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Oracle® Multimedia User's Guide
12c Release 1 (12.1)

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9 Oracle Multimedia Examples

This chapter provides examples that show common operations with Oracle Multimedia.

This chapter includes these sections:

9.1 Audio Data Examples

Audio data examples using Oracle Multimedia include common operations on audio data, such as using audio types with object views and using a set of scripts for populating an ORDAudio object with BLOB data stored in the database. The following subsections describe these operations:

See Also:

Oracle Multimedia Reference for reference information about the methods used in these examples

9.1.1 Using Audio Types with Object Views

This section describes how to use audio types with object views. Just as a view is a virtual table, an object view is a virtual object table.

Oracle provides object views as an extension of the basic relational view mechanism. By using object views, you can create virtual object tables -- of either built-in or user-defined types -- from data stored in the columns of relational or object tables in the database.

Object views can offer specialized or restricted access to the data and objects in a database. For example, you might use an object view to provide a version of an employee object table that does not have attributes containing sensitive data or a deletion method. Object views also let you try object-oriented programming without permanently converting your tables. Using object views, you can convert data gradually and transparently from relational tables to object-relational tables.

In Example 9-1, consider the following relational table (containing no ORDAudio objects).

Example 9-1 Define a Relational Table Containing No ORDAudio Object

create table flat (
   id                NUMBER,
   description       VARCHAR2(4000),
   localData         BLOB,
   srcType           VARCHAR2(4000),
   srcLocation       VARCHAR2(4000),
   srcName           VARCHAR2(4000),
   upDateTime        DATE,
   local             NUMBER,
   format            VARCHAR2(31),
   mimeType          VARCHAR2(4000),
   comments          CLOB,
   encoding          VARCHAR2(256),
   numberOfChannels  NUMBER,
   samplingRate      NUMBER,
   sampleSize        NUMBER,
   compressionType   VARCHAR2(4000),
   audioDuration     NUMBER,
)
--
-- Store audio data as SecureFiles LOBs.
--
LOB(localData) STORE AS SECUREFILE;

You can create an object view on the relational table shown in Example 9-1, as shown in Example 9-2.

Example 9-2 Define an Object View Containing an ORDAudio Object and Relational Columns

create or replace view object_audio_v as 
  select
      id,
      ORDSYS.ORDAudio(T.description,
      ORDSYS.ORDSource(
         T.localData, T.srctype, T.srcLocation, T.srcName, T.updateTime,
         T.local),
         T.format,
         T.mimeType,
         T.comments, 
         T.encoding, 
         T.numberOfChannels, 
         T.samplingRate, 
         T.sampleSize, 
         T.compressionType, 
         T.audioDuration)
   from flat T;

Object views provide the flexibility of looking at the same relational or object data in more than one way. Therefore, you can use different in-memory object representations for different applications without changing the way you store the data in the database.

See Also:

Oracle Database Concepts for more information about defining, using, and updating object views

9.1.2 Scripts for Populating an ORDAudio Object with BLOB Data

The scripts presented in this section demonstrate how to populate an Oracle Multimedia ORDAudio object from an existing BLOB stored in the database.

Table 9-1 lists each script by name, along with a brief description of the operations it performs. Each script is included and described in further detail in the following sections.

Table 9-1 Audio Scripts

Script Name Operations Performed

create_mediadir.sql

(See Example 9-3)

Creates an audio data load directory.

(See Section 9.1.2.1)

create_soundtable.sql

(See Example 9-4)

Creates and populates the soundtable table.

(See Section 9.1.2.2)

create_audtable.sql

(See Example 9-5)

Creates the audio_table table.

(See Section 9.1.2.3)

import_aud.sql

(See Example 9-6)

Loads the audio data. This script imports the audio data from an audio file into the audio_table table using the ORDAudio import( ) method.

(See Section 9.1.2.4)

copy_audblob.sql

(See Example 9-7)

Copies the BLOB data from the soundtable table to the audio_table table.

(See Section 9.1.2.5)

showprop_aud.sql

(See Example 9-8)

Displays the properties of the loaded audio data stored in the audio_table table.

(See Section 9.1.2.6)

setup_audsample.sql

(See Example 9-9)

Automates the process by running the previous audio scripts in the required order.

(See Section 9.1.2.7)

cleanup_audsample.sql

(See Example 9-10)

Cleans up by removing the sample tables, directories, and procedures from your database.

(See Section 9.1.2.8)


9.1.2.1 Create an Audio Data Load Directory

The create_mediadir.sql script creates the audio data load directory. This script is shown in Example 9-3. (See Section 9.2.1.1 and Section 9.3.1.1, respectively, for information about how to use this script to create the load directories for media data and image data.)

To load the audio data successfully, you must create a database directory object that points to a file directory on your system. Example 9-3 uses the media_dir directory, which points to the file directory C:\media_dir. You can edit the create_mediadir.sql script to replace the directory path in the CREATE OR REPLACE DIRECTORY statement with your directory specification.

