x265-1.7版本-x265.h代码注释
2024-05-10 09:41:00
注：问号以及未注释部分 会在x265-1.8版本内更新
/*****************************************************************************
* Copyright (C) 2013 x265 project
*
* Authors: Steve Borho <steve@borho.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
*
* This program is also available under a commercial proprietary license.
* For more information, contact us at license @ x265.com.
*****************************************************************************/
#ifndef X265_H
#define X265_H
#include <stdint.h>
#include "x265_config.h"
#ifdef __cplusplus
extern "C" {
#endif
/* x265_encoder:
* opaque handler for encoder */
typedef struct x265_encoder x265_encoder;
/* Application developers planning to link against a shared library version of
* libx265 from a Microsoft Visual Studio or similar development environment
* will need to define X265_API_IMPORTS before including this header.
* This clause does not apply to MinGW, similar development environments, or non
* Windows platforms. */
#ifdef X265_API_IMPORTS
#define X265_API __declspec(dllimport)
#else
#define X265_API
#endif
//IRAP(Intra Random Access Point） 参考IRAP且在前面的称为前置图像 参考IRAP且在后面的称为后置图像
//前置图像: RADL(Random Access Decodable Leading)(不依赖IRAP前的帧) RASL（Random Access Skipped Leading)(依赖IRAP前的帧)
//三种IRAP IDR(Instantaneous Decoding Refresh) CRA(Clean Random Access) BLA(Broken Link Access)
//IDR 要求前置图像必须是RADL 即 IDR后续帧不依赖IDR前向帧
//CRA 允许前置图像是RASL（编码效率高） 直接从CRA进入，则其前置图像RASL的不能解码
//BLA 如果直接从CRA介入，其前置RASL不能解码，则此图像被称为BLA
//时域号：关键帧号为0 底层不参考高层 最高为6
//下切换：从任何图像开始，可以丢弃其后（码率顺序）具有更高时域层标识号的图像
//上切换：从某一图像开始，可以发送具有该图像时域层标示号的图像，而该图像之前发送的图像的时域标示号小于该图像的时域标识号。 要求：从这个图像开始，其所在时域层内的所有图像不依赖该图像之前(码流顺序)相同时域层中的图像
//TSA（Temporal Sub-layer Access）和 STSA(Step-wise Temporal Sub-layer Access)，用于标识时域子层切换点，即从这些图像开始可以进行时域子层上切换
//STSA：从该图像可以切换到该图像所属的时域层，要求：同一层中后续帧不依赖该图像之前的图像
//TSA：可以切换到大于或等于该图像时域层的图像
typedef enum
{
NAL_UNIT_CODED_SLICE_TRAIL_N = 0,//未被参考的后置图像，且非TSA、非STSA的视频片段
NAL_UNIT_CODED_SLICE_TRAIL_R, //被参考的后置图像，且非TSA、非STSA的视频片段
NAL_UNIT_CODED_SLICE_TSA_N,//未被参考的TSA图像 在时域子层打开的时候有
NAL_UNIT_CODED_SLICE_TLA_R, //被参考的TSA图像 不应该是TLA？？？ x265中未使用
NAL_UNIT_CODED_SLICE_STSA_N,//不被参考的STSA图像 x265中未使用
NAL_UNIT_CODED_SLICE_STSA_R,//被参考的STSA图像 x265中未使用
NAL_UNIT_CODED_SLICE_RADL_N,//RADL 前置图像(不依赖IRAP前的帧) 不被参考的前置图像 只在openGOP关闭才会有此类型
NAL_UNIT_CODED_SLICE_RADL_R,//RADL 前置图像(不依赖IRAP前的帧) 被参考的前置图像 只在openGOP关闭才会有此类型
NAL_UNIT_CODED_SLICE_RASL_N,//RASL 前置图像(依赖IRAP前的帧) 不被参考的前置图像 只在openGOP打开才会有此类型
NAL_UNIT_CODED_SLICE_RASL_R,//RASL 前置图像(依赖IRAP前的帧) 被参考的前置图像 只在openGOP打开才会有此类型
NAL_UNIT_CODED_SLICE_BLA_W_LP = 16,//BLA x265中未使用 未完成
NAL_UNIT_CODED_SLICE_BLA_W_RADL,//RADL BLA 前置图像(不依赖IRAP前的帧) x265中未使用 未完成
NAL_UNIT_CODED_SLICE_BLA_N_LP, //BLA x265中未使用 未完成
NAL_UNIT_CODED_SLICE_IDR_W_RADL,//RADL IDR 前置图像(不依赖IRAP前的帧) 可能有RADL图像的SS(视频片段)编码数据
NAL_UNIT_CODED_SLICE_IDR_N_LP,//IDR 未完成
NAL_UNIT_CODED_SLICE_CRA,//CRA 关键帧 在openGOP时使用
NAL_UNIT_VPS = 32,
NAL_UNIT_SPS,
NAL_UNIT_PPS,
NAL_UNIT_ACCESS_UNIT_DELIMITER,
NAL_UNIT_EOS,
NAL_UNIT_EOB,
NAL_UNIT_FILLER_DATA,
NAL_UNIT_PREFIX_SEI,
NAL_UNIT_SUFFIX_SEI,
NAL_UNIT_INVALID = 64,
} NalUnitType;
/* The data within the payload is already NAL-encapsulated; the type is merely
* in the struct for easy access by the calling application. All data returned
* in an x265_nal, including the data in payload, is no longer valid after the
* next call to x265_encoder_encode. Thus it must be used or copied before
* calling x265_encoder_encode again. */
typedef struct x265_nal
{
uint32_t type; /* NalUnitType */
uint32_t sizeBytes; /* size in bytes */
uint8_t* payload;
} x265_nal;
/* Stores all analysis data for a single frame */
typedef struct x265_analysis_data
{
void* interData;
void* intraData;
uint32_t frameRecordSize;
uint32_t poc;
uint32_t sliceType;
uint32_t numCUsInFrame;
uint32_t numPartitions;
} x265_analysis_data;
/* Used to pass pictures into the encoder, and to get picture data back out of
* the encoder. The input and output semantics are different */
typedef struct x265_picture
{
/* presentation time stamp: user-specified, returned on output */
int64_t pts;//显示时间戳，在编码器内环里一般就是poc的值，用于标记显示的顺序
/* display time stamp: ignored on input, copied from reordered pts. Returned
* on output */
int64_t dts;
/* force quantizer for != X265_QP_AUTO */
/* The value provided on input is returned with the same picture (POC) on
* output */
void* userData;
/* Must be specified on input pictures, the number of planes is determined
* by the colorSpace value */
void* planes[3];
/* Stride is the number of bytes between row starts */
int stride[3];
/* Must be specified on input pictures. x265_picture_init() will set it to
* the encoder's internal bit depth, but this field must describe the depth
* of the input pictures. Must be between 8 and 16. Values larger than 8
* imply 16bits per input sample. If input bit depth is larger than the
* internal bit depth, the encoder will down-shift pixels. Input samples
* larger than 8bits will be masked to internal bit depth. On output the
* bitDepth will be the internal encoder bit depth */
int bitDepth;
/* Must be specified on input pictures: X265_TYPE_AUTO or other.
* x265_picture_init() sets this to auto, returned on output */
int sliceType;
/* Ignored on input, set to picture count, returned on output */
int poc;
/* Must be specified on input pictures: X265_CSP_I420 or other. It must
* match the internal color space of the encoder. x265_picture_init() will
* initialize this value to the internal color space */
int colorSpace;
/* Force the slice base QP for this picture within the encoder. Set to 0
* to allow the encoder to determine base QP */
int forceqp;
/* If param.analysisMode is X265_ANALYSIS_OFF this field is ignored on input
* and output. Else the user must call x265_alloc_analysis_data() to
* allocate analysis buffers for every picture passed to the encoder.
