[FFmpeg-devel] [PATCH] lavfi: add quirc filter

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Tue Dec 26 21:08:10 EET 2023


Stefano Sabatini:
> ---
>  Changelog                |   1 +
>  configure                |   4 +
>  doc/filters.texi         |  35 ++++++++
>  libavfilter/Makefile     |   1 +
>  libavfilter/allfilters.c |   1 +
>  libavfilter/vf_quirc.c   | 183 +++++++++++++++++++++++++++++++++++++++
>  6 files changed, 225 insertions(+)
>  create mode 100644 libavfilter/vf_quirc.c
> 
> diff --git a/Changelog b/Changelog
> index b483bb9c69..424bfc11af 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -14,6 +14,7 @@ version <next>:
>  - D3D12VA hardware accelerated H264, HEVC, VP9, AV1, MPEG-2 and VC1 decoding
>  - tiltandshift filter
>  - qrencode filter and qrencodesrc source
> +- quirc filter
>  
>  version 6.1:
>  - libaribcaption decoder
> diff --git a/configure b/configure
> index 0b2f4e9792..419ff76bc1 100755
> --- a/configure
> +++ b/configure
> @@ -257,6 +257,7 @@ External library support:
>    --enable-libplacebo      enable libplacebo library [no]
>    --enable-libpulse        enable Pulseaudio input via libpulse [no]
>    --enable-libqrencode     enable QR encode generation via libqrencode [no]
> +  --enable-libquirc        enable QR decoding via libquirc [no]
>    --enable-librabbitmq     enable RabbitMQ library [no]
>    --enable-librav1e        enable AV1 encoding via rav1e [no]
>    --enable-librist         enable RIST via librist [no]
> @@ -1883,6 +1884,7 @@ EXTERNAL_LIBRARY_LIST="
>      libplacebo
>      libpulse
>      libqrencode
> +    libquirc
>      librabbitmq
>      librav1e
>      librist
> @@ -3793,6 +3795,7 @@ ocv_filter_deps="libopencv"
>  openclsrc_filter_deps="opencl"
>  qrencode_filter_deps="libqrencode"
>  qrencodesrc_filter_deps="libqrencode"
> +quirc_filter_deps="libquirc"
>  overlay_opencl_filter_deps="opencl"
>  overlay_qsv_filter_deps="libmfx"
>  overlay_qsv_filter_select="qsvvpp"
> @@ -6845,6 +6848,7 @@ enabled libopus           && {
>  enabled libplacebo        && require_pkg_config libplacebo "libplacebo >= 4.192.0" libplacebo/vulkan.h pl_vulkan_create
>  enabled libpulse          && require_pkg_config libpulse libpulse pulse/pulseaudio.h pa_context_new
>  enabled libqrencode       && require_pkg_config libqrencode libqrencode qrencode.h QRcode_encodeString
> +enabled libquirc          && require libquirc quirc.h quirc_decode -lquirc
>  enabled librabbitmq       && require_pkg_config librabbitmq "librabbitmq >= 0.7.1" amqp.h amqp_new_connection
>  enabled librav1e          && require_pkg_config librav1e "rav1e >= 0.5.0" rav1e.h rav1e_context_new
>  enabled librist           && require_pkg_config librist "librist >= 0.2.7" librist/librist.h rist_receiver_create
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 04898ede31..5fbe381d74 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -20368,6 +20368,41 @@ qrencode=text=%@{pts@}
>  
>  @end itemize
>  
> + at section quirc
> +
> +Identify and decode a QR code using the libquirc library (see
> + at url{https://github.com/dlbeer/quirc/}), and print the identified QR codes
> +positions and payload as metadata.
> +
> +To enable the compilation of this filter, you need to configure FFmpeg with with
> + at code{--enable-libquirc}.
> +
> +For each found QR code in the input video, some metadata entries are added with
> +the prefix @var{lavfi.quirc.N}, where @var{N} is the index, starting from 0,
> +associated to the QR code.
> +
> +A description of each metadata value follows:
> +
> + at table @option
> + at item lavfi.quirc.count
> +the number of found QR codes, it is not set in case none was found
> +
> + at item lavfi.quirc.N.x
> + at item lavfi.quirc.N.y
> +the top-left position of the @var{N} QR code
> +
> + at item lavfi.quirc.N.X
> + at item lavfi.quirc.N.Y
> +the bottom-right position of the @var{N} QR code
> +
> + at item lavfi.quirc.N.w
> + at item lavfi.quirc.N.h
> +the size of the @var{N} QR code
> +
> + at item lavfi.quirc.N.payload
> +the payload of the QR code
> + at end table
> +
>  @section random
>  
>  Flush video frames from internal cache of frames into a random order.
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 31371ceb1a..f65fb9a5a7 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -437,6 +437,7 @@ OBJS-$(CONFIG_PSEUDOCOLOR_FILTER)            += vf_pseudocolor.o
>  OBJS-$(CONFIG_PSNR_FILTER)                   += vf_psnr.o framesync.o
>  OBJS-$(CONFIG_PULLUP_FILTER)                 += vf_pullup.o
>  OBJS-$(CONFIG_QP_FILTER)                     += vf_qp.o
> +OBJS-$(CONFIG_QUIRC_FILTER)                  += vf_quirc.o
>  OBJS-$(CONFIG_RANDOM_FILTER)                 += vf_random.o
>  OBJS-$(CONFIG_READEIA608_FILTER)             += vf_readeia608.o
>  OBJS-$(CONFIG_READVITC_FILTER)               += vf_readvitc.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 20feb37967..b8570dbab2 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -412,6 +412,7 @@ extern const AVFilter ff_vf_psnr;
>  extern const AVFilter ff_vf_pullup;
>  extern const AVFilter ff_vf_qp;
>  extern const AVFilter ff_vf_qrencode;
> +extern const AVFilter ff_vf_quirc;
>  extern const AVFilter ff_vf_random;
>  extern const AVFilter ff_vf_readeia608;
>  extern const AVFilter ff_vf_readvitc;
> diff --git a/libavfilter/vf_quirc.c b/libavfilter/vf_quirc.c
> new file mode 100644
> index 0000000000..6945a6aa31
> --- /dev/null
> +++ b/libavfilter/vf_quirc.c
> @@ -0,0 +1,183 @@
> +/*
> + * 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
> + */
> +
> +/**
> + * @file QR decoder video filter
> + *
> + * Use libquirc library to decode the content of QR codes, and put the decoded
> + * content to metadata. See:
> + * https://github.com/dlbeer/quirc
> + */
> +
> +#include "config_components.h"