This directory specified in the create_mediadir.sql script must contain your sample audio files. The audio examples use the sample file aud1.wav, which is installed in the <ORACLE_HOME>/ord/aud/demo directory. You can copy any supported audio files to the C:\media_dir directory to run the scripts in these examples.

Before running the create_mediadir.sql script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY (to specify the directory specification for your audio files)

  • DROP ANY DIRECTORY (to delete previous instances of the audio data load directory)

Note:

If you run the create_mediadir.sql script as a different user than the user who ran the other audio scripts, you must perform these steps:
  1. Uncomment the GRANT READ ON DIRECTORY statement.

  2. Replace the string <USER> in this statement with the new user (for example: SCOTT).

Example 9-3 create_mediadir.sql Script

-- create_mediadir.sql
--
SET SERVEROUTPUT ON;
SET ECHO ON;
 
-- To delete the directory, uncomment the next statement; 
-- otherwise, leave it commented out.
-- DROP DIRECTORY media_dir;
 
-- To specify a different directory path, replace the default directory 
-- path with the new path in the next statement.
CREATE OR REPLACE DIRECTORY media_dir AS 'C:\media_dir';

-- To change the user, uncomment the next statement and replace the 
-- string "<USER>" with the new user. Otherwise, leave the statement 
-- commented out.
-- GRANT READ ON DIRECTORY media_dir TO <USER>;

9.1.2.2 Create and Populate the soundtable Table

The create_soundtable.sql script creates and populates the soundtable table. This table contains a BLOB column; it is created to demonstrate how to populate a table with an Oracle Multimedia ORDAudio column from a table with a BLOB column. This script is shown in Example 9-4.

This script creates the soundtable table, inserts a row with an empty BLOB, loads the BLOB with audio data, and then checks the length of the BLOB data. You can replace the name of the data file in the create_soundtable.sql script with the name of the data file you plan to use.

Before running this script, ensure that you have the CREATE TABLE privilege.

Example 9-4 create_soundtable.sql Script

-- create_soundtable.sql
--
-- Create the soundtable table. This table is used ONLY to show
-- how to copy data from a BLOB column to an ORDAudio column.
--
-- Insert a row into the table with an empty BLOB.
-- Load the row with BLOB data by pointing to the audio file to 
-- be loaded from the directory specified using the BFILE data 
-- type.
-- Close the files and commit the transaction.
-- Check the length of the BLOB loaded. Is the length
-- what you are expecting?
--
SET SERVEROUTPUT ON;
 
CREATE TABLE soundtable ( id number,
                         sound BLOB default EMPTY_BLOB() )
--
-- Store audio data as SecureFiles LOBs.
--
LOB(sound) STORE AS SECUREFILE;
 
-- 
INSERT INTO soundtable(id, sound) VALUES (1, EMPTY_BLOB());
COMMIT;

DECLARE
   f_lob BFILE := BFILENAME('MEDIA_DIR','aud1.wav');
   b_lob BLOB;
   length INTEGER;
BEGIN
 
  SELECT sound INTO b_lob FROM soundtable WHERE id=1 FOR UPDATE;
 
  -- Open the LOBs.
  dbms_lob.open(f_lob, dbms_lob.file_readonly);
  dbms_lob.open(b_lob, dbms_lob.lob_readwrite);
 
  -- Populate the BLOB from the 'aud1.wav' file in the BFILE.
  dbms_lob.loadfromfile (b_lob, f_lob, dbms_lob.getlength(f_lob));
 
  -- Close the LOBs.
  dbms_lob.close(b_lob);
  dbms_lob.close(f_lob);
  COMMIT;
 
  -- Check the length of the LOB.
  SELECT dbms_lob.getlength(t.sound) INTO length FROM soundtable t WHERE id = 1;
  DBMS_OUTPUT.PUT_LINE('The length is '|| length);
END;
/

9.1.2.3 Create the audio_table Table

The create_audtable.sql script creates the audio_table table with the two columns id and audio. The audio column is defined as type ORDAudio. This script is shown in Example 9-5.

Before running this script, ensure that you have the CREATE TABLE privilege.

Example 9-5 create_audtable.sql Script

-- create_audtable.sql
--
CREATE TABLE audio_table ( id NUMBER,
                       audio ORDAudio )
LOB(audio.source.localData) STORE AS SECUREFILE;

9.1.2.4 Load the Audio Data

The import_aud.sql script inserts a row into the audio_table table, and imports audio data from an audio file into the audio column in the audio_table table using the ORDAudio import( ) method. This script is shown in Example 9-6.

To run this script successfully, you must copy one audio clip to your media_dir directory using the name specified in this script, or modify this script to match the file names of your audio clips.

This script loads the same audio clip that was loaded by the create_soundtable.sql script. It is used later in the showprop_aud.sql script to show that data loaded with the import( ) method matches the data copied from the BLOB column of the soundtable table.

