Transcoding refers to the process to process an OSS input file according to specified parameters, and output the result to specified OSSfile. When submitting a transcodig task, note the following objects:
Specify an OSS input file.
Note: The Location of OSS must correspond to the region of MPS. For example, the oss-cn-hangzhou of OSScorresponds to the cn-hangzhou of MPS.
Several output objects can be specified for each transcoding task, which includes multiple parameters and subobjects. Three important parameters and subobjects are introduced as follows:
The output container type (file format). The video supports mp4, flv, ts, and m3u8, and the audio supports mp3 and mp4.
The output video parameter, for example, the codec format, bitrate, width, height, and frame rate.
The output audio parameter, for example, the audio codec forma, bitrate, channels, and samplerate.
Parameters specified through API have higher priority than parameters set by templates, and overwrite the corrosponding parameters set in the templates.
MPS provides Preset static templates.
Also, you can Custom transcoding template.
Each region provides an MPS queue. You can log on to the Media Processing cosole > Library > Settings > MPS queue to check.
The video in any format is transcoded to MP4 video file with the definition
720P(1280x720), and the audio and video parameters are set as follows:
H.264 coder is used, the bitrate is 1500Kbps, the width is 1280, the height is adaptive (to avoid the picture is scaled out of proportion due to a fixed height value), and the frame rate value is 25.
AAC encoder is used, the bit rate is 128Kbps, the channels are 2 and the samplerate is 44100.
The preset static template “MP4-fluent” is used: S00000001-200010, the video bitrate set in the template is 400Kbps, the audio bit rate is 64Kbps, and the width is 640 (The height is adaptive).
The API parameters overwrite the template parameters, therefore, in the output video, the bitrate is 1500Kbps, the width is 1280, the fram rate is 25, and in the output audio, the bitrate is 128Kps, the channels are 2, adn the samplerate is 44100.