[FFmpeg-devel] [PATCH] avfilter: add fbsink for video display.

Shiqi Zhu hiccupzhu at gmail.com
Tue Jun 11 16:03:10 EEST 2024


This patch wants to extend the functionality of sink-filter.

Signed-off-by: Shiqi Zhu <hiccupzhu at gmail.com>
---
 configure                  |   1 +
 libavfilter/Makefile       |   1 +
 libavfilter/allfilters.c   |   1 +
 libavfilter/vsink_fbsink.c | 319 +++++++++++++++++++++++++++++++++++++
 4 files changed, 322 insertions(+)
 create mode 100644 libavfilter/vsink_fbsink.c

diff --git a/configure b/configure
index 6c5b8aab9a..986bf9b069 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"
+fbsink_filter_deps="linux_fb_h"
 
 # examples
 avio_http_serve_files_deps="avformat avutil fork"
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5992fd161f..7b9167ab8c 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_FBSINK_FILTER)                 += vsink_fbsink.o
 
 # multimedia filters
 OBJS-$(CONFIG_A3DSCOPE_FILTER)               += avf_a3dscope.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index c532682fc2..9d565f2376 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_fbsink;
 
 /* multimedia filters */
 extern const AVFilter ff_avf_a3dscope;
diff --git a/libavfilter/vsink_fbsink.c b/libavfilter/vsink_fbsink.c
new file mode 100644
index 0000000000..97d94def46
--- /dev/null
+++ b/libavfilter/vsink_fbsink.c
@@ -0,0 +1,319 @@
+/*
+ * 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 "libavutil/opt.h"
+#include "libavfilter/filters.h"
+#include "libavfilter/formats.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/common.h"
+#include "libavutil/file_open.h"
+#include "libavutil/mem.h"
+#include "libavutil/pixdesc.h"
+#include <linux/fb.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#define SAFE_CLOSE(fd) do { if (fd >= 0) { close(fd); fd = -1; } } while (0)
+
+typedef struct FBSinkContext {
+    const AVClass *class;
+    int xoffset;                      ///< x coordinate of top left corner
+    int yoffset;                      ///< y coordinate of top left corner
+    struct fb_var_screeninfo varinfo; ///< framebuffer variable info
+    struct fb_fix_screeninfo fixinfo; ///< framebuffer fixed info
+    int fd;                           ///< framebuffer device file descriptor
+    uint8_t *data;                    ///< framebuffer data
+    const char    *devname;           ///< framebuffer device
+    int           width, height;
+    int           format;
+    AVRational    sample_aspect_ratio;
+    AVRational    frame_rate;
+    int           bits_per_coded_sample;
+} FBSinkContext;
+
+struct rgb_pixfmt_map_entry {
+    int bits_per_pixel;
+    int red_offset, green_offset, blue_offset, alpha_offset;
+    enum AVPixelFormat pixfmt;
+};
+
+static const char *ff_fbdev_default_device(void)
+{
+    const char *dev = getenv("FRAMEBUFFER");
+    if (!dev)
+        dev = "/dev/fb0";
+    return dev;
+}
+
+static const struct rgb_pixfmt_map_entry rgb_pixfmt_map[] = {
+    // bpp, red_offset,  green_offset, blue_offset, alpha_offset, pixfmt
+    {  32,       0,           8,          16,           24,   AV_PIX_FMT_RGBA  },
+    {  32,      16,           8,           0,           24,   AV_PIX_FMT_BGRA  },
+    {  32,       8,          16,          24,            0,   AV_PIX_FMT_ARGB  },
+    {  32,       3,           2,           8,            0,   AV_PIX_FMT_ABGR  },
+    {  24,       0,           8,          16,            0,   AV_PIX_FMT_RGB24 },
+    {  24,      16,           8,           0,            0,   AV_PIX_FMT_BGR24 },
+    {  16,      11,           5,           0,            0,   AV_PIX_FMT_RGB565 },
+};
+