Note:

Run this script as the user who ran the previous audio scripts.

Example 9-6 import_aud.sql Script

--import_aud.sql
--
DECLARE
  obj ORDAUDIO;
  ctx RAW(64) := NULL;
 
BEGIN
 
  -- Insert a row with an ORDAudio object.
  INSERT INTO audio_table VALUES 
    (1, ORDAudio('FILE', 'MEDIA_DIR', 'aud1.wav'))
    returning audio into obj;
 
  --Import the audio clip aud1.wav from media_dir.
  obj.import(ctx);
 
  --Set the properties.
  obj.setProperties(ctx);
 
  --Update the table with the audio object. 
  UPDATE audio_table SET audio = obj WHERE id = 1;
 
  COMMIT;
 
END;
/

9.1.2.5 Copy the BLOB Data to the ORDAudio Object

The copy_audblob.sql script inserts a row with id=2 into the audio_table table and copies the audio data in the sound column of the soundtable table into the audio column of the audio_table table for a row with id=2. The script uses the ORDAudio constructor that takes a BLOB as the input parameter. It also sets the properties of the audio data after inserting it. This script is shown in Example 9-7.

Note:

Run this script as the user who ran the previous audio scripts.

Example 9-7 copy_audblob.sql Script

--copy_audblob.sql
-- 
-- Use the ORDAudio constructor that takes a BLOB as the input parameter
-- in the SQL INSERT statement.
-- 
-- In this case, the BLOB (an audio clip), which was stored in
-- a row with ID = 1 in the soundtable table, is copied to a row 
-- with ID = 2 in the audio_table table containing an audio column 
-- defined as an ORDAudio object type.
-- 
INSERT INTO audio_table
  (select 2, ORDAudio(S.sound) FROM soundtable S WHERE S.id = 1);
 
DECLARE
 obj ORDSYS.ORDAudio;
 ctx RAW(40) := NULL;
BEGIN
SELECT audio INTO obj FROM audio_table WHERE id = 2 for update;
obj.setProperties(ctx);
UPDATE audio_table SET audio = obj WHERE ID = 2;
END;
/
 
COMMIT; 

9.1.2.6 Show the Properties of the Loaded Audio Data

The showprop_aud.sql script displays the properties of the audio data clips stored in the audio_table table. They should be identical. Different load methods were used to load the same audio clip into two rows in the audio_table table. This script verifies that the audio data that was loaded using the ORDAudio import( ) method matches the audio data that was copied from a BLOB column of the soundtable table. This script is shown in Example 9-8.

Note:

Run this script as the user who ran the previous audio scripts.

Example 9-8 showprop_aud.sql Script

-- showprop_aud.sql
--
SET SERVEROUTPUT ON;
 
--
--Query audio_table for ORDAudio content in PL/SQL.
--
 
BEGIN
  -- Check the properties of the audio data clip imported into the
  -- ORDAudio object type. Properties for ID=1 should be identical
  -- with ID=2.
 
  dbms_output.put_line(' Properties of these audio clips are identical:');
 
  FOR rec in (SELECT id, audio FROM audio_table ORDER BY id) LOOP 
    dbms_output.put_line('Properties for id: ' || rec.id);
 
    dbms_output.put_line('audio encoding: ' || rec.audio.getEncoding);
    dbms_output.put_line('audio number of channels: '|| 
                        rec.audio.getNumberOfChannels);
    dbms_output.put_line('audio MIME type: ' || rec.audio.getMimeType);
    dbms_output.put_line('audio file format: ' || rec.audio.getFormat);
    dbms_output.put_line
        ('----------------------------------------------');
  END LOOP;
END;
/
--
-- Query audio_table for ORDAudio and list the properties using SQL.
--
clear columns
column id       format 99;
column encoding format a15;
column mimetype   format a20;
column fileformat   format a15;
column channels     format 99;
SELECT t.id, 
       t.audio.getEncoding() encoding, 
       t.audio.getNumberOfChannels() channels, 
       t.audio.getMimetype() mimetype, 
       t.audio.getFormat() fileformat 
from audio_table t ORDER BY t.id;

The results from running the script showprop_aud.sql show that the properties are identical for each stored audio clip.

Properties of these audio clips are identical:
Properties for id: 1
audio encoding: MS_PCM
audio number of channels: 1
audio MIME type: audio/x-wav
audio file format: WAVE
----------------------------------------------
Properties for id: 2
audio encoding: MS_PCM
audio number of channels: 1
audio MIME type: audio/x-wav
audio file format: WAVE
----------------------------------------------
 
PL/SQL procedure successfully completed.
 
 
ID ENCODING        CHANNELS MIMETYPE             FILEFORMAT     
--- --------------- -------- -------------------- ---------------
  1 MS_PCM                 1 audio/x-wav          WAVE
  2 MS_PCM                 1 audio/x-wav          WAVE

9.1.2.7 Automate the ORDAudio Examples

The setup_audsample.sql script runs each of the previous audio scripts in the correct order to automate this process. This script is shown in Example 9-9.

