bool chroma_weight_flag; + int luma_weight[32]; + int luma_offset[32]; + int chroma_weight[32][2]; + int chroma_offset[32][2]; +}; + +struct MEDIA_EXPORT H264DecRefPicMarking { + int memory_mgmnt_control_operation; + int difference_of_pic_nums_minus1; + int long_term_pic_num; + int long_term_frame_idx; + int max_long_term_frame_idx_plus1; +}; + +struct MEDIA_EXPORT H264SliceHeader { + H264SliceHeader(); + + enum { + kRefListSize = 32, + kRefListModSize = kRefListSize + }; + + enum Type { + kPSlice = 0, + kBSlice = 1, + kISlice = 2, + kSPSlice = 3, + kSISlice = 4, + }; + + bool IsPSlice() const; + bool IsBSlice() const; + bool IsISlice() const; + bool IsSPSlice() const; + bool IsSISlice() const; + + bool idr_pic_flag; // from NAL header + int nal_ref_idc; // from NAL header + const uint8* nalu_data; // from NAL header + off_t nalu_size; // from NAL header + off_t header_bit_size; // calculated + + int first_mb_in_slice; + int slice_type; + int pic_parameter_set_id; + int colour_plane_id; // TODO(posciak): use this! http://crbug.com/139878 + int frame_num; + bool field_pic_flag; + bool bottom_field_flag; + int idr_pic_id; + int pic_order_cnt_lsb; + int delta_pic_order_cnt_bottom; + int delta_pic_order_cnt[2]; + int redundant_pic_cnt; + bool direct_spatial_mv_pred_flag; + + bool num_ref_idx_active_override_flag; + int num_ref_idx_l0_active_minus1; + int num_ref_idx_l1_active_minus1; + bool ref_pic_list_modification_flag_l0; + bool ref_pic_list_modification_flag_l1; + H264ModificationOfPicNum ref_list_l0_modifications[kRefListModSize]; + H264ModificationOfPicNum ref_list_l1_modifications[kRefListModSize]; + + int luma_log2_weight_denom; + int chroma_log2_weight_denom; + + bool luma_weight_l0_flag; + bool chroma_weight_l0_flag; + H264WeightingFactors pred_weight_table_l0; + + bool luma_weight_l1_flag; + bool chroma_weight_l1_flag; + H264WeightingFactors pred_weight_table_l1; + + bool no_output_of_prior_pics_flag; + bool long_term_reference_flag; + + bool adaptive_ref_pic_marking_mode_flag; + H264DecRefPicMarking ref_pic_marking[kRefListSize]; + + int cabac_init_idc; + int slice_qp_delta; + bool sp_for_switch_flag; + int slice_qs_delta; + int disable_deblocking_filter_idc; + int slice_alpha_c0_offset_div2; + int slice_beta_offset_div2; +}; + +struct H264SEIRecoveryPoint { + int recovery_frame_cnt; + bool exact_match_flag; + bool broken_link_flag; + int changing_slice_group_idc; +}; + +struct MEDIA_EXPORT H264SEIMessage { + H264SEIMessage(); + + enum Type { + kSEIRecoveryPoint = 6, + }; + + int type; + int payload_size; + union { + // Placeholder; in future more supported types will contribute to more + // union members here. + H264SEIRecoveryPoint recovery_point; + }; +}; + +// Class to parse an Annex-B H.264 stream, +// as specified in chapters 7 and Annex B of the H.264 spec. +class MEDIA_EXPORT H264Parser { + public: + enum Result { + kOk, + kInvalidStream, // error in stream + kUnsupportedStream, // stream not supported by the parser + kEOStream, // end of stream + }; + + // Find offset from start of data to next NALU start code + // and size of found start code (3 or 4 bytes). + // If no start code is found, offset is pointing to the first unprocessed byte + // (i.e. the first byte that was not considered as a possible start of a start + // code) and |*start_code_size| is set to 0. + // Preconditions: + // - |data_size| >= 0 + // Postconditions: + // - |*offset| is between 0 and |data_size| included. + // It is strictly less than |data_size| if |data_size| > 0. + // - |*start_code_size| is either 0, 3 or 4. + static bool FindStartCode(const uint8* data, off_t data_size, + off_t* offset, off_t* start_code_size); + + H264Parser(); + ~H264Parser(); + + void Reset(); + // Set current stream pointer to |stream| of |stream_size| in bytes, + // |stream| owned by caller. + void SetStream(const uint8* stream, off_t stream_size); + + // Read the stream to find the next NALU, identify it and return + // that information in |*nalu|. This advances the stream to the beginning + // of this NALU, but not past it, so subsequent calls to NALU-specific + // parsing functions (ParseSPS, etc.) will