[FFmpeg-devel] [PATCH] Extract QP from h264 encoded videos

Juan De León juandl at google.com
Thu Aug 1 20:33:53 EEST 2019


On Tue, Jul 30, 2019 at 6:50 PM Juan De León <juandl at google.com> wrote:

> Removed AVQuantizationParamsArray to prevent ambiguous memory allocation.
> For simplicity, the side data will be allocated as an array of
> AVQuantizationParams and the last element of the array will have w and h
> set to 0.
>
> Better explained in the doc.
> design doc:
> https://docs.google.com/document/d/1WClt3EqhjwdGXhEw386O0wfn3IBQ1Ib-_5emVM1gbnA/edit?usp=sharing
>
> Signed-off-by: Juan De León <juandl at google.com>
> ---
>  libavutil/Makefile              |   2 +
>  libavutil/frame.h               |   6 ++
>  libavutil/quantization_params.c |  41 +++++++++++++
>  libavutil/quantization_params.h | 101 ++++++++++++++++++++++++++++++++
>  4 files changed, 150 insertions(+)
>  create mode 100644 libavutil/quantization_params.c
>  create mode 100644 libavutil/quantization_params.h
>
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index 8a7a44e4b5..be1a9c3a9c 100644
> --- a/libavutil/Makefile
> +++ b/libavutil/Makefile
> @@ -60,6 +60,7 @@ HEADERS = adler32.h
>                \
>            pixdesc.h                                                     \
>            pixelutils.h                                                  \
>            pixfmt.h                                                      \
> +          quantization_params.h                                         \
>            random_seed.h                                                 \
>            rc4.h                                                         \
>            rational.h                                                    \
> @@ -140,6 +141,7 @@ OBJS = adler32.o
>                   \
>         parseutils.o                                                     \
>         pixdesc.o                                                        \
>         pixelutils.o                                                     \
> +       quantization_params.o                                            \
>         random_seed.o                                                    \
>         rational.o                                                       \
>         reverse.o                                                        \
> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index 5d3231e7bb..b64fd9c02c 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -179,6 +179,12 @@ enum AVFrameSideDataType {
>       * array element is implied by AVFrameSideData.size /
> AVRegionOfInterest.self_size.
>       */
>      AV_FRAME_DATA_REGIONS_OF_INTEREST,
> +    /**
> +     * To extract quantization parameters from supported decoders.
> +     * The data is stored as AVQuantizationParamsArray type, described in
> +     * libavuitl/quantization_params.h
> +     */
> +    AV_FRAME_DATA_QUANTIZATION_PARAMS,
>  };
>
>  enum AVActiveFormatDescription {
> diff --git a/libavutil/quantization_params.c
> b/libavutil/quantization_params.c
> new file mode 100644
> index 0000000000..7d8b0a4526
> --- /dev/null
> +++ b/libavutil/quantization_params.c
> @@ -0,0 +1,41 @@
> +/*
> + * 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/quantization_params.h"
> +
> +static const char* const QP_NAMES_H264[] = {"qp", "qpcb", "qpcr"};
> +
> +static const char* const QP_NAMES_VP9[] = {"qyac", "qydc", "quvdc",
> "quvac",
> +                                           "qiyac", "qiydc", "qiuvdc",
> "qiuvac"};
> +
> +static const char* const QP_NAMES_AV1[] = {"qyac", "qydc", "qudc",
> "quac", "qvdc", "qvac",
> +                                      "qiyac", "qiydc", "qiudc", "qiuac",
> "qivdc", "qivac"};
> +
> +const char* av_get_qp_type_string(enum AVExtractQPSupportedCodecs
