Re: [FFmpeg-devel] [PATCH] avfilter: add sdlvsink for video display

[Hiccup Zhu <hiccupzhu@gmail.com>]

On Thu, 6 Jun 2024 at 20:20, Zhao Zhili <quinkblack@foxmail.com> wrote:
>
>
> On Jun 6, 2024, at 19:51, Shiqi Zhu <hiccupzhu@gmail.com> wrote:
>
>
> I’m afraid this has the same issue as libavdevice/sdl[1].
>
> [1] https://patchwork.ffmpeg.org/project/ffmpeg/patch/20230918063728.198377-1-haihao.xiang@intel.com/
>

Thank you for the reminder. This patch does not have that issue. All
SDL initialization is within the filter_frame() function, so there's
no problem with different threads being created.

Furthermore, my expertise lies primarily in multimedia framework
development. I've noticed that the libavfilter now offers a
comprehensive basic framework, providing various types of filters such
as src, trans, and sink within the filter-graph.

There are already many src and trans type filters in the existing
codebase, with rich functionalities. However, there are only two sink
filters: buffersink and nullsink, which is not quite sufficient for
the development of filter-graphs.

Thus, I submitted this patch with the intention of enriching the types
of sink filters available.

Many thanks for your valuable comments.

>
> Signed-off-by: Shiqi Zhu <hiccupzhu@gmail.com>
> ---
> configure                    |   1 +
> libavfilter/Makefile         |   1 +
> libavfilter/allfilters.c     |   1 +
> libavfilter/vsink_sdlvsink.c | 142 +++++++++++++++++++++++++++++++++++
> 4 files changed, 145 insertions(+)
> create mode 100644 libavfilter/vsink_sdlvsink.c
>
> diff --git a/configure b/configure
> index 6c5b8aab9a..968b5c8912 100755
> --- a/configure
> +++ b/configure
> @@ -3977,6 +3977,7 @@ xstack_qsv_filter_deps="libmfx"
> xstack_qsv_filter_select="qsvvpp"
> pad_vaapi_filter_deps="vaapi_1"
> drawbox_vaapi_filter_deps="vaapi_1"
> +sdlvsink_filter_deps="sdl2"
>
> # examples
> avio_http_serve_files_deps="avformat avutil fork"
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 5992fd161f..feac6b464d 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -616,6 +616,7 @@ OBJS-$(CONFIG_YUVTESTSRC_FILTER)             += vsrc_testsrc.o
> OBJS-$(CONFIG_ZONEPLATE_FILTER)              += vsrc_testsrc.o
>
> OBJS-$(CONFIG_NULLSINK_FILTER)               += vsink_nullsink.o
> +OBJS-$(CONFIG_SDLVSINK_FILTER)               += vsink_sdlvsink.o
>
> # multimedia filters
> OBJS-$(CONFIG_A3DSCOPE_FILTER)               += avf_a3dscope.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index c532682fc2..d5f942ffb5 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -579,6 +579,7 @@ extern const AVFilter ff_vsrc_yuvtestsrc;
> extern const AVFilter ff_vsrc_zoneplate;
>
> extern const AVFilter ff_vsink_nullsink;
> +extern const AVFilter ff_vsink_sdlvsink;
>
> /* multimedia filters */
> extern const AVFilter ff_avf_a3dscope;
> diff --git a/libavfilter/vsink_sdlvsink.c b/libavfilter/vsink_sdlvsink.c
> new file mode 100644
> index 0000000000..630f719c7e
> --- /dev/null
> +++ b/libavfilter/vsink_sdlvsink.c
> @@ -0,0 +1,142 @@
> +/*
> + * 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 "avfilter.h"
> +#include "internal.h"
> +#include "libavutil/internal.h"
> +#include <SDL2/SDL.h>
> +#include <unistd.h>
> +
> +typedef struct {
> +    SDL_Window   *window;
> +    SDL_Renderer *render;
> +    SDL_Texture  *texture;
> +} SDLVideoContext;
> +
> +static int init(AVFilterContext *ctx)
> +{
> +    if (SDL_Init(SDL_INIT_VIDEO) < 0)
> +    {
> +        av_log(ctx, AV_LOG_ERROR, "SDL2 could not initialize! %s\n", SDL_GetError());
> +        return -ENOMEM;
