mpegplayer: Make playback engine fully seekable and frame-accurate and split into logical parts. Be sure to have all current features work. Actual UI for seeking will be added soon. Recommended GOP size is about 15-30 frames depending on target or seeking can be slow with really long GOPs (nature of MPEG video). More refined encoding recommendations for a particular player should be posted soon.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15977 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 96 insertions, 0 deletions

diff --git a/apps/plugins/mpegplayer/mpeg_misc.c b/apps/plugins/mpegplayer/mpeg_misc.c
new file mode 100644
index 0000000000..f5ecb6d6c8
--- /dev/null
+++ b/apps/plugins/mpegplayer/mpeg_misc.c
@@ -0,0 +1,96 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Miscellaneous helper API definitions
+ *
+ * Copyright (c) 2007 Michael Sevakis
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+#include "mpegplayer.h"
+
+/** Streams **/
+
+/* Ensures direction is -1 or 1 and margin is properly initialized */
+void stream_scan_normalize(struct stream_scan *sk)
+{
+    if (sk->dir >= 0)
+    {
+        sk->dir = SSCAN_FORWARD;
+        sk->margin = sk->len;
+    }
+    else if (sk->dir < 0)
+    {
+        sk->dir = SSCAN_REVERSE;
+        sk->margin = 0;
+    }
+}
+
+/* Moves a scan cursor. If amount is positive, the increment is in the scan
+ * direction, otherwise opposite the scan direction */
+void stream_scan_offset(struct stream_scan *sk, off_t by)
+{
+    off_t bydir = by*sk->dir;
+    sk->pos += bydir;
+    sk->margin -= bydir;
+    sk->len -= by;
+}
+
+/** Time helpers **/
+void ts_to_hms(uint32_t pts, struct hms *hms)
+{
+    hms->frac = pts % TS_SECOND;
+    hms->sec = pts / TS_SECOND;
+    hms->min = hms->sec / 60;
+    hms->hrs = hms->min / 60;
+    hms->sec %= 60;
+    hms->min %= 60;
+}
+
+void hms_format(char *buf, size_t bufsize, struct hms *hms)
+{
+    /* Only display hours if nonzero */
+    if (hms->hrs != 0)
+    {
+        rb->snprintf(buf, bufsize, "%u:%02u:%02u",
+                     hms->hrs, hms->min, hms->sec);
+    }
+    else
+    {
+        rb->snprintf(buf, bufsize, "%u:%02u",
+                     hms->min, hms->sec);
+    }
+}
+
+/** Maths **/
+uint32_t muldiv_uint32(uint32_t multiplicand,
+                       uint32_t multiplier,
+                       uint32_t divisor)
+{
+    if (divisor != 0)
+    {
+        uint64_t prod = (uint64_t)multiplier*multiplicand + divisor/2;
+
+        if ((uint32_t)(prod >> 32) < divisor)
+            return (uint32_t)(prod / divisor);
+    }
+    else if (multiplicand == 0 || multiplier == 0)
+    {
+        return 0; /* 0/0 = 0 : yaya */
+    }
+    /* else (> 0) / 0 = UINT32_MAX */
+
+    return UINT32_MAX; /* Saturate */
+}