h264_ps.h

Go to the documentation of this file.

/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
 
/**
 * @file
 * H.264 parameter set handling
 */
 
#ifndef AVCODEC_H264_PS_H
#define AVCODEC_H264_PS_H
 
#include <stdint.h>
 
#include "libavutil/buffer.h"
#include "libavutil/pixfmt.h"
#include "libavutil/rational.h"
 
#include "avcodec.h"
#include "get_bits.h"
#include "h264.h"
 
#define MAX_SPS_COUNT          32
#define MAX_PPS_COUNT         256
#define MAX_LOG2_MAX_FRAME_NUM    (12 + 4)
 
/**
 * Sequence parameter set
 */
typedef struct SPS {
    unsigned int sps_id;
    int profile_idc;
    int level_idc;
    int chroma_format_idc;
    int transform_bypass;              ///< qpprime_y_zero_transform_bypass_flag
    int log2_max_frame_num;            ///< log2_max_frame_num_minus4 + 4
    int poc_type;                      ///< pic_order_cnt_type
    int log2_max_poc_lsb;              ///< log2_max_pic_order_cnt_lsb_minus4
    int delta_pic_order_always_zero_flag;
    int offset_for_non_ref_pic;
    int offset_for_top_to_bottom_field;
    int poc_cycle_length;              ///< num_ref_frames_in_pic_order_cnt_cycle
    int ref_frame_count;               ///< num_ref_frames
    int gaps_in_frame_num_allowed_flag;
    int mb_width;                      ///< pic_width_in_mbs_minus1 + 1
    ///< (pic_height_in_map_units_minus1 + 1) * (2 - frame_mbs_only_flag)
    int mb_height;
    int frame_mbs_only_flag;
    int mb_aff;                        ///< mb_adaptive_frame_field_flag
    int direct_8x8_inference_flag;
    int crop;                          ///< frame_cropping_flag
 
    /* those 4 are already in luma samples */
    unsigned int crop_left;            ///< frame_cropping_rect_left_offset
    unsigned int crop_right;           ///< frame_cropping_rect_right_offset
    unsigned int crop_top;             ///< frame_cropping_rect_top_offset
    unsigned int crop_bottom;          ///< frame_cropping_rect_bottom_offset
    int vui_parameters_present_flag;
    AVRational sar;
    int video_signal_type_present_flag;
    int full_range;
    int colour_description_present_flag;
    enum AVColorPrimaries color_primaries;
    enum AVColorTransferCharacteristic color_trc;
    enum AVColorSpace colorspace;
    enum AVChromaLocation chroma_location;
 
    int timing_info_present_flag;
    uint32_t num_units_in_tick;
    uint32_t time_scale;
    int fixed_frame_rate_flag;
    int32_t offset_for_ref_frame[256];
    int bitstream_restriction_flag;
    int num_reorder_frames;
    int scaling_matrix_present;
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    int nal_hrd_parameters_present_flag;
    int vcl_hrd_parameters_present_flag;
    int pic_struct_present_flag;
    int time_offset_length;
    int cpb_cnt;                          ///< See H.264 E.1.2
    int initial_cpb_removal_delay_length; ///< initial_cpb_removal_delay_length_minus1 + 1
    int cpb_removal_delay_length;         ///< cpb_removal_delay_length_minus1 + 1
    int dpb_output_delay_length;          ///< dpb_output_delay_length_minus1 + 1
    int bit_depth_luma;                   ///< bit_depth_luma_minus8 + 8
    int bit_depth_chroma;                 ///< bit_depth_chroma_minus8 + 8
    int residual_color_transform_flag;    ///< residual_colour_transform_flag
    int constraint_set_flags;             ///< constraint_set[0-3]_flag
    uint8_t data[4096];
    size_t data_size;
} SPS;
 
/**
 * Picture parameter set
 */
typedef struct PPS {
    unsigned int sps_id;
    int cabac;                  ///< entropy_coding_mode_flag
    int pic_order_present;      ///< pic_order_present_flag
    int slice_group_count;      ///< num_slice_groups_minus1 + 1
    int mb_slice_group_map_type;
    unsigned int ref_count[2];  ///< num_ref_idx_l0/1_active_minus1 + 1
    int weighted_pred;          ///< weighted_pred_flag
    int weighted_bipred_idc;
    int init_qp;                ///< pic_init_qp_minus26 + 26
    int init_qs;                ///< pic_init_qs_minus26 + 26
    int chroma_qp_index_offset[2];
    int deblocking_filter_parameters_present; ///< deblocking_filter_parameters_present_flag
    int constrained_intra_pred;     ///< constrained_intra_pred_flag
    int redundant_pic_cnt_present;  ///< redundant_pic_cnt_present_flag
    int transform_8x8_mode;         ///< transform_8x8_mode_flag
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    uint8_t chroma_qp_table[2][QP_MAX_NUM+1];  ///< pre-scaled (with chroma_qp_index_offset) version of qp_table
    int chroma_qp_diff;
    uint8_t data[4096];
    size_t data_size;
 
    uint32_t dequant4_buffer[6][QP_MAX_NUM + 1][16];
    uint32_t dequant8_buffer[6][QP_MAX_NUM + 1][64];
    uint32_t(*dequant4_coeff[6])[16];
    uint32_t(*dequant8_coeff[6])[64];
 
    AVBufferRef *sps_ref;
    const SPS   *sps;
} PPS;
 
typedef struct H264ParamSets {
    AVBufferRef *sps_list[MAX_SPS_COUNT];
    AVBufferRef *pps_list[MAX_PPS_COUNT];
 
    AVBufferRef *pps_ref;
    /* currently active parameters sets */
    const PPS *pps;
    const SPS *sps;
 
    int overread_warning_printed[2];
} H264ParamSets;
 
/**
 * Decode SPS
 */
int ff_h264_decode_seq_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
                                     H264ParamSets *ps, int ignore_truncation);
 
/**
 * Decode PPS
 */
int ff_h264_decode_picture_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
                                         H264ParamSets *ps, int bit_length);
 
/**
 * Uninit H264 param sets structure.
 */
void ff_h264_ps_uninit(H264ParamSets *ps);
 
#endif /* AVCODEC_H264_PS_H */