/* * 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 */