From 3005dbc55ab03ebcf99e4fc97ba4dd48a94e5622 Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Date: Wed, 19 Jan 2022 15:53:05 -0500
Subject: [PATCH] v4l2codecs: Add support for multi planar buffers

V4L2 have some pixel formats that produces 2 dmabuf, this add
support for these format.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1567>
---
 .../sys/v4l2codecs/gstv4l2format.c            | 59 +++++++++++++++----
 1 file changed, 46 insertions(+), 13 deletions(-)

diff --git a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2format.c b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2format.c
index 3a6a06f451..ed3f757c0b 100644
--- a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2format.c
+++ b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2format.c
@@ -102,12 +102,21 @@ gst_v4l2_format_to_video_info (struct v4l2_format *fmt, GstVideoInfo * out_info)
   struct v4l2_pix_format *pix = &fmt->fmt.pix;
   gint plane;
   gsize offset = 0;
+  gboolean extrapolate = FALSE;
 
   if (!entry)
     return FALSE;
 
-  if (entry->num_planes != 1) {
-    GST_FIXME ("Multi allocation formats are not supported yet");
+  /* validate the entry against the format */
+  if (V4L2_TYPE_IS_MULTIPLANAR (fmt->type)) {
+    if (entry->num_planes != pix_mp->num_planes) {
+      GST_ERROR ("Miss-matched number of planes in internal entry "
+          "(%i != %i)", entry->num_planes, pix_mp->num_planes);
+      return FALSE;
+    }
+  } else if (entry->num_planes != 1) {
+    GST_ERROR ("Miss-matched number of planes in internal entry "
+        "(must be 1 for non-multiplanar, got %i)", entry->num_planes);
     return FALSE;
   }
 
@@ -116,28 +125,52 @@ gst_v4l2_format_to_video_info (struct v4l2_format *fmt, GstVideoInfo * out_info)
     return FALSE;
 
   if (V4L2_TYPE_IS_MULTIPLANAR (fmt->type)) {
-    /* TODO: We don't support multi-allocation yet */
-    g_return_val_if_fail (pix_mp->num_planes == 1, FALSE);
-    out_info->size = pix_mp->plane_fmt[0].sizeimage;
+    out_info->size = 0;
+    for (plane = 0; plane < pix_mp->num_planes; plane++)
+      out_info->size += pix_mp->plane_fmt[plane].sizeimage;
   } else {
     out_info->size = pix->sizeimage;
   }
 
+  /*
+   * When single allocation formats are used for planar formats we need to
+   * extrapolate the per-plane stride. Do this check once to prevent
+   * complex inner loop.
+   */
+  if (entry->num_planes == 1 && out_info->finfo->n_planes != entry->num_planes)
+    extrapolate = TRUE;
+
   for (plane = 0; plane < GST_VIDEO_INFO_N_PLANES (out_info); plane++) {
     gint stride;
 
-    if (V4L2_TYPE_IS_MULTIPLANAR (fmt->type))
-      stride = gst_video_format_info_extrapolate_stride (out_info->finfo, plane,
-          pix_mp->plane_fmt[0].bytesperline);
-    else
-      stride = gst_video_format_info_extrapolate_stride (out_info->finfo, plane,
-          pix->bytesperline);
+    if (V4L2_TYPE_IS_MULTIPLANAR (fmt->type)) {
+      if (extrapolate)
+        stride = gst_video_format_info_extrapolate_stride (out_info->finfo,
+            plane, pix_mp->plane_fmt[0].bytesperline);
+      else
+        stride = pix_mp->plane_fmt[plane].bytesperline;
+    } else {
+      if (extrapolate)
+        stride = gst_video_format_info_extrapolate_stride (out_info->finfo,
+            plane, pix->bytesperline);
+      else
+        stride = pix->bytesperline;
+    }
 
     set_stride (out_info, plane, stride);
     out_info->offset[plane] = offset;
 
-    offset += stride * GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (out_info->finfo,
-        plane, pix_mp->height);
+    if ((V4L2_TYPE_IS_MULTIPLANAR (fmt->type) && !extrapolate))
+      offset += pix_mp->plane_fmt[plane].sizeimage;
+    else
+      offset += stride * GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (out_info->finfo,
+          plane, pix_mp->height);
+  }
+
+  /* Check that the extrapolation didn't overflow the reported sizeimage */
+  if (extrapolate && offset > out_info->size) {
+    GST_ERROR ("Extrapolated plane offset overflow the image size.");
+    return FALSE;
   }
 
   return TRUE;