The HRCs will be selected separately by the ILG. While audio will not be used in the present tests, the audio tracks on source sequences should be retained wherever possible in both source and processed video clips (SRCs and PVSs) for use in future tests. In cases where IP is involved in the HRC, transport streams should be saved and Ethereal dumps should be captured and stored whenever possible.
7.1.1. Format Conversions
A PVS must be the same scale, resolution, and format as the original. An HRC can include transformations such as 1080i to 720p 1080i as long as one pixel of video is displayed as one pixel native display. No up-sampling or down-sampling of the video image is allowed in the final PVS.
Thus, it is not allowable to show 720p footage that is “windowed” in a 1280 x 720 region of a 1080 video.
7.1.2. PVS Duration
All SRCs and PVSs to be used in testing will be 10 seconds long. SRC may be longer and trimmed to length before testing.
7.2. Constraints on Hypothetical Reference Circuits (HRCs)
HRCs in one experiment may be the same or different from HRCs in other experiments. The HDTV group will determine an equitable way to aggregate models’ performances across different kinds of HRCs.
The overall selection of the HRCs should be done such that most, but not necessarily all, of the codecs, bit rates, encoding modes and impairments set out in the following sections are represented.
The encoding modes that will be used may include, but are not limited to:
Constant-bit-rate encoding (CBR)
(option) Variable-bit-rate encoding (VBR)
7.2.4. Frame rates
For those codecs that only offer automatically-set frame rate, this rate will be decided by the codec. Some codecs will have options to set the frame rate either automatically or manually. For those codecs that have options for manually setting the frame rate, and should an HRC require a manually set frame rate, the minimum frame rate used will be 24 fps.
Manually set frame rates (new-frame refresh rate) may include:
The VQEG will recommend methods of objective video quality testing methodology for 3D TV The SDOs involved (e.g., ITU-T SG 12, ITU-T SG 9, and ITU-R SG 6) will make the final decision(s) on ITU Recommendations.
Annex I - Method for Post-Experiment Screening of Subjects
A statistical criterion for rejecting a subject’s data is that it correlates with the average of the other subjects’ data no better than chance. The linear Pearson correlation coefficient per PVS for one viewer vs. all viewers is defined as:
xi = MOS of all viewers per PVS
yi = individual score of one viewer for the corresponding PVS