From 4b60569c4a78987c28b12d7353a687bafee1568e Mon Sep 17 00:00:00 2001
From: Huang-Huang Bao <eh5@sokka.cn>
Date: Fri, 3 Feb 2023 19:45:50 +0800
Subject: [PATCH] gst: correct buffer & meta offset calculation

The offset in GstVideoMeta point to location of merge-mapped buffer memories (see "gst_buffer_find_memory()") instead of raw memory location for each plane, make adjustment to comply this rule.

Also some cleanups.

Fixes 023577e3912b5193ea969d54bef7ec7743fce939
---
 src/gst/gstpipewiresink.c | 7 +++++--
 src/gst/gstpipewiresrc.c  | 9 ++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/gst/gstpipewiresink.c b/src/gst/gstpipewiresink.c
index ff235cbd7..cbfbd1de0 100644
--- a/src/gst/gstpipewiresink.c
+++ b/src/gst/gstpipewiresink.c
@@ -508,13 +508,16 @@ do_send_buffer (GstPipeWireSink *pwsink, GstBuffer *buffer)
   GstVideoMeta *meta = gst_buffer_get_video_meta (buffer);
   if (meta) {
     if (meta->n_planes == b->n_datas) {
+      gsize video_size = 0;
       for (i = 0; i < meta->n_planes; i++) {
         struct spa_data *d = &b->datas[i];
-        d->chunk->offset = meta->offset[i];
+        d->chunk->offset += meta->offset[i] - video_size;
         d->chunk->stride = meta->stride[i];
+
+        video_size += d->chunk->size;
       }
     } else {
-      GST_ERROR ("plane num not matching, meta:%d buffer:%d", meta->n_planes, b->n_datas);
+      GST_ERROR ("plane num not matching, meta:%u buffer:%u", meta->n_planes, b->n_datas);
     }
   }
 
diff --git a/src/gst/gstpipewiresrc.c b/src/gst/gstpipewiresrc.c
index 5c3043634..9c5cf1f76 100644
--- a/src/gst/gstpipewiresrc.c
+++ b/src/gst/gstpipewiresrc.c
@@ -616,6 +616,7 @@ static GstBuffer *dequeue_buffer(GstPipeWireSrc *pwsrc)
   }
 
   if (pwsrc->is_video) {
+    gsize video_size = 0;
     GstVideoInfo *info = &pwsrc->video_info;
     GstVideoMeta *meta = gst_buffer_add_video_meta_full (buf, GST_VIDEO_FRAME_FLAG_NONE,
                              GST_VIDEO_INFO_FORMAT (info),
@@ -625,11 +626,13 @@ static GstBuffer *dequeue_buffer(GstPipeWireSrc *pwsrc)
                              info->offset,
                              info->stride);
 
-    meta->n_planes = b->buffer->n_datas;
-    for (i = 0; i < b->buffer->n_datas; i++) {
+    meta->n_planes = MIN(meta->n_planes, b->buffer->n_datas);
+    for (i = 0; i < meta->n_planes; i++) {
       struct spa_data *d = &b->buffer->datas[i];
-      meta->offset[i] = d->chunk->offset;
+      meta->offset[i] = video_size;
       meta->stride[i] = d->chunk->stride;
+
+      video_size += d->chunk->size;
     }
   }