Adaptive media playback (AMP) techniques dynamically adjust playback speed based on buffer conditions and network performance to reduce interruptions. Early work in 1996 introduced buffer-based smoothing to vary playback when buffers were full or empty. Later approaches in 2001 considered channel conditions, slowing playback during losses and speeding up during recoveries. Additional techniques estimated frame properties to selectively play frames most important for the viewer experience. Recent research focuses on optimizing buffer sizes and frame selection algorithms while accounting for packet-level transmission characteristics of high-definition video over specific network types like 802.11 wireless networks.

1. Adaptive Video Playback
Mohammed Sinky

2. Background
 Proposed concept falls under the general category of
“Adaptive Media Playback or (AMP)”
l
2l
AMP:
l ×s
/f

3. Historical Perspective
Adaptive Media Playout
(AMP) Content Adaptive
Optimal frame
VDoP [Laoutaris] selection
Laoutaris and
Yet another AMP
buffer design
algorithm
Video Smoothing First HD video
used for
evaluation
Motion based AMP

4. Video Smoother -1996
Playout buffer (size N)
Video frames playout of frames
Threshold
(TH)
Playout rate Time
controller
 If number of frames in playout buffer exceeds
TH, maximum playout rate (m) is employed.
 Otherwise smoother uses proportionally reduced rates to
eliminate playout pauses due to empty buffer.
[1] M. C. Yuang, S. T. Liang, Y. G. Chen, and C. L. Shen, “Dynamic video playout smoothing method for
multimedia applications,” in IEEE International Conference on Communications, 1996, vol. 3, pp. 1365–1369.

5. Video Smoother
 Metrics as TH increases (l: mean frame arrival rate)
p0: probability of empty buffer pL: frame loss probability

6. Video Smoother

7. Video Smoother
 hh

8. Adaptive Media Playout (AMP) - 2001
 Adaptive Media Playout: the adjustment of the playout
speed of the media packets depending on the condition
of the channel and the current client buffer fullness.
 Video playout based on channel conditions:
 Bad conditions: slow down playout, virtual increase in buffer
 Good conditions: following recovery of bad
conditions, playout is done faster than normal
[2] E. Steinbach, N. Farber, and B. Girod, “Adaptive playout for low latency video streaming,” in Image
Processing, 2001. Proceedings. 2001 International Conference on, 2001, vol. 1, pp. 962–965.

9. AMP
 Assumptions: Audio+Video frame fit into one packet
Lost packets:
retransmission requests are
sent from client to server
(application layer)

10. AMP
 Packet burst error and the arrival of retransmissions
 If a packet burst loss exceeds the maximum playout time,
we get buffer underflow: freeze video

11. AMP
 Two main criteria for evaluation
 Probability of buffer underflow
Average value of max burst length:
 Average end-to-end delay introduced by adaptive playout

12. AMP
 Metric: Mean Time Between Buffer Underflow (MTBBU)
s: slowdown factor
(s≥1)
f: speed-up factor
(f≤1)

13. Variance of Distortion of Playout
(VDoP) - 2001
 New metric to gage interruptions in video playback
 Extension of 1996 work done by Yuang which suffered
from an undesirable fast forward effect
[3] N. Laoutaris and I. Stavrakakis, “Adaptive playout strategies for packet video receivers with finite buffer
capacity,” in Communications, 2001. ICC 2001. IEEE International Conference on, 2001, vol. 3, pp. 969–973.

14. VDoP
 Some Results

15. Recent
 Take into consideration motion characteristics of frames
 Choosing specific frames (frame selection)
 Most work revolves around finding the optimum buffer
size, threshold and corresponding frame rate adjustment
in the context of AMP

16.  Many of the works consider the network to be a cloud
(possibly internet, LAN, etc.)
 We consider specific home network, ad hoc, 802.11 based
 Most deal with frames as a whole, and don’t get into details
of packetization
 We are relying on frames split across packets
 Assumptions are made on frame arrival rates
 In our scenario a more accurate estimation of frame arrival
rates can be considered
 HD video is not considered
 Our work is centralized around HD video