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video_enc_params.h
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/*
* 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
*/
#ifndef AVUTIL_VIDEO_ENC_PARAMS_H
#define AVUTIL_VIDEO_ENC_PARAMS_H
#include <stddef.h>
#include <stdint.h>
#include "libavutil/avassert.h"
#include "libavutil/frame.h"
enum AVVideoEncParamsType {
AV_VIDEO_ENC_PARAMS_NONE = -1,
/**
* VP9 stores:
* - per-frame base (luma AC) quantizer index, exported as AVVideoEncParams.qp
* - deltas for luma DC, chroma AC and chroma DC, exported in the
* corresponding entries in AVVideoEncParams.delta_qp
* - per-segment delta, exported as for each block as AVVideoBlockParams.delta_qp
*
* To compute the resulting quantizer index for a block:
* - for luma AC, add the base qp and the per-block delta_qp, saturating to
* unsigned 8-bit.
* - for luma DC and chroma AC/DC, add the corresponding
* AVVideoBlockParams.delta_qp to the luma AC index, again saturating to
* unsigned 8-bit.
*/
AV_VIDEO_ENC_PARAMS_VP9,
/**
* H.264 stores:
* - in PPS (per-picture):
* * initial QP_Y (luma) value, exported as AVVideoEncParams.qp
* * delta(s) for chroma QP values (same for both, or each separately),
* exported as in the corresponding entries in AVVideoEncParams.delta_qp
* - per-slice QP delta, not exported directly, added to the per-MB value
* - per-MB delta; not exported directly; the final per-MB quantizer
* parameter - QP_Y - minus the value in AVVideoEncParams.qp is exported
* as AVVideoBlockParams.qp_delta.
*/
AV_VIDEO_ENC_PARAMS_H264,
/*
* MPEG-2-compatible quantizer.
*
* Summing the frame-level qp with the per-block delta_qp gives the
* resulting quantizer for the block.
*/
AV_VIDEO_ENC_PARAMS_MPEG2,
};
/**
* Video encoding parameters for a given frame. This struct is allocated along
* with an optional array of per-block AVVideoBlockParams descriptors.
* Must be allocated with av_video_enc_params_alloc().
*/
typedef struct AVVideoEncParams {
/**
* Number of blocks in the array.
*
* May be 0, in which case no per-block information is present. In this case
* the values of blocks_offset / block_size are unspecified and should not
* be accessed.
*/
unsigned int nb_blocks;
/**
* Offset in bytes from the beginning of this structure at which the array
* of blocks starts.
*/
size_t blocks_offset;
/*
* Size of each block in bytes. May not match sizeof(AVVideoBlockParams).
*/
size_t block_size;
/**
* Type of the parameters (the codec they are used with).
*/
enum AVVideoEncParamsType type;
/**
* Base quantisation parameter for the frame. The final quantiser for a
* given block in a given plane is obtained from this value, possibly
* combined with {@code delta_qp} and the per-block delta in a manner
* documented for each type.
*/
int32_t qp;
/**
* Quantisation parameter offset from the base (per-frame) qp for a given
* plane (first index) and AC/DC coefficients (second index).
*/
int32_t delta_qp[4][2];
} AVVideoEncParams;
/**
* Data structure for storing block-level encoding information.
* It is allocated as a part of AVVideoEncParams and should be retrieved with
* av_video_enc_params_block().
*
* sizeof(AVVideoBlockParams) is not a part of the ABI and new fields may be
* added to it.
*/
typedef struct AVVideoBlockParams {
/**
* Distance in luma pixels from the top-left corner of the visible frame
* to the top-left corner of the block.
* Can be negative if top/right padding is present on the coded frame.
*/
int src_x, src_y;
/**
* Width and height of the block in luma pixels.
*/
int w, h;
/**
* Difference between this block's final quantization parameter and the
* corresponding per-frame value.
*/
int32_t delta_qp;
} AVVideoBlockParams;
/**
* Get the block at the specified {@code idx}. Must be between 0 and nb_blocks - 1.
*/
static av_always_inline AVVideoBlockParams*
av_video_enc_params_block(AVVideoEncParams *par, unsigned int idx)
{
av_assert0(idx < par->nb_blocks);
return (AVVideoBlockParams *)((uint8_t *)par + par->blocks_offset +
idx * par->block_size);
}
/**
* Allocates memory for AVVideoEncParams of the given type, plus an array of
* {@code nb_blocks} AVVideoBlockParams and initializes the variables. Can be
* freed with a normal av_free() call.