*
* On input when param.analysisMode is X265_ANALYSIS_LOAD and analysisData
* member pointers are valid, the encoder will use the data stored here to
* reduce encoder work.
*
* On output when param.analysisMode is X265_ANALYSIS_SAVE and analysisData
* member pointers are valid, the encoder will write output analysis into
* this data structure */
x265_analysis_data analysisData;
} x265_picture;
typedef enum
{
X265_DIA_SEARCH, // 菱形搜索
X265_HEX_SEARCH, // 六边形搜索
X265_UMH_SEARCH, // UMH搜索
X265_STAR_SEARCH,// 星型搜索，与HM中的TZ很像，但是有一些区别
X265_FULL_SEARCH // 全搜索
} X265_ME_METHODS;
/* CPU flags */
/* x86 */
#define X265_CPU_CMOV 0x0000001
#define X265_CPU_MMX 0x0000002
#define X265_CPU_MMX2 0x0000004 /* MMX2 aka MMXEXT aka ISSE */
#define X265_CPU_MMXEXT X265_CPU_MMX2
#define X265_CPU_SSE 0x0000008
#define X265_CPU_SSE2 0x0000010
#define X265_CPU_SSE3 0x0000020
#define X265_CPU_SSSE3 0x0000040
#define X265_CPU_SSE4 0x0000080 /* SSE4.1 */
#define X265_CPU_SSE42 0x0000100 /* SSE4.2 */
#define X265_CPU_LZCNT 0x0000200 /* Phenom support for "leading zero count" instruction. */
#define X265_CPU_AVX 0x0000400 /* AVX support: requires OS support even if YMM registers aren't used. */
#define X265_CPU_XOP 0x0000800 /* AMD XOP */
#define X265_CPU_FMA4 0x0001000 /* AMD FMA4 */
#define X265_CPU_AVX2 0x0002000 /* AVX2 */
#define X265_CPU_FMA3 0x0004000 /* Intel FMA3 */
#define X265_CPU_BMI1 0x0008000 /* BMI1 */
#define X265_CPU_BMI2 0x0010000 /* BMI2 */
/* x86 modifiers */
#define X265_CPU_CACHELINE_32 0x0020000 /* avoid memory loads that span the border between two cachelines */
#define X265_CPU_CACHELINE_64 0x0040000 /* 32/64 is the size of a cacheline in bytes */
#define X265_CPU_SSE2_IS_SLOW 0x0080000 /* avoid most SSE2 functions on Athlon64 */
#define X265_CPU_SSE2_IS_FAST 0x0100000 /* a few functions are only faster on Core2 and Phenom */
#define X265_CPU_SLOW_SHUFFLE 0x0200000 /* The Conroe has a slow shuffle unit (relative to overall SSE performance) */
#define X265_CPU_STACK_MOD4 0x0400000 /* if stack is only mod4 and not mod16 */
#define X265_CPU_SLOW_CTZ 0x0800000 /* BSR/BSF x86 instructions are really slow on some CPUs */
#define X265_CPU_SLOW_ATOM 0x1000000 /* The Atom is terrible: slow SSE unaligned loads, slow
* SIMD multiplies, slow SIMD variable shifts, slow pshufb,
* cacheline split penalties -- gather everything here that
* isn't shared by other CPUs to avoid making half a dozen
* new SLOW flags. */
#define X265_CPU_SLOW_PSHUFB 0x2000000 /* such as on the Intel Atom */
#define X265_CPU_SLOW_PALIGNR 0x4000000 /* such as on the AMD Bobcat */
/* ARM */
#define X265_CPU_ARMV6 0x0000001
#define X265_CPU_NEON 0x0000002 /* ARM NEON */
#define X265_CPU_FAST_NEON_MRC 0x0000004 /* Transfer from NEON to ARM register is fast (Cortex-A9) */
#define X265_MAX_SUBPEL_LEVEL 7
/* Log level */
#define X265_LOG_NONE (-1)
#define X265_LOG_ERROR 0
#define X265_LOG_WARNING 1
#define X265_LOG_INFO 2
#define X265_LOG_FRAME 3
#define X265_LOG_DEBUG 4
#define X265_LOG_FULL 5
#define X265_B_ADAPT_NONE 0
#define X265_B_ADAPT_FAST 1
#define X265_B_ADAPT_TRELLIS 2
#define X265_REF_LIMIT_DEPTH 1
#define X265_REF_LIMIT_CU 2
#define X265_BFRAME_MAX 16
#define X265_MAX_FRAME_THREADS 16
#define X265_TYPE_AUTO 0x0000 /* Let x265 choose the right type */
#define X265_TYPE_IDR 0x0001
#define X265_TYPE_I 0x0002
#define X265_TYPE_P 0x0003
#define X265_TYPE_BREF 0x0004 /* Non-disposable B-frame */
#define X265_TYPE_B 0x0005
#define IS_X265_TYPE_I(x) ((x) == X265_TYPE_I || (x) == X265_TYPE_IDR)
#define IS_X265_TYPE_B(x) ((x) == X265_TYPE_B || (x) == X265_TYPE_BREF)
#define X265_QP_AUTO 0
#define X265_AQ_NONE 0
#define X265_AQ_VARIANCE 1
#define X265_AQ_AUTO_VARIANCE 2
/* NOTE! For this release only X265_CSP_I420 and X265_CSP_I444 are supported */
/* Supported internal color space types (according to semantics of chroma_format_idc) */
#define X265_CSP_I400 0 /* yuv 4:0:0 planar */
#define X265_CSP_I420 1 /* yuv 4:2:0 planar */
#define X265_CSP_I422 2 /* yuv 4:2:2 planar */
#define X265_CSP_I444 3 /* yuv 4:4:4 planar */
#define X265_CSP_COUNT 4 /* Number of supported internal color spaces */
/* These color spaces will eventually be supported as input pictures. The pictures will
* be converted to the appropriate planar color spaces at ingest */
#define X265_CSP_NV12 4 /* yuv 4:2:0, with one y plane and one packed u+v */
#define X265_CSP_NV16 5 /* yuv 4:2:2, with one y plane and one packed u+v */
/* Interleaved color-spaces may eventually be supported as input pictures */
#define X265_CSP_BGR 6 /* packed bgr 24bits */
#define X265_CSP_BGRA 7 /* packed bgr 32bits */
#define X265_CSP_RGB 8 /* packed rgb 24bits */
#define X265_CSP_MAX 9 /* end of list */
#define X265_EXTENDED_SAR 255 /* aspect ratio explicitly specified as width:height */
/* Analysis options */
#define X265_ANALYSIS_OFF 0
#define X265_ANALYSIS_SAVE 1
#define X265_ANALYSIS_LOAD 2
typedef struct x265_cli_csp
{
int planes;
int width[3];
int height[3];
} x265_cli_csp;
static const x265_cli_csp x265_cli_csps[] =
{
{ 1, { 0, 0, 0 }, { 0, 0, 0 } }, /* i400 */
{ 3, { 0, 1, 1 }, { 0, 1, 1 } }, /* i420 */
{ 3, { 0, 1, 1 }, { 0, 0, 0 } }, /* i422 */
{ 3, { 0, 0, 0 }, { 0, 0, 0 } }, /* i444 */
{ 2, { 0, 0 }, { 0, 1 } }, /* nv12 */
{ 2, { 0, 0 }, { 0, 0 } }, /* nv16 */
};
/* rate tolerance method */
typedef enum
{
X265_RC_ABR,//可用比特率（ABR: available bit-rate） 固定码率
X265_RC_CQP,//固定QP模式
X265_RC_CRF
} X265_RC_METHODS;
/* Output statistics from encoder */
typedef struct x265_stats
{
double globalPsnrY;
double globalPsnrU;
double globalPsnrV;
double globalPsnr;
double globalSsim;
double elapsedEncodeTime; /* wall time since encoder was opened */
double elapsedVideoTime; /* encoded picture count / frame rate */
double bitrate; /* accBits / elapsed video time */
uint64_t accBits; /* total bits output thus far */
uint32_t encodedPictureCount; /* number of output pictures thus far */
uint32_t totalWPFrames; /* number of uni-directional weighted frames used */
} x265_stats;
/* String values accepted by x265_param_parse() (and CLI) for various parameters */
static const char * const x265_motion_est_names[] = { "dia", "hex", "umh", "star", "full", 0 };
static const char * const x265_source_csp_names[] = { "i400", "i420", "i422", "i444", "nv12", "nv16", 0 };
static const char * const x265_video_format_names[] = { "component", "pal", "ntsc", "secam", "mac", "undef", 0 };
static const char * const x265_fullrange_names[] = { "limited", "full", 0 };
static const char * const x265_colorprim_names[] = { "", "bt709", "undef", "", "bt470m", "bt470bg", "smpte170m", "smpte240m", "film", "bt2020", 0 };
static const char * const x265_transfer_names[] = { "", "bt709", "undef", "", "bt470m", "bt470bg", "smpte170m", "smpte240m", "linear", "log100",
"log316", "iec61966-2-4", "bt1361e", "iec61966-2-1", "bt2020-10", "bt2020-12",
"smpte-st-2084", "smpte-st-428", 0 };
static const char * const x265_colmatrix_names[] = { "GBR", "bt709", "undef", "", "fcc", "bt470bg", "smpte170m", "smpte240m",
"YCgCo", "bt2020nc", "bt2020c", 0 };
static const char * const x265_sar_names[] = { "undef", "1:1", "12:11", "10:11", "16:11", "40:33", "24:11", "20:11",
"32:11", "80:33", "18:11", "15:11", "64:33", "160:99", "4:3", "3:2", "2:1", 0 };
static const char * const x265_interlace_names[] = { "prog", "tff", "bff", 0 };
static const char * const x265_analysis_names[] = { "off", "save", "load", 0 };
/* Zones: override ratecontrol for specific sections of the video.
