Today I performed a benchmarking test with MediaCoder iPhone Edition which has got improved support for Intel MSDK recently, by transcoding the same 720p H.264 MKV file to a MP4 file of iPhone 4 profile. In order to obtain transcoded videos with near visual quality, x264 was set to fast preset and Intel MSDK encoder was set to balanced mode. The difference in transcoding speed and CPU utilization is significant. With x264, the CPU utilization is near 100% and the overall transcoding speed is approximately 3.4x (versus playback speed). When using Intel MSDK encoder, with computation off-loaded to CPU built-in GPU, the CPU utilization is near 50% and the overall speed is about 7.9x, which is 2.3 times of that of x264.
Tag Archive: H.264
MediaCoder 0.7.1 released – first free transcoder accelerated with NVIDIA CUDA technology (Stanley posted on June 8th, 2009 )
We are pleased to announce the release of the new version of MediaCoder 0.7.1. In this version, we start to make use of NVIDIA CUDA technology to accelerate H.264 encoding and video filtering.
A new encoder backend of “CUDA encoder” is added which can be chosen active on the Video tab.
Since 0.6.1.4135, MediaCoder has integrated the support for JM H.264 decoder and encoder. JM H.264 decoder is able to decode the H.264 streams generated by many HD camcorders correctly which other open-source H.264 decoders cannot. JM H.264 encoder is one of the three major open-source H.264 encoder implementations. It has very rich parameters and support most features of H.264. Some frequently used parameters have been added into MediaCoder while the rest of thundreds of paramters can be adjusted by loading a JM configuration file (by specifying the configuration file path at “Configuration File” option). A JM configuration file is a plain text file.
MediaCoder 0.6.1.4130 has be added with AVCHD support. AVCHD is the format used by most HD camcorder, like Sony HD camcorder. With following settings, MediaCoder can decode AVCHD correctly and encode to any supported target formats.
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The standard includes the following seven sets of capabilities, which are referred to as profiles, targeting specific classes of applications:
- Baseline Profile (BP): Primarily for lower-cost applications with limited computing resources, this profile is used widely in videoconferencing and mobile applications.
- Main Profile (MP): Originally intended as the mainstream consumer profile for broadcast and storage applications, the importance of this profile faded when the High profile was developed for those applications.
- Extended Profile (XP): Intended as the streaming video profile, this profile has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching.
- High Profile (HiP): The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (this is the profile adopted into HD DVD and Blu-ray Disc, for example).
- High 10 Profile (Hi10P): Going beyond today’s mainstream consumer product capabilities, this profile builds on top of the High Profile—adding support for up to 10 bits per sample of decoded picture precision.
- High 4:2:2 Profile (Hi422P): Primarily targeting professional applications that use interlaced video, this profile builds on top of the High 10 Profile—adding support for the 4:2:2 chroma subsampling format while using up to 10 bits per sample of decoded picture precision.
- High 4:4:4 Predictive Profile (Hi444PP): This profile builds on top of the High 4:2:2 Profile—supporting up to 4:4:4 chroma sampling, up to 14 bits per sample, and additionally supporting efficient lossless region coding and the coding of each picture as three separate color planes.
The x264 profile option changes to the encoder settings to let the encoded bit stream comforted to specified H.264 profile (baseline, main, high).