[FFmpeg-devel] [PATCH] libavutil: AVEncodeInfo data structures and AV_FRAME_DATA_ENCODE_INFO AVFrameSideDataType

James Almer jamrial at gmail.com
Fri Aug 9 20:52:09 EEST 2019


On 8/9/2019 2:38 PM, Juan De León wrote:
> 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 struct 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 at google.com>
> ---
> fixed a typo in frame.h comment
>  libavutil/Makefile      |  2 +
>  libavutil/encode_info.c | 67 +++++++++++++++++++++++++++++++
>  libavutil/encode_info.h | 87 +++++++++++++++++++++++++++++++++++++++++
>  libavutil/frame.c       |  1 +
>  libavutil/frame.h       |  7 ++++
>  5 files changed, 164 insertions(+)
>  create mode 100644 libavutil/encode_info.c
>  create mode 100644 libavutil/encode_info.h
> 
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index 57e6e3d7e8..37cfb099e9 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                                                        \
> @@ -111,6 +112,7 @@ 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..68c30af4d7
> --- /dev/null
> +++ b/libavutil/encode_info.c
> @@ -0,0 +1,67 @@
> +/*
> + * 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 "libavutil/encode_info.h"
> +#include "libavutil/mem.h"
> +
> +static int init_encode_info_data(AVEncodeInfoFrame *ptr, int nb_blocks) {
> +    ptr->nb_blocks = nb_blocks;
> +    ptr->dc_q = ptr->ac_q = -1;
> +    ptr->dc_chroma_q = ptr->ac_chroma_q = -1;
> +
> +    for(int i=0;i<AV_NUM_DATA_POINTERS;i++)
> +        ptr->plane_q[i] = -1;
> +
> +    return 0;
> +}
> +
> +AVEncodeInfoFrame *av_encode_info_alloc(int nb_blocks)
> +{
> +    AVEncodeInfoFrame *ptr;
> +    size_t size = sizeof(AVEncodeInfoFrame) + sizeof(AVEncodeInfoBlock)*nb_blocks;
> +
> +    if (nb_blocks < 0 || size >= INT_MAX)
> +        return NULL;
> +
> +    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, int nb_blocks)
> +{
> +    size_t size = sizeof(AVEncodeInfoFrame) + sizeof(AVEncodeInfoBlock)*nb_blocks;
> +
> +    if (nb_blocks < 0 || size >= INT_MAX)
> +        return NULL;
> +
> +    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..cbe8be2891
> --- /dev/null
> +++ b/libavutil/encode_info.h
> @@ -0,0 +1,87 @@
> +/*
> + * 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/frame.h"
> +
> +/**
> + * Data structure for extracting block data stored in 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
> +     */
> +    int delta_q;
> +
> +    uint8_t reserved[128];
> +} AVEncodeInfoBlock;
> +
> +/**
> + * Frame encoding info, used as AVFrameSideData
> + */
> +typedef struct AVEncodeInfoFrame {
> +    /**
> +     * Number of blocks in the array
> +     */
> +    int nb_blocks;
> +    /**
> +     * 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;
> +
> +    uint8_t reserved[256];
> +
> +    AVEncodeInfoBlock blocks[];

Flexible array members will break compatibility with C++ projects.

> +} AVEncodeInfoFrame;
> +
> +/**
> + * 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(int 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, int nb_blocks);
> +
> +#endif /* AVUTIL_ENCODE_INFO_H */
> diff --git a/libavutil/frame.c b/libavutil/frame.c
> index dcf1fc3d17..c5ec6d13ca 100644
> --- a/libavutil/frame.c
> +++ b/libavutil/frame.c
> @@ -842,6 +842,7 @@ 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 5d3231e7bb..f2865b6146 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 block data from supported decoders. The data is stored in
> +     * AVEncodeInfoFrame type, which contains an array of AVEncodeInfoBLock
> +     * described in libavuitl/encode_info.h
> +     * Can be allocated in the frame directly with av_encode_info_create_side_data().
> +     */
> +    AV_FRAME_DATA_ENCODE_INFO,
>  };
>  
>  enum AVActiveFormatDescription {

No comments about the actual feature. Will leave that to other developers.


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