Merge branch 'gst-plugins-good-fix-alternate-interlacing' into 'main'

WIP: v4l2: Fix alternate interlacing caps and field values See merge request gstreamer/gstreamer!961
meson: Fix Python library searching on Windows
2024-05-11 04:52:42 +00:00 · 2024-04-27 18:13:06 +00:00 · 2024-04-27 01:30:21 +00:00 · 2024-04-27 01:30:21 +00:00 · 2021-09-29 09:48:06 -04:00 · 2021-09-29 09:48:05 -04:00
3 changed files with 41 additions and 21 deletions
--- a/subprojects/gst-plugins-good/sys/v4l2/gstv4l2bufferpool.c
+++ b/subprojects/gst-plugins-good/sys/v4l2/gstv4l2bufferpool.c
@ -1173,6 +1173,15 @@ gst_v4l2_buffer_pool_qbuf (GstV4l2BufferPool * pool, GstBuffer * buf,
    else
      field = obj->format.fmt.pix.field;

+    /* If interlaced alternate, specify if buffer is top or bottom */
+    if (field == V4L2_FIELD_ALTERNATE) {
+      if ((GST_BUFFER_FLAGS (buf) & GST_VIDEO_BUFFER_FLAG_TOP_FIELD) ==
+          GST_VIDEO_BUFFER_FLAG_TOP_FIELD)
+        field = V4L2_FIELD_TOP;
+      else
+        field = V4L2_FIELD_BOTTOM;
+    }
+
    group->buffer.field = field;
  }

--- a/subprojects/gst-plugins-good/sys/v4l2/gstv4l2object.c
+++ b/subprojects/gst-plugins-good/sys/v4l2/gstv4l2object.c
@ -2886,6 +2886,7 @@ static void
 check_alternate_and_append_struct (GstCaps * caps, GstStructure * s)
 {
  const GValue *mode;
+  GstCapsFeatures *features = NULL;

  mode = gst_structure_get_value (s, "interlace-mode");
  if (!mode)
@ -2894,12 +2895,9 @@ check_alternate_and_append_struct (GstCaps * caps, GstStructure * s)
  if (G_VALUE_HOLDS_STRING (mode)) {
    /* Add the INTERLACED feature if the mode is alternate */
    if (!g_strcmp0 (gst_structure_get_string (s, "interlace-mode"),
-            "alternate")) {
-      GstCapsFeatures *feat;
-
-      feat = gst_caps_features_new (GST_CAPS_FEATURE_FORMAT_INTERLACED, NULL);
-      gst_caps_set_features (caps, gst_caps_get_size (caps) - 1, feat);
-    }
+            "alternate"))
+      features =
+          gst_caps_features_new (GST_CAPS_FEATURE_FORMAT_INTERLACED, NULL);
  } else if (GST_VALUE_HOLDS_LIST (mode)) {
    /* If the mode is a list containing alternate, remove it from the list and add a
     * variant with interlace-mode=alternate and the INTERLACED feature. */
@ -2927,7 +2925,7 @@ check_alternate_and_append_struct (GstCaps * caps, GstStructure * s)
  }

 done:
-  gst_caps_append_structure (caps, s);
+  gst_caps_append_structure_full (caps, s, features);
 }