+static enum AVPixelFormat ff_get_pixfmt_from_fb_varinfo(struct fb_var_screeninfo *varinfo)
+{
+    int i;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(rgb_pixfmt_map); i++) {
+        const struct rgb_pixfmt_map_entry *entry = &rgb_pixfmt_map[i];
+        if (entry->bits_per_pixel == varinfo->bits_per_pixel &&
+            entry->red_offset == varinfo->red.offset &&
+            entry->green_offset == varinfo->green.offset &&
+            entry->blue_offset == varinfo->blue.offset)
+            return entry->pixfmt;
+    }
+
+    return AV_PIX_FMT_NONE;
+}
+
+static int fbsink_init(AVFilterContext *ctx)
+{
+    FBSinkContext *fbdev = ctx->priv;
+    const char *device;
+    int ret;
+
+    if (fbdev->devname)
+        device = fbdev->devname;
+    else
+        device = ff_fbdev_default_device();
+
+    if ((fbdev->fd = avpriv_open(device, O_RDWR)) == -1) {
+        ret = AVERROR(errno);
+        av_log(ctx, AV_LOG_ERROR,
+               "Could not open framebuffer device '%s': %s\n",
+               device, av_err2str(ret));
+        return ret;
+    }
+
+    if (ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->varinfo) < 0) {
+        ret = AVERROR(errno);
+        av_log(ctx, AV_LOG_ERROR, "FBIOGET_VSCREENINFO: %s\n", av_err2str(ret));
+        goto fail;
+    }
+
+    if (ioctl(fbdev->fd, FBIOGET_FSCREENINFO, &fbdev->fixinfo) < 0) {
+        ret = AVERROR(errno);
+        av_log(ctx, AV_LOG_ERROR, "FBIOGET_FSCREENINFO: %s\n", av_err2str(ret));
+        goto fail;
+    }
+
+    fbdev->format = ff_get_pixfmt_from_fb_varinfo(&fbdev->varinfo);
+    if (fbdev->format == AV_PIX_FMT_NONE) {
+        ret = AVERROR(EINVAL);
+        av_log(ctx, AV_LOG_ERROR, "Framebuffer pixel format not supported.\n");
+        goto fail;
+    }
+
+    fbdev->bits_per_coded_sample = av_get_bits_per_pixel(av_pix_fmt_desc_get(fbdev->format));
+
+    fbdev->data = mmap(NULL, fbdev->fixinfo.smem_len, PROT_WRITE, MAP_SHARED, fbdev->fd, 0);
+    if (fbdev->data == MAP_FAILED) {
+        ret = AVERROR(errno);
+        av_log(ctx, AV_LOG_ERROR, "Error in mmap(): %s\n", av_err2str(ret));
+        goto fail;
+    }
+
+    return 0;
+fail:
+    close(fbdev->fd);
+    return 0;
+}
+
+static void fbsink_uninit(AVFilterContext *ctx)
+{
+    FBSinkContext *fbdev = ctx->priv;
+    if (fbdev->data != MAP_FAILED && fbdev->data != NULL) {
+        munmap(fbdev->data, fbdev->fixinfo.smem_len);
+        fbdev->data = MAP_FAILED;
+    }
+    SAFE_CLOSE(fbdev->fd);
+}
+
+static int fbsink_activate(AVFilterContext *ctx)
+{
+    AVFilterLink *inlink = ctx->inputs[0];
+    FBSinkContext *fbdev = ctx->priv;
+    const uint8_t *pin;
+    uint8_t *pout;
+    int disp_height;
+    int bytes_to_copy;
+    int64_t pts;
+    AVFrame *frame;
+    int bytes_per_pixel = fbdev->bits_per_coded_sample >> 3;
+    int video_width = fbdev->width;
+    int video_height = fbdev->height;
+    int src_line_size;
+    int i, ret;
+
+    if (!ff_inlink_check_available_frame(inlink)) {
+        ff_inlink_acknowledge_status(inlink, &ret, &pts);
+        if (ret >= 0)
+            ff_inlink_request_frame(inlink);
+
+        return ret;
+    }
+
+    ret = ff_inlink_consume_frame(inlink, &frame);
+    if (ret < 0)
+        return ret;
+
+    src_line_size = frame->linesize[0];
+    disp_height = FFMIN(fbdev->varinfo.yres, video_height);
+    bytes_to_copy = FFMIN(fbdev->varinfo.xres, video_width) * bytes_per_pixel;
+
+    pin = frame->data[0];
+    pout = fbdev->data +
+           bytes_per_pixel * fbdev->varinfo.xoffset +
+           fbdev->varinfo.yoffset * fbdev->fixinfo.line_length;
+
+    if (fbdev->xoffset) {
+        if (fbdev->xoffset < 0) {
+            if (-fbdev->xoffset >= video_width) // nothing to display
