ffmpeg-0.4.9-p20051120.rar_ffmpeg_ffmpeg源码分析

/* * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ /** * @file h264.c * H.264 / AVC / MPEG4 part10 codec. * @author Michael Niedermayer <michaelni@gmx.at> */ #include "common.h" #include "dsputil.h" #include "avcodec.h" #include "mpegvideo.h" #include "h264data.h" #include "golomb.h" #include "cabac.h" #undef NDEBUG #include <assert.h> #define interlaced_dct interlaced_dct_is_a_bad_name #define mb_intra mb_intra_isnt_initalized_see_mb_type #define LUMA_DC_BLOCK_INDEX 25 #define CHROMA_DC_BLOCK_INDEX 26 #define CHROMA_DC_COEFF_TOKEN_VLC_BITS 8 #define COEFF_TOKEN_VLC_BITS 8 #define TOTAL_ZEROS_VLC_BITS 9 #define CHROMA_DC_TOTAL_ZEROS_VLC_BITS 3 #define RUN_VLC_BITS 3 #define RUN7_VLC_BITS 6 #define MAX_SPS_COUNT 32 #define MAX_PPS_COUNT 256 #define MAX_MMCO_COUNT 66 /** * Sequence parameter set */ typedef struct SPS{ int profile_idc; int level_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; ///< frame_width_in_mbs_minus1 + 1 int mb_height; ///< frame_height_in_mbs_minus1 + 1 int frame_mbs_only_flag; int mb_aff; ///<mb_adaptive_frame_field_flag int direct_8x8_inference_flag; int crop; ///< frame_cropping_flag int crop_left; ///< frame_cropping_rect_left_offset int crop_right; ///< frame_cropping_rect_right_offset int crop_top; ///< frame_cropping_rect_top_offset int crop_bottom; ///< frame_cropping_rect_bottom_offset int vui_parameters_present_flag; AVRational sar; int timing_info_present_flag; uint32_t num_units_in_tick; uint32_t time_scale; int fixed_frame_rate_flag; short offset_for_ref_frame[256]; //FIXME dyn aloc? int bitstream_restriction_flag; int num_reorder_frames; int scaling_matrix_present; uint8_t scaling_matrix4[6][16]; uint8_t scaling_matrix8[2][64]; }SPS; /** * Picture parameter set */ typedef struct PPS{ 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; 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; 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[2][64]; }PPS; /** * Memory management control operation opcode. */ typedef enum MMCOOpcode{ MMCO_END=0, MMCO_SHORT2UNUSED, MMCO_LONG2UNUSED, MMCO_SHORT2LONG, MMCO_SET_MAX_LONG, MMCO_RESET, MMCO_LONG, } MMCOOpcode; /** * Memory management control operation. */ typedef struct MMCO{ MMCOOpcode opcode; int short_frame_num; int long_index; } MMCO; /** * H264Context */ typedef struct H264Context{ MpegEncContext s; int nal_ref_idc; int nal_unit_type; #define NAL_SLICE 1 #define NAL_DPA 2 #define NAL_DPB 3 #define NAL_DPC 4 #define NAL_IDR_SLICE 5 #define NAL_SEI 6 #define NAL_SPS 7 #define NAL_PPS 8 #define NAL_PICTURE_DELIMITER 9 #define NAL_FILTER_DATA 10 uint8_t *rbsp_buffer; int rbsp_buffer_size; /** * Used to parse AVC variant of h264 */ int is_avc; ///< this flag is != 0 if codec is avc1 int got_avcC; ///< flag used to parse avcC data only once int nal_length_size; ///< Number of bytes used for nal length (1, 2 or 4) int chroma_qp; //QPc int prev_mb_skipped; //FIXME remove (IMHO not used) //prediction stuff int chroma_pred_mode; int intra16x16_pred_mode; int top_mb_xy; int left_mb_xy[2]; int8_t intra4x4_pred_mode_cache[5*8]; int8_t (*intra4x4_pred_mode)[8]; void (*pred4x4 [9+3])(uint8_t *src, uint8_t *topright, int stride);//FIXME move to dsp? void (*pred8x8l [9+3])(uint8_t *src, int topleft, int topright, int stride); void (*pred8x8 [4+3])(uint8_t *src, int stride); void (*pred16x16[4+3])(uint8_t *src, int stride); unsigned int topleft_samples_available; unsigned int top_samples_available; unsigned int topright_samples_available; unsigned int left_samples_available; uint8_t (*top_borders[2])[16+2*8]; uint8_t left_border[2*(17+2*9)]; /** * non zero coeff count cache. * is 64 if not available. */ uint8_t non_zero_count_cache[6*8] __align8; uint8_t (*non_zero_count)[16]; /** * Motion vector cache. */ int16_t mv_cache[2][5*8][2] __align8; int8_t ref_cache[2][5*8] __align8; #define LIST_NOT_USED -1 //FIXME rename? #define PART_NOT_AVAILABLE -2 /** * is 1 if the specific list MV&references are set to 0,0,-2. */ int mv_cache_clean[2]; /** * number of neighbors (top and/or left) that used 8x8 dct */ int neighbor_transform_size; /** * block_offset[ 0..23] for frame macroblocks * block_offset[24..47] for field macroblocks */ int block_offset[2*(16+8)]; uint32_t *mb2b_xy; //FIXME are these 4 a good idea? uint32_t *mb2b8_xy; int b_stride; //FIXME use s->b4_stride int b8_stride; int halfpel_flag; int thirdpel_flag; int unknown_svq3_flag; int next_slice_index; SPS sps_buffer[MAX_SPS_COUNT]; SPS sps; ///< current sps PPS pps_buffer[MAX_PPS_COUNT]; /** * current pps */ PPS pps; //FIXME move to Picture perhaps? (->no) do we need that? uint32_t dequant4_buffer[6][52][16]; uint32_t dequant8_buffer[2][52][64]; uint32_t (*dequant4_coeff[6])[16]; uint32_t (*dequant8_coeff[2])[64]; int dequant_coeff_pps; ///< reinit tables when pps changes int slice_num; uint8_t *slice_table_base; uint8_t *slice_table; ///< slice_table_base + mb_stride + 1 int slice_type; int slice_type_fixed; //interlacing specific flags int mb_aff_frame; int mb_field_decoding_flag; int sub_mb_type[4]; //POC stuff int poc_lsb; int poc_msb; int delta_poc_bottom; int delta