file format Windows PC uses WMA/WMV and AVI. The latest implementation of the
WMV is Microsoft’s own version WMV 9 which is the first to support interlaced
video, frame interpolation and non-square pixels. WMV 9 relates to the VC-1
SMPTE standard as VC-1 contains coding tools for interlaced video sequences. WMV
uses certain supporting profiles such as SONAR 4, this includes several
profiles for exporting WMV files.
1.2 Android Phone
file formats Android phones use are 3GPP(.3gp), MPEG-4(.mp4) and H.264. The
latest standard of MPEG-4 is MPEG4-AVC, it covers all common video applications
ranging from mobile services to HDTV and HD video storage. The benefits of
H.264 encoding is for recording, typically used for lossy compression and
distribution of video content. It is also capable supporting high resolutions
such as 4K UHD. MPG4 uses over 20 profiles such as XP (Extended Profile) which
uses high compression.
1.3 Nexus 7 Tablet
file format that the Nexus 7 Tablet uses is H.264/MPEG-4. Unfortunately, video
formats such as AVI, MKV and FLV are not compatible with the Nexus 7. A
disadvantage to the nexus 7 tablet is that DivX is not supported and an AVI
file must be converted to H.264 before it is playable also including MKV files
which need to be loaded in the Nexus 7 Video Converter Mac.
1.4 Compression of Video File Formats
WMV is an
output format that is used after a file has been compressed using WinAVI which
is a video compression software. 3GP file format is a multimedia container
which can be used on 3G mobiles as well as 2G and 4G mobiles as well.
formats are compressed using H.264
1.5 Comparison of Video File Formats
WMV is a
windows Video file compressed with one or more of Microsoft’s compression
formats. WMV stands for Windows Media Video and is aimed at devices supported
by windows such as mobiles, tablets and PC’s. It is generally used for internet
streaming applications and storing videos in Windows such as short animations
but has now gained physical delivery formats such as HD, DVD and Blu-ray Disc.
The bitrates used within WMV to that used for MP4 bitrate is that WMV requires
specialised plugins and is generally only supported by Microsoft products
unlike MP4 which is universally supported and can use H.264 codec which is the
best choice when compressing. MP4 has better video quality than WMV and costs
more system resources when editing although WMV is smaller in size than an MP4.
Disadvantages to WMV on a non-windows platform means that the files will need
to be converted to another format such as MP4 or .MOV. Another name for H.264
and AVC (Advanced Video Coding, MPEG-4 Part 10) are known as an identical pair
of standards maintained by different organisations also known as JVT (Joint
Video Team). It is also known as the ‘Successor’ of existing formats such as
MPEG-2, MPEG-4 and DivX as it aims to offer similar video quality in half the
file size. The format was introduced in 2014 and is best suited for mobile
devices. DivX is like H.264 because of the file compression, allowing it to be
more efficient and smaller file sizes but is different to H.264 because it is
adding support of h.264 to bring seamless transition between video library and
electronic devices as well as other media player software.
different types of artefacts, each artefact causing different issues such as
the compression artefact, this is when noticeable distortion of media such as
images, audio and video is caused by lossy compression as it discards some of
the data so that it decreases in size, so it can be stored and streamed. Another
artefact used is the block boundary which is when low bitrates used in
compression make block pixels visible in the media. This is called the Mosquito
noise dues to the fact that they resemble mosquitoes swarming around the
object. Another artefact is the Video artefact deduction, this is when block
boundaries can be reduced by applying a deblocking filter to the decoder output
as post-processing which deblocks the picture and is used as a reference
picture for motion compensation. The standards which specify the deblocking
filter are H.264/AVC.
1.0 Audio File Formats
2.1 Windows PC
file format Windows PC uses is WAV. WAV stands for Waveform Audio Format. These
files are not compressed and are a large file size but because the format is
not owned it is easy to open and edited using the appropriate software.
2.2 Android Phone
file format Android phones use is MP3. MP3 stands for Moving Pictures Experts
Group, ‘3’ refers to Audio Layer 3. The format is to reduce the file size of an
audio track by permanently removing masked data such as sounds that are covered
up by other sounds.
2.3 Nexus 7 Tablet
The audio file format the Nexus 7 Tablet uses is AAC. AAC stands for
Advanced Audio Coding and is the ‘Successor’ to the MP3. It offers
higher-quality sound while using the same amount of space or less.