Before running this script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY

  • CREATE TABLE

Example 9-9 setup_audsample.sql Script

-- setup_audsample.sql
--
 
-- Create the media_dir load directory:
@create_mediadir.sql
 
-- Create the soundtable table and populate it with
-- an audio clip:
@create_soundtable.sql
 
-- Create the audio_table table:
@create_audtable.sql
 
--Import an audio clip:
@import_aud.sql
 
-- Copy a BLOB into an ORDAudio object, set the properties,
-- and update the time:
@copy_audblob.sql
 
-- Check the properties of the audio clips. The properties
-- should be identical:
@showprop_aud.sql
 
--exit;

9.1.2.8 Clean Up the ORDAudio Examples

The cleanup_audsample.sql script removes the sample tables, directories, and procedures created by the previous audio scripts from your database. This script is shown in Example 9-10.

Before running this script, ensure that you have the DROP ANY DIRECTORY privilege.

Note:

Run this script as the user who ran the previous audio scripts.

Example 9-10 cleanup_audsample.sql Script

-- cleanup_audsample.sql
--
-- Drop the audio load directory.
-- DROP DIRECTORY media_dir;
 
-- Drop the tables created by the demo.
DROP TABLE soundtable PURGE;
DROP TABLE audio_table PURGE;

exit;

9.2 Media Data Examples

Media data examples using Oracle Multimedia include common operations on heterogeneous data, such as using a set of scripts for populating an ORDDoc object from a file data source. The following subsection describes this operation:

See Also:

Oracle Multimedia Reference for reference information about the methods used in these examples

9.2.1 Scripts for Populating an ORDDoc Object from a File Data Source

The scripts presented in this section demonstrate how to populate an ORDDoc object from an existing file.

Table 9-2 lists each script by name, along with a brief description of the operations it performs. Each script is included and described in further detail in the following sections.

Table 9-2 Media Scripts

Script Name Operations Performed

create_mediadir.sql

(See Example 9-3)

Creates a media data load directory.

(See Section 9.2.1.1)

create_doctable.sql

(See Example 9-11)

Creates the doc_table table.

(See Section 9.2.1.2)

import_doc.sql

(See Example 9-12)

Loads the media data. This script imports the media data from a file into the doc_table table using the ORDDoc import( ) method.

(See Section 9.2.1.3)

read_doc.sql

(See Example 9-13)

Reads the media data from a BLOB using a stored procedure.

(See Section 9.2.1.4)

showprop_doc.sql

(See Example 9-14)

Displays the properties of the loaded media data stored in the doc_table table.

(See Section 9.2.1.5)

setup_docsample.sql

(See Example 9-15)

Automates the process by running the previous media scripts in the required order.

(See Section 9.2.1.6)

cleanup_docsample.sql

(See Example 9-16)

Cleans up by removing the sample tables, directories, and procedures from your database.

(See Section 9.2.1.7)


9.2.1.1 Create a Media Data Load Directory

The create_mediadir.sql script creates the media data load directory. This script is shown in Example 9-3.

To load the media data successfully, you must create a database directory object that points to a file directory on your system. Example 9-3 uses the media_dir directory, which points to the file directory C:\media_dir. You can edit the create_mediadir.sql script to replace the directory path in the CREATE OR REPLACE DIRECTORY statement with your directory specification.

This directory specified in the create_mediadir.sql script must contain your sample media files. The media examples use the sample files aud1.wav and aud2.mp3, which are installed in the <ORACLE_HOME>/ord/aud/demo directory. You can copy any supported media files to the C:\media_dir directory to run the scripts in these examples.

Before running the create_mediadir.sql script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY (to specify the directory specification for your media files)

  • DROP ANY DIRECTORY (to delete previous instances of the media data load directory)

Note:

If you run the create_mediadir.sql script as a different user than the user who ran the other media scripts, you must perform these steps:
  1. Uncomment the GRANT READ ON DIRECTORY statement.

  2. Replace the string <USER> in this statement with the new user (for example: SCOTT).

9.2.1.2 Create the doc_table Table

The create_doctable.sql script creates the doc_table table with the two columns id and document. The document column is defined as type ORDDoc. This script is shown in Example 9-11.

Before running this script, ensure that you have the CREATE TABLE privilege.

Example 9-11 create_doctable.sql Script

-- create_doctable.sql
--
CREATE TABLE doc_table ( id NUMBER,
                         document ORDDoc )
LOB(document.source.localData) STORE AS SECUREFILE;

9.2.1.3 Load the Media Data

The import_doc.sql script inserts two rows into the doc_table table, and imports media data from a media file into the document column in the doc_table table using the ORDDoc import( ) method. This script is shown in Example 9-12.