Unneeded.

> +//#include "libavutil/internal.h"
> +#include "libavutil/opt.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "video.h"
> +#include <quirc.h>
> +
> +typedef struct QuircContext {
> +    const AVClass *class;
> +
> +    struct quirc *quirc;
> +} QuircContext;
> +
> +static const AVOption quirc_options[] = {
> +    { NULL }
> +};

There is no need for empty options (and also no need for an AVClass for
a filter without options).

> +
> +static av_cold int init(AVFilterContext *ctx)
> +{
> +    QuircContext *quirc = ctx->priv;
> +
> +    quirc->quirc = quirc_new();
> +    if (!quirc->quirc) {
> +        return AVERROR(ENOMEM);
> +    }
> +
> +    return 0;
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx)
> +{
> +    QuircContext *quirc = ctx->priv;
> +
> +    quirc_destroy(quirc->quirc);
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    QuircContext *quirc = ctx->priv;
> +    int err;
> +
> +    err = quirc_resize(quirc->quirc, inlink->w, inlink->h);
> +    if (err == -1) {
> +        return AVERROR(ENOMEM);
> +    }
> +
> +    return 0;
> +}
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum AVPixelFormat pix_fmts[] = {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE};
> +    return ff_set_common_formats_from_list(ctx, pix_fmts);
> +}

FILTER_QUERY_FUNC is inappropriate for this.

