gst-dsp/debian/patches/0003-parse-add-MPEG-4.patch

From f6a8b85db4d85d8e6101d1a73c825c7e6df52f3a Mon Sep 17 00:00:00 2001
From: Marco Ballesio <marco.ballesio@nokia.com>
Date: Fri, 5 Jun 2009 15:35:06 +0300
Subject: [PATCH] parse: add MPEG-4

Signed-off-by: Felipe Contreras <felipe.contreras@nokia.com>
---
 gstdspparse.c |  242 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 gstdspparse.h |    1 +
 gstdspvdec.c  |    4 +-
 3 files changed, 245 insertions(+), 2 deletions(-)

diff --git a/gstdspparse.c b/gstdspparse.c
index 299e86b..15c55a1 100644
--- a/gstdspparse.c
+++ b/gstdspparse.c
@@ -3,7 +3,8 @@
  * Copyright (C) 2007-2009 Nokia Corporation
  *
  * Authors:
- * Marco Ballesio <marco.ballesio@gmail.com>
+ * Juha Alanen <juha.m.alanen@nokia.com>
+ * Marco Ballesio <marco.ballesio@nokia.com>
  * Felipe Contreras <felipe.contreras@nokia.com>
  *
  * This library is free software; you can redistribute it and/or
@@ -384,3 +385,242 @@ not_enough_data:
 bail:
 	return FALSE;
 }
+
+/* From mpeg4videoparse */
+/* Used for parsing frame size from codec data */
+typedef struct
+{
+  const guint8 *data;
+  /* byte offset */
+  gsize offset;
+  /* bit offset */
+  gsize b_offset;
+  /* size in bytes */
+  gsize size;
+} bitstream_t;
+
+static gboolean
+get_bits (bitstream_t * b, int num, guint32 * bits)
+{
+  *bits = 0;
+
+  if (b->offset + ((b->b_offset + num) / 8) > b->size)
+    return FALSE;
+
+  if (b->b_offset + num <= 8) {
+    *bits = b->data[b->offset];
+    *bits = (*bits >> (8 - num - b->b_offset)) & (((1 << num)) - 1);
+
+    b->offset += (b->b_offset + num) / 8;
+    b->b_offset = (b->b_offset + num) % 8;
+    return TRUE;
+  } else {
+    /* going over the edge.. */
+    int next;
+
+    next = (8 - b->b_offset);
+    do {
+      guint32 t;
+
+      if (!get_bits (b, next, &t))
+        return FALSE;
+      *bits <<= next;
+      *bits |= t;
+      num -= next;
+      next = MIN (8, num);
+    } while (num > 0);
+
+    return TRUE;
+  }
+}
+
+#define GET_BITS(b, num, bits) G_STMT_START { \
+  if (!get_bits(b, num, bits))                \
+    goto failed;                              \
+} G_STMT_END
+
+#define MARKER_BIT(b) G_STMT_START {  \
+  guint32 i;                          \
+  GET_BITS(b, 1, &i);                 \
+  if (i != 0x1)                       \
+    goto failed;                      \
+} G_STMT_END
+
+static inline gboolean
+next_start_code (bitstream_t * b)
+{
+  guint32 bits;
+
+  GET_BITS (b, 1, &bits);
+  if (bits != 0)
+    goto failed;
+
+  while (b->b_offset != 0) {
+    GET_BITS (b, 1, &bits);
+    if (bits != 0x1)
+      goto failed;
+  }
+
+  return TRUE;
+
+failed:
+  return FALSE;
+}
+
+gboolean
+gst_dsp_mpeg4_parse(GstDspBase* base, GstBuffer *buf)
+{
+  guint32 bits;
+  bitstream_t bs;
+  guint8 *codec_data;
+  guint codec_data_size;
+  guint16 time_increment_resolution;
+  guint16 width, height;
+
+  codec_data = GST_BUFFER_DATA (buf);
+  codec_data_size = GST_BUFFER_SIZE (buf);
+
+  bs.data = codec_data;
+  bs.size = codec_data_size;
+  bs.offset = 0;
+  bs.b_offset = 0;
+
+  /* Expect Visual Object Sequence startcode (0x000001B0) */
+  GET_BITS (&bs, 32, &bits);
+  if (bits != 0x1B0)
+    goto failed;
+
+  /* profile and level indication */
+  GET_BITS (&bs, 8, &bits);
+  if (bits == 0)
+    goto failed;
+
+  /* Expect Visual Object startcode (0x000001B5) */
+  GET_BITS (&bs, 32, &bits);
+  if (bits != 0x1B5)
+    goto failed;
+
+  GET_BITS (&bs, 1, &bits);
+  if (bits == 0x1) {