> codec_id, int index)
> +{
> +    switch (codec_id) {
> +        case AV_EXTRACT_QP_CODEC_ID_H264:
> +            return index < AV_QP_ARR_SIZE_H264 ? QP_NAMES_H264[index]
> :NULL;
> +        case AV_EXTRACT_QP_CODEC_ID_VP9:
> +            return index < AV_QP_ARR_SIZE_VP9  ? QP_NAMES_VP9[index]
> :NULL;
> +        case AV_EXTRACT_QP_CODEC_ID_AV1:
> +            return index < AV_QP_ARR_SIZE_AV1  ? QP_NAMES_AV1[index]
> :NULL;
> +        default:
> +            return NULL;
> +    }
> +}
> diff --git a/libavutil/quantization_params.h
> b/libavutil/quantization_params.h
> new file mode 100644
> index 0000000000..23f4311293
> --- /dev/null
> +++ b/libavutil/quantization_params.h
> @@ -0,0 +1,101 @@
> +/*
> + * 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_QUANTIZATION_PARAMS_H
> +#define AVUTIL_QUANTIZATION_PARAMS_H
> +
> +/*
> + * Supported decoders for extraction and filter
> + */
> +enum AVExtractQPSupportedCodecs {
> +    AV_EXTRACT_QP_CODEC_ID_H264 = 0,
> +    AV_EXTRACT_QP_CODEC_ID_VP9,
> +    AV_EXTRACT_QP_CODEC_ID_AV1,
> +};
> +
> +/**
> + * Enums for different codecs to store qp in the type array
> + * Each enum must have an array of strings describing each field
> + * declared in quantization_params.c
> + */
> +
> +enum AVQPArrIndexesH264 {
> +    AV_QP_Y_H264 = 0,      // QPy
> +    AV_QP_U_H264,          // QPcb
> +    AV_QP_V_H264,          // QPcr
> +    AV_QP_ARR_SIZE_H264
> +};
> +
> +enum AVQPArrIndexesVP9 {
> +    AV_QP_YAC_VP9 = 0,     // get_dc_quant[][base_q_idx] - in spec
> +    AV_QP_YDC_VP9,         // get_dc_quant[][base_q_idx+delta_q_y_dc]
> +    AV_QP_UVDC_VP9,        // get_dc_quant[][base_q_idx+delta_q_uv_dc]
> +    AV_QP_UVAC_VP9,        // get_ac_quant[][base_q_idx+delta_q_uv_ac]
> +    AV_QP_INDEX_YAC_VP9,   // base_q_idx
> +    AV_QP_INDEX_YDC_VP9,   // base_q_idx+delta_q_y_dc
> +    AV_QP_INDEX_UVDC_VP9,  // base_q_idx+delta_q_uv_dc
> +    AV_QP_INDEX_UVAC_VP9,  // base_q_idx+delta_q_uv_ac
> +    AV_QP_ARR_SIZE_VP9
> +};
> +
> +enum AVQPArrIndexesAV1 {
> +    AV_QP_YAC_AV1 = 0,    // dc_q(base_q_idx) - in spec
> +    AV_QP_YDC_AV1,        // dc_q(base_q_idx+DeltaQYDc)
> +    AV_QP_UDC_AV1,        // dc_q(base_q_idx+DeltaQUDc)
> +    AV_QP_UAC_AV1,        // dc_q(base_q_idx+DeltaQUAc)
> +    AV_QP_VDC_AV1,        // dc_q(base_q_idx+DeltaQVDc)
> +    AV_QP_VAC_AV1,        // dc_q(base_q_idx+DeltaQVAc)
> +    AV_QP_INDEX_YAC_AV1,  // base_q_idx
> +    AV_QP_INDEX_YDC_AV1,  // base_q_idx+DeltaQYDc
> +    AV_QP_INDEX_UDC_AV1,  // base_q_idx+DeltaQUDc
> +    AV_QP_INDEX_UAC_AV1,  // base_q_idx+DeltaQUAc
> +    AV_QP_INDEX_VDC_AV1,  // base_q_idx+DeltaQVDc
> +    AV_QP_INDEX_VAC_AV1,  // base_q_idx+DeltaQVAc
> +    AV_QP_ARR_SIZE_AV1
> +};
> +
> +/**
> + * Data structure for extracting Quantization Parameters, codec
> independent
> + */
> +typedef struct AVQuantizationParams {
> +    /**
> +     * x and y coordinates of the block in pixels
> +     */
> +    int x, y;
> +    /**
> +     * width and height of the block in pixels
> +     * set to 0 for the last block in the array
> +     */
> +    int w, h;
> +    /**
> +     * qp array, indexed by type according to
> +     * the enum corresponding to the codec
> +     */
> +    int qp_type[AV_QP_ARR_SIZE_AV1];
> +    /**
> +     * Stores an id corresponding to one of the supported codecs
> +     */
> +    enum AVExtractQPSupportedCodecs codec_id;
> +} AVQuantizationParams;
> +
> +/**
> + * Get the string describing the qp type for the given codec
> + */
> +const char* av_get_qp_type_string(enum AVExtractQPSupportedCodecs
> codec_id, int index);
> +
> +#endif /* AVUTIL_QUANTIZATION_PARAMS_H */
> --
> 2.22.0.709.g102302147b-goog
>
>
Pinging. I'll be in the IRC if anyone wants to discuss it.
Thanks.


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