[xiph-commits] r6926 - experimental/giles

[giles at dactyl.lonelymoon.com]

Author: giles
Date: Tue Jun 29 13:24:55 2004
New Revision: 6926

Added:
experimental/giles/oggfilter.c
Log:
Oggz-based packet filtering example that changes the aspect ratio on theora video files.



Added: experimental/giles/oggfilter.c
===================================================================
--- experimental/giles/oggfilter.c	2004-06-29 19:21:29 UTC (rev 6925)
+++ experimental/giles/oggfilter.c	2004-06-29 20:24:54 UTC (rev 6926)
@@ -0,0 +1,167 @@
+/*
+   Copyright (C) 2004 Xiph.org Foundation
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+   - Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+   - Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+   - Neither the name of CSIRO Australia nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+   PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ORGANISATION OR
+   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/* quick program to filter an ogg file
+   correcting (for example) header errors */
+
+/* compile with:
+   gcc -o oggfilter oggfilter.c `pkg-config --cflags oggz` \
+     `pkg-config --libs oggz`
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <oggz/oggz.h>
+
+#define BUFSIZE 4096
+
+/* write out a big-endian 32 bit integer */
+static void write_uint32(unsigned char *p, unsigned int v)
+{
+  p[0] = (v >> 24) & 0xFF;
+  p[1] = (v >> 16) & 0xFF;
+  p[2] = (v >> 8) & 0xFF;
+  p[3] = (v) & 0xFF;
+}
+
+/* write out a big-endian 32 bit integer */
+static void write_uint24(unsigned char *p, unsigned int v)
+{
+  p[0] = (v >> 16) & 0xFF;
+  p[1] = (v >> 8) & 0xFF;
+  p[2] = (v) & 0xFF;
+}
+
+/* write out a big-endian 16 bit integer */
+static void write_uint16(unsigned char *p, unsigned int v)
+{
+  p[0] = (v >> 8) & 0xFF;
+  p[1] = (v) & 0xFF;
+}
+
+/* copy an ogg packet from reader to writer */
+static int
+packet_copy (OGGZ *oggz, ogg_packet *op, long serialno, void *user_data)
+{
+  OGGZ *writer = (OGGZ *)user_data;
+  int flush;
+  int ret;
+
+  if (op->granulepos == -1) {
+    flush = 0;
+  } else {
+    flush = OGGZ_FLUSH_AFTER;
+  }
+
+  if ((ret = oggz_write_feed(writer, op, serialno, flush, NULL)) != 0) {
+    printf ("oggz_write_feed: %d\n", ret);
+  }
+
+  return 0;
+}
+
+/* do our special processing on a packet */
+static int
+packet_fix(OGGZ *oggz, ogg_packet *op, long serialno, void *user_data)
+{
+  int aspect_numerator = 1;
+  int aspect_denominator = 1;
+
+  /* fix the aspect ratio */
+  write_uint24(op->packet+30, aspect_numerator);
+  write_uint24(op->packet+33, aspect_denominator);
+
+  /* pass the packet on and replace ourselves so we're
+     only called for the first packet in the stream */
+  if (!packet_copy(oggz, op, serialno, user_data))
+    oggz_set_read_callback (oggz, -1, packet_copy, user_data);
+
+  return 0;
+}
+
+/* packet dispatch; called for new streams */
+static int
+packet_dispatch(OGGZ *oggz, ogg_packet *op, long serialno, void *user_data)
+{
+  OGGZ *writer = (OGGZ *)user_data;
+  const unsigned char theora_magic[] = "\x80theora";
+  const unsigned char vorbis_magic[] = "\x01vorbis";
+
+  if (!memcmp(op->packet, theora_magic, 7)) {
+    /* filter theora streams */
+    packet_fix(oggz, op, serialno, user_data);
+  } else {
+    /* just copy anything else */
+    if (!packet_copy(oggz, op, serialno, user_data))
+      oggz_set_read_callback(oggz, serialno, packet_copy, user_data);
+  }
+
+  return 0;
+}
+
+
+int
+main (int argc, char ** argv)
+{
+  OGGZ *reader, *writer;
+  int n;
+
+  if (argc < 3) {
+    printf("usage: %s <in.ogg> <out.ogg>\n", argv[0]);
+    printf("  filters in.ogg into out.ogg, doing\n");
+    printf("  whatever it was compiled to do.\n");
+  }
+
+  reader = oggz_open(argv[1], OGGZ_READ);
+  if (reader == NULL) {
+    printf ("unable to open file %s\n", argv[1]);
+    exit (1);
+  }
+
+  writer = oggz_open(argv[2], OGGZ_WRITE);
+  if (writer == NULL) {
+    printf ("unable to open file %s\n", argv[2]);
+    oggz_close(reader);
+    exit (1);
+  }
+
+  /* set the callback for stream dispatch */
+  oggz_set_read_callback(reader, -1, packet_dispatch, writer);
+
+  while ((n = oggz_read(reader, BUFSIZE)) > 0) {
+    while (oggz_write(writer, n) > 0);
+  }
+
+  oggz_close(writer);
+  oggz_close(reader);
+
+  return 0;
+}