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