> +
> +static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    AVFilterLink *outlink = ctx->outputs[0];
> +    QuircContext *quirc = ctx->priv;
> +    int codes_count;
> +    int i, w, h;
> +    uint8_t *image, *imagep, *srcp;
> +
> +    image = quirc_begin(quirc->quirc, &w, &h);
> +
> +    /* copy input image to quirc buffer */
> +    imagep = image;
> +    srcp = frame->data[0];
> +    for (i = 0; i < inlink->h; i++) {
> +        memcpy(imagep, srcp, w);
> +        imagep += w;
> +        srcp += frame->linesize[0];
> +    }
> +
> +    quirc_end(quirc->quirc);
> +
> +    codes_count = quirc_count(quirc->quirc);
> +    av_log(ctx, AV_LOG_VERBOSE,
> +           "Found count %d codes in image #%ld\n", codes_count, inlink->frame_count_out);
> +
> +    if (codes_count) {
> +        AVDictionary **metadata = &frame->metadata;
> +
> +        av_dict_set_int(metadata, "lavfi.quirc.count", codes_count, 0);
> +
> +        for (i = 0; i < codes_count; i++) {
> +            struct quirc_code code;
> +            struct quirc_data data;
> +            struct quirc_point top_left, bottom_right;
> +            quirc_decode_error_t err;
> +            int w, h;
> +            char metadata_key[64];
> +
> +            quirc_extract(quirc->quirc, i, &code);
> +
> +            err = quirc_decode(&code, &data);
> +            if (err) {
> +                av_log(ctx, AV_LOG_WARNING,
> +                       "Failed to decode image: %s\n", quirc_strerror(err));
> +                continue;
> +            }
> +
> +            top_left = code.corners[0];
> +            bottom_right = code.corners[2];
> +            w = bottom_right.x - top_left.x;
> +            h = bottom_right.y - top_left.y;
> +
> +#define SET_METADATA_I(key_, value_)                                    \
> +            snprintf(metadata_key, sizeof(metadata_key)-1, "lavfi.quirc.%d." #key_, i); \
> +            av_dict_set_int(metadata, metadata_key, value_, AV_DICT_MATCH_CASE)
> +
> +            SET_METADATA_I(x, top_left.x);
> +            SET_METADATA_I(y, top_left.y);
> +            SET_METADATA_I(X, bottom_right.x);
> +            SET_METADATA_I(Y, bottom_right.y);
> +            SET_METADATA_I(w, w);
> +            SET_METADATA_I(h, h);
> +            snprintf(metadata_key, sizeof(metadata_key)-1, "lavfi.quirc.%d.payload", i); \
> +            av_dict_set(metadata, metadata_key, data.payload, 0);
> +
> +            av_log(ctx, AV_LOG_INFO,
> +                   "Found QR code at position %d+%d:%dx%d with payload: %s\n",
> +                   top_left.x, top_left.y, w, h, data.payload);
> +        }
> +    }
> +
> +    return ff_filter_frame(outlink, frame);
> +}
> +
> +AVFILTER_DEFINE_CLASS(quirc);
> +
> +static const AVFilterPad inputs[] = {
> +    {
> +        .name         = "default",
> +        .type         = AVMEDIA_TYPE_VIDEO,
> +        .filter_frame = filter_frame,
> +        .config_props = config_input
> +    },
> +};
> +
> +const AVFilter ff_vf_quirc = {
> +    .name        = "quirc",
> +    .description = NULL_IF_CONFIG_SMALL("Decode and show QR codes content."),
> +    .priv_size   = sizeof(QuircContext),
> +    .priv_class  = &quirc_class,
> +    .init        = init,
> +    .uninit      = uninit,
> +    FILTER_INPUTS(inputs),
> +    FILTER_OUTPUTS(ff_video_default_filterpad),
> +    FILTER_QUERY_FUNC(query_formats),
> +    .flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
> +                   AVFILTER_FLAG_METADATA_ONLY,
> +};
> +



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