Attachment 73556 Details for Bug 54797 – typefind: detect VC-1 elementary streams

[patch] typefind: detect VC-1 elementary streams

0001-typefind-detect-VC-1-elementary-streams.patch (text/plain), 4.88 KB, created by Gwenole Beauchesne on 2013-01-24 10:36:06 UTC

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Creator: Gwenole Beauchesne

Created: 2013-01-24 10:36:06 UTC

Size: 4.88 KB

patch

obsolete

>From 54329ade6a5032cf04975229b835cf0973dd1585 Mon Sep 17 00:00:00 2001
>From: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
>Date: Thu, 24 Jan 2013 11:21:28 +0100
>Subject: [PATCH] typefind: detect VC-1 elementary streams.
>
>Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
>---
> gst/typefind/gsttypefindfunctions.c |  120 +++++++++++++++++++++++++++++++++++
> 1 file changed, 120 insertions(+)
>
>diff --git a/gst/typefind/gsttypefindfunctions.c b/gst/typefind/gsttypefindfunctions.c
>index 19ee389..0a2de49 100644
>--- a/gst/typefind/gsttypefindfunctions.c
>+++ b/gst/typefind/gsttypefindfunctions.c
>@@ -2470,6 +2470,123 @@ h264_video_type_find (GstTypeFind * tf, gpointer unused)
>   }
> }
> 
>+/*** video/x-wmv VC-1 elementary video stream ***/
>+
>+static GstStaticCaps vc1_video_caps =
>+GST_STATIC_CAPS ("video/x-wmv,wmvversion=3,stream-format=bdu");
>+
>+#define VC1_VIDEO_CAPS gst_static_caps_get(&vc1_video_caps)
>+
>+#define VC1_MAX_PROBE_LENGTH (128 * 1024)
>+
>+static void
>+vc1_video_type_find (GstTypeFind * tf, gpointer unused)
>+{
>+  DataScanCtx c = { 0, NULL, 0 };
>+
>+  /* BDUs consist of the Start Code Prefix (SCP = 00 00 01) followed
>+   * by the Start Code Suffix (SCS), which represents the BDU type */
>+  guint8 scs;
>+  guint8 profile = 0;
>+  guint eos_hdrs = 0;
>+  guint seq_hdrs = 0;
>+  guint pic_hdrs = 0;
>+  guint etp_hdrs = 0;
>+  guint bad = 0;
>+
>+  while (c.offset < VC1_MAX_PROBE_LENGTH) {
>+    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 4)))
>+      break;
>+
>+    if (!IS_MPEG_HEADER (c.data)) {
>+      data_scan_ctx_advance (tf, &c, 1);
>+      continue;
>+    }
>+
>+    /* Collect statistics about the BDU types */
>+    scs = c.data[3];
>+    switch (scs) {
>+      case 0x0a:
>+        /* End-of-Sequence */
>+        eos_hdrs++;
>+        break;
>+      case 0x0f:
>+        /* Sequence Header */
>+        seq_hdrs++;
>+        if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 5)))
>+          break;
>+        profile = (c.data[4] >> 6) & 3;
>+        if (profile != 3)
>+          bad++;
>+        if (((c.data[4] >> 3) & 7) > 4) /* level */
>+          bad++;
>+        if (((c.data[4] >> 1) & 3) != 1)        /* color difference format */
>+          bad++;
>+        break;
>+      case 0x0b:
>+        /* Slice */
>+      case 0x0c:
>+        /* Field */
>+      case 0x0d:
>+        /* Frame */
>+        pic_hdrs++;
>+        break;
>+      case 0x0e:
>+        /* Entry-point header */
>+        etp_hdrs++;
>+        if (profile != 3)
>+          bad++;
>+        break;
>+      default:
>+        /* User data */
>+        if (scs >= 0x1b && scs <= 0x1f)
>+          break;
>+
>+        /* Forbidden */
>+        if (scs >= 0x80 && scs <= 0xff)
>+          bad++;
>+
>+        /* SMPTE Reserved */
>+        else
>+          bad++;
>+        break;
>+    }
>+
>+    if (seq_hdrs + etp_hdrs + pic_hdrs >= 10 && bad < 4)
>+      break;
>+
>+    data_scan_ctx_advance (tf, &c, 4);
>+  }
>+
>+  GST_LOG ("bad:%u, seq:%u, pic:%u, etp:%u", bad, seq_hdrs, pic_hdrs, etp_hdrs);
>+
>+  if (pic_hdrs > 0) {
>+    GstTypeFindProbability probability = 0;
>+    GstCaps *caps;
>+
>+    if (seq_hdrs > 0 && pic_hdrs >= GST_MPEGVID_TYPEFIND_TRY_PICTURES &&
>+        etp_hdrs > 0 && eos_hdrs <= seq_hdrs && bad == 0)
>+      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 9;
>+    else if (pic_hdrs >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && bad == 0)
>+      probability = GST_TYPE_FIND_LIKELY + 5;
>+    else if (pic_hdrs >= 3 && bad == 0)
>+      probability = GST_TYPE_FIND_LIKELY;
>+    else if (pic_hdrs > 0 && bad == 0)
>+      probability = GST_TYPE_FIND_POSSIBLE;
>+    else if (pic_hdrs > 0 && bad < 4)
>+      probability = GST_TYPE_FIND_POSSIBLE - 5;
>+    else
>+      probability = GST_TYPE_FIND_POSSIBLE - 10;
>+
>+    caps = gst_caps_copy (VC1_VIDEO_CAPS);
>+    if (seq_hdrs > 0 && profile == 3)
>+      gst_caps_set_simple (caps, "format", GST_TYPE_FOURCC,
>+          GST_MAKE_FOURCC ('W', 'V', 'C', '1'), NULL);
>+    gst_type_find_suggest (tf, probability, caps);
>+    gst_caps_unref (caps);
>+  }
>+}
>+
> /*** video/mpeg video stream ***/
> 
> static GstStaticCaps mpeg_video_caps = GST_STATIC_CAPS ("video/mpeg, "
>@@ -4540,6 +4657,7 @@ plugin_init (GstPlugin * plugin)
>   static const gchar *dsstore_exts[] = { "DS_Store", NULL };
>   static const gchar *psd_exts[] = { "psd", NULL };
>   static const gchar *y4m_exts[] = { "y4m", NULL };
>+  static const gchar *vc1_exts[] = { "vc1", NULL };
> 
>   GST_DEBUG_CATEGORY_INIT (type_find_debug, "typefindfunctions",
>       GST_DEBUG_FG_GREEN | GST_DEBUG_BG_RED, "generic type find functions");
>@@ -4611,6 +4729,8 @@ plugin_init (GstPlugin * plugin)
>       h264_video_type_find, h264_exts, H264_VIDEO_CAPS, NULL, NULL);
>   TYPE_FIND_REGISTER (plugin, "video/x-nuv", GST_RANK_SECONDARY, nuv_type_find,
>       nuv_exts, NUV_CAPS, NULL, NULL);
>+  TYPE_FIND_REGISTER (plugin, "video/x-wmv", GST_RANK_PRIMARY,
>+      vc1_video_type_find, vc1_exts, VC1_VIDEO_CAPS, NULL, NULL);
> 
>   /* ISO formats */
>   TYPE_FIND_REGISTER (plugin, "audio/x-m4a", GST_RANK_PRIMARY, m4a_type_find,
>-- 
>1.7.9.5
>

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