Efficient techniques for modifying audio playback rates
First Claim
Patent Images
1. A computing resource efficient method for playing back a data stream formed of data blocks at a selected playback rate SPR, the method comprising:
- determining a minimum frequency of data blocks for modification to achieve the selected playback rate SPR;
computing a data block modification period based upon the minimum frequency;
receiving the data stream;
passing through data blocks of the received data stream until an occurrence of the data block modification period occurs; and
modifying a current data block corresponding to the occurrence of the data block modification period, wherein the selected playback rate SPR is no more than twice a normal playback rate NPR, and wherein the modifying the current data block corresponding to the occurrence of the data block modification period, comprises;
if a ratio of the SPR to the NPR is greater than 1.0, cross-fading the current data block with a next data block in the data stream; and
if a ratio of the SPR to the NPR is less than 1.0, then cross-fading the current data block with itself.
0 Assignments
0 Petitions
Accused Products
Abstract
Improved techniques for modifying a playback rate of an audio item (e.g., an audio stream) are disclosed. As a result, the audio item can be played back faster or slower than normal. The improved techniques are resource efficient and well suited for audio items containing speech. The resource efficiency of the improved techniques make them well suited for use with portable media devices, such as portable media players.
8 Citations
20 Claims
-
1. A computing resource efficient method for playing back a data stream formed of data blocks at a selected playback rate SPR, the method comprising:
-
determining a minimum frequency of data blocks for modification to achieve the selected playback rate SPR; computing a data block modification period based upon the minimum frequency; receiving the data stream; passing through data blocks of the received data stream until an occurrence of the data block modification period occurs; and modifying a current data block corresponding to the occurrence of the data block modification period, wherein the selected playback rate SPR is no more than twice a normal playback rate NPR, and wherein the modifying the current data block corresponding to the occurrence of the data block modification period, comprises; if a ratio of the SPR to the NPR is greater than 1.0, cross-fading the current data block with a next data block in the data stream; and if a ratio of the SPR to the NPR is less than 1.0, then cross-fading the current data block with itself. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A computing device comprising:
-
a data storage unit, the data storage unit arranged to store at least a data stream formed of data blocks, the data stream including audio files formed of a plurality of audio frames; and a processor connected to the data storage unit, wherein the processor is configured to playback a data stream received from the data storage at a selected playback rate SPR by; determining a minimum frequency of data blocks for modification to achieve the selected playback rate SPR, computing a data block modification period based upon the minimum frequency, receiving the data stream, passing through data blocks of the received data stream until an occurrence of the data block modification period occurs, and modifying a current data block corresponding to the occurrence of the data block modification period, wherein the selected playback rate SPR is no more than twice a normal playback rate NPR, and wherein the modifying the current data block corresponding to the occurrence of the data block modification period, comprises; if a ratio of the SPR to the NPR is greater than 1.0, cross-fading the current data block with a next data block in the data stream; and if a ratio of the SPR to the NPR is less than 1.0, then cross-fading the current data block with itself. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
-
-
15. Non-transitory computer readable medium including at least computer program code for playing back a data stream formed of data blocks at a selected playback rate SPR, the computer readable medium comprising:
-
computer code for determining a minimum frequency of data blocks for modification to achieve the selected playback rate SPR; computer code for computing a data block modification period based upon the minimum frequency; computer code for receiving the data stream; computer code for passing through data blocks of the received data stream until an occurrence of the data block modification period occurs; and computer code for modifying a current data block corresponding to the occurrence of the data block modification period, wherein the selected playback rate SPR is no more than twice a normal playback rate NPR, and wherein the computer code for modifying the current data block corresponding to the occurrence of the data block modification period, comprises; computer code for cross-fading the current data block with a next data block in the audio stream if a ratio of the SPR to the NPR is greater than 1.0; and computer code for cross-fading the current data block with itself if a ratio of the SPR to the NPR is less than 1.0. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification