FLV files are encoded during export from various professional editing and encoding applications, through the Video Import Wizard in Flash Professional 8 and later, or the video files can be encoded with the stand-alone Adobe Media Encoder.
Note: These options require Flash Professional 8 or later.

• Video files are progressively downloaded, cached, and then played from the local disk. The entire video clip need not fit in memory.
• Longer video clips that are larger (720 × 480 and greater) and have a higher frame rate (up to 30 fps).
• Improved performance over embedded SWF video, with bigger and longer video and reliable audio synchronization. Provides best image quality, which is limited only by the amount of available hard drive space on the playback system.
• Flash CS3 Professional and later also support MPEG-4 formats encoded using the H.264 codec. This is a widely used format with many third-party encoding tools available.
• SWF and FLV files are kept separate resulting in a smaller SWF file size.

Different kinds of Streaming Media types

Designing a network protocol to support streaming media raises many options and issues, such as:

• Datagram protocols, such as the User Datagram Protocol (UDP), send the media stream as a series of small packets. This is simple and efficient; however, there is no mechanism within the protocol to guarantee delivery. It is up to the receiving application to detect loss or corruption and recover data using error correction techniques. If data is lost, the stream may suffer a dropout.
• The Real-time Streaming Protocol (RTSP), Real-time Transport Protocol (RTP) and the Real-time Transport Control Protocol (RTCP) were specifically designed to stream media over networks. The latter two are built on top of UDP.
• Transmission Control Protocol (TCP), guarantee correct delivery of each bit in the media stream. However, they accomplish this with a system of timeouts and retries, which makes them more complex to implement. It also means that when there is data loss on the network, the media stream stalls while the protocol handlers detect the loss and retransmit the missing data. Clients can minimize this effect by buffering data for display. While delay due to buffering is acceptable in video on demand scenarios, users of interactive applications such as video conferencing will experience a loss of fidelity if the delay that buffering contributes to exceeds 200 ms.[1]
• Unicast protocols send a separate copy of the media stream from the server to each recipient. Unicast is the norm for most Internet connections, but does not scale well when many users want to view the same program concurrently.
• Multicast protocols were developed to reduce the data replication (and consequent server/network loads) that occurs when many recipients receive unicast content streams independently. These protocols send a single stream from the source to a group of recipients. Depending on the network infrastructure and type, multicast transmission may or may not be feasible. One potential disadvantage of multicasting is the loss of video on demand functionality. Continuous streaming of radio or television material usually precludes the recipient's ability to control playback. However, this problem can be mitigated by elements such as caching servers, digital set-top boxes, and buffered media players.
• IP Multicast provides a means to send a single media stream to a group of recipients on a computer network. A multicast protocol, usually IGMP, is used to manage delivery of multicast streams to the groups of recipients on a LAN. One of the challenges in deploying IP multicast is that routers and firewalls between LANs must allow the passage of packets destined to multicast groups. If the organization that is serving the content has control over the network between server and recipients (i.e., educational, government, and corporate intranets), then routing protocols such as PIM can be used to deliver stream content to multiple LAN segments.
• Peer-to-peer (P2P) protocols arrange for prerecorded streams to be sent between computers. This prevents the server and its network connections from becoming a bottleneck. However, it raises technical, performance, quality, business, and legal issues.