| 1 | = Subjective Viewing = |
| 2 | |
| 3 | == Preparing material for subjective viewing == |
| 4 | |
| 5 | === Video data === |
| 6 | Please provide a directory per proposal or reference containing: |
| 7 | - decoded 8bit yuv files, using the naming convention of the original material on |
| 8 | the uni-hannover ftp site. Eg, "BQMall_832x480_60.yuv". |
| 9 | [[BR]] |
| 10 | This will allow scripts to automatically determine the display parameters. |
| 11 | |
| 12 | - if the same sequence at multiple QPs is to be tested, place video files in |
| 13 | directories called qpNN. |
| 14 | |
| 15 | - this data should be copied to {{{Z:\XXX\SomeUsefulIdentifierEgCE11}}} on the playout computer. |
| 16 | |
| 17 | - please avoid using spaces in file or directory names. |
| 18 | |
| 19 | For example, assuming two proposals, "REF" and "DUT" we should see the following: |
| 20 | {{{ |
| 21 | $ ls -R REF/ |
| 22 | REF/qp22/BQMall_832x480_60.yuv |
| 23 | REF/qp22/ParkScene_1920x1080_24.yuv |
| 24 | ... |
| 25 | REF/qp27/BQMall_832x480_60.yuv |
| 26 | REF/qp27/ParkScene_1920x1080_24.yuv |
| 27 | ... |
| 28 | |
| 29 | $ ls -R DUT/ |
| 30 | DUT/qp22/BQMall_832x480_60.yuv |
| 31 | DUT/qp22/ParkScene_1920x1080_24.yuv |
| 32 | ... |
| 33 | DUT/qp27/BQMall_832x480_60.yuv |
| 34 | DUT/qp27/ParkScene_1920x1080_24.yuv |
| 35 | ... |
| 36 | }}} |
| 37 | |
| 38 | === Preparing a playlist === |
| 39 | We have a script that will create a playlist in the correct form to do a randomized |
| 40 | A-B-A-B viewing. It requires an input file to list the sequences that are of interest |
| 41 | and the order in which to evaluate them: |
| 42 | |
| 43 | 1. Create a textfile that names the order you wish to view the test points. Eg, |
| 44 | {{{ |
| 45 | $ cat order.txt |
| 46 | qp22/BQMall_832x480_60.yuv |
| 47 | qp27/BQMall_832x480_60.yuv |
| 48 | ... |
| 49 | qp22/ParkScene_1920x1080_24.yuv |
| 50 | qp27/ParkScene_1920x1080_24.yuv |
| 51 | ... |
| 52 | }}} |
| 53 | Note the lack of any "DUT" or "REF" prefix. |
| 54 | 1. Run [[http://ftp.kw.bbc.co.uk/davidf/jctvc/gen-playlist-shuffled.pl|gen-playlist-shuffled.pl]] to generate a playlist: |
| 55 | [[BR]] |
| 56 | {{{ |
| 57 | $ gen-playlist-shuffled.pl /path/to/REF /path/to/DUT order.txt > out.plst |
| 58 | }}} |
| 59 | NB, the path given to REF and DUT should be fully qualified. |
| 60 | 1. For a subjective test with multiple viewing sessions, it is advisable to generate |
| 61 | multiple copies of the playlist, one for each viewing session. Each viewing session |
| 62 | is then randomized differently. |
| 63 | [[BR]] |
| 64 | For example, |
| 65 | {{{ |
| 66 | $ for N in 1 2 3 4 5 6; do |
| 67 | gen-playlist-shuffled.pl /path/to/REF /path/to/DUT order.txt > session$N.plst |
| 68 | done |
| 69 | }}} |
| 70 | |
| 71 | === Running the test === |
| 72 | Launch the [[http://ftp.kw.bbc.co.uk/davidf/videoplayer/|videoplayer]] using: |
| 73 | {{{ |
| 74 | $ /path/to/videoplayer --vt.readahead=128 --vdu-fps=60 --quit --full --osdstate=2 $ANYOPTIONS_IVE_MISSED out.plst |
| 75 | }}} |
| 76 | |
| 77 | The player will quit automatically when it reaches the end of the playlist. |
| 78 | |
| 79 | //DF: this could be made simpler if we create a small script and associate the .plst |
| 80 | file extension with it. Then people only have to double click on the correct playlist// |
| 81 | |
| 82 | == Notes on test configuration == |
| 83 | - The [[http://ftp.kw.bbc.co.uk/davidf/jctvc/gen-playlist-shuffled.pl|gen-playlist-shuffled.pl]] script |
| 84 | will produce an A-B-A-B stimulus, with A and B randomized for each test point. |
| 85 | [[BR]] |
| 86 | eg, for BQMall @ qp22, it might be REF-DUT-REF-DUT, but for qp27 it might be DUT-REF-DUT-REF. |
| 87 | |
| 88 | - If the test involves multiple proposals, an A-B-C-D-E-..Z-A-B-C-D-E-..Z stimulus can be generated |
| 89 | by providing multiple directories. The stimulus order for each test point is randomized. |
| 90 | Eg, {{{ gen-playlist-shuffled.pl REF DUT1 DUT2 DUT3 DUT4 order.txt }}} |
| 91 | [[BR]] |
| 92 | //DF: this seems kind of pointless, surely it should be A-A-B-B-C-C-D-D-E-E-...Z-Z, which is what we've done before// |
| 93 | |
| 94 | == Notes on black & white level == |
| 95 | By default, the videoplayer outputs R'G'B' at 16-235, however on a |
| 96 | computer monitor, this will look wrong. The following options will set |
| 97 | the output range to 0-255: {{{ --out-black=0 --out-range=256 }}} |
| 98 | |
| 99 | Alternatively, one can interactively toggle between the two to see the |
| 100 | difference by using the 'n' and 'b' keys. |
| 101 | |
| 102 | //DF: what range has the monitor been configured for? |