The videofile format Windows PC uses WMA/WMV and AVI. The latest implementation of theWMV is Microsoft’s own version WMV 9 which is the first to support interlacedvideo, frame interpolation and non-square pixels. WMV 9 relates to the VC-1SMPTE standard as VC-1 contains coding tools for interlaced video sequences.
WMVuses certain supporting profiles such as SONAR 4, this includes severalprofiles for exporting WMV files. 1.2 Android Phone The videofile formats Android phones use are 3GPP(.3gp), MPEG-4(.mp4) and H.264. Thelatest standard of MPEG-4 is MPEG4-AVC, it covers all common video applicationsranging from mobile services to HDTV and HD video storage. The benefits ofH.
264 encoding is for recording, typically used for lossy compression anddistribution of video content. It is also capable supporting high resolutionssuch as 4K UHD. MPG4 uses over 20 profiles such as XP (Extended Profile) whichuses high compression. 1.3 Nexus 7 Tablet The videofile format that the Nexus 7 Tablet uses is H.264/MPEG-4. Unfortunately, videoformats such as AVI, MKV and FLV are not compatible with the Nexus 7.
Adisadvantage to the nexus 7 tablet is that DivX is not supported and an AVIfile must be converted to H.264 before it is playable also including MKV fileswhich need to be loaded in the Nexus 7 Video Converter Mac. 1.4 Compression of Video File Formats WMV is anoutput format that is used after a file has been compressed using WinAVI whichis a video compression software. 3GP file format is a multimedia containerwhich can be used on 3G mobiles as well as 2G and 4G mobiles as well. MP4 fileformats are compressed using H.
264 1.5 Comparison of Video File Formats WMV is awindows Video file compressed with one or more of Microsoft’s compressionformats. WMV stands for Windows Media Video and is aimed at devices supportedby windows such as mobiles, tablets and PC’s. It is generally used for internetstreaming applications and storing videos in Windows such as short animationsbut 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 requiresspecialised plugins and is generally only supported by Microsoft productsunlike MP4 which is universally supported and can use H.
264 codec which is thebest choice when compressing. MP4 has better video quality than WMV and costsmore 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 needto be converted to another format such as MP4 or .MOV. Another name for H.264and AVC (Advanced Video Coding, MPEG-4 Part 10) are known as an identical pairof standards maintained by different organisations also known as JVT (JointVideo Team).
It is also known as the ‘Successor’ of existing formats such asMPEG-2, MPEG-4 and DivX as it aims to offer similar video quality in half thefile size. The format was introduced in 2014 and is best suited for mobiledevices. DivX is like H.
264 because of the file compression, allowing it to bemore efficient and smaller file sizes but is different to H.264 because it isadding support of h.264 to bring seamless transition between video library andelectronic devices as well as other media player software.
1.6 Artefacts There aredifferent types of artefacts, each artefact causing different issues such asthe compression artefact, this is when noticeable distortion of media such asimages, audio and video is caused by lossy compression as it discards some ofthe data so that it decreases in size, so it can be stored and streamed. Anotherartefact used is the block boundary which is when low bitrates used incompression make block pixels visible in the media. This is called the Mosquitonoise dues to the fact that they resemble mosquitoes swarming around theobject. Another artefact is the Video artefact deduction, this is when blockboundaries can be reduced by applying a deblocking filter to the decoder outputas post-processing which deblocks the picture and is used as a referencepicture for motion compensation. The standards which specify the deblockingfilter are H.
264/AVC. 1.0 Audio File Formats 2.1 Windows PC The audiofile format Windows PC uses is WAV.
WAV stands for Waveform Audio Format. Thesefiles are not compressed and are a large file size but because the format isnot owned it is easy to open and edited using the appropriate software. 2.2 Android Phone The audiofile format Android phones use is MP3. MP3 stands for Moving Pictures ExpertsGroup, ‘3’ refers to Audio Layer 3. The format is to reduce the file size of anaudio track by permanently removing masked data such as sounds that are coveredup by other sounds.
2.3 Nexus 7 Tablet The audio file format the Nexus 7 Tablet uses is AAC. AAC stands forAdvanced Audio Coding and is the ‘Successor’ to the MP3. It offershigher-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 beenused for the platforms above are MP3, WAV and AAC. WAV was invented byMicrosoft and IBM for storing audio on PC’s. The newest version is WavesVersion 9 which features 64-bit support, faster scanning, faster loading andfaster processing with high performance plug in power.