*
* @param out_size if non-NULL, the size in bytes of the resulting data array is
* written here.
*/
AVVideoEncParams *av_video_enc_params_alloc(enum AVVideoEncParamsType type,
unsigned int nb_blocks, size_t *out_size);
/**
* Allocates memory for AVEncodeInfoFrame plus an array of
* {@code nb_blocks} AVEncodeInfoBlock in the given AVFrame {@code frame}
* as AVFrameSideData of type AV_FRAME_DATA_VIDEO_ENC_PARAMS
* and initializes the variables.
*/
AVVideoEncParams*
av_video_enc_params_create_side_data(AVFrame *frame, enum AVVideoEncParamsType type,
unsigned int nb_blocks);
#endif /* AVUTIL_VIDEO_ENC_PARAMS_H */
av_always_inline
#define av_always_inline
Definition attributes.h:45
avassert.h
simple assert() macros that are a bit more flexible than ISO C assert().
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition avassert.h:40
frame
static AVFrame * frame
Definition demux_decode.c:54
frame.h
reference-counted frame API
AVFrame
This structure describes decoded (raw) audio or video data.
Definition frame.h:389
AVVideoBlockParams
Data structure for storing block-level encoding information.
Definition video_enc_params.h:120
AVVideoBlockParams::h
int h
Definition video_enc_params.h:130
AVVideoBlockParams::src_y
int src_y
Definition video_enc_params.h:126
AVVideoBlockParams::src_x
int src_x
Distance in luma pixels from the top-left corner of the visible frame to the top-left corner of the b...
Definition video_enc_params.h:126
AVVideoBlockParams::w
int w
Width and height of the block in luma pixels.
Definition video_enc_params.h:130
AVVideoBlockParams::delta_qp
int32_t delta_qp
Difference between this block's final quantization parameter and the corresponding per-frame value.
Definition video_enc_params.h:136
AVVideoEncParams
Video encoding parameters for a given frame.
Definition video_enc_params.h:73
AVVideoEncParams::delta_qp
int32_t delta_qp[4][2]
Quantisation parameter offset from the base (per-frame) qp for a given plane (first index) and AC/DC ...
Definition video_enc_params.h:109
AVVideoEncParams::block_size
size_t block_size
Definition video_enc_params.h:90
AVVideoEncParams::type
enum AVVideoEncParamsType type
Type of the parameters (the codec they are used with).
Definition video_enc_params.h:95
AVVideoEncParams::nb_blocks
unsigned int nb_blocks
Number of blocks in the array.
Definition video_enc_params.h:81
AVVideoEncParams::qp
int32_t qp
Base quantisation parameter for the frame.
Definition video_enc_params.h:103
AVVideoEncParams::blocks_offset
size_t blocks_offset
Offset in bytes from the beginning of this structure at which the array of blocks starts.
Definition video_enc_params.h:86
av_video_enc_params_create_side_data
AVVideoEncParams * av_video_enc_params_create_side_data(AVFrame *frame, enum AVVideoEncParamsType type, unsigned int nb_blocks)
Allocates memory for AVEncodeInfoFrame plus an array of nb_blocks AVEncodeInfoBlock in the given AVFr...
av_video_enc_params_block
static av_always_inline AVVideoBlockParams * av_video_enc_params_block(AVVideoEncParams *par, unsigned int idx)
Get the block at the specified idx.
Definition video_enc_params.h:143
av_video_enc_params_alloc
AVVideoEncParams * av_video_enc_params_alloc(enum AVVideoEncParamsType type, unsigned int nb_blocks, size_t *out_size)
Allocates memory for AVVideoEncParams of the given type, plus an array of nb_blocks AVVideoBlockParam...
AVVideoEncParamsType
AVVideoEncParamsType
Definition video_enc_params.h:28
AV_VIDEO_ENC_PARAMS_NONE
@ AV_VIDEO_ENC_PARAMS_NONE
Definition video_enc_params.h:29
AV_VIDEO_ENC_PARAMS_VP9
@ AV_VIDEO_ENC_PARAMS_VP9
VP9 stores:
Definition video_enc_params.h:44
AV_VIDEO_ENC_PARAMS_MPEG2
@ AV_VIDEO_ENC_PARAMS_MPEG2
Definition video_enc_params.h:65
AV_VIDEO_ENC_PARAMS_H264
@ AV_VIDEO_ENC_PARAMS_H264
H.264 stores:
Definition video_enc_params.h:57