mayank tiwari - Academia.edu (original) (raw)

Papers by mayank tiwari

IEEE Transactions on Image Processing, 2011

ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (... more ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (STR) frames are used for mo-tion estimation and compensation. In previous work, it was shown that the performance of video coding can be improved by pulsing the quality of LTR ...

IEEE Transactions on Image Processing, 2010

In dual frame video coding, one short-term reference frame and one long-term reference frame are ... more In dual frame video coding, one short-term reference frame and one long-term reference frame are available for motion compensation. In prior research, it was shown that overall video quality was improved by allocating bits unevenly among frames so as to periodically create a high-quality frame that could serve as the long-term reference frame for some time. We extend this work to a cognitive radio scenario where pulses of extra bandwidth can be rented by the second, but rental agreements can be cancelled on short notice if the legacy user of that spectrum returns. With a scalable video coder, this pulse of extra bandwidth can be used to improve the quality of the current frame being encoded, or of the past long term frame, or can be spent on future frames if the encoder has access to them in advance. We compare these various uses to explore the advantages of allocating some of the available bandwidth to past or future frames

We consider rate allocation for multiple video users sharing a constant bitrate channel. Previous... more We consider rate allocation for multiple video users sharing a constant bitrate channel. Previously, overall quality of multiple users was improved by exploiting relative complexity. Users with high complexity video benefit at the expense of video quality reduction for other users with simpler videos. The quality of all users can be improved by collectively allocating the bitrate which requires sharing video information with a central controller. In this paper, we present an informationally decentralized rate allocation for multiple users where a user only needs to inform its demand to an allocator based on its video complexity and bitrate price. Simulation results show that all users improve their quality by our pricing-based decentralized rate allocation method compared to their allocation when acting individually and the results are comparable to the centralized rate allocation.

Current methods for multiplexing video streams often rely on identifying the relative complexity ... more Current methods for multiplexing video streams often rely on identifying the relative complexity of the video streams to improve the combined overall quality. In such methods, not all the videos benefit from the multiplexing process. Typically, the quality of high motion videos is improved at the expense of reduction in the quality of low motion videos. In our approach, we use a competitive equilibrium allocation of bitrate to simultaneously improve the quality of all the video streams by finding trades between videos across time. The proposed method not only uses information about the differing complexity of the video streams at every moment but also the differing complexity of each stream over time.

We consider the transmission of multiple video source streams over a shared channel from a server... more We consider the transmission of multiple video source streams over a shared channel from a server. Using the rate-distortion curves and dual-frame video coding with high quality long-term reference (LTR) frames, we propose a method to reduce the sum of mean squared error for all the video streams. A simple motion activity detection algorithm was used to determine the amount of high quality given to the LTR frames. Using H.264/AVC, the results show considerable improvement over a baseline scheme where each video stream is provided with equal bitrate.

IEEE Transactions on Image Processing, 2010

IEEE Signal Processing Letters, 2008

Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) ... more Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) and a long-term reference (LTR) frame for motion compensation. In past work, LTR frames at regular intervals were assigned higher quality than the other frames to improve overall ...

IEEE Transactions on Image Processing, 2011

ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (... more ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (STR) frames are used for mo-tion estimation and compensation. In previous work, it was shown that the performance of video coding can be improved by pulsing the quality of LTR ...

IEEE Transactions on Image Processing, 2010

In dual frame video coding, one short-term reference frame and one long-term reference frame are ... more In dual frame video coding, one short-term reference frame and one long-term reference frame are available for motion compensation. In prior research, it was shown that overall video quality was improved by allocating bits unevenly among frames so as to periodically create a high-quality frame that could serve as the long-term reference frame for some time. We extend this work to a cognitive radio scenario where pulses of extra bandwidth can be rented by the second, but rental agreements can be cancelled on short notice if the legacy user of that spectrum returns. With a scalable video coder, this pulse of extra bandwidth can be used to improve the quality of the current frame being encoded, or of the past long term frame, or can be spent on future frames if the encoder has access to them in advance. We compare these various uses to explore the advantages of allocating some of the available bandwidth to past or future frames

