System for controlling and enforcing playback restrictions for a media file by splitting the media file into usable and unusable portions for playback
Files are divided into parts and at least some of the parts are transmitted to a client using a communication channel. At least some of the transmitted parts are cached locally. This allows subsequent streaming playback of the file while using less bandwidth by transmitting the part of the file that hasn't been cached, and combining the cached parts with the transmitted parts. In some embodiments, files may be represented at a low quality level by a first data set, and at higher quality levels with additional data sets. Data sets are cached locally, so that during subsequent streaming playback of the file, the quality level of the playback may be improved by sending additional data sets using bandwidth that would otherwise be dedicated to transmitting the cached data sets.
1. In a client connected to a network and including a local storage device, a computer-implemented method of receiving and playing a media file comprising at least a first part and a second part, comprising:
receiving over the network and from a remote server m a first session the second part of the media file;
storing the second part at the local storage device;
receiving over the network and from a remote server m a second session subsequent to the first session the first part of the media file and not the second part of the media file;
combining the first part received in the second session with the stored second part after the start of the second session; and
playing a representation of the media file at the local client after combining at least part of the first and second parts after the start of the second session; wherein the second part is not usable for playback without being combined with the first part.
2. The computer-implemented method of claim 1 , wherein the received parts of the media file are encoded, and the second part is undecodable unless combined with the first part.
3. The computer-implemented method of claim 1 , wherein the representation of the media file is unplayable at the local client without authorization by a remote server.
4. The computer-implemented method of claim 3 , wherein authorization comprises the reception over the network and from a remote server the first part of the media file.
5. The computer-implemented method of claim 1 , wherein the neither the first part nor the second part is independently usable to recreate a recognizable facsimile of the content of the media file.
6. The computer-implemented method of claim 1 , wherein the media file is divided into a plurality of sections, each section comprising a plurality of bits, wherein the first part comprises a first subset of bits from each section, and the second part comprises the remaining bits from each section.
7. The computer-implemented method of claim 1 , wherein the media ifie is divided into a plurality of sections, each section comprising a plurality of bits, wherein the first part comprises a first bit from each section, and the second part comprises the remaining bits from each section.
8. The computer-implemented method of claim 1 , further comprising:
receiving over the network and from a remote server during the first session the first part of the media file; and
playing the representation of the media file back at the local client during the first session.
9. The computer-implemented method of claim 1 or 8 , wherein the first part is not stored at the local storage device after the playing of the media file.
10. The computer-implemented method of claim 1 or 8 , wherein the combined first and second parts are not stored at the local storage device after the playing of the media file.
11. The computer-implemented method of claim 1 , wherein the played representation of the media file is an exact digital copy of the media file.
12. The computer implemented method of claim 1 , wherein:
the media file further comprises a third part;
the first and second parts are combinable to form a representation of the media file at a first quality level; and
the first, second, and third parts are combinable to form a representation of the media file at a second quality level higher than the first quality level.
13. The computer implemented method of claim 12 , further comprising:
receiving over the network and from a remote server the third part of the media file;
storing the third part at the local storage device;
combining the received third part with the stored first part and the stored second part to form the representation of the media file at the second quality level; and
playing the representation of the media file after combining the first, second, and third parts.
14. The computer implemented method of claim 13 , wherein the third part is received over the network and from a remote server in a session other than the first session.
15. The computer implemented method of claim 13 , wherein the third part and not the second part is received over the network and from a remote server in a session other than the first session.
16. The computer-implemented method of claim 13 , wherein the first part is not stored at the local storage device after the playing of the media file.
17. The computer-implemented method of claim 13 , wherein the combined first, second, and third parts are not stored at the local storage device after the playing of the representation of the media file.
18. In a client connected to a network and including a local storage device, a computer-implemented method of receiving and playing a media file comprising at least a first part and a second part, comprising:
receiving over the network and from a remote server in a first session the second part of the media file;
storing the second part at the local storage device;
receiving over the network and from a remote server in a second session subsequent to the first session the first part of the media file and not the second part of the media file;
combining the first part received in the second session with the stored second part after the start of the second session; and
playing a representation of the media file at the local client after combining at least part of the first and second parts after the start of the second session;
wherein the media file is divided into a plurality of sections, wherein one of the sections contains exactly X bits, and wherein each of the remaining sections contains exactly Y bits, wherein X is less than or equal to Y, and wherein the first part comprises a first subset of bits from each section, and the second part comprises the remaining bits from each section.
19. The computer implemented method of claim 18 , wherein Y equals 20.
20. In a client connected to a network and including a local storage device, a computer-implemented method of receiving and playing a media file comprising at least a first part and a second parts, comprising:
receiving over the network and from a remote server in a first session the second part of the media file;
storing the second part at the local storage device;
receiving over the network and from a remote server in a second session subsequent to the first session the first part of the media file and not the second part of the media file;
combining the first part received in the second session with the stored second part after the start of the second session; and
playing a representation of the media file at the local client after combining at least part of the first and second parts after the start of the second session; wherein the first part comprises headers, compression table selectors and scale factors of the media file.
21. In a client connected to a network and including a local storage device, a computer-implemented method of receiving and playing a media file comprising at least a first part and a second part, comprising:
receiving over the network and from a remote server in a first session the first part of the media file, the first part of the media file comprising a representation of the media file at a first quality level;
receiving over the network and from a remote server the second part of the media file, wherein the first and second parts are combinable to form a representation of the media file at a second quality level higher than the first quality level;
storing the second part at the local storage device;
receiving over the network and from a remote server in a second session subsequent to the first session the first part of the media file and not the second part of the media file;
combining the received first part with the stored second part; and
playing a representation of the media file at the local client;
wherein the second part is not usable for playback without being combined with the first part.
22. The computer-implemented method of claim 21 , wherein the first part is not stored at the local storage device after the playing of the media file.
23. The computer-implemented method of claim 21 , wherein the representation of the media file is played after combining the first and second parts.
24. The computer-implemented method of claim 21 , wherein the representation of the media file is played in response to a command, and the representation of the media file is generated from at least the first part.
25. The computer-implemented method of claim 24 , wherein the representation of the media file is generated from the second part as well as the first part if both the first part and the second part have been received at the time of playback.
26. In a client connected to a network and including a local storage device, a computer-implemented method of receiving and playing a media file comprising at least a first part and a second part, comprising:
receiving over the network and from a remote server in a first session the second part of the media file;
storing the second part at the local storage device;
receiving over the network and from a remote server in a second session subsequent to the first session the first part of the media file and not the second part of the media file;
combining the first part received in the second session with the stored second part after the start of the second session; and
playing a representation of the media file at the local client after combining at least part of the first and second parts after the start of the second session;
wherein the media file is divided into a plurality of sections, wherein one of the sections contains exactly X bits, and wherein each of the remaining sections contains exactly Y bits, wherein X is less than or equal to Y, and wherein the first part comprises a first bit from each section, and the second part comprises the remaining bits from each section.
27. The computer implemented method of claim 26 , wherein Y equals 20.