To run this script successfully, you must copy two media files to your media_dir directory using the names specified in this script, or modify this script to match the file names of your media files.

Note:

Run this script as the user who ran the previous media scripts.

Example 9-12 import_doc.sql Script

-- import_doc.sql
--
CREATE OR REPLACE PROCEDURE load_document (in_id INTEGER, 
                                           in_dir VARCHAR2, 
                                           in_fname VARCHAR2)
AS
  obj ORDDOC;
  ctx RAW(64) := NULL;
BEGIN
  INSERT INTO doc_table VALUES 
    (in_id, ORDDoc('FILE', in_dir, in_fname))
    RETURNING document INTO obj;
  obj.import(ctx,TRUE);
  UPDATE doc_table SET document = obj WHERE id = in_id;
  COMMIT;
END;
/
show errors;
 
-- Import the audio files aud1.wav and aud2.mp3 from the MEDIA_DIR directory
-- on a local file system. 
EXECUTE load_document(1, 'MEDIA_DIR', 'aud1.wav');
EXECUTE load_document(2, 'MEDIA_DIR', 'aud2.mp3');

9.2.1.4 Read the Media Data from the BLOB

The read_doc.sql script reads media data from a BLOB by creating the stored procedure read_document. This procedure reads a specified amount of media data from the BLOB attribute, beginning at a particular offset, until all the media data is read. This script is shown in Example 9-13.

Note:

Run this script as the user who ran the previous media scripts.

Example 9-13 read_doc.sql Script

--read_doc.sql
--
SET SERVEROUTPUT ON
 
create or replace procedure read_document( in_id integer) as
obj ORDDoc;
buffer RAW (32767);
numBytes integer;
bytesRead integer := 0;
startpos integer := 1;
ctx RAW(64) := NULL;
BEGIN
  select document into obj from doc_table where id = in_id;
  DBMS_OUTPUT.PUT_LINE('Content length is: ' || obj.getContentLength());
 
  LOOP
    numBytes := 32767;
    startpos := startpos + bytesRead;
    obj.readFromSource(ctx,startPos,numBytes,buffer);
    bytesRead := numBytes;
 
    DBMS_OUTPUT.PUT_LINE('start position: '|| startPos);
    DBMS_OUTPUT.PUT_LINE('read ' || bytesRead || ' bytes.');
 
   -- Note: Add your own code here to process the media data being read.
   -- This routine reads the data into the buffer 32767 bytes at a time,
   -- then reads the next chunk, overwriting the first buffer full of data.
 END LOOP;
 EXCEPTION
     WHEN NO_DATA_FOUND THEN
       DBMS_OUTPUT.PUT_LINE('End of data ');
     WHEN ORDSYS.ORDSourceExceptions.METHOD_NOT_SUPPORTED THEN
       DBMS_OUTPUT.PUT_LINE('ORDSourceExceptions.METHOD_NOT_SUPPORTED caught');
     WHEN OTHERS THEN
       DBMS_OUTPUT.PUT_LINE('EXCEPTION caught:' || SQLERRM);
END;
/
show errors
 

To execute the stored procedure, enter the following SQL statements:

SQL> set serveroutput on; 
SQL> execute read_document(1); 

Content length is: 93594
start position: 1
read 32767 bytes.
start position: 32768
read 32767 bytes.
start position: 65535
read 28060 bytes.
End of data

PL/SQL procedure successfully completed.

9.2.1.5 Show the Properties of the Loaded Media Data

The showprop_doc.sql script displays the properties of the media data loaded into the doc_table table. This script is shown in Example 9-14.

Note:

Run this script as the user who ran the previous media scripts.

Example 9-14 showprop_doc.sql Script

-- showprop_doc.sql
--
SET SERVEROUTPUT ON;
 
--
-- Query doc_table for ORDDoc and print the properties using PL/SQL.
--
 
BEGIN
  FOR rec in (SELECT id, document FROM doc_table ORDER BY id) LOOP 
    dbms_output.put_line('document id: '|| rec.id);
    dbms_output.put_line('document MIME type: '|| rec.document.getMimeType());
    dbms_output.put_line('document file format: '|| rec.document.getFormat());
    dbms_output.put_line('BLOB Length: '|| rec.document.getContentLength());
    dbms_output.put_line('----------------------------------------------');
  END loop;
END;
/
 
--
-- Query doc_table for ORDDoc and list the properties using SQL.
--
clear columns
column id    format 99;
column mimetype format a20;
column format   format a10;
column length   format 99999999;
SELECT t.id, 
       t.document.getMimeType() mimetype, 
       t.document.getFormat() format, 
       t.document.getContentLength() length
from doc_table t ORDER BY t.id;

The results from running the script showprop_doc.sql are the following:

SQL> @showprop_doc.sql 

document id: 1
document MIME type: audio/x-wav
document file format: WAVE
BLOB Length: 93594
----------------------------------------------
document id: 2
document MIME type: audio/mpeg
document file format: MPGA
BLOB Length: 51537
----------------------------------------------
 
PL/SQL procedure successfully completed.
 