> +    }
> +
> +    SDL_PollEvent(NULL);
> +    SDL_SetHint(SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR, "0");
> +
> +    return 0;
> +}
> +
> +static void uninit(AVFilterContext *ctx)
> +{
> +    SDLVideoContext *sink = ctx->priv;
> +
> +    if (sink->texture) {
> +        SDL_DestroyTexture(sink->texture);
> +        sink->texture = NULL;
> +    }
> +
> +    if (sink->render) {
> +        SDL_DestroyRenderer(sink->render);
> +        sink->render = NULL;
> +    }
> +
> +    if (sink->window) {
> +        SDL_DestroyWindow(sink->window);
> +        sink->window = NULL;
> +    }
> +
> +    SDL_Quit();
> +}
> +
> +static int filter_frame(AVFilterLink *link, AVFrame *frame)
> +{
> +    AVFilterContext *ctx = link->dst;
> +    SDLVideoContext *sink = ctx->priv;
> +    SDL_RendererInfo renderer_info;
> +
> +    if (!sink->window) {
> +        sink->window = SDL_CreateWindow("YUV Player",
> +                                         SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
> +                                         frame->width, frame->height, SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
> +        if (!sink->window) {
> +            av_log(ctx, AV_LOG_ERROR, "SDL2 could not create window %s\n", SDL_GetError());
> +            return -ENOMEM;
> +        }
> +    }
> +
> +    if (!sink->render) {
> +        sink->render = SDL_CreateRenderer(sink->window, -1, 0);
> +        if (!sink->render) {
> +            av_log(ctx, AV_LOG_ERROR, "SDL2 could not create render %s\n", SDL_GetError());
> +            return -ENOMEM;
> +        }
> +        SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
> +
> +        SDL_GetRendererInfo(sink->render, &renderer_info);
> +        av_log(ctx, AV_LOG_INFO, "sdl2 renderer name:%s\n", renderer_info.name);
> +    }
> +
> +    if (!sink->texture) {
> +        sink->texture = SDL_CreateTexture(sink->render, SDL_PIXELFORMAT_IYUV,
> +                                           SDL_TEXTUREACCESS_STREAMING, frame->width, frame->height);
> +        if (!sink->texture) {
> +            av_log(ctx, AV_LOG_ERROR, "create texture failed %s\n", SDL_GetError());
> +            return -EINVAL;
> +        }
> +    }
> +
> +    SDL_UpdateYUVTexture(sink->texture, NULL,
> +                         frame->data[0], frame->linesize[0],
> +                         frame->data[1], frame->linesize[1],
> +                         frame->data[2], frame->linesize[2]);
> +
> +    SDL_RenderClear(sink->render);
> +
> +    SDL_RenderCopy(sink->render, sink->texture, NULL, NULL);
> +    SDL_RenderPresent(sink->render);
> +
> +    av_frame_free(&frame);
> +
> +    return 0;
> +}
> +
> +static const AVFilterPad avfilter_vsink_sdlvsink_inputs[] = {
> +    {
> +        .name        = "default",
> +        .type        = AVMEDIA_TYPE_VIDEO,
> +        .filter_frame = filter_frame,
> +    },
> +};
> +
> +static const AVFilterPad avfilter_vsink_sdlvsink_outputs[] = {
> +    {
> +        .name = NULL,
> +        .type = AVMEDIA_TYPE_VIDEO,
> +    },
> +};
> +
> +const AVFilter ff_vsink_sdlvsink = {
> +    .name        = "sdlvsink",
> +    .description = NULL_IF_CONFIG_SMALL("Do absolutely nothing with the input video."),
> +    .priv_size   = sizeof(SDLVideoContext),
> +    .init        = init,
> +    .uninit      = uninit,
> +    FILTER_INPUTS(avfilter_vsink_sdlvsink_inputs),
> +    FILTER_OUTPUTS(avfilter_vsink_sdlvsink_outputs),
> +};
> --
> 2.34.1
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>
>
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".