parse this NALU. + // If the caller wishes to skip the current NALU, it can call this function + // again, instead of any NALU-type specific parse functions below. + Result AdvanceToNextNALU(H264NALU* nalu); + + // NALU-specific parsing functions. + // These should be called after AdvanceToNextNALU(). + + // SPSes and PPSes are owned by the parser class and the memory for their + // structures is managed here, not by the caller, as they are reused + // across NALUs. + // + // Parse an SPS/PPS NALU and save their data in the parser, returning id + // of the parsed structure in |*pps_id|/|*sps_id|. + // To get a pointer to a given SPS/PPS structure, use GetSPS()/GetPPS(), + // passing the returned |*sps_id|/|*pps_id| as parameter. + // TODO(posciak,fischman): consider replacing returning Result from Parse*() + // methods with a scoped_ptr and adding an AtEOS() function to check for EOS + // if Parse*() return NULL. + Result ParseSPS(int* sps_id); + Result ParsePPS(int* pps_id); + + // Return a pointer to SPS/PPS with given |sps_id|/|pps_id| or NULL if not + // present. + const H264SPS* GetSPS(int sps_id); + const H264PPS* GetPPS(int pps_id); + + // Slice headers and SEI messages are not used across NALUs by the parser + // and can be discarded after current NALU, so the parser does not store + // them, nor does it manage their memory. + // The caller has to provide and manage it instead. + + // Parse a slice header, returning it in |*shdr|. |*nalu| must be set to + // the NALU returned from AdvanceToNextNALU() and corresponding to |*shdr|. + Result ParseSliceHeader(const H264NALU& nalu, H264SliceHeader* shdr); + + // Parse a SEI message, returning it in |*sei_msg|, provided and managed + // by the caller. + Result ParseSEI(H264SEIMessage* sei_msg); + + private: + // Move the stream pointer to the beginning of the next NALU, + // i.e. pointing at the next start code. + // Return true if a NALU has been found. + // If a NALU is found: + // - its size in bytes is returned in |*nalu_size| and includes + // the start code as well as the trailing zero bits. + // - the size in bytes of the start code is returned in |*start_code_size|. + bool LocateNALU(off_t* nalu_size, off_t* start_code_size); + + // Exp-Golomb code parsing as specified in chapter 9.1 of the spec. + // Read one unsigned exp-Golomb code from the stream and return in |*val|. + Result ReadUE(int* val); + + // Read one signed exp-Golomb code from the stream and return in |*val|. + Result ReadSE(int* val); + + // Parse scaling lists (see spec). + Result ParseScalingList(int size, int* scaling_list, bool* use_default); + Result ParseSPSScalingLists(H264SPS* sps); + Result ParsePPSScalingLists(const H264SPS& sps, H264PPS* pps); + + // Parse optional VUI parameters in SPS (see spec). + Result ParseVUIParameters(H264SPS* sps); + // Set |hrd_parameters_present| to true only if they are present. + Result ParseAndIgnoreHRDParameters(bool* hrd_parameters_present); + + // Parse reference picture lists' modifications (see spec). + Result ParseRefPicListModifications(H264SliceHeader* shdr); + Result ParseRefPicListModification(int num_ref_idx_active_minus1, + H264ModificationOfPicNum* ref_list_mods); + + // Parse prediction weight table (see spec). + Result ParsePredWeightTable(const H264SPS& sps, H264SliceHeader* shdr); + + // Parse weighting factors (see spec). + Result ParseWeightingFactors(int num_ref_idx_active_minus1, + int chroma_array_type, + int luma_log2_weight_denom, + int chroma_log2_weight_denom, + H264WeightingFactors* w_facts); + + // Parse decoded reference picture marking information (see spec). + Result ParseDecRefPicMarking(H264SliceHeader* shdr); + + // Pointer to the current NALU in the stream. + const uint8* stream_; + + // Bytes left in the stream after the current NALU. + off_t bytes_left_; + + H264BitReader br_; + + // PPSes and SPSes stored for future reference. + typedef std::map<int, H264SPS*> SPSById; + typedef std::map<int, H264PPS*> PPSById; + SPSById active_SPSes_; + PPSById active_PPSes_; + + DISALLOW_COPY_AND_ASSIGN(H264Parser); +}; + +} // namespace media + +#endif // MEDIA_FILTERS_H264_PARSER_H_ |