screenshot: add --screenshot-sw option

Probably worthless. As usual, the manpage dumps all the subtle
differences due to implementation details on the user.

4 files changed, 19 insertions, 1 deletions

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index fd19d3d25c..c5e8aeb5c0 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -4224,6 +4224,21 @@ Screenshot
     more CPU time. Note that this also affects the screenshot quality when used
     with lossy WebP files. The default is 4.
 
+``--screenshot-sw=<yes|no>``
+    Whether to use software rendering for screenshots (default: no).
+
+    If set to no, the screenshot will be rendered by the current VO if possible
+    (only vo_gpu currently). The advantage is that this will (probably) always
+    show up as in the video window, because the same code is used for rendering.
+    But since the renderer needs to be reinitialized, this can be slow and
+    interrupt playback. (Unless the ``window`` mode is used with the
+    ``screenshot`` command.)
+
+    If set to yes, the software scaler is used to convert the video to RGB (or
+    whatever the target screenshot requires). In this case, conversion will
+    run in a separate thread and will probably not interrupt playback. The
+    software renderer may lack some capabilities, such as HDR rendering.
+
 Software Scaler
 ---------------
 
diff --git a/options/options.c b/options/options.c
index a4d3d3250d..c297200a45 100644
--- a/options/options.c
+++ b/options/options.c
@@ -752,6 +752,7 @@ static const m_option_t mp_opts[] = {
     {"screenshot-template", OPT_STRING(screenshot_template)},
     {"screenshot-directory", OPT_STRING(screenshot_directory),
         .flags = M_OPT_FILE},
+    {"screenshot-sw", OPT_BOOL(screenshot_sw)},
 
     {"record-file", OPT_STRING(record_file), .flags = M_OPT_FILE,
         .deprecation_message = "use --stream-record or the dump-cache command"},
diff --git a/options/options.h b/options/options.h
index 606bc6c8a2..b865ff8896 100644
--- a/options/options.h
+++ b/options/options.h
@@ -276,6 +276,7 @@ typedef struct MPOpts {
     struct image_writer_opts *screenshot_image_opts;
     char *screenshot_template;
     char *screenshot_directory;
+    bool screenshot_sw;
 
     int index_mode;
 
diff --git a/player/screenshot.c b/player/screenshot.c
index e731e02e21..f0af132efb 100644
--- a/player/screenshot.c
+++ b/player/screenshot.c
@@ -346,7 +346,8 @@ static struct mp_image *screenshot_get(struct MPContext *mpctx, int mode,
             .high_bit_depth = high_depth &&
                               mpctx->opts->screenshot_image_opts->high_bit_depth,
         };
-        vo_control(mpctx->video_out, VOCTRL_SCREENSHOT, &ctrl);
+        if (!mpctx->opts->screenshot_sw)
+            vo_control(mpctx->video_out, VOCTRL_SCREENSHOT, &ctrl);
         image = ctrl.res;
         if (image)
             need_add_subs = false;