[FFmpeg-devel] [PATCH] avdevice/avfoundation: add scaleFactor attribute for avfoundation

[sharpbai]

From: sharpbai <tian.bai at duobei.com>

feature: add scaleFactor attribute for avfoundation
added by: siyuan.wang at duobei.com
added by: yiren.li at duobei.com
---
 doc/indevs.texi            | 6 ++++++
 libavdevice/avfoundation.m | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/doc/indevs.texi b/doc/indevs.texi
index 09e3321..3d25930 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -139,6 +139,12 @@ Capture the mouse pointer. Default is 0.
 @item -capture_mouse_clicks
 Capture the screen mouse clicks. Default is 0.
 
+ at item -scale_factor
+Scale factor for capture the screen. Set this property to scale the buffers
+by a given factor. For example a 320x240 capture area with a scale_factor of 2.0
+produces video buffers at 640x480. Another example a 320x240 capture area with
+a scale_factor of 0.5 produces video buffers at 160x120. Default is 1.0 (no scaling).
+
 @end table
 
 @subsection Examples
diff --git a/libavdevice/avfoundation.m b/libavdevice/avfoundation.m
index e2ddf47..3764de8 100644
--- a/libavdevice/avfoundation.m
+++ b/libavdevice/avfoundation.m
@@ -96,6 +96,7 @@ typedef struct
 
     int             capture_cursor;
     int             capture_mouse_clicks;
+    float           scale_factor;
 
     int             list_devices;
     int             video_device_index;
@@ -735,6 +736,12 @@ static int avf_read_header(AVFormatContext *s)
                 capture_screen_input.minFrameDuration = CMTimeMake(ctx->framerate.den, ctx->framerate.num);
             }
 
+            if (ctx->scale_factor <= 2.0 && ctx->scale_factor > 0.0) {
+                capture_screen_input.scaleFactor = ctx->scale_factor;
+            } else {
+                av_log(ctx, AV_LOG_ERROR, "The value of scale_factor must be more than 0.0 and less than or equal to 2.0");
+            }
+
 #if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1080
             if (ctx->capture_cursor) {
                 capture_screen_input.capturesCursor = YES;
@@ -1025,6 +1032,7 @@ static const AVOption options[] = {
     { "video_size", "set video size", offsetof(AVFContext, width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
     { "capture_cursor", "capture the screen cursor", offsetof(AVFContext, capture_cursor), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
     { "capture_mouse_clicks", "capture the screen mouse clicks", offsetof(AVFContext, capture_mouse_clicks), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
+    { "scale_factor", "scale screen factor range", offsetof(AVFContext, scale_factor), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, 0.0, 2.0, AV_OPT_FLAG_DECODING_PARAM },
 
     { NULL },
 };
-- 
2.2.1