 
 ID MIMETYPE             FORMAT        LENGTH
--- -------------------- ---------- ---------
  1 audio/x-wav          WAVE           93594
  2 audio/mpeg           MPGA           51537

9.2.1.6 Automate the ORDDoc Examples

The setup_docsample.sql script runs each of the previous media scripts in the correct order to automate this process. This script is shown in Example 9-15.

Before running this script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY

  • CREATE TABLE

Example 9-15 setup_docsample.sql Script

-- setup_docsample.sql
--
 
-- Create the media_dir load directory:
@create_mediadir.sql
 
-- Create the doc_table table:
@create_doctable.sql
 
--Import 2 media clips and set the properties:
@import_doc.sql
 
--Display the properties of the media clips:
@showprop_doc.sql
 
--Create a stored procedure to read from ordDoc:
@read_doc.sql
 
--Execute the stored procedure:
execute read_document(1);
 
--exit;

9.2.1.7 Clean Up the ORDDoc Examples

The cleanup_docsample.sql script removes the sample tables, directories, and procedures created by the previous media scripts from your database. This script is shown in Example 9-16.

Before running this script, ensure that you have the DROP ANY DIRECTORY privilege.

Note:

Run this script as the user who ran the previous media scripts.

Example 9-16 cleanup_docsample.sql Script

-- cleanup_docsample.sql
--
-- Drop the doc load directory.
-- DROP DIRECTORY media_dir;
 
-- Drop the table and procedures created by the demo.
DROP TABLE doc_table PURGE;
DROP PROCEDURE read_document;
DROP PROCEDURE load_document;

exit;

9.3 Image Data Examples

Image data examples using Oracle Multimedia include common operations on image data, such as using a set of scripts for populating an ORDImage object from a file data source, using a set of scripts for loading an image table from an HTTP data source, and addressing issues related to globalization support. The following subsections describe these operations:

See Also:

Oracle Multimedia Reference for reference information about the methods used in these examples

9.3.1 Scripts for Populating an ORDImage Object from a File Data Source

The scripts presented in this section demonstrate how to populate an Oracle Multimedia ORDImage object from an existing file.

Table 9-3 lists each script by name, along with a brief description of the operations it performs. Each script is included and described in further detail in the following sections.

Table 9-3 Image Scripts

Script Name Operations Performed

create_mediadir.sql

(See Example 9-3)

Creates an image data load directory.

(See Section 9.3.1.1)

create_imgtable.sql

(See Example 9-17)

Creates the image_table table.

(See Section 9.3.1.2)

import_img.sql

(See Example 9-18)

Loads the image data. This script imports the image data from a file into the image_table table using the ORDImage import( ) method.

(See Section 9.3.1.3)

read_image.sql

(See Example 9-19)

Reads the image data from a BLOB using a stored procedure.

(See Section 9.3.1.4)

showprop_img.sql

(See Example 9-20)

Displays the properties of the loaded image data stored in the image_table table.

(See Section 9.3.1.5)

setup_imgsample.sql

(See Example 9-21)

Automates the process by running the previous image scripts in the required order.

(See Section 9.3.1.6)

cleanup_imgsample.sql

(See Example 9-22)

Cleans up by removing the sample tables, directories, and procedures from your database.

(See Section 9.3.1.7)


9.3.1.1 Create an Image Data Load Directory

The create_mediadir.sql script creates the image data load directory. This script is shown in Example 9-3.

To load the image data successfully, you must create a database directory object that points to a file directory on your system. Example 9-3 uses the media_dir directory, which points to the file directory C:\media_dir. You can edit the create_mediadir.sql script to replace the directory path in the CREATE OR REPLACE DIRECTORY statement with your directory specification.

This directory specified in the create_mediadir.sql script must contain your sample image files. The image examples use the sample files img71.gif and img50.gif, which are installed in the <ORACLE_HOME>/ord/img/demo directory. You can copy any supported image files to the C:\media_dir directory to run the scripts in these examples.

Before running the create_mediadir.sql script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY (to specify the directory specification for your image files)

  • DROP ANY DIRECTORY (to delete previous instances of the image data load directory)

Note:

If you run the create_mediadir.sql script as a different user than the user who ran the other image scripts, you must perform these steps:
  1. Uncomment the GRANT READ ON DIRECTORY statement.

  2. Replace the string <USER> in this statement with the new user (for example: SCOTT).

9.3.1.2 Create the image_table Table

The create_imgtable.sql script creates the image_table table with the two columns id and image. The image column is defined as type ORDImage. This script is shown in Example 9-17.

Before running this script, ensure that you have the CREATE TABLE privilege.