* If zones overlap, whichever comes later in the list takes precedence. */
typedef struct x265_zone
{
int startFrame, endFrame; /* range of frame numbers */
int bForceQp; /* whether to use qp vs bitrate factor */
int qp;
float bitrateFactor;
} x265_zone;
/* x265 input parameters
*
* For version safety you may use x265_param_alloc/free() to manage the
* allocation of x265_param instances, and x265_param_parse() to assign values
* by name. By never dereferencing param fields in your own code you can treat
* x265_param as an opaque data structure */
typedef struct x265_param
{
/* x265_param_default() will auto-detect this cpu capability bitmap. it is
* recommended to not change this value unless you know the cpu detection is
* somehow flawed on your target hardware. The asm function tables are
* process global, the first encoder configures them for all encoders */
int cpuid;
/*== Parallelism Features ==*/
/* Number of concurrently encoded frames between 1 and X265_MAX_FRAME_THREADS
* or 0 for auto-detection. By default x265 will use a number of frame
* threads empirically determined to be optimal for your CPU core count,
* between 2 and 6. Using more than one frame thread causes motion search
* in the down direction to be clamped but otherwise encode behavior is
* unaffected. With CQP rate control the output bitstream is deterministic
* for all values of frameNumThreads greater than 1. All other forms of
* rate-control can be negatively impacted by increases to the number of
* frame threads because the extra concurrency adds uncertainty to the
* bitrate estimations. Frame parallelism is generally limited by the the
* is generally limited by the the number of CU rows
*
* When thread pools are used, each frame thread is assigned to a single
* pool and the frame thread itself is given the node affinity of its pool.
* But when no thread pools are used no node affinity is assigned. */
int frameNumThreads;//同时几个frame编码，0：自动检测（根据内核数） 1 ~ X265_MAX_FRAME_THREADS 表示有几个同时编码 ，默认为内核数
/* Comma seperated list of threads per NUMA node. If "none", then no worker
* pools are created and only frame parallelism is possible. If NULL or ""
* (default) x265 will use all available threads on each NUMA node.
*
* '+' is a special value indicating all cores detected on the node
* '*' is a special value indicating all cores detected on the node and all
* remaining nodes.
* '-' is a special value indicating no cores on the node, same as '0'
*
* example strings for a 4-node system:
* "" - default, unspecified, all numa nodes are used for thread pools
* "*" - same as default
* "none" - no thread pools are created, only frame parallelism possible
* "-" - same as "none"
* "10" - allocate one pool, using up to 10 cores on node 0
* "-,+" - allocate one pool, using all cores on node 1
* "+,-,+" - allocate two pools, using all cores on nodes 0 and 2
* "+,-,+,-" - allocate two pools, using all cores on nodes 0 and 2
* "-,*" - allocate three pools, using all cores on nodes 1, 2 and 3
* "8,8,8,8" - allocate four pools with up to 8 threads in each pool
*
* The total number of threads will be determined by the number of threads
* assigned to all nodes. The worker threads will each be given affinity for
* their node, they will not be allowed to migrate between nodes, but they
* will be allowed to move between CPU cores within their node.
*
* If the three pool features: bEnableWavefront, bDistributeModeAnalysis and
* bDistributeMotionEstimation are all disabled, then numaPools is ignored
* and no thread pools are created.
*
* If "none" is specified, then all three of the thread pool features are
* implicitly disabled.
*
* Multiple thread pools will be allocated for any NUMA node with more than
* 64 logical CPU cores. But any given thread pool will always use at most
* one NUMA node.
*
* Frame encoders are distributed between the available thread pools, and
* the encoder will never generate more thread pools than frameNumThreads */
const char* numaPools;
/* Enable wavefront parallel processing, greatly increases parallelism for
* less than 1% compression efficiency loss. Requires a thread pool, enabled
* by default */
int bEnableWavefront; // 波前并行处理 (Wavefront Parallel Processing,WPP） 默认打开（行并行）
/* Use multiple threads to measure CU mode costs. Recommended for many core
* CPUs. On RD levels less than 5, it may not offload enough work to warrant
* the overhead. It is useful with the slow preset since it has the
* rectangular predictions enabled. At RD level 5 and 6 (preset slower and
* below), this feature should be an unambiguous win if you have CPU
* cores available for work. Default disabled */
int bDistributeModeAnalysis;
/* Use multiple threads to perform motion estimation to (ME to one reference
* per thread). Recommended for many core CPUs. The more references the more
* motion searches there will be to distribute. This option is often not a
* win, particularly in video sequences with low motion. Default disabled */
int bDistributeMotionEstimation;
/*== Logging Features ==*/
/* Enable analysis and logging distribution of CUs encoded across various
* modes during mode decision. Default disabled */
int bLogCuStats;
/* Enable the measurement and reporting of PSNR. Default is enabled */
int bEnablePsnr;
/* Enable the measurement and reporting of SSIM. Default is disabled */
int bEnableSsim;
/* The level of logging detail emitted by the encoder. X265_LOG_NONE to
* X265_LOG_FULL, default is X265_LOG_INFO */
int logLevel;
/* filename of CSV log. If logLevel greater than or equal to X265_LOG_FRAME,
* the encoder will emit per-slice statistics to this log file in encode
* order. Otherwise the encoder will emit per-stream statistics into the log
* file when x265_encoder_log is called (presumably at the end of the
* encode) */
const char* csvfn;
/*== Internal Picture Specification ==*/
/* Internal encoder bit depth. If x265 was compiled to use 8bit pixels
* (HIGH_BIT_DEPTH=0), this field must be 8, else this field must be 10.
