-Web interface based work from BBC R&D TV
+HTML5TV
-http://open.bbc.co.uk/rad/demos/html5/rdtv/episode2/index.html
+This is my attempt to finish my masters degree. I'm just kidding :-)
-http://www.bbc.co.uk/blogs/rad/2009/08/html5.html
+Actually, in 1997 I had idea to have masters degree on topic of video
+delivery over Internet. I was few years too early to make it actually
+work, but now-days we have all components needed to create good video
+archive on the web.
+
+I envision this as combination of two parts:
+
+ * powerful video editing suite running locally with annotations
+ * good web interface with sync between slides and video
+
+
+SOURCE MATERIAL
+
+I have some of my presentations in video with slides, but I also have
+few of freely available presentations which would benefit from
+audio-video slide annotation. So you are assumed to have two files:
+
+ 1. video file in Ogg Theora format
+ 2. pdf file with slides of presentation
+ 3. create html file with meta-data
+
+All of this is stored under media in directory conference-lecture.
+
+If you have different file formats, go ahead and use ffmpeg2theora:
+
+ http://v2v.cc/~j/ffmpeg2theora/
+
+New Theora encoder 1.1 create videos that are better than anything I saw
+on the web, oggz tool has chop support, so extracting part of video is
+very easy and possible.
+
+When re-encoding video materials following command line gives more-or-less
+resonable video size while inserting keyframes for nice seek:
+
+ ffmpeg2theora -p padma --keyint 1 source_video.flv
+
+
+VIDEO EDITING
+
+I like mplayer, and lerning another set of tools to do video editing
+didn't make sense to me.
+
+It works on all platforms I'm interested in (including EeePC and
+PlayStation 3) and I know keyboard shortcuts for it.
+
+So, I used it over it's slave protocol which is described on
+
+ http://www.mplayerhq.hu/DOCS/tech/slave.txt
+
+and available locally as docs/slave.txt which I used to implement new keyboard
+commands:
+
+ dpavlin@t61p:~/t61p/html5tv$ grep -A10 'keyboard' bin/mplayer.pl
+
+ # XXX keyboard shortcuts
+
+ $1 eq 'c' ? repl
+ : $1 eq ',' ? add_subtitle
+ : $1 eq 'F1' ? prev_subtitle
+ : $1 eq 'F2' ? move_subtitle( -0.3 )
+ : $1 eq 'F3' ? move_subtitle( +0.3 )
+ : $1 eq 'F4' ? next_subtitle
+ : $1 eq 'F5' ? save_subtitles
+ : $1 eq 'F9' ? add_subtitle
+ : $1 eq 'F12' ? edit_subtitles
+ : warn "CUSTOM $1\n"
+ ;
+
+I used to work with semi-professional Sony U-matic video montage back in 1990
+and have grown to love it's workflow which doesn't force you to click
+all over the screen to do something useful.
+
+In fact, with this tool, I need 3-5 times more time to finish material,
+and with most video editing solutions available in open source,
+I needed at least 10-20 times more time to do anything useful.
+
+
+SUBTITLING
+
+I decided to store subtitles in array-of-arrays in yaml with simple structure
+of start,end,title. On every save, I need also to create .srt subtitle format
+for mplayer and json data for web interface.
+
+Effective subtitle editing requires preroll. This is feature from my U-matic days
+because scopes (U-matic video recorders with magnetic tape) couldn't speed up
+instantly, so they would rewind, and than start FEW SECONDS BEFORE your edit point.
+
+This was crucial concept for implementing the following workflow with mplayer:
+
+ 1. press i to record EDL point (start of subtitle)
+ 2. press i to end EDL (end of subtitle)
+ 3. press , to enter subtitle (usually you want to enter subtitle after end of sentence)
+ 4. mplayer will preroll 3 seconds before subtitle and review it
+ 5. continue subtitling, goto 1
+
+You can also use F9 to add subtitle (nicely located near i key) or F12 to enter vi
+and make bulk subtitle changes (remove empty subtitles and so on).
+
+SLIDES
+
+Subtitles are least common denominator for meta data which I want to preserve.
+However, to sync subtitles with slides, I have introduced magic syntax:
+
+ [42] slide title
+
+which triggers switch to slide 42.
+
+In presentations which are created using Takahashi method (lot of slides with
+transitions which follow speaker) you might use just add subtitle to mark
+transition to next slide.
+
+
+HTML5 WEB INTERFACE
+
+Web interface using HTML5 <video> tag based on work from BBC R&D TV
+
+ http://open.bbc.co.uk/rad/demos/html5/rdtv/episode2/index.html
+
+ http://www.bbc.co.uk/blogs/rad/2009/08/html5.html
+
+Which in turn is based on jCarousel from
+
+ http://sorgalla.com/projects/jcarousel/
+
+I removed most of nice design, added support for slides and made it
+scale to accomodate different resolutions of video materials.
+
+
+Additional media info (author, title, location, date) is kept in hcalendar.html
+using microformat which defines classes. For more info about hCalendar see
+
+ http://microformats.org/wiki/hcalendar-cheatsheet
+
+
+TRY IT OUT
+
+Create media/conference-title/www file with source urls for video and presentation
+
+ # install dependecies from Debian packages
+ $ sudo bin/install-debian.sh
+
+ $ cd media/conference-title
+ $ wget -nc -i www
+
+ # create metadata
+ $ vi hCalendar.html
+
+ # create presentation.pdf symlink from pdf file with slides
+ $ ln -s original-slides.pdf presentation.pdf
+
+ # annotate some material
+ $ ./bin/mplayer.pl media/conference-Title/video.ogv
+
+After adding first slide you will get visual overview of all slides
+which is useful when typing in slide markers [42] in subtitles.
+
+When slide reisze finish, you might want to open http://localhost/html5tv/www/_editing.html
+in Firefox (you will have to open it through http server!) and check final result.
+
+MULTI MONITOR SETUP
+
+I'm using awesome as window manager, and since HTML5TV uses xdotool to focus between terminal
+to enter subtitle and mplayer, it will switch to same virtual desktop on *both* monitors,
+so it's helpful to start ./bin/mplayer.pl on same virtual desktop at least with awesome.
projects / HTML5TV.git / blobdiff