AAC was invented by Sonyand Nokia in 1997 and is considered superior to the MP3. AAC uses bit ratesranging from 8 kbit/s up to a maximum of 320 kbit/s and sampling frequenciesranging from 8kHz to a maximum of 96 kHz. AAC supports up to 48 channels and iswidely accepted by iOS, Android and handheld gaming devices. MP3 uses bit ratesranging from 8 kbit/s to a maximum of 320 kbit/s and sampling frequenciesranging from 16 kHz to a maximum of 48 kHz.
The smaller file sizes mean fasterfile transferring and less space used but at the cost of a reduction in soundquality. WAV was also developed by Microsoft and is compatible with a varietyof software applications. WAV uses lossless compression format, this causesfiles to take up significant amount of space making the format more ideal forarchiving 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 uselossy compression, AAC generally achieves better sound quality than MP3 atsimilar 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 highbit rate is used such as 320 kbps which would make the file size 60% of thesize of a WAV file.
AAC files can only play on Apple products while MP3’s canbe played on any device. 2.5 Comparison of Audio File Formats WAV, MP3, AAC The Mp3 was developed by Moving Pictures Expert Group andthe initial release was in 1993. The standard sample rate for MP3 is 192 kbpsbut varies for different types of audio such as voice and different genres ofmusic. For audio recordings, 32 kbps the audio will sound flat but if thebitrate is at 64 kbps then it will sound nearly identical to the original.
2.6 Artefacts Dynamic range compression is an audio signal processingoperation that reduces the volume of loud sounds and amplifies quiet soundswhich reduces an audios signal’s dynamic range. Downward compression reducesloud sounds over a certain level while quiet sounds remain the same.
Upwardcompression increases the loudness of sounds over a certain level while loudsounds remain the same. This is done by using a compressor which is a hardwareunit or audio software. 2.0 Common Mobile Audio Video Applications 3.
1 Live Tv There aremany ways of watching live TV on a mobile. This can be by inserting a portableantenna into the mobile device which does not need internet connection or todownload apps such as BBC iPlayer, ITV Hub, TV Catch up and many more, theseapps require internet connection to use preferably 4G as connection speed willbe faster and more reliable for the app to run smoothly. Most phones andtablets support the portable antenna but when downloading apps, the apps mustbe able to be downloaded from Google or Apple store. 3.2 On Demand Media Services On DemandMedia provides are BBC iPlayer, My5 and the popular app being Mediaset OnDemand, these apps require internet connection to use. The difference betweenstreaming live tv and on demand tv is that when streaming live tv it is when avideo is taken from live tv and then broadcasted live over the internet but ondemand streaming is when the pre-recorded video is uploaded so viewers canwatch them as many times as they like 24/7. 3.3 Other Available Services TwitterPeriscope is an app that allows users to share and experience live videobroadcasts from a mobile phone.
To use the app must be downloaded to an IOS orAndroid device, then signing in to twitter. In the tabs it will show who iscurrently live out of the people you are following on Twitter as well as a listof broadcasts that you have watched during the past 24 hours. You can also joinlive public broadcasts around the world.
3.4 Streaming Media Streamingmedia is when video or audio content is sent in compressed form over theinternet and played immediately rather than being saved to a hard drive.Instead of waiting for the file to download it can be played instantly becausethe 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 populardevice that is easy to use, and it requires the internet to work. 3.5 Download and Play Streaming isused when referring to shared media. It an act of playing media on one devicewhile the media is saved on another. Streaming media allows you to watch andlisten to media as it goes on your device or media player.
While downloadablemedia is when a file is downloaded onto a computer or device to be able to playthe media. Downloadable media is when your device connects to the source of thefile being downloaded, then copies and saves it to your computer. 3.6 Media Casting Mediacasting comes in many forms, such as podcasting. Podcasting is another way ofsaying portable media, podcasts are digital media files mostly audio, which areproduced in a series. The files are distributed as an audio format but caninclude other file formats such as PDF and EPUB. RSS feeds support podcastingdistribution with automated delivery and syncing of textual content to portableaudio players. The benefits of using podcasts is that the content iscommunicated straight to the user and new podcasts will be automatically downloadedto the device as soon as they are available.
3.7 User Generated Content The way wegenerate media using services like younow.com and older services such asustream are reshaping the media landscape because it’s now easier to life-castto your social media followers or even build a legion of fans online. Havingthe technology at your fingertips is enticing. Online videoing is quicklybecoming the means to get information which affects businesses if they don’thave a video on their website as it deters viewers from reading the informationinstead of listening and watching through a video.