We consider rate allocation for multiple video users sharing a constant bitrate channel. Previous... more We consider rate allocation for multiple video users sharing a constant bitrate channel. Previously, overall quality of multiple users was improved by exploiting relative complexity. Users with high complexity video benefit at the expense of video quality reduction for other users with simpler videos. The quality of all users can be improved by collectively allocating the bitrate which requires sharing video information with a central controller. In this paper, we present an informationally decentralized rate allocation for multiple users where a user only needs to inform its demand to an allocator based on its video complexity and bitrate price. Simulation results show that all users improve their quality by our pricing-based decentralized rate allocation method compared to their allocation when acting individually and the results are comparable to the centralized rate allocation.

Current methods for multiplexing video streams often rely on identifying the relative complexity ... more Current methods for multiplexing video streams often rely on identifying the relative complexity of the video streams to improve the combined overall quality. In such methods, not all the videos benefit from the multiplexing process. Typically, the quality of high motion videos is improved at the expense of reduction in the quality of low motion videos. In our approach, we use a competitive equilibrium allocation of bitrate to simultaneously improve the quality of all the video streams by finding trades between videos across time. The proposed method not only uses information about the differing complexity of the video streams at every moment but also the differing complexity of each stream over time.

We consider the transmission of multiple video source streams over a shared channel from a server... more We consider the transmission of multiple video source streams over a shared channel from a server. Using the rate-distortion curves and dual-frame video coding with high quality long-term reference (LTR) frames, we propose a method to reduce the sum of mean squared error for all the video streams. A simple motion activity detection algorithm was used to determine the amount of high quality given to the LTR frames. Using H.264/AVC, the results show considerable improvement over a baseline scheme where each video stream is provided with equal bitrate.

IEEE Transactions on Image Processing, 2010

IEEE Signal Processing Letters, 2008

Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) ... more Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) and a long-term reference (LTR) frame for motion compensation. In past work, LTR frames at regular intervals were assigned higher quality than the other frames to improve overall ...

IEEE Transactions on Image Processing, 2011

ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (... more ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (STR) frames are used for mo-tion estimation and compensation. In previous work, it was shown that the performance of video coding can be improved by pulsing the quality of LTR ...

IEEE Transactions on Image Processing, 2010

In dual frame video coding, one short-term reference frame and one long-term reference frame are ... more In dual frame video coding, one short-term reference frame and one long-term reference frame are available for motion compensation. In prior research, it was shown that overall video quality was improved by allocating bits unevenly among frames so as to periodically create a high-quality frame that could serve as the long-term reference frame for some time. We extend this work to a cognitive radio scenario where pulses of extra bandwidth can be rented by the second, but rental agreements can be cancelled on short notice if the legacy user of that spectrum returns. With a scalable video coder, this pulse of extra bandwidth can be used to improve the quality of the current frame being encoded, or of the past long term frame, or can be spent on future frames if the encoder has access to them in advance. We compare these various uses to explore the advantages of allocating some of the available bandwidth to past or future frames

We consider rate allocation for multiple video users sharing a constant bitrate channel. Previous... more We consider rate allocation for multiple video users sharing a constant bitrate channel. Previously, overall quality of multiple users was improved by exploiting relative complexity. Users with high complexity video benefit at the expense of video quality reduction for other users with simpler videos. The quality of all users can be improved by collectively allocating the bitrate which requires sharing video information with a central controller. In this paper, we present an informationally decentralized rate allocation for multiple users where a user only needs to inform its demand to an allocator based on its video complexity and bitrate price. Simulation results show that all users improve their quality by our pricing-based decentralized rate allocation method compared to their allocation when acting individually and the results are comparable to the centralized rate allocation.

Current methods for multiplexing video streams often rely on identifying the relative complexity ... more Current methods for multiplexing video streams often rely on identifying the relative complexity of the video streams to improve the combined overall quality. In such methods, not all the videos benefit from the multiplexing process. Typically, the quality of high motion videos is improved at the expense of reduction in the quality of low motion videos. In our approach, we use a competitive equilibrium allocation of bitrate to simultaneously improve the quality of all the video streams by finding trades between videos across time. The proposed method not only uses information about the differing complexity of the video streams at every moment but also the differing complexity of each stream over time.