+                return 0;
+            bytes_to_copy += fbdev->xoffset * bytes_per_pixel;
+            pin -= fbdev->xoffset * bytes_per_pixel;
+        } else {
+            int diff = (video_width + fbdev->xoffset) - fbdev->varinfo.xres;
+            if (diff > 0) {
+                if (diff >= video_width) // nothing to display
+                    return 0;
+                bytes_to_copy -= diff * bytes_per_pixel;
+            }
+            pout += bytes_per_pixel * fbdev->xoffset;
+        }
+    }
+
+    if (fbdev->yoffset) {
+        if (fbdev->yoffset < 0) {
+            if (-fbdev->yoffset >= video_height) // nothing to display
+                return 0;
+            disp_height += fbdev->yoffset;
+            pin -= fbdev->yoffset * src_line_size;
+        } else {
+            int diff = (video_height + fbdev->yoffset) - fbdev->varinfo.yres;
+            if (diff > 0) {
+                if (diff >= video_height) // nothing to display
+                    return 0;
+                disp_height -= diff;
+            }
+            pout += fbdev->yoffset * fbdev->fixinfo.line_length;
+        }
+    }
+
+    for (i = 0; i < disp_height; i++) {
+        memcpy(pout, pin, bytes_to_copy);
+        pout += fbdev->fixinfo.line_length;
+        pin += src_line_size;
+    }
+
+    if (fbdev->frame_rate.den > 0 && fbdev->frame_rate.num > 0)
+        usleep(av_rescale(AV_TIME_BASE, fbdev->frame_rate.den, fbdev->frame_rate.num));
+
+    return ff_filter_frame(ctx->outputs[0], frame);
+}
+
+static int fbsink_query_formats(AVFilterContext *ctx)
+{
+    FBSinkContext *fbdev = ctx->priv;
+    AVFilterFormats *formats = NULL;
+    int ret;
+
+    ret = ff_add_format(&formats, fbdev->format);
+    if (ret < 0)
+        return ret;
+
+    ret = ff_set_common_formats(ctx, formats);
+    if (ret < 0)
+        return ret;
+
+    return 0;
+}
+
+static int fbsink_input_props(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    FBSinkContext *sink = ctx->priv;
+
+    switch (inlink->type) {
+    case AVMEDIA_TYPE_VIDEO:
+        sink->width  = inlink->w;
+        sink->height = inlink->h;
+        sink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+        sink->frame_rate = inlink->frame_rate;
+        break;
+    default:
+        break;
+    }
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(FBSinkContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption fbsink_options[] = {
+    { "devname", "fb device name", OFFSET(devname), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, .flags = FLAGS },
+    { NULL },
+};
+
+static const AVClass fbsink_class = {
+    .class_name = "fbsink_class",
+    .item_name  = av_default_item_name,
+    .option     = fbsink_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+    .category   = AV_CLASS_CATEGORY_FILTER,
+};
+
+static const AVFilterPad avfilter_vsink_fbsink_inputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .config_props = fbsink_input_props,
+    },
+};
+
+static const AVFilterPad avfilter_vsink_fbsink_outputs[] = {
+    {
+        .name = NULL,
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+};
+
+const AVFilter ff_vsink_fbsink = {
+    .name        = "fbsink",
+    .description = NULL_IF_CONFIG_SMALL("Frame buffer video display."),
+    .priv_class  = &fbsink_class,
+    .priv_size   = sizeof(FBSinkContext),
+    .init        = fbsink_init,
+    .uninit      = fbsink_uninit,
+    .activate    = fbsink_activate,
+    FILTER_QUERY_FUNC(fbsink_query_formats),
+    FILTER_INPUTS(avfilter_vsink_fbsink_inputs),
+    FILTER_OUTPUTS(avfilter_vsink_fbsink_outputs),
+};
-- 
2.34.1



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