[FFmpeg-devel,4/4] libavutil: AVEncodeInfo data structures

From: Juan De León <juandl-at-google.com@ffmpeg.org>

AVEncodeInfoFrame data structure to store as AVFrameSideData of type
AV_FRAME_DATA_ENCODE_INFO.
The structure stores quantization index for each plane, DC/AC deltas
for luma and chroma planes, and an array of AVEncodeInfoBlock type
denoting position, size, and delta quantizer for each block in the
frame.
Can be extended to support extraction of other block information.

Signed-off-by: Juan De León <juandl@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavutil/Makefile      |   2 +
 libavutil/encode_info.c |  72 ++++++++++++++++++++++++++
 libavutil/encode_info.h | 110 ++++++++++++++++++++++++++++++++++++++++
 libavutil/frame.c       |   1 +
 libavutil/frame.h       |   7 +++
 5 files changed, 192 insertions(+)
 create mode 100644 libavutil/encode_info.c
 create mode 100644 libavutil/encode_info.h

On Sat, Feb 29, 2020 at 2:23 PM Michael Niedermayer <michael@niedermayer.cc>
wrote:

> From: Juan De León <juandl-at-google.com@ffmpeg.org>
>
> AVEncodeInfoFrame data structure to store as AVFrameSideData of type
> AV_FRAME_DATA_ENCODE_INFO.
> The structure stores quantization index for each plane, DC/AC deltas
> for luma and chroma planes, and an array of AVEncodeInfoBlock type
> denoting position, size, and delta quantizer for each block in the
> frame.
> Can be extended to support extraction of other block information.
>
> Signed-off-by: Juan De León <juandl@google.com>
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavutil/Makefile      |   2 +
>  libavutil/encode_info.c |  72 ++++++++++++++++++++++++++
>  libavutil/encode_info.h | 110 ++++++++++++++++++++++++++++++++++++++++
>  libavutil/frame.c       |   1 +
>  libavutil/frame.h       |   7 +++
>  5 files changed, 192 insertions(+)
>  create mode 100644 libavutil/encode_info.c
>  create mode 100644 libavutil/encode_info.h
>
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index a2dae8e89a..df01424c31 100644
> --- a/libavutil/Makefile
> +++ b/libavutil/Makefile
> @@ -24,6 +24,7 @@ HEADERS = adler32.h
>                \
>            dict.h                                                        \
>            display.h                                                     \
>            downmix_info.h                                                \
> +          encode_info.h                                                 \
>            encryption_info.h                                             \
>            error.h                                                       \
>            eval.h                                                        \
> @@ -112,6 +113,7 @@ OBJS = adler32.o
>                   \
>         dict.o                                                           \
>         display.o                                                        \
>         downmix_info.o                                                   \
> +       encode_info.o                                                    \
>         encryption_info.o                                                \
>         error.o                                                          \
>         eval.o                                                           \
> diff --git a/libavutil/encode_info.c b/libavutil/encode_info.c
> new file mode 100644
> index 0000000000..1048173e7f
> --- /dev/null
> +++ b/libavutil/encode_info.c
> @@ -0,0 +1,72 @@
> +/*
> + * 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
> + */
> +#include <limits.h>
> +
> +#include "libavutil/encode_info.h"
> +#include "libavutil/mem.h"
> +
> +/**
> + * Get the size to allocate of AVEncodeInfoFrame and the array of
> AVEncodeInfoBlock.
> + * AVEncodeInfoFrame already allocates size for one element of
> AVEncodeInfoBlock.
> + */
> +#define AV_ENCODE_INFO_GET_SIZE(SIZE, N) \
> +    if (N > (SIZE_MAX - sizeof(AVEncodeInfoFrame)) /
> sizeof(AVEncodeInfoBlock) + 1) \
> +        return NULL; \
> +    SIZE = sizeof(AVEncodeInfoFrame) - sizeof(AVEncodeInfoBlock) \
> +            + FFMAX(1, N) * sizeof(AVEncodeInfoBlock)
> +
> +static int init_encode_info_data(AVEncodeInfoFrame *info, unsigned
> nb_blocks)
> +{
> +    info->nb_blocks = nb_blocks;
> +    info->block_size = sizeof(AVEncodeInfoBlock);
> +    info->blocks_offset = offsetof(AVEncodeInfoFrame, blocks);
> +
> +    for(int i = 0; i < AV_NUM_DATA_POINTERS; i++)
> +        info->plane_q[i] = -1;
> +
> +    return 0;
> +}
> +
> +AVEncodeInfoFrame *av_encode_info_alloc(unsigned nb_blocks)
> +{
> +    size_t size;
> +    AV_ENCODE_INFO_GET_SIZE(size, nb_blocks);
> +    AVEncodeInfoFrame *ptr = av_mallocz(size);
> +    if (!ptr)
> +        return NULL;
> +
> +    init_encode_info_data(ptr, nb_blocks);
> +
> +    return ptr;
> +}
> +
> +AVEncodeInfoFrame *av_encode_info_create_side_data(AVFrame *frame,
> unsigned nb_blocks)