 static void
--- a/subprojects/gst-python/meson.build
+++ b/subprojects/gst-python/meson.build
@ -45,35 +45,53 @@ pylib_loc = get_option('libpython-dir')
 fsmod = import('fs')
 pylib_prefix = 'lib'
 pylib_suffix = 'so'
+pylib_ver = python_dep.version()
+pylib_locs = []
 if host_system == 'windows'
  if cc.get_argument_syntax() == 'msvc'
    pylib_prefix = ''
  endif
  pylib_suffix = 'dll'
+  pylib_ver = pylib_ver.replace('.', '')
 elif host_system == 'darwin'
  pylib_suffix = 'dylib'
 endif
 pylib_fnames = []
 # Library name with soversion, non-devel package
-pylib_fnames += python.get_variable('INSTSONAME', [])
+if python.has_variable('INSTSONAME')
+  # For example, libpython3.12.so.1.0 (Linux), libpython3.11.dll.a (MSYS2), etc.
+  pylib_fnames += python.get_variable('INSTSONAME')
+endif
 # Library name without soversion, devel package, framework, etc.
-pylib_fnames += python.get_variable('LDLIBRARY', [])
+if python.has_variable('LDLIBRARY')
+  # For example, libpython3.12.so (Linux), libpython3.11.dll.a (MSYS2), etc.
+  pylib_fnames += python.get_variable('LDLIBRARY')
+endif
 # Manually construct name as a fallback
 pylib_fnames += [
-  pylib_prefix + 'python' + python_dep.version() + python_abi_flags + '.' + pylib_suffix
+  pylib_prefix + 'python' + pylib_ver + python_abi_flags + '.' + pylib_suffix
 ]
 if pylib_loc != ''
  pylib_locs = [pylib_loc]
 else
-  pylib_locs = [
-    python.get_variable('LIBDIR', ''),
-    python.get_variable('LIBPL', ''),
-  ]
+  if python.has_variable('LIBDIR')
+    pylib_locs += python.get_variable('LIBDIR')
+  endif
+  if python.has_variable('LIBPL')
+    pylib_locs += python.get_variable('LIBPL')
+  endif
+  # On Windows, python312.dll is in the rootdir where Python is installed,
+  # which is configured as the "prefix" in sysconfig.
+  if host_system == 'windows'
+    pylib_locs += python.get_variable('prefix')
+  endif
 endif
 pylib_fname = ''
 foreach loc: pylib_locs
  foreach fname: pylib_fnames
-    if fsmod.exists(loc / fname)
+    fpath = loc / fname
+    debug(f'Looking for Python library at: @fpath@')
+    if fsmod.exists(fpath)
      pylib_fname = fname
      message(f'PY_LIB_FNAME = @fname@ (@loc@)')
      break
@ -81,12 +99,7 @@ foreach loc: pylib_locs
  endforeach
 endforeach
 if pylib_fname == ''
-  error_msg = 'Could not find python library to load'
-  if python_opt.enabled()
-    error(error_msg)
-  else
-    message(error_msg)
-  endif
+  message('Could not find python library to load, will try loading at runtime')
 endif

 pygi_override_dir = get_option('pygi-overrides-dir')
Author	SHA1	Message	Date
Nicolas Dufresne	7a8fc93561	Merge branch 'gst-plugins-good-fix-alternate-interlacing' into 'main' WIP: v4l2: Fix alternate interlacing caps and field values See merge request gstreamer/gstreamer!961	2024-04-27 18:13:06 +00:00
Nirbheek Chauhan	d7eeb62f38	meson: Fix Python library searching on Windows Neither LIBDIR nor LIBPL are set with the native windows Python (unlike MSYS2), so we need to use `prefix` which takes us to the rootdir of the Python installation. The name is also different: it's python312.dll, not python3.12.dll. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6734>	2024-04-27 01:30:21 +00:00
Nirbheek Chauhan	753aeccde7	meson: Fix Python library name fetching on Windows `python.get_variable('FOO', [])` becomes `python.get_variable('FOO')` due to how Meson treats empty arrays in arguments, which breaks the fallback feature of get_variable(). So we need to actually check whether the variable exists before trying to fetch it. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6734>	2024-04-27 01:30:21 +00:00
Dylan Yip	d7fb8ed66c	v4l2object: Fix interlaced feature insertion for alternate caps Currently the interlaced feature is being appended to the last structure of the caps. However, there is no guarantee that the last structure has interlace-mode=alternate. Instead, this patch first adds the structure to the end of the list then adds the interlaced feature to the last structure of the caps.	2021-09-29 09:48:06 -04:00
Dylan Yip	ecef2e4e7d	v4l2bufferpool: Set top/bottom field in v4l2 buffers for alternate mode output devices Currently, v4l2 output buffers are being passed down to v4l2 with the V4L2_FIELD_ALTERNATE field. This is incorrect since each buffer needs to correspond to either a top or bottom field. This patch corrects this by checking the GstBuffer flags and setting the correct field in the v4l2 buffer.	2021-09-29 09:48:05 -04:00