2011年5月31日星期二

Comparison of 3gpp, 3GPP2, 3GP and MP4

3gpp is for GSM phones, with the extension .3 gp. Third Generation Partnership Project (3rdGenerationPartnershipProject, ie 3GPP) is established in December 1998 of the standardization bodies. Its members now include Europe, ETSI, ARIB in Japan and the TTC, China, CCSA, TTA in Korea and North America ATIS. The goal of 3GPP is the ITU IMT-2000 within the scope of the development and global in nature (third generation) mobile phone system specification. Its commitment to GSM to UMTS (WCDMA) evolution of GSM to WCDMA air interface, although very different, but the GPRS core network using the framework, it remains continuity.

3GPP2 is for CDMA phones, with the extension .3 g2. Third Generation Partnership Project 2 (3rdGenerationPartnershipProject2, or 3GPP2) was established in December 1998, members include: TIA (North America), CCSA (China), ARIB / TTC (Japan) and TTA (South Korea). 3GPP2 committed to the ITU's IMT-2000 plan (3G) mobile phone system specification development in the world, in fact it's CDMAOne from 2G IS-95 or CDMA2000 standard system developed from the standardization bodies, it has been a number of key technology patents, Qualcomm CDMA's more support. 3GPP and 3GPP2 in fact there is a certain competition between the two, 3GPP2 committed to IS-95 (widely used in North America and South Korea's CDMA standard, is compatible with China Unicom CDMA) to 3G, and Qualcomm closer together.

3GPP corresponding commitment from the GSM to WCDMA (UMTS) transition, so the two bodies there is a certain competition. 3gp-how to make and market a number of plays 3GP files player installed Realplay smart phone can play rm file suffix, so that, in the smart phone in rm format video to see some nature is not difficult. However, smart phones are in the minority, most of the mobile phone does not support rm format video, to the realization of video playback on those phones, you must use a video format called 3GP. There are many mobile phones with camera functions, film are in fact out of the video file to 3GP suffix, such as the Nokia 6230, Motorola V600, and Alcatel.

3GP format video using MPEG-4 and H.263 encoding, and AAC or AMR audio standard is applied. H.263 is the International Telecommunication Union (ITU) video coding algorithm proposed standard. It is proposed in order to solve the narrow-band video conferencing video compression issues. The bandwidth is mainly for very low bit rate (less than 64Kbps). The high-bandwidth, high-quality video compression is not in the standard coverage. MPEG-4 of the main applications of the Internet and wireless transmission, interactive television, compared with other standards, MPEG-4 has the following advantages: 1) high compression rate: either with the same family of MPEG1 and MPEG2 video compression algorithm, compared or with the ITU's H.261, H.263 algorithm is compared, MPEG4 video data compression algorithm to rate the clear edge. This is effective in saving precious bandwidth video conferencing resources have a huge advantage. 2) The ability to adapt to different bandwidth: MPEG4 can be applied not only in the narrow band (bandwidth of less than 64Kbps), but also the flexibility to extend to high-quality, high-definition on broadband. This ensures that meet the needs of different users. Users according to their actual situation, set the appropriate bandwidth, so as to achieve the best effect of video conferencing.

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