2.4 Compression of Audio Information
MP3 uses lossy data compression to discard partial data,
this allows a large reduction in file size. The file formats that have been
used for the platforms above are MP3, WAV and AAC. WAV was invented by
Microsoft and IBM for storing audio on PC’s. The newest version is Waves
Version 9 which features 64-bit support, faster scanning, faster loading and
faster processing with high performance plug in power. AAC was invented by Sony
and Nokia in 1997 and is considered superior to the MP3. AAC uses bit rates
ranging from 8 kbit/s up to a maximum of 320 kbit/s and sampling frequencies
ranging from 8kHz to a maximum of 96 kHz. AAC supports up to 48 channels and is
widely accepted by iOS, Android and handheld gaming devices. MP3 uses bit rates
ranging from 8 kbit/s to a maximum of 320 kbit/s and sampling frequencies
ranging from 16 kHz to a maximum of 48 kHz. The smaller file sizes mean faster
file transferring and less space used but at the cost of a reduction in sound
quality. WAV was also developed by Microsoft and is compatible with a variety
of software applications. WAV uses lossless compression format, this causes
files to take up significant amount of space making the format more ideal for
archiving and audio editing. WAV files are similar to PCM and AIFF audio files.
The difference between AAC and MP3 is that even though both file formats use
lossy compression, AAC generally achieves better sound quality than MP3 at
similar bit rates which is more obvious at lower bitrates. When comparing WAV,
MP3 and ACC the best file format for casual listening would be MP3 when a high
bit rate is used such as 320 kbps which would make the file size 60% of the
size of a WAV file. AAC files can only play on Apple products while MP3’s can
be played on any device.
2.5 Comparison of Audio File Formats
WAV, MP3, AAC
The Mp3 was developed by Moving Pictures Expert Group and
the initial release was in 1993. The standard sample rate for MP3 is 192 kbps
but varies for different types of audio such as voice and different genres of
music. For audio recordings, 32 kbps the audio will sound flat but if the
bitrate is at 64 kbps then it will sound nearly identical to the original.
Dynamic range compression is an audio signal processing
operation that reduces the volume of loud sounds and amplifies quiet sounds
which reduces an audios signal’s dynamic range. Downward compression reduces
loud sounds over a certain level while quiet sounds remain the same. Upward
compression increases the loudness of sounds over a certain level while loud
sounds remain the same. This is done by using a compressor which is a hardware
unit or audio software.
2.0 Common Mobile Audio Video Applications
3.1 Live Tv
many ways of watching live TV on a mobile. This can be by inserting a portable
antenna into the mobile device which does not need internet connection or to
download apps such as BBC iPlayer, ITV Hub, TV Catch up and many more, these
apps require internet connection to use preferably 4G as connection speed will
be faster and more reliable for the app to run smoothly. Most phones and
tablets support the portable antenna but when downloading apps, the apps must
be able to be downloaded from Google or Apple store.
3.2 On Demand Media
Services On Demand
Media provides are BBC iPlayer, My5 and the popular app being Mediaset On
Demand, these apps require internet connection to use. The difference between
streaming live tv and on demand tv is that when streaming live tv it is when a
video is taken from live tv and then broadcasted live over the internet but on
demand streaming is when the pre-recorded video is uploaded so viewers can
watch them as many times as they like 24/7.
3.3 Other Available Services
Periscope is an app that allows users to share and experience live video
broadcasts from a mobile phone. To use the app must be downloaded to an IOS or
Android device, then signing in to twitter. In the tabs it will show who is
currently live out of the people you are following on Twitter as well as a list
of broadcasts that you have watched during the past 24 hours. You can also join
live public broadcasts around the world.
3.4 Streaming Media
media is when video or audio content is sent in compressed form over the
internet and played immediately rather than being saved to a hard drive.
Instead of waiting for the file to download it can be played instantly because
the media is sent is a continuous stream of data, so it plays as it arrives.
Anyone who wants to stream media can get the Chromecast which is a popular
device that is easy to use, and it requires the internet to work.
3.5 Download and Play
used when referring to shared media. It an act of playing media on one device
while the media is saved on another. Streaming media allows you to watch and
listen to media as it goes on your device or media player. While downloadable
media is when a file is downloaded onto a computer or device to be able to play
the media. Downloadable media is when your device connects to the source of the
file being downloaded, then copies and saves it to your computer.
3.6 Media Casting
casting comes in many forms, such as podcasting. Podcasting is another way of
saying portable media, podcasts are digital media files mostly audio, which are
produced in a series. The files are distributed as an audio format but can
include other file formats such as PDF and EPUB. RSS feeds support podcasting
distribution with automated delivery and syncing of textual content to portable
audio players. The benefits of using podcasts is that the content is
communicated straight to the user and new podcasts will be automatically downloaded
to the device as soon as they are available.
3.7 User Generated Content
The way we
generate media using services like younow.com and older services such as
ustream are reshaping the media landscape because it’s now easier to life-cast
to your social media followers or even build a legion of fans online. Having
the technology at your fingertips is enticing. Online videoing is quickly
becoming the means to get information which affects businesses if they don’t
have a video on their website as it deters viewers from reading the information
instead of listening and watching through a video.