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161 lines
3.1 KiB
C
161 lines
3.1 KiB
C
/*
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* The contents of this file are subject to the Mozilla Public License
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* Version 1.1 (the "License"); you may not use this file except in
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* compliance with the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/.
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*
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* Software distributed under the License is distributed on an "AS IS"
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* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
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* License for the specific language governing rights and limitations
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* under the License.
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*
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* The Original Code is Fluendo MPEG Demuxer plugin.
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*
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* The Initial Developer of the Original Code is Fluendo, S.L.
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* Portions created by Fluendo, S.L. are Copyright (C) 2005
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* Fluendo, S.L. All Rights Reserved.
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*
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* Contributor(s): Wim Taymans <wim@fluendo.com>
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* Jan Schmidt <thaytan@noraisin.net>
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*/
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#include <string.h>
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#include <gst/gst.h>
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#include "gstmpegdesc.h"
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void
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gst_mpeg_descriptor_free (GstMPEGDescriptor * desc)
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{
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g_return_if_fail (desc != NULL);
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g_free (desc);
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}
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static guint
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gst_mpeg_descriptor_parse_1 (guint8 * data, guint size)
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{
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#ifndef GST_DISABLE_GST_DEBUG
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guint8 tag;
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#endif
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guint8 length;
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/* need at least 2 bytes for tag and length */
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if (size < 2)
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return 0;
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#ifndef GST_DISABLE_GST_DEBUG
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tag = *data;
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#endif
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data += 1;
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length = *data++;
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size -= 2;
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GST_DEBUG ("tag: 0x%02x, length: %d", tag, length);
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if (length > size)
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return 0;
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return length + 2;
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}
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GstMPEGDescriptor *
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gst_mpeg_descriptor_parse (guint8 * data, guint size)
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{
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guint8 *current;
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guint consumed, total, n_desc;
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GstMPEGDescriptor *result;
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g_return_val_if_fail (data != NULL, NULL);
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current = data;
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total = 0;
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n_desc = 0;
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do {
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consumed = gst_mpeg_descriptor_parse_1 (current, size);
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if (consumed > 0) {
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current += consumed;
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total += consumed;
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size -= consumed;
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n_desc++;
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}
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}
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while (consumed > 0);
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GST_DEBUG ("parsed %d descriptors", n_desc);
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if (total == 0)
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return NULL;
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result = g_malloc (sizeof (GstMPEGDescriptor) + total);
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result->n_desc = n_desc;
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result->data_length = total;
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result->data = ((guint8 *) result) + sizeof (GstMPEGDescriptor);
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memcpy (result->data, data, total);
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return result;
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}
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guint
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gst_mpeg_descriptor_n_desc (GstMPEGDescriptor * desc)
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{
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g_return_val_if_fail (desc != NULL, 0);
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return desc->n_desc;
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}
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guint8 *
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gst_mpeg_descriptor_find (GstMPEGDescriptor * desc, gint tag)
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{
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gint length;
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guint8 *current;
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guint size;
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g_return_val_if_fail (desc != NULL, NULL);
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current = desc->data;
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length = desc->data_length;
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while (length > 0) {
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if (DESC_TAG (current) == tag)
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return current;
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size = DESC_LENGTH (current) + 2;
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current += size;
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length -= size;
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}
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return NULL;
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}
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guint8 *
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gst_mpeg_descriptor_nth (GstMPEGDescriptor * desc, guint i)
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{
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gint length;
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guint8 *current;
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guint size;
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g_return_val_if_fail (desc != NULL, NULL);
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if (i > desc->n_desc)
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return NULL;
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current = desc->data;
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length = desc->data_length;
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while (length > 0) {
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if (i == 0)
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return current;
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size = DESC_LENGTH (current) + 2;
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current += size;
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length -= size;
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i--;
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}
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return NULL;
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}
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