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19 #ifndef AVUTIL_VIDEO_ENC_PARAMS_H
20 #define AVUTIL_VIDEO_ENC_PARAMS_H
25 #include "libavutil/avassert.h"
26 #include "libavutil/frame.h"
28 enum AVVideoEncParamsType {
29 AV_VIDEO_ENC_PARAMS_NONE = -1,
32 * - per-frame base (luma AC) quantizer index, exported as AVVideoEncParams.qp
33 * - deltas for luma DC, chroma AC and chroma DC, exported in the
34 * corresponding entries in AVVideoEncParams.delta_qp
35 * - per-segment delta, exported as for each block as AVVideoBlockParams.delta_qp
37 * To compute the resulting quantizer index for a block:
38 * - for luma AC, add the base qp and the per-block delta_qp, saturating to
40 * - for luma DC and chroma AC/DC, add the corresponding
41 * AVVideoBlockParams.delta_qp to the luma AC index, again saturating to
44 AV_VIDEO_ENC_PARAMS_VP9,
48 * - in PPS (per-picture):
49 * * initial QP_Y (luma) value, exported as AVVideoEncParams.qp
50 * * delta(s) for chroma QP values (same for both, or each separately),
51 * exported as in the corresponding entries in AVVideoEncParams.delta_qp
52 * - per-slice QP delta, not exported directly, added to the per-MB value
53 * - per-MB delta; not exported directly; the final per-MB quantizer
54 * parameter - QP_Y - minus the value in AVVideoEncParams.qp is exported
55 * as AVVideoBlockParams.qp_delta.
57 AV_VIDEO_ENC_PARAMS_H264,
60 * MPEG-2-compatible quantizer.
62 * Summing the frame-level qp with the per-block delta_qp gives the
63 * resulting quantizer for the block.
65 AV_VIDEO_ENC_PARAMS_MPEG2,
69 * Video encoding parameters for a given frame. This struct is allocated along
70 * with an optional array of per-block AVVideoBlockParams descriptors.
71 * Must be allocated with av_video_enc_params_alloc().
73 typedef struct AVVideoEncParams {
75 * Number of blocks in the array.
77 * May be 0, in which case no per-block information is present. In this case
78 * the values of blocks_offset / block_size are unspecified and should not
81 unsigned int nb_blocks;
83 * Offset in bytes from the beginning of this structure at which the array
88 * Size of each block in bytes. May not match sizeof(AVVideoBlockParams).
93 * Type of the parameters (the codec they are used with).
95 enum AVVideoEncParamsType type;
98 * Base quantisation parameter for the frame. The final quantiser for a
99 * given block in a given plane is obtained from this value, possibly
100 * combined with {@code delta_qp} and the per-block delta in a manner
101 * documented for each type.
106 * Quantisation parameter offset from the base (per-frame) qp for a given
107 * plane (first index) and AC/DC coefficients (second index).
109 int32_t delta_qp[4][2];
113 * Data structure for storing block-level encoding information.
114 * It is allocated as a part of AVVideoEncParams and should be retrieved with
115 * av_video_enc_params_block().
117 * sizeof(AVVideoBlockParams) is not a part of the ABI and new fields may be
120 typedef struct AVVideoBlockParams {
122 * Distance in luma pixels from the top-left corner of the visible frame
123 * to the top-left corner of the block.
124 * Can be negative if top/right padding is present on the coded frame.
128 * Width and height of the block in luma pixels.
133 * Difference between this block's final quantization parameter and the
134 * corresponding per-frame value.
137 } AVVideoBlockParams;
140 * Get the block at the specified {@code idx}. Must be between 0 and nb_blocks.
142 static av_always_inline AVVideoBlockParams*
143 av_video_enc_params_block(AVVideoEncParams *par, unsigned int idx)
145 av_assert0(idx < par->nb_blocks);
146 return (AVVideoBlockParams *)((uint8_t *)par + par->blocks_offset +
147 idx * par->block_size);
151 * Allocates memory for AVVideoEncParams of the given type, plus an array of
152 * {@code nb_blocks} AVVideoBlockParams and initializes the variables. Can be
153 * freed with a normal av_free() call.
155 * @param out_size if non-NULL, the size in bytes of the resulting data array is
158 AVVideoEncParams *av_video_enc_params_alloc(enum AVVideoEncParamsType type,
159 unsigned int nb_blocks, size_t *out_size);
162 * Allocates memory for AVEncodeInfoFrame plus an array of
163 * {@code nb_blocks} AVEncodeInfoBlock in the given AVFrame {@code frame}
164 * as AVFrameSideData of type AV_FRAME_DATA_VIDEO_ENC_PARAMS
165 * and initializes the variables.
168 av_video_enc_params_create_side_data(AVFrame *frame, enum AVVideoEncParamsType type,
169 unsigned int nb_blocks);
171 #endif /* AVUTIL_VIDEO_ENC_PARAMS_H */