Example 9-17 create_imgtable.sql Script

-- create_imgtable.sql
--
CREATE TABLE image_table ( id NUMBER,
                           image ORDImage )
LOB(image.source.localData) STORE AS SECUREFILE;

9.3.1.3 Load the Image Data

The import_img.sql script inserts two rows into the image_table table, and imports image data from an image file into the image column in the image_table table using the ORDImage import( ) method. This script is shown in Example 9-18.

To run this script successfully , you must copy two image files to your media_dir directory using the file names specified in this script, or modify this script to match the file names of your image files.

Note:

Run this script as the user who ran the previous image scripts.

Example 9-18 import_img.sql Script

-- import_img.sql
--
CREATE OR REPLACE PROCEDURE load_image(in_id INTEGER,
                                       in_dir VARCHAR2,
                                       in_fname VARCHAR2)
AS
  obj ORDIMAGE;
  ctx RAW(64) := NULL;
BEGIN
  INSERT INTO image_table VALUES
      (in_id, ORDImage('FILE', in_dir, in_fname))
      RETURNING image INTO obj;
  obj.import(ctx);
  UPDATE image_table SET image = obj WHERE id = in_id;
  COMMIT;
END;
/
show errors
 
-- Import the two files into the database.
EXECUTE load_image(1, 'MEDIA_DIR', 'img71.gif');
EXECUTE load_image(2, 'MEDIA_DIR', 'img50.gif');

9.3.1.4 Read the Image Data from the BLOB

The read_image.sql script reads image data from a BLOB by creating the stored procedure read_image. This procedure reads a specified amount of image data from the BLOB attribute, beginning at a particular offset, until all the image data is read. This script is shown in Example 9-19.

Note:

Run this script as the user who ran the previous image scripts.

Example 9-19 read_image.sql Script

-- read_image.sql
--
set serveroutput on
create or replace procedure read_image (in_id integer) as
-- Note: ORDImage has no readFromSource method like ORDAudio
-- and ORDVideo; therefore, you must use the DBMS_LOB package to
-- read image data from a BLOB.
buffer RAW (32767);
src BLOB;
amt integer; 
pos integer := 1;
bytesRead integer := 0;
length integer;
BEGIN
  Select t.image.getcontent(), t.image.getContentLength()
    into src, length from image_table t where t.id = in_id;
  DBMS_OUTPUT.PUT_LINE('Content length is: '|| length);
 
  LOOP
    amt := 32767;
    pos := pos + bytesRead;
    DBMS_LOB.READ(src,amt,pos,buffer);
    bytesRead := amt;
 
    DBMS_OUTPUT.PUT_LINE('start position: '|| pos);
    DBMS_OUTPUT.PUT_LINE('bytes read '|| bytesRead);
-- Note: Add your own code here to process the image data being read.
-- This routine reads data into the buffer 32767 bytes at a time, 
-- then reads the next chunk, overwriting the first buffer full of data.
  END LOOP;
  EXCEPTION
  WHEN NO_DATA_FOUND THEN
    DBMS_OUTPUT.PUT_LINE('----------------');
    DBMS_OUTPUT.PUT_LINE('End of data ');
END;
/
show errors
 

To execute the stored procedure, enter the following SQL statements:

SQL> set serveroutput on;
SQL> execute read_image(1);
Content length is: 1124
start position: 1
bytes read 1124
----------------
End of data

PL/SQL procedure successfully completed.

9.3.1.5 Show the Properties of the Loaded Image Data

The showprop_img.sql script displays the properties of the image data loaded into the image_table table. This script is shown in Example 9-20.

Note:

Run this script as the user who ran the previous image scripts.

Example 9-20 showprop_img.sql Script

-- showprop_img.sql
--
SET SERVEROUTPUT ON;
 
--
-- Display the properties of the images stored in image_table using PL/SQL.
--
 
BEGIN
 
  FOR rec in (SELECT id, image from image_table ORDER BY id) LOOP
    dbms_output.put_line('Image properties:');
    dbms_output.put_line('image id: '|| rec.id);
    dbms_output.put_line('image height: '|| rec.image.getHeight());
    dbms_output.put_line('image width: '|| rec.image.getWidth());
    dbms_output.put_line('image MIME type: '|| rec.image.getMimeType());
    dbms_output.put_line('image file format: '|| rec.image.getFileFormat());
    dbms_output.put_line('BLOB Length: '|| rec.image.getContentLength());
    dbms_output.put_line('-------------------------------------------');
  END loop;
END;
/

--
-- Display the properties of the images stored in image_table using SQL.
--
clear columns
column id        format 99;
column height    format 999999;
column width     format 999999;
column mimetype  format a15;
column fileformat format a10;
column length     format 999999999;
select t.id, 
       t.image.getHeight() height,
       t.image.getWidth() width,
       t.image.getMimetype() mimetype,
       t.image.getFileFormat() fileformat,
       t.image.getContentLength() length
from image_table t ORDER BY t.id;

The results from running the script showprop_img.sql are the following:

SQL> @showprop_img.sql
Image properties:
image id: 1
image height: 15
image width: 43
image MIME type: image/gif
image file format: GIFF
BLOB Length: 1124
-------------------------------------------
Image properties:
image id: 2
image height: 32
image width: 110
image MIME type: image/gif
image file format: GIFF
BLOB Length: 686
-------------------------------------------
 
PL/SQL procedure successfully completed.
 
