From: sharpbai <tian....@duobei.com>
feature: add scaleFactor attribute for avfoundation
added by: siyuan.w...@duobei.com
added by: yiren...@duobei.com
---
doc/indevs.texi | 22 ++++++++++++++++++++++
libavdevice/avfoundation.m | 6 ++++++
2 files changed, 28 insertions(+)
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 09e3321..1ba71d7 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -139,6 +139,13 @@ Capture the mouse pointer. Default is 0.
@item -capture_mouse_clicks
Capture the screen mouse clicks. Default is 0.
+@item -scale_factor
+Scale factor for capture the screen. Set this property to scale the buffers
+by a given factor. For example capturing a retina screen which resolution
2880x1800
+with a scale_factor of 0.5 (or 0.05) produces video buffers at 1440x900 (or
144x90).
+This is useful for reducing captured file size and increasing performance
+in capturing screen. Default is 1.0 (no scaling).
+
@end table
@subsection Examples
@@ -169,6 +176,21 @@ Record video from the system default video device using
the pixel format bgr0 an
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
@end example
+@item
+Capture video from the first screen using the pixel format bgr0 and scaling in
half size into out.avi.
+First command use the avfoundation device command to enumerate all the
available input devices including
+screens ready to be captured:
+@example
+$ ffmpeg -f avfoundation -list_devices true -i ""
+@end example
+Once you've figured out the device index corresponding to the screen to be
captured use, run the second
+command with the correct screen device index to execute screen capture. For
example on my mac the index
+of "Screen Capture 0" is "1", I should replace @code{-i
"<screen_device_index>"} with @code{-i "1"} in the second command.
+@example
+$ ffmpeg -f avfoundation -pixel_format bgr0 -scale_factor 0.5 -i
"<screen_device_index>" out.avi
+@end example
+
+
@end itemize
@section bktr
diff --git a/libavdevice/avfoundation.m b/libavdevice/avfoundation.m
index e2ddf47..1196cf3 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 +736,10 @@ static int avf_read_header(AVFormatContext *s)
capture_screen_input.minFrameDuration =
CMTimeMake(ctx->framerate.den, ctx->framerate.num);
}
+ if (ctx->scale_factor > 0.0) {
+ capture_screen_input.scaleFactor = ctx->scale_factor;
+ }
+
#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1080
if (ctx->capture_cursor) {
capture_screen_input.capturesCursor = YES;
@@ -1025,6 +1030,7 @@ 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, 1.0,
AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
--
2.2.1
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