+    /* Skip visual_object_verid and priority */
+    GET_BITS (&bs, 7, &bits);
+  }
+
+  GET_BITS (&bs, 4, &bits);
+  /* Only support video ID */
+  if (bits != 0x1)
+    goto failed;
+
+  /* video signal type */
+  GET_BITS (&bs, 1, &bits);
+
+  if (bits == 0x1) {
+    /* video signal type, ignore format and range */
+    GET_BITS (&bs, 4, &bits);
+
+    GET_BITS (&bs, 1, &bits);
+    if (bits == 0x1) {
+      /* ignore color description */
+      GET_BITS (&bs, 24, &bits);
+    }
+  }
+
+  if (!next_start_code (&bs))
+    goto failed;
+
+  /* expecting a video object startcode */
+  GET_BITS (&bs, 32, &bits);
+  if (bits > 0x11F)
+    goto failed;
+
+  /* expecting a video object layer startcode */
+  GET_BITS (&bs, 32, &bits);
+  if (bits < 0x120 || bits > 0x12F)
+    goto failed;
+
+  /* ignore random accessible vol and video object type indication */
+  GET_BITS (&bs, 9, &bits);
+
+  GET_BITS (&bs, 1, &bits);
+  if (bits) {
+    /* skip video object layer verid and priority */
+    GET_BITS (&bs, 7, &bits);
+  }
+
+  /* aspect ratio info */
+  GET_BITS (&bs, 4, &bits);
+  if (bits == 0)
+    goto failed;
+
+  /* check if aspect ratio info is extended par */
+  if (bits == 0xff) {
+    /* aspect_ratio_width */
+    GET_BITS (&bs, 4, &bits);
+    /* aspect_ratio_height */
+    GET_BITS (&bs, 4, &bits);
+  } else if (bits < 0x6) {
+    /* get aspect ratio width and height from aspect ratio table */
+  }
+
+  GET_BITS (&bs, 1, &bits);
+  if (bits) {
+    /* vol control parameters, skip chroma and low delay */
+    GET_BITS (&bs, 3, &bits);
+    GET_BITS (&bs, 1, &bits);
+    if (bits) {
+      /* skip vbv_parameters */
+      GET_BITS (&bs, 79, &bits);
+    }
+  }
+
+  /* layer shape */
+  GET_BITS (&bs, 2, &bits);
+  /* only support rectangular */
+  if (bits != 0)
+    goto failed;
+
+  MARKER_BIT (&bs);
+  GET_BITS (&bs, 16, &bits);
+  time_increment_resolution = bits;
+  MARKER_BIT (&bs);
+
+  GET_BITS (&bs, 1, &bits);
+  if (bits) {
+    /* fixed time increment */
+    int n;
+
+    /* Lenght of the time increment is the minimal number of bits needed to
+     * represent time_increment_resolution */
+    for (n = 0; (time_increment_resolution >> n) != 0; n++);
+    GET_BITS (&bs, n, &bits);
+    /* fixed_time_increment = bits; */
+  } else {
+    /* fixed_time_increment = 1; */
+  }
+
+  /* assuming rectangular shape */
+  MARKER_BIT (&bs);
+  GET_BITS (&bs, 13, &bits);
+  if (bits == 0)
+    goto failed;
+  width = bits;
+
+  MARKER_BIT (&bs);
+  GET_BITS (&bs, 13, &bits);
+  if (bits == 0)
+    goto failed;
+  height = bits;
+  MARKER_BIT (&bs);
+
+  pr_debug (base, "width=%u, height=%u", width, height);
+
+  set_framesize(base, width, height);
+  return TRUE;
+
+  /* ERRORS */
+failed:
+  {
+	GST_DEBUG_OBJECT (base, "Could not parse MPEG4 codec data");
+    return FALSE;
+  }
+}
diff --git a/gstdspparse.h b/gstdspparse.h
index cbaf711..c06abea 100644
--- a/gstdspparse.h
+++ b/gstdspparse.h
@@ -26,5 +26,6 @@
 
 gboolean gst_dsp_h263_parse(GstDspBase *base, GstBuffer *buf);
 gboolean gst_dsp_h264_parse(GstDspBase *base, GstBuffer *buf);
+gboolean gst_dsp_mpeg4_parse(GstDspBase *base, GstBuffer *buf);
 
 #endif
diff --git a/gstdspvdec.c b/gstdspvdec.c
index b842bbd..f4cd0a7 100644
--- a/gstdspvdec.c
+++ b/gstdspvdec.c
@@ -1008,8 +1008,10 @@ sink_setcaps(GstPad *pad,
 				self->wmv_is_vc1 = FALSE;
 		}
 	}
-	else
+	else {
 		base->alg = GSTDSP_MPEG4VDEC;
+		base->parse_func = gst_dsp_mpeg4_parse;
+	}
 
 	out_caps = gst_caps_new_empty();