How to do quick user assign in kanban in Odoo 17 ERP
App Design for Business: Video, Audio Compression & Recording
1. App Design for Business
Topic: Video and Sound
Topic Number: 8
2. Key topics / learning outcomes
of this lecture
• Learn about video, compression and
file size
• Learn about digital audio, sample
rate and open source software for
recording
2
3. Video for Android
• What is a video?
– a series of images that display in sequence to create
movement in time with the real world;
– images are called ‘frames’ in video;
• How many images make a video?
– a motion picture film will typically have 24 frames
display every one second;
– early silent films had frame rates between 26 – 24
frames per second;
• cameras were manually managed by turning a wheel holding
the film, so the camera manager could slow the frame rate
down, to match the film mood!
4. Importance of frame rate
• 48 fps is currently being trialled in the film
industry:
– this will reduce flicker;
– this will reduce motion blur
• motion blur occurs when images being filmed move faster in
the real world than the frame rate being captured;
• 300 fps has been tested by BBC research for use
in sports broadcasts:
– 300 fps can be converted to both 50 and 60 fps
transmission formats without major issues
B4004A L1 4
6. In photoshop, inspect the element
Image size:
850.8K
Width 710 px
Height 409 px
B4004A L1 6
7. Image compression
• This image was possibly originally around 3MB
when it was first taken;
• It has been compressed to achieve an image size
of 850.8KB:
– this is still quite a high KB size, it could be reduced a
lot further, making transmission faster as there are
less bits;
– the image could be compressed further, by running
further jpeg (or other) compression algorithms on the
content to reduce the size;
– the image can be made physically smaller, this will
reduce the file size also;
B4004A L1 7
8. Video Compression
Year Standard Publisher Popular Implementations
1984 H.120 ITU-T
1988 H.261 ITU-T Videoconferencing, Videotelephony
1993 MPEG-1 Part 2 ISO, IEC Video-CD
1995 H.262/MPEG-2 Part 2 ISO, IEC, ITU-T
DVD Video, Blu-ray, Digital Video
Broadcasting, SVCD
1996 H.263 ITU-T
Videoconferencing, Videotelephony, Video on
Mobile Phones (3GP)
1999 MPEG-4 Part 2 ISO, IEC Video on Internet (DivX, Xvid ...)
2003 H.264/MPEG-4 AVC
Sony, Panasonic, Sam
sung,ISO, IEC, ITU-T
Blu-ray, HD DVD Digital Video
Broadcasting,iPod Video, Apple TV,
2009 VC-2 (Dirac) SMPTE Video on Internet, HDTV broadcast, UHDTV
2013 H.265 ISO, IEC, ITU-T
B4004A L1 8
10. Video - Flash Player
• There is no longer support for Flash Player as
it is very processor consumptive and drains
battery.
• Avoid designing with Flash until the issues are
resolved.
B4004A L1 10
11. Tips to reduce video file size
• Keep the video short in terms of time;
• Keep the video camera completely still where
possible, when actually filming content
– compression will be more efficient if the background
of the subject remains still;
• Reduce the physical size of the video before
filming, whilst keeping the aspect ratio
• Run the video through a good quality and
appropriate compression technique.
B4004A L1 11
12. Embed Video within Android App
• Put the final video into the app resources, the
res/raw folder.
• use Java to code
or
• use the YouTube
Player API
for Android
B4004A L1 12
13. … end of Video section…
… next is Audio …
B4004A L1 13
14. What is Audio
Audio used to be created by recording sound waves;
B4004A L1 14
Digital audio
takes those
sound waves
and reproduces
them digitally.
15. Sampling (signal processing)
• A sound wave is a continuous signal
• A sample refers to a set of values at a given
point
• this is one cycle;
• this = 1hz;
• this equals
1 hz per second;
B4004A L1 15
16. Sound Hz (Hertz)
• The more hertz, the different the sound,
known also as the pitch;
Voice Frequency
Male 85 – 180 Hz
Female 165 – 255 Hz
B4004A L1 16
17. Sample rate
• Sample rate for a CD is 44,100 samples from
the sound wave per second;
B4004A L1 17
18. Decibels (Loudness)
Noise Decibels
Whisper in quiet library at 6 feet 30dB
Normal conversation at 3 feet 60dB
Normal piano practice 70dB
Loud rock concert 115dB
Jet engine at 100 feet 140dB
Death of hearing tissue 180dB
Loudest sound possible 194dB
B4004A L1 18
19. Creating and recording sound
Copyright issues
• when using existing sounds, ensure there are
no copyright issues’
• generally, any music that was published 75
years ago becomes copyright free;
• a small sound loop of less than 3 seconds is
allowed to be made from published sound
which is not yet copyright free;
B4004A L1 19
20. Audacity
• well known open source software for sound
manipulation:
B4004A L1 20
21. Audacity setup
• Facility to
– connect a microphone (if required);
– set up an audio host and playback device;
– select input;
– make a test recording;
– edit the recording;
– save the recording in the appropriate file format;
B4004A L1 21
22. Using Audio with Android
Starting an Activity - request audio focus
B4004A L1 22
23. Essential work for next week
• Please consult the OLE for details of:
– Essential readings*
– Seminar/workshop preparation work*
– Recommended further readings
– Any additional learning
* Essential readings and preparation work must always be completed in time
for the next session
23
