Introduction

 

In this article, we’ll learn how to add multiple FLV movies in a single SWF file and then extract all or any of those movies using FLVExtractor class.

 

Explanation

 

FLVExtractor class allows you to extract FLV movies from an SWF file using Extract method. We need to pass the video stream id in order to extract a particular movie. This id is assigned while adding the FLV movie in the SWF file. To have a better understanding of the whole process, we’ll see the code snippets for adding FLV videos in the SWF file and extracting those videos. 

 

Adding multiple FLV movies

 

In order to add an FLV movie in an SWF file, we’ll use FLVUnpacker class. This class provides a method named Unpack, which is used to unpack an FLV to a flash container. While adding a new movie to the SWF file, we need to provide two parameters i.e. video stream id and depth. So, we can add multiple FLV movies with different IDs and at different depth. However, the Unpack overload without any parameters would add the movie with default ID i.e. 1.

 

[C#]

 

//create flash container to hold movies

FlashContainer flash = null;

//create unpacker object to add movies

IUnpacker unpacker = null;

 

//Open input stream with FLV data

using (Stream inputStream = new FileStream("simpleMovie.flv", FileMode.Open))

{

//create FLVUnpacker object

unpacker = new FLVUnpacker(inputStream);

//unpack FLV to flash container

flash = unpacker.Unpack(); //use default stream id =1

}

 

//load second FLV movie

using (Stream inputStream2 = new FileStream("longMovie.flv", FileMode.Open))

{

//create FLVUnpackager object

unpacker = new FLVUnpacker(inputStream2);

//unpack FLV to flash contianer; set different stream id and depth

flash.AddFlash(unpacker.Unpack(2, 2));

}

 

//load third FLV movie

using (Stream inputStream3 = new FileStream("simpleMovie2.flv", FileMode.Open))

{

//create FLVUnpackager object

unpacker = new FLVUnpacker(inputStream3);

//unpack FLV to flash contianer; set different stream id and depth

flash.AddFlash(unpacker.Unpack(3, 3));

}

 

//write SWF output file

flash.Write("SWFContainingMultipleFLV.swf");

 

[VB.NET]

 

'create flash container to hold movies

Dim flash As FlashContainer = Nothing

'create unpacker object to add movies

Dim unpacker As IUnpacker = Nothing

 

'Open input stream with FLV data

Using inputStream As Stream = New FileStream("simpleMovie.flv", FileMode.Open)

'create FLVUnpacker object

unpacker = New FLVUnpacker(inputStream)

'unpack FLV to flash container

flash = unpacker.Unpack() 'use default stream id =1

End Using

 

'load second FLV movie

Using inputStream2 As Stream = New FileStream("longMovie.flv", FileMode.Open)

'create FLVUnpackager object

unpacker = New FLVUnpacker(inputStream2)

'unpack FLV to flash contianer; set different stream id and depth

flash.AddFlash(unpacker.Unpack(2, 2))

End Using

 

'load third FLV movie

Using inputStream3 As Stream = New FileStream("simpleMovie2.flv", FileMode.Open)

'create FLVUnpackager object

unpacker = New FLVUnpacker(inputStream3)

'unpack FLV to flash contianer; set different stream id and depth

flash.AddFlash(unpacker.Unpack(3, 3))

End Using

 

'write SWF output file

flash.Write("SWFContainingMultipleFLV.swf")

 

 

Extracting Multiple FLV movies

 

Once the movies are added in the SWF file, we can extract these movies using FLVExtractor. We can use Extract method to achieve this goal. This method requires two parameters i.e. output stream and video stream id.

 

[C#]

 

//open SWF flash file and create flash container

FlashContainer flash = new FlashContainer("SWFContainingMultipleFLV.swf");

 

//create FLVExtractor object to extract FLV movies

FLVExtractor packer = new FLVExtractor(flash);

 

//open output file stream for first movie

using (Stream outputStream = new FileStream("FLVExtractedFromSWF.flv", FileMode.Create))

{

//created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 1);

}

 

//open output file stream for second movie

using (Stream outputStream = new FileStream("FLVExtractedFromSWF2.flv", FileMode.Create))

{

//created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 2);

}

 

//open output file stream for third movie

using (Stream outputStream = new FileStream("FLVExtractedFromSWF3.flv", FileMode.Create))

{

//created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 3);

}

 

[VB.NET]

 

'open SWF flash file and create flash container

Dim flash As New FlashContainer("SWFContainingMultipleFLV.swf")

 

'create FLVExtractor object to extract FLV movies

Dim packer As New FLVExtractor(flash)

 

'open output file stream for first movie

Using outputStream As Stream = New FileStream("FLVExtractedFromSWF.flv", FileMode.Create)

'created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 1)

End Using

 

'open output file stream for second movie

Using outputStream As Stream = New FileStream("FLVExtractedFromSWF2.flv", FileMode.Create)

'created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 2)

End Using

 

'open output file stream for third movie

Using outputStream As Stream = New FileStream("FLVExtractedFromSWF3.flv", FileMode.Create)

'created FLV movie and write it to the stream; get video by id

packer.Extract(outputStream, 3)

End Using

 

Conclusion

 

In this article, we have seen the use of FLVExtractor class to extract multiple FLV movies. We have also learned to add multiple FLV movies in an SWF file.