We consider the transmission of multiple video source streams over a shared channel from a server... more We consider the transmission of multiple video source streams over a shared channel from a server. Using the rate-distortion curves and dual-frame video coding with high quality long-term reference (LTR) frames, we propose a method to reduce the sum of mean squared error for all the video streams. A simple motion activity detection algorithm was used to determine the amount of high quality given to the LTR frames. Using H.264/AVC, the results show considerable improvement over a baseline scheme where each video stream is provided with equal bitrate.

IEEE Transactions on Image Processing, 2010

IEEE Signal Processing Letters, 2008

Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) ... more Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) and a long-term reference (LTR) frame for motion compensation. In past work, LTR frames at regular intervals were assigned higher quality than the other frames to improve overall ...

IEEE Transactions on Image Processing, 2011

ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (... more ABSTRACT In dual-frame video coding, one long-term reference (LTR) and one short-term reference (STR) frames are used for mo-tion estimation and compensation. In previous work, it was shown that the performance of video coding can be improved by pulsing the quality of LTR ...

IEEE Transactions on Image Processing, 2010

In dual frame video coding, one short-term reference frame and one long-term reference frame are ... more In dual frame video coding, one short-term reference frame and one long-term reference frame are available for motion compensation. In prior research, it was shown that overall video quality was improved by allocating bits unevenly among frames so as to periodically create a high-quality frame that could serve as the long-term reference frame for some time. We extend this work to a cognitive radio scenario where pulses of extra bandwidth can be rented by the second, but rental agreements can be cancelled on short notice if the legacy user of that spectrum returns. With a scalable video coder, this pulse of extra bandwidth can be used to improve the quality of the current frame being encoded, or of the past long term frame, or can be spent on future frames if the encoder has access to them in advance. We compare these various uses to explore the advantages of allocating some of the available bandwidth to past or future frames

We consider rate allocation for multiple video users sharing a constant bitrate channel. Previous... more We consider rate allocation for multiple video users sharing a constant bitrate channel. Previously, overall quality of multiple users was improved by exploiting relative complexity. Users with high complexity video benefit at the expense of video quality reduction for other users with simpler videos. The quality of all users can be improved by collectively allocating the bitrate which requires sharing video information with a central controller. In this paper, we present an informationally decentralized rate allocation for multiple users where a user only needs to inform its demand to an allocator based on its video complexity and bitrate price. Simulation results show that all users improve their quality by our pricing-based decentralized rate allocation method compared to their allocation when acting individually and the results are comparable to the centralized rate allocation.

Current methods for multiplexing video streams often rely on identifying the relative complexity ... more Current methods for multiplexing video streams often rely on identifying the relative complexity of the video streams to improve the combined overall quality. In such methods, not all the videos benefit from the multiplexing process. Typically, the quality of high motion videos is improved at the expense of reduction in the quality of low motion videos. In our approach, we use a competitive equilibrium allocation of bitrate to simultaneously improve the quality of all the video streams by finding trades between videos across time. The proposed method not only uses information about the differing complexity of the video streams at every moment but also the differing complexity of each stream over time.

We consider the transmission of multiple video source streams over a shared channel from a server... more We consider the transmission of multiple video source streams over a shared channel from a server. Using the rate-distortion curves and dual-frame video coding with high quality long-term reference (LTR) frames, we propose a method to reduce the sum of mean squared error for all the video streams. A simple motion activity detection algorithm was used to determine the amount of high quality given to the LTR frames. Using H.264/AVC, the results show considerable improvement over a baseline scheme where each video stream is provided with equal bitrate.

IEEE Transactions on Image Processing, 2010

IEEE Signal Processing Letters, 2008

Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) ... more Abstract—In dual-frame video coding, both encoder and decoder store a short-term reference (STR) and a long-term reference (LTR) frame for motion compensation. In past work, LTR frames at regular intervals were assigned higher quality than the other frames to improve overall ...