 
 ID  HEIGHT   WIDTH MIMETYPE        FILEFORMAT     LENGTH
--- ------- ------- --------------- ---------- ----------
  1      15      43 image/gif       GIFF             1124
  2      32     110 image/gif       GIFF              686
 

9.3.1.6 Automate the ORDImage Examples

The setup_imgsample.sql script runs each of the previous image scripts in the correct order to automate this process. This script is shown in Example 9-21.

Before running this script, ensure that you have these privileges:

  • CREATE ANY DIRECTORY

  • CREATE TABLE

Example 9-21 setup_imgsample.sql Script

-- setup_imgsample.sql
--
 
--Create the media_dir load directory:
@create_mediadir.sql
 
--Create the image_table table:
@create_imgtable.sql
 
--Import images into the image_table table:
@import_img.sql
 
--Show the properties of the images:
@showprop_img.sql
 
--Create a stored procedure to read from ordImage:
@read_image.sql
 
--Execute the stored procedure:
execute read_image(1);
 
--exit;

9.3.1.7 Clean Up the ORDImage Examples

The cleanup_imgsample.sql script removes the sample tables, directories, and procedures created by the previous image scripts from your database. This script is shown in Example 9-22.

Before running this script, ensure that you have the DROP ANY DIRECTORY privilege.

Note:

Run this script as the user who ran the previous image scripts.

Example 9-22 cleanup_imgsample.sql Script

-- cleanup_imgsample.sql
--
-- Drop the image load directory.
DROP DIRECTORY media_dir;
 
-- Drop the tables created by the demo.
DROP TABLE image_table PURGE;
 
-- Drop the procedures.
DROP PROCEDURE read_image;
DROP PROCEDURE load_image;
 
exit;

9.3.2 Loading an Image Table from an HTTP Data Source

The import_imghttp.sql script imports the image data from an HTTP data source. This script inserts two rows into the image_table table and loads the image data from the specified HTTP data source (source type HTTP, URL location, and HTTP object name). This script is shown in Example 9-23.

To run this script successfully, you must modify it to point to two images located on your Web site, as described in Example 9-23.

Example 9-23 Import Image Data from an HTTP Data Source

-- import_imghttp.sql
--
-- Import the two HTTP images from a Web site into the database.
-- Prerequisites
--    Follow these steps before running this script:
--        1. Run create_imgdir.sql.
--        2. Run create_imgtable.sql.
--        3. Modify the HTTP URL and object name to point to two images on 
--           your Web site.

-- Insert two rows with an empty BLOB.
 
insert into image_table values (7,ORDImage(
'http','http://your_website/images','image1.jpg'));
 
insert into image_table values (8,ORDImage(
'http','http://your_website/images','image2.gif'));
 
commit;
 
DECLARE 
  obj ORDSYS.ORDIMAGE;
  ctx RAW(64) := NULL;
BEGIN
-- This imports the image file image1.gif from the HTTP source URL 
-- (srcType=HTTP), and automatically sets the properties.
 
  select Image into obj from image_table where id = 7 for update;
    obj.import(ctx);
 
  update image_table set image = obj where id = 7;
  commit;
 
-- This imports the image file image2.gif from the HTTP source URL
-- (srcType=HTTP), and automatically sets the properties.
 
  select Image into obj from image_table where id = 8 for update;
    obj.import(ctx);
 
  update image_table set image = obj where id = 8;
  commit;
END;
/

9.3.3 Addressing Globalization Support Issues

The globalization.sql script demonstrates how to address issues related to globalization support. It shows how to use the process( ) method with language settings that use the comma as the decimal point. For example, when the territory is FRANCE, the decimal point is expected to be a comma. Thus,",75" is specified as the scale factor. This script is shown in Example 9-24.

Example 9-24 Address a Globalization Support Issue

-- globalization.sql
--
ALTER SESSION SET NLS_LANGUAGE = FRENCH;
ALTER SESSION SET NLS_TERRITORY = FRANCE;
DECLARE
myimage ORDImage;
BEGIN
 
SELECT image into myimage from image_table where id=1 for update;
myimage.process('scale=",75"');
UPDATE image_table SET image = myimage where id=1;
COMMIT;
END;
/

Run the showprop_img.sql script (Example 9-20) to see the properties of the scaled image.

See Also:

Oracle Multimedia Reference for more information about ensuring the correct globalization support interpretation when using the process( ) method

9.4 Video Data Examples

Video data examples using Oracle Multimedia are not available in this chapter.

See Also:

Oracle Multimedia Reference for reference information and video data examples