* Future builds may support 12bit pixels. */
int internalBitDepth;
/* Color space of internal pictures, must match color space of input
* pictures */
int internalCsp;
/* Numerator and denominator of frame rate */
uint32_t fpsNum;
uint32_t fpsDenom;
/* Width (in pixels) of the source pictures. If this width is not an even
* multiple of 4, the encoder will pad the pictures internally to meet this
* minimum requirement. All valid HEVC widths are supported */
int sourceWidth;
/* Height (in pixels) of the source pictures. If this height is not an even
* multiple of 4, the encoder will pad the pictures internally to meet this
* minimum requirement. All valid HEVC heights are supported */
int sourceHeight;
/* Interlace type of source pictures. 0 - progressive pictures (default).
* 1 - top field first, 2 - bottom field first. HEVC encodes interlaced
* content as fields, they must be provided to the encoder in the correct
* temporal order */
int interlaceMode;//场编码： 默认为0 (非场编码) 1顶场 2底场
/* Total Number of frames to be encoded, calculated from the user input
* (--frames) and (--seek). In case, the input is read from a pipe, this can
* remain as 0. It is later used in 2 pass RateControl, hence storing the
* value in param */
int totalFrames;
/*== Profile / Tier / Level ==*/
/* Note: the profile is specified by x265_param_apply_profile() */
/* Minimum decoder requirement level. Defaults to 0, which implies auto-
* detection by the encoder. If specified, the encoder will attempt to bring
* the encode specifications within that specified level. If the encoder is
* unable to reach the level it issues a warning and emits the actual
* decoder requirement. If the requested requirement level is higher than
* the actual level, the actual requirement level is signaled. The value is
* an specified as an integer with the level times 10, for example level
* "5.1" is specified as 51, and level "5.0" is specified as 50. */
int levelIdc;
/* if levelIdc is specified (non-zero) this flag will differentiate between
* Main (0) and High (1) tier. Default is Main tier (0) */
int bHighTier;
/* The maximum number of L0 references a P or B slice may use. This
* influences the size of the decoded picture buffer. The higher this
* number, the more reference frames there will be available for motion
* search, improving compression efficiency of most video at a cost of
* performance. Value must be between 1 and 16, default is 3 */
int maxNumReferences; //L0可以取的最大参考帧个数 取值范围（1~16,默认为3)
/* Allow libx265 to emit HEVC bitstreams which do not meet strict level
* requirements. Defaults to false */
int bAllowNonConformance;
/*== Bitstream Options ==*/
/* Flag indicating whether VPS, SPS and PPS headers should be output with
* each keyframe. Default false */
int bRepeatHeaders;//是否将VPS SPS PPS 在每一个关键帧中都写入 默认为false
/* Flag indicating whether the encoder should generate start codes (Annex B
* format) or length (file format) before NAL units. Default true, Annex B.
* Muxers should set this to the correct value */
int bAnnexB;
/* Flag indicating whether the encoder should emit an Access Unit Delimiter
* NAL at the start of every access unit. Default false */
int bEnableAccessUnitDelimiters;//分解符????？？？
/* Enables the buffering period SEI and picture timing SEI to signal the HRD
* parameters. Default is disabled */
int bEmitHRDSEI;
/* Enables the emission of a user data SEI with the stream headers which
* describes the encoder version, build info, and parameters. This is
* very helpful for debugging, but may interfere with regression tests.
* Default enabled */
int bEmitInfoSEI;
/* Enable the generation of SEI messages for each encoded frame containing
* the hashes of the three reconstructed picture planes. Most decoders will
* validate those hashes against the reconstructed images it generates and
* report any mismatches. This is essentially a debugging feature. Hash
* types are MD5(1), CRC(2), Checksum(3). Default is 0, none */
int decodedPictureHashSEI;
/* Enable Temporal Sub Layers while encoding, signals NAL units of coded
* slices with their temporalId. Output bitstreams can be extracted either
* at the base temporal layer (layer 0) with roughly half the frame rate or
* at a higher temporal layer (layer 1) that decodes all the frames in the
* sequence. */
int bEnableTemporalSubLayers;//是否应用时域子层？？？？
/*== GOP structure and slice type decisions (lookahead) ==*/
/* Enable open GOP - meaning I slices are not necessarily IDR and thus frames
* encoded after an I slice may reference frames encoded prior to the I
* frame which have remained in the decoded picture buffer. Open GOP
* generally has better compression efficiency and negligible encoder
* performance impact, but the use case may preclude it. Default true */
int bOpenGOP; //打开表示，除第一帧为 X265_TYPE_IDR外，其它I帧为 X265_TYPE_I，打开可以提高压缩率，但是要保留前一个I帧，目的是可以获取当前I帧（IDR无须参考任何帧，I帧可能参考其它I帧）
//关闭表示，全部I帧都为IDR帧 默认为打开，但是打开不适用随机访问
//打开即其关键帧为CAR 不同CVS(GOP）可以相互参考 关闭为IDR（不同GOP不相互参考）
//打开情况：编码顺序。I帧后可能有小于I帧号的帧（RDSL） 关闭情况：I帧后的帧号一定大于I帧
/* Scene cuts closer together than this are coded as I, not IDR. */
int keyframeMin;//默认为fps长度(如果keyframeMax/10 小于fps 则等于keyframeMax/10)
//功能一：最小IDR帧间隔，如果当前判断为I帧并且距离上一IDR帧大于此值，则将其置为IDR帧
//功能二：场景切换判断，值越小越容易判断为场景切换，编码I帧的概率越大
/* Maximum keyframe distance or intra period in number of frames. If 0 or 1,
* all frames are I frames. A negative value is casted to MAX_INT internally
* which effectively makes frame 0 the only I frame. Default is 250 */
int keyframeMax; //标记相邻两个关键帧(IDR帧)的最大间隔
/* Maximum consecutive B frames that can be emitted by the lookahead. When
* b-adapt is 0 and keyframMax is greater than bframes, the lookahead emits
* a fixed pattern of `bframes` B frames between each P. With b-adapt 1 the
* lookahead ignores the value of bframes for the most part. With b-adapt 2
* the value of bframes determines the search (POC) distance performed in
* both directions, quadratically increasing the compute load of the
* lookahead. The higher the value, the more B frames the lookahead may
* possibly use consecutively, usually improving compression. Default is 3,
* maximum is 16 */
int bframes; //一个GOP中的连续B帧的最大个数，默认为3，最大为16
/* Sets the operating mode of the lookahead. With b-adapt 0, the GOP
* structure is fixed based on the values of keyframeMax and bframes.
* With b-adapt 1 a light lookahead is used to chose B frame placement.
* With b-adapt 2 (trellis) a viterbi B path selection is performed */
int bFrameAdaptive; //B帧决策 默认为2。如果为0，固定B帧位置，如果为1快速决定B帧位置， 如果为2比较精细的决定B帧位置
/* When enabled, the encoder will use the B frame in the middle of each
* mini-GOP larger than 2 B frames as a motion reference for the surrounding
* B frames. This improves compression efficiency for a small performance
* penalty. Referenced B frames are treated somewhere between a B and a P
* frame by rate control. Default is enabled. */
int bBPyramid; //是否有B帧参考 开：有B 关：无B ，默认打开.注意 B：表示可以参考的B帧， b表示不可以参考的b帧， 关闭此开关，只拥有b
/* A value which is added to the cost estimate of B frames in the lookahead.
