gstreamer/ext/metadata/metadataparseutil.c

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/*
* GStreamer
* Copyright 2007 Edgard Lima <edgard.lima@indt.org.br>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Alternatively, the contents of this file may be used under the
* GNU Lesser General Public License Version 2.1 (the "LGPL"), in
* which case the following provisions apply instead of the ones
* mentioned above:
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* SECTION: metadataparseutil
* @short_description: This module has some util function for parsing.
*
* Last reviewed on 2008-01-24 (0.10.15)
*/
/*
* includes
*/
#include "metadataparseutil.h"
#include <string.h>
GST_DEBUG_CATEGORY_EXTERN (gst_metadata_demux_debug);
#define GST_CAT_DEFAULT gst_metadata_demux_debug
/*
* extern functions implementations
*/
/*
* metadataparse_util_tag_list_add_chunk:
* @taglist: tag list in which the whole chunk tag will be added
* @mode: GStreamer merge mode
* @name: name of the tag (ex: GST_TAG_EXIF, GST_TAG_IPTC, GST_TAG_XMP)
* @adapter: contains the whole chunk to be added as tag to @taglist
*
* This function get all the bytes from @adapter, create a GST_BUFFER, copy
* the bytes to it and then add it to @taglist as a tage @name using a
* merge @mode.
*
* Returns: nothing.
*/
void
metadataparse_util_tag_list_add_chunk (GstTagList * taglist,
GstTagMergeMode mode, const gchar * name, GstAdapter * adapter)
{
GstBuffer *buf;
guint size;
if (adapter && (size = gst_adapter_available (adapter))) {
buf = gst_buffer_new_and_alloc (size);
gst_adapter_copy (adapter, GST_BUFFER_DATA (buf), 0, size);
gst_tag_list_add (taglist, mode, name, buf, NULL);
gst_buffer_unref (buf);
}
}
/*
* metadataparse_util_hold_chunk:
* @read: number of bytes that still need to be hold
* @buf: [in] data to be parsed
* @bufsize: [in] size of @buf in bytes
* @next_start: indicates a pointer after the @buf where the next parsing step
* should start from
* @next_size: indicates the minimal size of the the buffer to be given on
* the next call to the parser
* @adapter: adapter to hold the chunk
* NOTE: To have a explanation of each parameters of this function look at the
* documentation of #metadataparse_jpeg_reading or #metadataparse_png_reading
*
* This function holds a chunk into the adapter. If there is enough bytes
* (*@read > *@bufsize), then it just hold and make the parser continue after
* the chunk by setting @next_start properly. Otherwise, if there is not
* enough bytes in @buf, it just set @next_start and @next_size, to make the
* parse return META_PARSING_NEED_MORE_DATA and request the caller the proper
* offset and size, so in the sencond time this function is called it should
* (or must) have enough data hold the whole chunk.
*
* Returns:
* <itemizedlist>
* <listitem><para>%META_PARSING_ERROR
* </para></listitem>
* <listitem><para>%META_PARSING_DONE if the chunk bas been completely hold
* </para></listitem>
* <listitem><para>%META_PARSING_NEED_MORE_DATA if this function should be
* called again (look @next_start and @next_size)
* </para></listitem>
* </itemizedlist>
*/
MetadataParsingReturn
metadataparse_util_hold_chunk (guint32 * read, guint8 ** buf,
guint32 * bufsize, guint8 ** next_start,
guint32 * next_size, GstAdapter ** adapter)
{
int ret;
if (*read > *bufsize) {
*next_start = *buf;
*next_size = *read;
ret = META_PARSING_NEED_MORE_DATA;
} else {
GstBuffer *gst_buf;
if (NULL == *adapter) {
*adapter = gst_adapter_new ();
}
gst_buf = gst_buffer_new_and_alloc (*read);
memcpy (GST_BUFFER_DATA (gst_buf), *buf, *read);
gst_adapter_push (*adapter, gst_buf);
*next_start = *buf + *read;
*buf += *read;
*bufsize -= *read;
*read = 0;
ret = META_PARSING_DONE;
}
return ret;
}
/*
* metadataparse_util_jump_chunk:
* NOTE: To have a explanation of each parameters of this function look at
* the documentation of #metadataparse_util_hold_chunk
*
* This function works in the same way as #metadataparse_util_hold_chunk, but
* just skip the bytes instead of also hold it
*
*/
MetadataParsingReturn
metadataparse_util_jump_chunk (guint32 * read, guint8 ** buf,
guint32 * bufsize, guint8 ** next_start, guint32 * next_size)
{
int ret;
if (*read > *bufsize) {
*read -= *bufsize;
*next_size = 2;
*next_start = *buf + *bufsize + *read;
*read = 0;
*bufsize = 0;
ret = META_PARSING_NEED_MORE_DATA;
} else {
*next_start = *buf + *read;
*buf += *read;
*bufsize -= *read;
*read = 0;
ret = META_PARSING_DONE;
}
return ret;
}