[vlc-commits] Revert "Revert "MP4: Parse transformation matrix""

[Jean-Baptiste Kempf]

vlc | branch: master | Jean-Baptiste Kempf <jb at videolan.org> | Mon Oct 22 17:07:04 2012 +0200| [5691e088d17599e27a7da0463c90556adb26406b] | committer: Jean-Baptiste Kempf

Revert "Revert "MP4: Parse transformation matrix""

This reverts commit 9fe34445c3f44e043a75b54782fa286f8299f89b.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=5691e088d17599e27a7da0463c90556adb26406b
---

 modules/demux/mp4/libmp4.c |   36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/modules/demux/mp4/libmp4.c b/modules/demux/mp4/libmp4.c
index 265efab..70198d8 100644
--- a/modules/demux/mp4/libmp4.c
+++ b/modules/demux/mp4/libmp4.c
@@ -32,11 +32,19 @@
 #endif
 
 #include "libmp4.h"
+#include <math.h>
 
 /* Some assumptions:
  * The input method HAS to be seekable
  */
 
+/* convert 16.16 fixed point to floating point */
+static double conv_fx( int32_t fx ) {
+    double fp = fx;
+    fp /= 65536.;
+    return fp;
+}
+
 /* some functions for mp4 encoding of variables */
 #ifdef MP4_VERBOSE
 static void MP4_ConvertDate2Str( char *psz, uint64_t i_date )
@@ -786,12 +794,33 @@ static int MP4_ReadBox_tkhd(  stream_t *p_stream, MP4_Box_t *p_box )
     MP4_GET4BYTES( p_box->data.p_tkhd->i_width );
     MP4_GET4BYTES( p_box->data.p_tkhd->i_height );
 
+    double rotation;    //angle in degrees to be rotated clockwise
+    double scale[2];    // scale factor; sx = scale[0] , sy = scale[1]
+    double translate[2];// amount to translate; tx = translate[0] , ty = translate[1]
+
+    int *matrix = p_box->data.p_tkhd->i_matrix;
+
+    translate[0] = conv_fx(matrix[6]);
+    translate[1] = conv_fx(matrix[7]);
+
+    scale[0] = sqrt(conv_fx(matrix[0]) * conv_fx(matrix[0]) +
+                    conv_fx(matrix[3]) * conv_fx(matrix[3]));
+    scale[1] = sqrt(conv_fx(matrix[1]) * conv_fx(matrix[1]) +
+                    conv_fx(matrix[4]) * conv_fx(matrix[4]));
+
+    rotation = atan2(conv_fx(matrix[1]) / scale[1], conv_fx(matrix[0]) / scale[0]) * 180 / M_PI;
+
+    if (rotation < 0)
+        rotation += 360.;
+
+    p_box->data.p_tkhd->f_rotation = rotation;
+
 #ifdef MP4_VERBOSE
     MP4_ConvertDate2Str( s_creation_time, p_box->data.p_mvhd->i_creation_time );
     MP4_ConvertDate2Str( s_modification_time, p_box->data.p_mvhd->i_modification_time );
     MP4_ConvertDate2Str( s_duration, p_box->data.p_mvhd->i_duration );
 
-    msg_Dbg( p_stream, "read box: \"tkhd\" creation %s modification %s duration %s track ID %d layer %d volume %f width %f height %f. "
+    msg_Dbg( p_stream, "read box: \"tkhd\" creation %s modification %s duration %s track ID %d layer %d volume %f rotation %f scaleX %f scaleY %f translateX %f translateY %f width %f height %f. "
             "Matrix: %i %i %i %i %i %i %i %i %i",
                   s_creation_time,
                   s_modification_time,
@@ -799,6 +828,11 @@ static int MP4_ReadBox_tkhd(  stream_t *p_stream, MP4_Box_t *p_box )
                   p_box->data.p_tkhd->i_track_ID,
                   p_box->data.p_tkhd->i_layer,
                   (float)p_box->data.p_tkhd->i_volume / 256 ,
+                  rotation,
+                  scale[0],
+                  scale[1],
+                  translate[0],
+                  translate[1],
                   (float)p_box->data.p_tkhd->i_width / 65536,
                   (float)p_box->data.p_tkhd->i_height / 65536,
                   p_box->data.p_tkhd->i_matrix[0],