From 4efc15dffb28f03d4042fa36979b8c57bef8a81b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Mon, 28 Nov 2016 10:12:49 +0200
Subject: [PATCH] discoverer: Extract video information from caps manually
 without GstVideoInfo

The caps might not be fixated (which is required by GstVideoInfo) and we
would assert otherwise. However the caps often contain useful
information in the already-fixed parts that we can use here.
---
 gst-libs/gst/pbutils/gstdiscoverer.c | 59 ++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 16 deletions(-)

diff --git a/gst-libs/gst/pbutils/gstdiscoverer.c b/gst-libs/gst/pbutils/gstdiscoverer.c
index dcd6f703e1..9774d7e8ed 100644
--- a/gst-libs/gst/pbutils/gstdiscoverer.c
+++ b/gst-libs/gst/pbutils/gstdiscoverer.c
@@ -47,6 +47,8 @@
 #include <gst/video/video.h>
 #include <gst/audio/audio.h>
 
+#include <string.h>
+
 #include "pbutils.h"
 #include "pbutils-private.h"
 
@@ -806,7 +808,7 @@ collect_information (GstDiscoverer * dc, const GstStructure * st,
   GstStructure *caps_st;
   GstTagList *tags_st;
   const gchar *name;
-  int tmp;
+  gint tmp, tmp2;
   guint utmp;
 
   if (!st || !gst_structure_id_has_field (st, _CAPS_QUARK)) {
@@ -840,7 +842,8 @@ collect_information (GstDiscoverer * dc, const GstStructure * st,
 
       format = gst_audio_format_from_string (format_str);
       finfo = gst_audio_format_get_info (format);
-      info->depth = GST_AUDIO_FORMAT_INFO_DEPTH (finfo);
+      if (finfo)
+        info->depth = GST_AUDIO_FORMAT_INFO_DEPTH (finfo);
     }
 
     if (gst_structure_id_has_field (st, _TAGS_QUARK)) {
@@ -872,27 +875,51 @@ collect_information (GstDiscoverer * dc, const GstStructure * st,
   } else if (g_str_has_prefix (name, "video/") ||
       g_str_has_prefix (name, "image/")) {
     GstDiscovererVideoInfo *info;
-    GstVideoInfo vinfo;
+    const gchar *caps_str;
 
     info = (GstDiscovererVideoInfo *) make_info (parent,
         GST_TYPE_DISCOVERER_VIDEO_INFO, caps);
 
-    if (gst_video_info_from_caps (&vinfo, caps)) {
-      info->width = (guint) vinfo.width;
-      info->height = (guint) vinfo.height;
+    if (gst_structure_get_int (caps_st, "width", &tmp))
+      info->width = (guint) tmp;
+    if (gst_structure_get_int (caps_st, "height", &tmp))
+      info->height = (guint) tmp;
 
-      info->depth = vinfo.finfo->bits * vinfo.finfo->n_components;
-
-      info->par_num = vinfo.par_n;
-      info->par_denom = vinfo.par_d;
-
-      info->framerate_num = vinfo.fps_n;
-      info->framerate_denom = vinfo.fps_d;
-
-      info->interlaced =
-          vinfo.interlace_mode != GST_VIDEO_INTERLACE_MODE_PROGRESSIVE;
+    if (gst_structure_get_fraction (caps_st, "framerate", &tmp, &tmp2)) {
+      info->framerate_num = (guint) tmp;
+      info->framerate_denom = (guint) tmp2;
+    } else {
+      info->framerate_num = 0;
+      info->framerate_denom = 1;
     }
 
+    if (gst_structure_get_fraction (caps_st, "pixel-aspect-ratio", &tmp, &tmp2)) {
+      info->par_num = (guint) tmp;
+      info->par_denom = (guint) tmp2;
+    } else {
+      info->par_num = 1;
+      info->par_denom = 1;
+    }
+
+    /* FIXME: we only want to extract depth if raw video is what's in the
+     * container (i.e. not if there is a decoder involved) */
+    caps_str = gst_structure_get_string (caps_st, "format");
+    if (caps_str != NULL) {
+      const GstVideoFormatInfo *finfo;
+      GstVideoFormat format;
+
+      format = gst_video_format_from_string (caps_str);
+      finfo = gst_video_format_get_info (format);
+      if (finfo)
+        info->depth = finfo->bits * finfo->n_components;
+    }
+
+    caps_str = gst_structure_get_string (caps_st, "interlace-mode");
+    if (!caps_str || strcmp (caps_str, "progressive") == 0)
+      info->interlaced = FALSE;
+    else
+      info->interlaced = TRUE;
+
     if (gst_structure_id_has_field (st, _TAGS_QUARK)) {
       gst_structure_id_get (st, _TAGS_QUARK, GST_TYPE_TAG_LIST, &tags_st, NULL);
       if (gst_tag_list_get_uint (tags_st, GST_TAG_BITRATE, &utmp) ||