* It may be a positive value (making B frames appear more expensive, which
* causes the lookahead to chose more P frames) or negative, which makes the
* lookahead chose more B frames. Default is 0, there are no limits */
int bFrameBias; //设置B帧权重 默认值为0 取值范围(-90,100) 值越大B帧权重越高 score = score * 100 / (130 + param->bFrameBias) CostEstimateGroup::estimateFrameCost
/* The number of frames that must be queued in the lookahead before it may
* make slice decisions. Increasing this value directly increases the encode
* latency. The longer the queue the more optimally the lookahead may make
* slice decisions, particularly with b-adapt 2. When cu-tree is enabled,
* the length of the queue linearly increases the effectiveness of the
* cu-tree analysis. Default is 40 frames, maximum is 250 */
int lookaheadDepth;
/* Use multiple worker threads to measure the estimated cost of each frame
* within the lookahead. When bFrameAdaptive is 2, most frame cost estimates
* will be performed in batch mode, many cost estimates at the same time,
* and lookaheadSlices is ignored for batched estimates. The effect on
* performance can be quite small. The higher this parameter, the less
* accurate the frame costs will be (since context is lost across slice
* boundaries) which will result in less accurate B-frame and scene-cut
* decisions. Default is 0 - disabled. 1 is the same as 0. Max 16 */
int lookaheadSlices; //配置在lookachead可以多条slice并行操作，默认为0， 并行可能引起性能损失
/* An arbitrary threshold which determines how aggressively the lookahead
* should detect scene cuts. The default (40) is recommended. */
int scenecutThreshold; //场景切换的阈值： 值越大越容易判断为场景切换，编码I帧的概率越大
/*== Coding Unit (CU) definitions ==*/
/* Maximum CU width and height in pixels. The size must be 64, 32, or 16.
* The higher the size, the more efficiently x265 can encode areas of low
* complexity, greatly improving compression efficiency at large
* resolutions. The smaller the size, the more effective wavefront and
* frame parallelism will become because of the increase in rows. default 64
* All encoders within the same process must use the same maxCUSize, until
* all encoders are closed and x265_cleanup() is called to reset the value. */
uint32_t maxCUSize;//最大的CU大小
/* Minimum CU width and height in pixels. The size must be 64, 32, 16, or
* 8. Default 8. All encoders within the same process must use the same
* minCUSize. */
uint32_t minCUSize;
/* Enable rectangular motion prediction partitions (vertical and
* horizontal), available at all CU depths from 64x64 to 8x8. Default is
* disabled */
int bEnableRectInter;
/* Enable asymmetrical motion predictions. At CU depths 64, 32, and 16, it
* is possible to use 25%/75% split partitions in the up, down, right, left
* directions. For some material this can improve compression efficiency at
* the cost of extra analysis. bEnableRectInter must be enabled for this
* feature to be used. Default disabled */
int bEnableAMP;
/*== Residual Quadtree Transform Unit (TU) definitions ==*/
/* Maximum TU width and height in pixels. The size must be 32, 16, 8 or 4.
* The larger the size the more efficiently the residual can be compressed
* by the DCT transforms, at the expense of more computation */
uint32_t maxTUSize;
/* The additional depth the residual quad-tree is allowed to recurse beyond
* the coding quad-tree, for inter coded blocks. This must be between 1 and
* 4. The higher the value the more efficiently the residual can be
* compressed by the DCT transforms, at the expense of much more compute */
uint32_t tuQTMaxInterDepth;
/* The additional depth the residual quad-tree is allowed to recurse beyond
* the coding quad-tree, for intra coded blocks. This must be between 1 and
* 4. The higher the value the more efficiently the residual can be
* compressed by the DCT transforms, at the expense of much more compute */
uint32_t tuQTMaxIntraDepth;
/* Set the amount of rate-distortion analysis to use within quant. 0 implies
* no rate-distortion optimization. At level 1 rate-distortion cost is used to
* find optimal rounding values for each level (and allows psy-rdoq to be
* enabled). At level 2 rate-distortion cost is used to make decimate decisions
* on each 4x4 coding group (including the cost of signaling the group within
* the group bitmap). Psy-rdoq is less effective at preserving energy when
* RDOQ is at level 2 */
int rdoqLevel;
/* Enable the implicit signaling of the sign bit of the last coefficient of
* each transform unit. This saves one bit per TU at the expense of figuring
* out which coefficient can be toggled with the least distortion.
* Default is enabled */
int bEnableSignHiding;
/* Allow intra coded blocks to be encoded directly as residual without the
* DCT transform, when this improves efficiency. Checking whether the block
* will benefit from this option incurs a performance penalty. Default is
* disabled */
int bEnableTransformSkip;
/* An integer value in range of 0 to 2000, which denotes strength of noise
* reduction in intra CUs. 0 means disabled */
int noiseReductionIntra;
/* An integer value in range of 0 to 2000, which denotes strength of noise
* reduction in inter CUs. 0 means disabled */
int noiseReductionInter;
/* Quantization scaling lists. HEVC supports 6 quantization scaling lists to
* be defined; one each for Y, Cb, Cr for intra prediction and one each for
* inter prediction.
*
* - NULL and "off" will disable quant scaling (default)
* - "default" will enable the HEVC default scaling lists, which
* do not need to be signaled since they are specified
* - all other strings indicate a filename containing custom scaling lists
* in the HM format. The encode will fail if the file is not parsed
* correctly. Custom lists must be signaled in the SPS. */
const char *scalingLists;
/*== Intra Coding Tools ==*/
/* Enable constrained intra prediction. This causes intra prediction to
* input samples that were inter predicted. For some use cases this is
* believed to me more robust to stream errors, but it has a compression
* penalty on P and (particularly) B slices. Defaults to disabled */
int bEnableConstrainedIntra;
/* Enable strong intra smoothing for 32x32 blocks where the reference
* samples are flat. It may or may not improve compression efficiency,
* depending on your source material. Defaults to disabled */
int bEnableStrongIntraSmoothing;
/*== Inter Coding Tools ==*/
/* The maximum number of merge candidates that are considered during inter
* analysis. This number (between 1 and 5) is signaled in the stream
* headers and determines the number of bits required to signal a merge so
* it can have significant trade-offs. The smaller this number the higher
* the performance but the less compression efficiency. Default is 3 */
uint32_t maxNumMergeCand;//Merge选择的候选个数，默认值为3
/* Limit the motion references used for each search based on the results of
* previous motion searches already performed for the same CU: If 0 all
* references are always searched. If X265_REF_LIMIT_CU all motion searches
* will restrict themselves to the references selected by the 2Nx2N search
* at the same depth. If X265_REF_LIMIT_DEPTH the 2Nx2N motion search will
* only use references that were selected by the best motion searches of the
* 4 split CUs at the next lower CU depth. The two flags may be combined */
uint32_t limitReferences;
/* ME search method (DIA, HEX, UMH, STAR, FULL). The search patterns
* (methods) are sorted in increasing complexity, with diamond being the
* simplest and fastest and full being the slowest. DIA, HEX, and UMH were
* adapted from x264 directly. STAR is an adaption of the HEVC reference
* encoder's three step search, while full is a naive exhaustive search. The
* default is the star search, it has a good balance of performance and
* compression efficiency */
int searchMethod;
/* A value between 0 and X265_MAX_SUBPEL_LEVEL which adjusts the amount of
* effort performed during sub-pel refine. Default is 5 */
int subpelRefine;
/* The maximum distance from the motion prediction that the full pel motion
* search is allowed to progress before terminating. This value can have an
* effect on frame parallelism, as referenced frames must be at least this
* many rows of reconstructed pixels ahead of the referencee at all times.
* (When considering reference lag, the motion prediction must be ignored
* because it cannot be known ahead of time). Default is 60, which is the
* default max CU size (64) minus the luma HPEL half-filter length (4). If a
* smaller CU size is used, the search range should be similarly reduced */
int searchRange;
/* Enable availability of temporal motion vector for AMVP, default is enabled */
int bEnableTemporalMvp;
/* Enable weighted prediction in P slices. This enables weighting analysis
* in the lookahead, which influences slice decisions, and enables weighting
* analysis in the main encoder which allows P reference samples to have a
* weight function applied to them prior to using them for motion
* compensation. In video which has lighting changes, it can give a large
* improvement in compression efficiency. Default is enabled */
int bEnableWeightedPred; //是否应用加权P帧 （默认打开） 在亮度渐变场景中有帮助
/* Enable weighted prediction in B slices. Default is disabled */
int bEnableWeightedBiPred; //是否应用加权B帧 默认关闭
/*== Loop Filters ==*/
/* Enable the deblocking loop filter, which improves visual quality by
* reducing blocking effects at block edges, particularly at lower bitrates
* or higher QP. When enabled it adds another CU row of reference lag,
* reducing frame parallelism effectiveness. Default is enabled */
int bEnableLoopFilter;
/* deblocking filter tC offset [-6, 6] -6 light filter, 6 strong.
