A short summary of this paper. Adaptive progressive download based on the MPEG-4 file format. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately.
The client selects appropriate chunks from the MP4 file to be transferred based on 1 the header information i. The framework is completely client driven which allows for better server scalability and reduces signalling overhead. We discuss architecture and implementation issues such as complexity, interoperability and scalability and compare to 3GPP PSS Rel-6 adaptive streaming when appropriate. Therefore, it is most important that adaptive In recent years, significant progress has been streaming techniques disseminate from research into made in the area of adaptive streaming, i.
On the one hand, the challenge of trans- tems has been addressed most recently with the mitting a continuous stream of data under a real-time adoption of RTP retransmission Ott et al.
However, the specified solution commercial need has led to a quick adoption of has practical and conceptual limitations, especially adaptive techniques in commercial streaming solu- when used outside the mobile domain where it is tions, see e.
In particular for non real-time applica- Networks The key goal and argue that these two components are sufficient for of open standards is to achieve interoperability be- achieving an open but efficient streaming framework. I tive MP4-streaming framework and discuss several available open standard to make the structure of the architecture and implementation aspects. Finally, media available to the client, i. For each media for- work in the area of adaptive streaming, we will focus mat a specific payload format is required, describing on two items with particular relevance to our work.
The second is RD-optimal packet from the H. Adaptive streaming functionality is added in Rel-6 by two optional features. In addition, 3GPP has developed a new and Sehgal, provides a flexible framework to bit-rate adaptation mechanism in its specification. For a lay- buffer size to the server during setup. The framework shows that two basic RRs, the server can obtain detailed knowledge about components are required as input to the algorithm in the buffer state at the client and perform bit-stream order to derive optimal scheduling policies.
First, the switching or thinning to counter variations in network R-D structure of the media stream, i. Second, ceptual and practical problem. The conceptual prob- the channel properties, i. If the server wants has to be measured at the client. Hence, either of both to exploit all features to obtain optimal performance, has to be signaled to the other side resulting in cli- this is actually a quite challenging task.
Besides kee- ent-driven or server-driven approaches. Though both ping track of the size and content of packets which are approaches result in optimal solutions, a client-driven not yet acknowledged, the server has to analyze the approach reduces the complexity at the server and file structure and reconstruct the state of the client provides better scalability. In addition, constraints on the bit stream varia- simplifications are applied Chou and Miao, I served.
However, A practical problem results from the multitude of the file is not loaded linearly from the beginning to the specifications that need to be implemented simulta- end. Instead, the structure of the MP4 file is used to neously if interoperability between different vendors is dynamically select required parts from the file given to be achieved. Besides the fact that In the initial HTTP transfer the client obtains this simply becomes very difficult to implement, which knowledge about the structure of the media based on of course can be solved by major players by investing the MP4 header i.
For each track many man months, true interoperability is at risk be- or media stream in the file, the moov box contains all cause any specification leaves room for interpretation. Progressive Download. A short period of time is required to buffer and cache the beginning of the media file before it starts playing. The file structure is object-oriented; a file can be decomposed into constituent objects very simply, and the structure of the objects inferred directly from their type.
The file format is designed to be independent of any particular network protocol while enabling efficient support for them in general. In this article I will explain the importance of moov atom structure from the perspective of progressive download of Mp4 videos. A short period of time is required to buffer and cache the beginning of the media file before it starts playing.
This process is different from a single large asset transferred via progressive download or by using byte-range requests.
For information on that style of media delivery, see Large file optimization. The general media delivery or video-on-demand media delivery optimization types use a CDN with back-end optimizations to deliver media assets faster.
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