From 38595ebe3b1303d85ab83f2fd0d0899af55abb00 Mon Sep 17 00:00:00 2001
From: Timo Rothenpieler <timo@rothenpieler.org>
Date: Sat, 6 Aug 2022 14:54:58 +0200
Subject: [PATCH] avfilter/vsrc_ddagrab: make output format user configurable

---
 doc/filters.texi           | 16 ++++++++++++++++
 libavfilter/vsrc_ddagrab.c | 29 ++++++++++++++++++++++++++++-
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 4a5412c91d..dd7ee1394a 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -26531,6 +26531,22 @@ Horizontal offset of the captured video.
 @item offset_y
 Vertical offset of the captured video.
 
+@item output_fmt
+Desired filter output format.
+Defaults to 8 Bit BGRA.
+
+It accepts the following values:
+@table @samp
+@item auto
+Passes all supported output formats to DDA and returns what DDA decides to use.
+@item 8bit
+@item bgra
+8 Bit formats always work, and DDA will convert to them if neccesary.
+@item 10bit
+@item x2bgr10
+Filter initialization will fail if 10 bit format is requested but unavailable.
+@end table
+
 @end table
 
 @subsection Examples
diff --git a/libavfilter/vsrc_ddagrab.c b/libavfilter/vsrc_ddagrab.c
index 2f33a40f6f..5300d46fc1 100644
--- a/libavfilter/vsrc_ddagrab.c
+++ b/libavfilter/vsrc_ddagrab.c
@@ -97,6 +97,7 @@ typedef struct DdagrabContext {
     int        height;
     int        offset_x;
     int        offset_y;
+    int        out_fmt;
 } DdagrabContext;
 
 #define OFFSET(x) offsetof(DdagrabContext, x)
@@ -108,6 +109,12 @@ static const AVOption ddagrab_options[] = {
     { "video_size", "set video frame size",        OFFSET(width),      AV_OPT_TYPE_IMAGE_SIZE, { .str = NULL },       0,       0, FLAGS },
     { "offset_x",   "capture area x offset",       OFFSET(offset_x),   AV_OPT_TYPE_INT,        { .i64 = 0    }, INT_MIN, INT_MAX, FLAGS },
     { "offset_y",   "capture area y offset",       OFFSET(offset_y),   AV_OPT_TYPE_INT,        { .i64 = 0    }, INT_MIN, INT_MAX, FLAGS },
+    { "output_fmt", "desired output format",       OFFSET(out_fmt),    AV_OPT_TYPE_INT,        { .i64 = DXGI_FORMAT_B8G8R8A8_UNORM },    0, INT_MAX, FLAGS, "output_fmt" },
+    { "auto",       "let dda pick its preferred format", 0,            AV_OPT_TYPE_CONST,      { .i64 = 0 },                             0, INT_MAX, FLAGS, "output_fmt" },
+    { "8bit",       "only output default 8 Bit format",  0,            AV_OPT_TYPE_CONST,      { .i64 = DXGI_FORMAT_B8G8R8A8_UNORM },    0, INT_MAX, FLAGS, "output_fmt" },
+    { "bgra",       "only output 8 Bit BGRA",            0,            AV_OPT_TYPE_CONST,      { .i64 = DXGI_FORMAT_B8G8R8A8_UNORM },    0, INT_MAX, FLAGS, "output_fmt" },
+    { "10bit",      "only output default 10 Bit format", 0,            AV_OPT_TYPE_CONST,      { .i64 = DXGI_FORMAT_R10G10B10A2_UNORM }, 0, INT_MAX, FLAGS, "output_fmt" },
+    { "x2bgr10",    "only output 10 Bit X2BGR10",        0,            AV_OPT_TYPE_CONST,      { .i64 = DXGI_FORMAT_R10G10B10A2_UNORM }, 0, INT_MAX, FLAGS, "output_fmt" },
     { NULL }
 };
 
@@ -208,6 +215,16 @@ static av_cold int init_dxgi_dda(AVFilterContext *avctx)
             DXGI_FORMAT_R10G10B10A2_UNORM,
             DXGI_FORMAT_B8G8R8A8_UNORM
         };
+        int nb_formats = FF_ARRAY_ELEMS(formats);
+
+        if(dda->out_fmt == DXGI_FORMAT_B8G8R8A8_UNORM) {
+            formats[0] = DXGI_FORMAT_B8G8R8A8_UNORM;
+            nb_formats = 1;
+        } else if (dda->out_fmt) {
+            formats[0] = dda->out_fmt;
+            formats[1] = DXGI_FORMAT_B8G8R8A8_UNORM;
+            nb_formats = 2;
+        }
 
         IDXGIOutput_Release(dxgi_output);
         dxgi_output = NULL;
@@ -219,7 +236,7 @@ static av_cold int init_dxgi_dda(AVFilterContext *avctx)
         hr = IDXGIOutput5_DuplicateOutput1(dxgi_output5,
             (IUnknown*)dda->device_hwctx->device,
             0,
-            FF_ARRAY_ELEMS(formats),
+            nb_formats,
             formats,
             &dda->dxgi_outdupl);
         IDXGIOutput5_Release(dxgi_output5);
@@ -242,6 +259,11 @@ static av_cold int init_dxgi_dda(AVFilterContext *avctx)
 #else
     {
 #endif
+        if (dda->out_fmt && dda->out_fmt != DXGI_FORMAT_B8G8R8A8_UNORM) {
+            av_log(avctx, AV_LOG_ERROR, "Only 8 bit output supported with legacy API\n");
+            return AVERROR(ENOTSUP);
+        }
+
         hr = IDXGIOutput_QueryInterface(dxgi_output, &IID_IDXGIOutput1, (void**)&dxgi_output1);
         IDXGIOutput_Release(dxgi_output);
         dxgi_output = NULL;
@@ -704,6 +726,11 @@ static int ddagrab_config_props(AVFilterLink *outlink)
     if (ret < 0)
         return ret;
 
+    if (dda->out_fmt && dda->raw_format != dda->out_fmt) {
+        av_log(avctx, AV_LOG_ERROR, "Requested output format unavailable.\n");
+        return AVERROR(ENOTSUP);
+    }
+
     dda->width -= FFMAX(dda->width - dda->raw_width + dda->offset_x, 0);
     dda->height -= FFMAX(dda->height - dda->raw_height + dda->offset_y, 0);