* This is the coded div2 value, actual offset is doubled at use */
int deblockingFilterTCOffset;
/* deblocking filter Beta offset [-6, 6] -6 light filter, 6 strong
* This is the coded div2 value, actual offset is doubled at use */
int deblockingFilterBetaOffset;
/* Enable the Sample Adaptive Offset loop filter, which reduces distortion
* effects by adjusting reconstructed sample values based on histogram
* analysis to better approximate the original samples. When enabled it adds
* a CU row of reference lag, reducing frame parallelism effectiveness.
* Default is enabled */
int bEnableSAO;
/* Note: when deblocking and SAO are both enabled, the loop filter CU lag is
* only one row, as they operate in series on the same row. */
/* Select the method in which SAO deals with deblocking boundary pixels. If
* disabled the right and bottom boundary areas are skipped. If enabled,
* non-deblocked pixels are used entirely. Default is disabled */
int bSaoNonDeblocked;
/*== Analysis tools ==*/
/* A value between X265_NO_RDO_NO_RDOQ and X265_RDO_LEVEL which determines
* the level of rate distortion optimizations to perform during mode
* decisions and quantization. The more RDO the better the compression
* efficiency at a major cost of performance. Default is no RDO (0) */
int rdLevel;
/* Enable early skip decisions to avoid intra and inter analysis in likely
* skip blocks. Default is disabled */
int bEnableEarlySkip;
/* Use a faster search method to find the best intra mode. Default is 0 */
int bEnableFastIntra;
/* Enable a faster determination of whether skipping the DCT transform will
* be beneficial. Slight performance gain for some compression loss. Default
* is enabled */
int bEnableTSkipFast;
/* The CU Lossless flag, when enabled, compares the rate-distortion costs
* for normal and lossless encoding, and chooses the best mode for each CU.
* If lossless mode is chosen, the cu-transquant-bypass flag is set for that
* CU */
int bCULossless;
/* Specify whether to attempt to encode intra modes in B frames. By default
* enabled, but only applicable for the presets which use rdLevel 5 or 6
* (veryslow and placebo). All other presets will not try intra in B frames
* regardless of this setting */
int bIntraInBFrames;
/* Apply an optional penalty to the estimated cost of 32x32 intra blocks in
* non-intra slices. 0 is disabled, 1 enables a small penalty, and 2 enables
* a full penalty. This favors inter-coding and its low bitrate over
* potential increases in distortion, but usually improves performance.
* Default is 0 */
int rdPenalty;
/* Psycho-visual rate-distortion strength. Only has an effect in presets
* which use RDO. It makes mode decision favor options which preserve the
* energy of the source, at the cost of lost compression. The value must
* be between 0 and 2.0, 1.0 is typical. Default 0.3 */
double psyRd;
/* Strength of psycho-visual optimizations in quantization. Only has an
* effect in presets which use RDOQ (rd-levels 4 and 5). The value must be
* between 0 and 50, 1.0 is typical. Default 1.0 */
double psyRdoq;
/* If X265_ANALYSIS_SAVE, write per-frame analysis information into analysis
* buffers. if X265_ANALYSIS_LOAD, read analysis information into analysis
* buffer and use this analysis information to reduce the amount of work
* the encoder must perform. Default X265_ANALYSIS_OFF */
int analysisMode;
/* Filename for analysisMode save/load. Default name is "x265_analysis.dat" */
const char* analysisFileName;
/*== Rate Control ==*/
/* The lossless flag enables true lossless coding, bypassing scaling,
* transform, quantization and in-loop filter processes. This is used for
* ultra-high bitrates with zero loss of quality. It implies no rate control */
int bLossless;
/* Generally a small signed integer which offsets the QP used to quantize
* the Cb chroma residual (delta from luma QP specified by rate-control).
* Default is 0, which is recommended */
int cbQpOffset;
/* Generally a small signed integer which offsets the QP used to quantize
* the Cr chroma residual (delta from luma QP specified by rate-control).
* Default is 0, which is recommended */
int crQpOffset;
struct
{
/* Explicit mode of rate-control, necessary for API users. It must
* be one of the X265_RC_METHODS enum values. */
int rateControlMode;
/* Base QP to use for Constant QP rate control. Adaptive QP may alter
* the QP used for each block. If a QP is specified on the command line
* CQP rate control is implied. Default: 32 */
int qp;
/* target bitrate for Average BitRate (ABR) rate control. If a non- zero
* bitrate is specified on the command line, ABR is implied. Default 0 */
int bitrate;
/* qComp sets the quantizer curve compression factor. It weights the frame
* quantizer based on the complexity of residual (measured by lookahead).
* Default value is 0.6. Increasing it to 1 will effectively generate CQP */
double qCompress; //强度系数：如果为1.0 则 qpCuTreeOffset = qpAqOffset qCompress越大 qpCuTreeOffset越大 默认值：0.6
/* QP offset between I/P and P/B frames. Default ipfactor: 1.4
* Default pbFactor: 1.3 */
double ipFactor;
double pbFactor;
/* Ratefactor constant: targets a certain constant "quality".
* Acceptable values between 0 and 51. Default value: 28 */
double rfConstant;
/* Max QP difference between frames. Default: 4 */
int qpStep;
/* Enable adaptive quantization. This mode distributes available bits between all
* CTUs of a frame, assigning more bits to low complexity areas. Turning
* this ON will usually affect PSNR negatively, however SSIM and visual quality
* generally improves. Default: X265_AQ_VARIANCE */
int aqMode; //自适应量化 默认打开，一般打开对psnr有损失，但是对ssim和主观质量优增益，选择一下几个值，默认为1
//#define X265_AQ_NONE 0
//#define X265_AQ_VARIANCE 1
//#define X265_AQ_AUTO_VARIANCE 2
/* Sets the strength of AQ bias towards low detail CTUs. Valid only if
* AQ is enabled. Default value: 1.0. Acceptable values between 0.0 and 3.0 */
double aqStrength;//自适应量化的强度 取值范围（0.0~3.0） 默认为1.0
//固定QP X265_RC_CQP 、aqMode关闭、tune psnr 都会使其关闭
/* Sets the maximum rate the VBV buffer should be assumed to refill at
* Default is zero */
int vbvMaxBitrate;//最大的bits值，默认值为0 CBR规定encoder的输出码率为恒定，但是各帧编码后的大小不是固定的（I,B,P帧的存在），因此需要在encoder后面加入VBV buffer。
// Video Buffer Verifier (VBV)是一个当输入码流遵从MPEG标准时，既不会上溢出，也不会下溢出的理论上的解码缓冲器模型。
/* Sets the size of the VBV buffer in kilobits. Default is zero */
int vbvBufferSize;// 默认值为0 Video Buffering Verifier 视频缓存检验器
/* Sets how full the VBV buffer must be before playback starts. If it is less than
* 1, then the initial fill is vbv-init * vbvBufferSize. Otherwise, it is
* interpreted as the initial fill in kbits. Default is 0.9 */
double vbvBufferInit;
/* Enable CUTree rate-control. This keeps track of the CUs that propagate temporally
* across frames and assigns more bits to these CUs. Improves encode efficiency.
