Content streaming, such as the streaming of audio, video, and/or text media content is becoming increasingly popular. The term “streaming” is typically used to indicate that the data representing the media is provided by a host computer over a network to a client computer (i.e., a media playback computer device implemented as any of a variety of conventional computing devices, such as a desktop PC, a notebook or portable computer, a cellular telephone or other wireless communications device, a personal digital assistant (PDA), a gaming console, an IP set-top box, a handheld PC, and so on), and the client computer renders the streaming content as it is received from the host, rather than waiting for an entire “file” to be delivered.
When media content is “streamed” over a network, it is typically streamed in data packets. However, there is not always a guarantee that the data packets will arrive at their destination in the same order in which they are sent, or even that they will arrive at their destination at all. Additionally, there is usually no guarantee that the time it takes a data packet to travel from the source to the destination will be of specific duration, or that the time will be the same for different data packets.
In order to account for these variances in data delivery to a client computer, the client computer typically maintains a buffer of data. This buffer allows the client computer to smooth out the variances in data delivery so that they are not as noticeable to the user during playback of the content. However, one problem with this buffering is that it may not always account for glitches in network bandwidth caused by network congestion (e.g., network cross-traffic, interference, poor wireless reception). If glitches in network bandwidth are sustained for a few seconds or more, they can exceed the ability of the client buffers to compensate, which can result in a significant adverse impact on the playback of content for the user. For example, a sustained glitch in network bandwidth can lead to a pause in the playback of video (i.e., audio/video) content on the client computer and the general inability to experience video content in real time.
One solution to such network bandwidth problems is to reduce the size (i.e., bit-rate) of the streaming content. Some current methods for reducing the bit-rate of streaming content involve the generation and storage of a number of copies of the same video content. Thus, a user or system has the option of selecting a version of video content at a lower bit-rate, reducing the chances that real time playback of video content will be interrupted by network bandwidth glitches. Another method for reducing the bit-rate of streaming content would be to perform bit-rate reduction “on-the-fly”.
Although these methods can reduce the interruption of real time video playback, they have various disadvantages. For example, in the method where different bit-rate copies of the same video content are stored, selecting a playback bit-rate for video content generally occurs at the beginning of playback and usually cannot be changed during playback. A change from one bit-rate copy of video content to another may necessitate the interruption of playback and the re-initiating of playback from the beginning of the content. Another disadvantage is that significant storage space is required to maintain numerous copies of the same content on a host device. Both of the methods mentioned above suffer the additional disadvantage of being extremely processor-intensive. That is, generating different bit-rate-encoded copies of the same video content and performing bit-rate reduction “on-the-fly” are both extremely processor-intensive. Such a process, typically performed on a host device, involves a complete decode of video content into non-compressed, or raw, video. The complete decode is followed by a full encode of the raw video to recompress it with parameter adjustments that will result in a smaller overall copy of the video content.
Accordingly, a need exists for a way to deliver streaming content that makes network bandwidth glitches more transparent to the user during content playback.