Automatic estimation of latency for synchronization of recordings in vocal capture applications
View Patent ↗Latency on different devices (e.g., devices of differing brand, model, vintage, etc.) can vary significantly and tens of milliseconds can affect human perception of lagging and leading components of a performance. As a result, use of a uniform latency estimate across a wide variety of devices is unlikely to provide good results, and hand-estimating round-trip latency across a wide variety of devices is costly and would constantly need to be updated for new devices. Instead, a system has been developed for automatically estimating latency through audio subsystems using feedback recording and analysis of recorded audio.
1. A method comprising:
using a portable computing device for vocal performance capture, the portable computing device having a touch screen, a microphone interface and a communications interface;
estimating a round-trip latency through an audio subsystem of the portable computing device using feedback recording and analysis of recorded audio; and
based on the estimated round-trip latency through the audio system of the portable computing device, adjusting operations of the portable computing device to adapt timing, latency, and/or synchronization of the vocal performance captured at the portable computing device relative to a backing track or vocal accompaniment sounded at the portable computing device.
2. The method of claim 1 ,
wherein the round-trip latency estimate includes both input and output latencies through the audio subsystem of the portable computing device.
3. The method of claim 2 , wherein the input latency includes a latency to capture and process the vocal performance against the backing track or vocal accompaniment.
4. The method of claim 1 , wherein the feedback recording and analysis includes:
audibly transducing a series of pulses using a speaker of the portable computing device; and
recording the audibly transduced pulses using a microphone of the portable computing device.
5. The method of claim 4 , wherein the feedback recording and analysis further includes:
recovering pulses from the recording by identifying correlated peaks in the recording based on an expected period of the audibly transduced pulses.
6. The method of claim 1 , further comprising:
adapting operation of a vocal capture application deployment using the estimated round-trip latency.
7. The method of claim 6 ,
wherein the vocal capture application deployment is on the portable computing device.
8. The method of claim 6 ,
wherein the portable computing device is selected from the set of a mobile phone, a personal digital assistant, a laptop or notebook computer, a pad-type computer and a net book.
9. The method of claim 1 , further comprising:
accommodating varied audio processing capabilities of a collection of device platforms by estimating the round-trip latency through the audio subsystem of the portable computing device and through audio subsystems of other device platforms of the collection.
10. The method of claim 1 , further comprising:
based on the estimated round-trip latency through the audio system of the portable computing device, adjusting a preroll of the vocal performance captured at the portable computing device relative to the backing track or vocal accompaniment sounded at the portable computing device.
11. A portable computing device comprising:
at least one non-transitory memory;
a touch screen, a microphone interface, and a communications interface; and
one or more processors coupled to the at least one non-transitory memory and configured to read instructions from the at least one non-transitory memory to perform the steps of:
estimating a round-trip latency through an audio subsystem of the portable computing device using feedback recording and analysis of recorded audio;
capturing a vocal performance; and
based on the estimated round-trip latency through the audio system of the portable computing device, adjusting operations of the portable computing device to adapt timing, latency, and/or synchronization of the captured vocal performance relative to a backing track or vocal accompaniment sounded at the portable computing device.
12. The portable computing device of claim 11 , wherein the round-trip latency estimate includes both an input latency and an output latency through the audio subsystem of the portable computing device.
13. The portable computing device of claim 11 , wherein the feedback recording and analysis includes:
audibly transducing a series of pulses using a speaker of the portable computing device; and
recording the audibly transduced pulses using a microphone of the portable computing device.
14. The portable computing device of claim 13 , wherein the feedback recording and analysis further includes:
recovering pulses from the recording by identifying correlated peaks in the recording based on an expected period of the audibly transduced pulses.
15. The portable computing device of claim 11 , wherein the steps include:
adapting operation of a vocal capture application deployment using the estimated round-trip latency.
16. The portable computing device of claim 15 , wherein the vocal capture application deployment is on the portable computing device.
17. The portable computing device of claim 15 , wherein the portable computing device is selected from the set of a mobile phone, a personal digital assistant, a laptop or notebook computer, a pad-type computer and a net book.
18. The portable computing device of claim 11 , wherein the one or more processors are further configured to perform steps that include:
accommodating varied audio processing capabilities of a collection of device platforms by estimating the round-trip latency through the audio subsystem of the portable computing device and through audio subsystems of other device platforms of the collection.
19. The portable computing device of claim 11 , wherein the one or more processors are further configured to perform steps that include:
based on the estimated round-trip latency through the audio system of the portable computing device, adjusting a preroll of the captured vocal performance relative to the backing track or vocal accompaniment sounded at the portable computing device.
20. The portable computing device of claim 11 , wherein the input latency includes a latency to capture and process the vocal performance against the backing track or vocal accompaniment.