* Default: enabled */
int cuTree;//如果当前可参考帧中的块的传播cost比较大，分配其更多的bits 默认：打开
/* In CRF mode, maximum CRF as caused by VBV. 0 implies no limit */
double rfConstantMax;
/* In CRF mode, minimum CRF as caused by VBV */
double rfConstantMin;
/* Multi-pass encoding */
/* Enable writing the stats in a multi-pass encode to the stat output file */
int bStatWrite;
/* Enable loading data from the stat input file in a multi pass encode */
int bStatRead;
/* Filename of the 2pass output/input stats file, if unspecified the
* encoder will default to using x265_2pass.log */
const char* statFileName;
/* temporally blur quants */
double qblur;
/* temporally blur complexity */
double complexityBlur;
/* Enable slow and a more detailed first pass encode in multi pass rate control */
int bEnableSlowFirstPass;
/* rate-control overrides */
int zoneCount;
x265_zone* zones;
/* specify a text file which contains MAX_MAX_QP + 1 floating point
* values to be copied into x265_lambda_tab and a second set of
* MAX_MAX_QP + 1 floating point values for x265_lambda2_tab. All values
* are separated by comma, space or newline. Text after a hash (#) is
* ignored. The lambda tables are process-global, so these new lambda
* values will affect all encoders in the same process */
const char* lambdaFileName;
/* Enable stricter conditions to check bitrate deviations in CBR mode. May compromise
* quality to maintain bitrate adherence */
int bStrictCbr;
/* Enable adaptive quantization at CU granularity. This parameter specifies
* the minimum CU size at which QP can be adjusted, i.e. Quantization Group
* (QG) size. Allowed values are 64, 32, 16 provided it falls within the
* inclusuve range [maxCUSize, minCUSize]. Experimental, default: maxCUSize*/
uint32_t qgSize;
} rc;
/*== Video Usability Information ==*/
struct
{
/* Aspect ratio idc to be added to the VUI. The default is 0 indicating
* the apsect ratio is unspecified. If set to X265_EXTENDED_SAR then
* sarWidth and sarHeight must also be set */
int aspectRatioIdc;
/* Sample Aspect Ratio width in arbitrary units to be added to the VUI
* only if aspectRatioIdc is set to X265_EXTENDED_SAR. This is the width
* of an individual pixel. If this is set then sarHeight must also be set */
int sarWidth;
/* Sample Aspect Ratio height in arbitrary units to be added to the VUI.
* only if aspectRatioIdc is set to X265_EXTENDED_SAR. This is the width
* of an individual pixel. If this is set then sarWidth must also be set */
int sarHeight;
/* Enable overscan info present flag in the VUI. If this is set then
* bEnabledOverscanAppropriateFlag will be added to the VUI. The default
* is false */
int bEnableOverscanInfoPresentFlag;
/* Enable overscan appropriate flag. The status of this flag is added
* to the VUI only if bEnableOverscanInfoPresentFlag is set. If this
* flag is set then cropped decoded pictures may be output for display.
* The default is false */
int bEnableOverscanAppropriateFlag;
/* Video signal type present flag of the VUI. If this is set then
* videoFormat, bEnableVideoFullRangeFlag and
* bEnableColorDescriptionPresentFlag will be added to the VUI. The
* default is false */
int bEnableVideoSignalTypePresentFlag;
/* Video format of the source video. 0 = component, 1 = PAL, 2 = NTSC,
* 3 = SECAM, 4 = MAC, 5 = unspecified video format is the default */
int videoFormat;
/* Video full range flag indicates the black level and range of the luma
* and chroma signals as derived from E′Y, E′PB, and E′PR or E′R, E′G,
* and E′B real-valued component signals. The default is false */
int bEnableVideoFullRangeFlag;
/* Color description present flag in the VUI. If this is set then
* color_primaries, transfer_characteristics and matrix_coeffs are to be
* added to the VUI. The default is false */
int bEnableColorDescriptionPresentFlag;
/* Color primaries holds the chromacity coordinates of the source
* primaries. The default is 2 */
int colorPrimaries;
/* Transfer characteristics indicates the opto-electronic transfer
* characteristic of the source picture. The default is 2 */
int transferCharacteristics;
/* Matrix coefficients used to derive the luma and chroma signals from
* the red, blue and green primaries. The default is 2 */
int matrixCoeffs;
/* Chroma location info present flag adds chroma_sample_loc_type_top_field and
* chroma_sample_loc_type_bottom_field to the VUI. The default is false */
int bEnableChromaLocInfoPresentFlag;
/* Chroma sample location type top field holds the chroma location in
* the top field. The default is 0 */
int chromaSampleLocTypeTopField;
/* Chroma sample location type bottom field holds the chroma location in
* the bottom field. The default is 0 */
int chromaSampleLocTypeBottomField;
/* Default display window flag adds def_disp_win_left_offset,
* def_disp_win_right_offset, def_disp_win_top_offset and
* def_disp_win_bottom_offset to the VUI. The default is false */
int bEnableDefaultDisplayWindowFlag;
/* Default display window left offset holds the left offset with the
* conformance cropping window to further crop the displayed window */
int defDispWinLeftOffset;
/* Default display window right offset holds the right offset with the
* conformance cropping window to further crop the displayed window */
int defDispWinRightOffset;
/* Default display window top offset holds the top offset with the
* conformance cropping window to further crop the displayed window */
int defDispWinTopOffset;
/* Default display window bottom offset holds the bottom offset with the
* conformance cropping window to further crop the displayed window */
int defDispWinBottomOffset;
} vui;
/* SMPTE ST 2086 mastering display color volume SEI info, specified as a
* string which is parsed when the stream header SEI are emitted. The string
* format is "G(%hu,%hu)B(%hu,%hu)R(%hu,%hu)WP(%hu,%hu)L(%u,%u)" where %hu
* are unsigned 16bit integers and %u are unsigned 32bit integers. The SEI
* includes X,Y display primaries for RGB channels, white point X,Y and
* max,min luminance values. */
const char* masteringDisplayColorVolume;
/* Content light level info SEI, specified as a string which is parsed when
* the stream header SEI are emitted. The string format is "%hu,%hu" where
* %hu are unsigned 16bit integers. The first value is the max content light
* level (or 0 if no maximum is indicated), the second value is the maximum
* picture average light level (or 0). */
const char* contentLightLevelInfo;
} x265_param;
/* x265_param_alloc:
* Allocates an x265_param instance. The returned param structure is not
* special in any way, but using this method together with x265_param_free()
* and x265_param_parse() to set values by name allows the application to treat
* x265_param as an opaque data struct for version safety */
x265_param *x265_param_alloc(void);
/* x265_param_free:
* Use x265_param_free() to release storage for an x265_param instance
* allocated by x265_param_alloc() */
void x265_param_free(x265_param *);//释放param信息，ffmpeg会调用此接口libx265_encode_close
/* x265_param_default:
* Initialize an x265_param structure to default values */
void x265_param_default(x265_param *param);
/* x265_param_parse:
* set one parameter by name.
* returns 0 on success, or returns one of the following errors.
* note: BAD_VALUE occurs only if it can't even parse the value,
* numerical range is not checked until x265_encoder_open().
* value=NULL means "true" for boolean options, but is a BAD_VALUE for non-booleans. */
#define X265_PARAM_BAD_NAME (-1)
#define X265_PARAM_BAD_VALUE (-2)
int x265_param_parse(x265_param *p, const char *name, const char *value);
/* x265_param_apply_profile:
* Applies the restrictions of the given profile. (one of below) */
static const char * const x265_profile_names[] = { "main", "main10", "mainstillpicture", 0 };
/* (can be NULL, in which case the function will do nothing)
* returns 0 on success, negative on failure (e.g. invalid profile name). */
int x265_param_apply_profile(x265_param *, const char *profile);
/* x265_param_default_preset:
* The same as x265_param_default, but also use the passed preset and tune
* to modify the default settings.
* (either can be NULL, which implies no preset or no tune, respectively)
*
* Currently available presets are, ordered from fastest to slowest: */
static const char * const x265_preset_names[] = { "ultrafast", "superfast", "veryfast", "faster", "fast", "medium", "slow", "slower", "veryslow", "placebo", 0 };
/* The presets can also be indexed numerically, as in:
* x265_param_default_preset( ¶m, "3", ... )
* with ultrafast mapping to "0" and placebo mapping to "9". This mapping may
* of course change if new presets are added in between, but will always be
* ordered from fastest to slowest.