> +{
> +    size_t size;
> +    AV_ENCODE_INFO_GET_SIZE(size, nb_blocks);
> +    AVFrameSideData *sd = av_frame_new_side_data(frame,
> +
>  AV_FRAME_DATA_ENCODE_INFO,
> +                                                 size);
> +    if (!sd)
> +        return NULL;
> +
> +    memset(sd->data, 0, size);
> +    init_encode_info_data((AVEncodeInfoFrame*)sd->data, nb_blocks);
> +
> +    return (AVEncodeInfoFrame*)sd->data;
> +}
> diff --git a/libavutil/encode_info.h b/libavutil/encode_info.h
> new file mode 100644
> index 0000000000..8afe0c9c9e
> --- /dev/null
> +++ b/libavutil/encode_info.h
> @@ -0,0 +1,110 @@
> +/*
> + * 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_ENCODE_INFO_H
> +#define AVUTIL_ENCODE_INFO_H
> +
> +#include "libavutil/avassert.h"
> +#include "libavutil/frame.h"
> +
> +/**
> + * Data structure for extracting block data, stored as an array in
> AVEncodeInfoFrame.
> + */
> +typedef struct AVEncodeInfoBlock{
> +    /**
> +     * 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;
> +    /**
> +     * Delta quantization index for the block with respect to the frame.
> +     */
> +    int delta_q;
> +} AVEncodeInfoBlock;
> +
> +/**
> + * Frame encoding info, used as AVFrameSideData. Data in this structure
> concerns
> + * the whole frame.
> + * Additional entries may be added without bumping major before nb_blocks,
> + * so using the accessor function av_encode_info_get_block() is
> recommended.
> + */
> +typedef struct AVEncodeInfoFrame {
> +    /**
> +     * Base plane quantizer for the frame, set to -1 when value is
> unsupported.
> +     */
> +    int plane_q[AV_NUM_DATA_POINTERS];
> +    /**
> +     * DC/AC quantizer index delta, set to -1 when value is value
> unsupported.
> +     */
> +    int ac_q, dc_q;
> +    /**
> +     * DC/AC chroma quantizer index delta, set to -1 when value is value
> unsupported.
> +     */
> +    int ac_chroma_q, dc_chroma_q;
> +    /**
> +     * Number of blocks in the array, may be 0.
> +     */
> +    unsigned nb_blocks;
> +    /**
> +     * Offset in this structure at which blocks begin in bytes. May not
> match
> +     * offsetof(AVEncodeInfoFrame, blocks).
> +     */
> +    size_t blocks_offset;
> +    /*
> +     * Size of each block in bytes. May not match
> sizeof(AVEncodeInfoBlock).
> +     */
> +    size_t block_size;
> +
> +    /*
> +     * Array of blocks, with a total size of block_size*nb_blocks, the [1]
> +     * is meant for compatibility with C++.
> +     */
> +    AVEncodeInfoBlock blocks[1];
> +} AVEncodeInfoFrame;
> +
> +/*
> + * Gets the block at the specified {@code idx}. Must be between 0 and
> nb_blocks.
> + */
> +static inline AVEncodeInfoBlock
> *av_encode_info_get_block(AVEncodeInfoFrame *info, unsigned idx)
> +{
> +    av_assert0(idx < info->nb_blocks);
> +
> +    return (AVEncodeInfoBlock *)((uint8_t *)info + info->blocks_offset +
> idx*info->block_size);
> +}
> +
> +/**
> + * Allocates memory for AVEncodeInfoFrame plus an array of
> + * {@code nb_blocks} AVEncodeInfoBlock and initializes the variables.
> + * Can be freed with a normal av_free() call.
> + */
> +AVEncodeInfoFrame *av_encode_info_alloc(unsigned nb_blocks);
> +
> +/**
> + * 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_ENCODE_INFO
> + * and initializes the variables.
> + */
> +AVEncodeInfoFrame *av_encode_info_create_side_data(AVFrame *frame,
> unsigned nb_blocks);
> +
> +#endif /* AVUTIL_ENCODE_INFO_H */
> diff --git a/libavutil/frame.c b/libavutil/frame.c
> index 2cd680c886..198272edb0 100644
> --- a/libavutil/frame.c
> +++ b/libavutil/frame.c
> @@ -825,6 +825,7 @@ const char *av_frame_side_data_name(enum
> AVFrameSideDataType type)
>  #endif
>      case AV_FRAME_DATA_DYNAMIC_HDR_PLUS: return "HDR Dynamic Metadata
> SMPTE2094-40 (HDR10+)";
>      case AV_FRAME_DATA_REGIONS_OF_INTEREST: return "Regions Of Interest";
> +    case AV_FRAME_DATA_ENCODE_INFO:                 return "AVEncodeInfo";
>      }
>      return NULL;
>  }
> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index 84ee94c7bb..954ad0c773 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -179,6 +179,13 @@ enum AVFrameSideDataType {
>       * array element is implied by AVFrameSideData.size /
> AVRegionOfInterest.self_size.
>       */
>      AV_FRAME_DATA_REGIONS_OF_INTEREST,
> +    /**
> +     * Extract frame and block encode info from supported decoders. The
> data
> +     * stored is an AVEncodeInfoFrame type, which contains an array of
> +     * AVEncodeInfoBlock. Described in libavuitls/encode_info.h
> +     * Can be allocated in the frame directly with
> av_encode_info_create_side_data().
> +     */
> +    AV_FRAME_DATA_ENCODE_INFO,
>  };
>
>  enum AVActiveFormatDescription {
>

This will be nice if applied because i have patch depend on it, see
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200115091908.81946-2-kaveasaf@gmail.com/