*
* Warning: the speed of these presets scales dramatically. Ultrafast is a full
* 100 times faster than placebo!
*
* Currently available tunings are: */
static const char * const x265_tune_names[] = { "psnr", "ssim", "grain", "zerolatency", "fastdecode", 0 };
/* returns 0 on success, negative on failure (e.g. invalid preset/tune name). */
int x265_param_default_preset(x265_param *, const char *preset, const char *tune);
/* x265_picture_alloc:
* Allocates an x265_picture instance. The returned picture structure is not
* special in any way, but using this method together with x265_picture_free()
* and x265_picture_init() allows some version safety. New picture fields will
* always be added to the end of x265_picture */
x265_picture *x265_picture_alloc(void);
/* x265_picture_free:
* Use x265_picture_free() to release storage for an x265_picture instance
* allocated by x265_picture_alloc() */
void x265_picture_free(x265_picture *);
/* x265_picture_init:
* Initialize an x265_picture structure to default values. It sets the pixel
* depth and color space to the encoder's internal values and sets the slice
* type to auto - so the lookahead will determine slice type. */
void x265_picture_init(x265_param *param, x265_picture *pic);
/* x265_max_bit_depth:
* Specifies the numer of bits per pixel that x265 uses internally to
* represent a pixel, and the bit depth of the output bitstream.
* param->internalBitDepth must be set to this value. x265_max_bit_depth
* will be 8 for default builds, 10 for HIGH_BIT_DEPTH builds. */
X265_API extern const int x265_max_bit_depth;
/* x265_version_str:
* A static string containing the version of this compiled x265 library */
X265_API extern const char *x265_version_str;
/* x265_build_info:
* A static string describing the compiler and target architecture */
X265_API extern const char *x265_build_info_str;
/* Force a link error in the case of linking against an incompatible API version.
* Glue #defines exist to force correct macro expansion; the final output of the macro
* is x265_encoder_open_##X265_BUILD (for purposes of dlopen). */
#define x265_encoder_glue1(x, y) x ## y
#define x265_encoder_glue2(x, y) x265_encoder_glue1(x, y)
#define x265_encoder_open x265_encoder_glue2(x265_encoder_open_, X265_BUILD)
/* x265_encoder_open:
* create a new encoder handler, all parameters from x265_param are copied */
x265_encoder* x265_encoder_open(x265_param *);
/* x265_encoder_parameters:
* copies the current internal set of parameters to the pointer provided
* by the caller. useful when the calling application needs to know
* how x265_encoder_open has changed the parameters.
* note that the data accessible through pointers in the returned param struct
* (e.g. filenames) should not be modified by the calling application. */
void x265_encoder_parameters(x265_encoder *, x265_param *);
/* x265_encoder_headers:
* return the SPS and PPS that will be used for the whole stream.
* *pi_nal is the number of NAL units outputted in pp_nal.
* returns negative on error, total byte size of payload data on success
* the payloads of all output NALs are guaranteed to be sequential in memory. */
int x265_encoder_headers(x265_encoder *, x265_nal **pp_nal, uint32_t *pi_nal);
/* x265_encoder_encode:
* encode one picture.
* *pi_nal is the number of NAL units outputted in pp_nal.
* returns negative on error, 1 if a picture and access unit were output,
* or zero if the encoder pipeline is still filling or is empty after flushing.
* the payloads of all output NALs are guaranteed to be sequential in memory.
* To flush the encoder and retrieve delayed output pictures, pass pic_in as NULL.
* Once flushing has begun, all subsequent calls must pass pic_in as NULL. */
int x265_encoder_encode(x265_encoder *encoder, x265_nal **pp_nal, uint32_t *pi_nal, x265_picture *pic_in, x265_picture *pic_out);
/* x265_encoder_reconfig:
* various parameters from x265_param are copied.
* this takes effect immediately, on whichever frame is encoded next;
* returns 0 on success, negative on parameter validation error.
*
* not all parameters can be changed; see the actual function for a
* detailed breakdown. since not all parameters can be changed, moving
* from preset to preset may not always fully copy all relevant parameters,
* but should still work usably in practice. however, more so than for
* other presets, many of the speed shortcuts used in ultrafast cannot be
* switched out of; using reconfig to switch between ultrafast and other
* presets is not recommended without a more fine-grained breakdown of
* parameters to take this into account. */
int x265_encoder_reconfig(x265_encoder *, x265_param *);
/* x265_encoder_get_stats:
* returns encoder statistics */
void x265_encoder_get_stats(x265_encoder *encoder, x265_stats *, uint32_t statsSizeBytes);
/* x265_encoder_log:
* write a line to the configured CSV file. If a CSV filename was not
* configured, or file open failed, or the log level indicated frame level
* logging, this function will perform no write. */
void x265_encoder_log(x265_encoder *encoder, int argc, char **argv);
/* x265_encoder_close:
* close an encoder handler */
void x265_encoder_close(x265_encoder *);//释放编码器 会在ffmpeg中调用
/* x265_cleanup:
* release library static allocations, reset configured CTU size */
void x265_cleanup(void);
/* === Multi-lib API ===
* By using this method to gain access to the libx265 interfaces, you allow shim
* implementations of x265_api_get() to choose between various available libx265
* libraries based on the encoder parameters. The most likely use case is to
* choose between 8bpp and 16bpp builds of libx265. */
typedef struct x265_api
{
/* libx265 public API functions, documented above with x265_ prefixes */
x265_param* (*param_alloc)(void);
void (*param_free)(x265_param*);
void (*param_default)(x265_param*);
int (*param_parse)(x265_param*, const char*, const char*);
int (*param_apply_profile)(x265_param*, const char*);
int (*param_default_preset)(x265_param*, const char*, const char *);
x265_picture* (*picture_alloc)(void);
void (*picture_free)(x265_picture*);
void (*picture_init)(x265_param*, x265_picture*);
x265_encoder* (*encoder_open)(x265_param*);
void (*encoder_parameters)(x265_encoder*, x265_param*);
int (*encoder_reconfig)(x265_encoder*, x265_param*);
int (*encoder_headers)(x265_encoder*, x265_nal**, uint32_t*);
int (*encoder_encode)(x265_encoder*, x265_nal**, uint32_t*, x265_picture*, x265_picture*);
void (*encoder_get_stats)(x265_encoder*, x265_stats*, uint32_t);
void (*encoder_log)(x265_encoder*, int, char**);
void (*encoder_close)(x265_encoder*);
void (*cleanup)(void);
const char* version_str;
const char* build_info_str;
int max_bit_depth;
} x265_api;
/* Force a link error in the case of linking against an incompatible API version.
* Glue #defines exist to force correct macro expansion; the final output of the macro
* is x265_api_get_##X265_BUILD (for purposes of dlopen). */
#define x265_api_glue1(x, y) x ## y
#define x265_api_glue2(x, y) x265_api_glue1(x, y)
#define x265_api_get x265_api_glue2(x265_api_get_, X265_BUILD)
/* x265_api_get:
* Retrieve the programming interface for a linked x265 library.
* May return NULL if no library is available that supports the
* requested bit depth. If bitDepth is 0 the function is guarunteed
* to return a non-NULL x265_api pointer, from the linked libx265.
*
* If the requested bitDepth is not supported by the linked libx265,
* it will attempt to dynamically bind x265_api_get() from a shared
* library with an appropriate name:
* 8bit: libx265_main.so
* 10bit: libx265_main10.so
* Obviously the shared library file extension is platform specific */
const x265_api* x265_api_get(int bitDepth);
#ifdef __cplusplus
}
#endif
#endif // X265_H
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