In this document you will learn about frequently asked questions about Encoding and Transcoding.For a complete description about Kaltura's Transcoding Services, see Kaltura Media Transcoding Services and Technology.
In addition to this article, you can also refer to best practices for Multi-Device Transcoding here.
[collapsed title="What is Transcoding?"]
When a video is uploaded to the KMC, the video is associated with a conversion profile, also known as a Transcoding Profile. A Transcoding profile may be comprised of a single flavor or multiple flavors. For each upload session, you can select the Transcoding Profile. You can also set a default Transcoding Profile. A transcode is made from taking an encoded piece of video and then converting it into one or more newly and more compressed streams that can then be played in a player on a computer or mobile device depending on the settings and methods used. Kaltura flavors are transcoded versions of an entry that are used to specify resolutions and formats. You can select to generate or add multiple flavors to an entry, including flavors geared towards displaying media on mobile devices (low bandwidth, small screens, and/or HTML5 supporting devices).
A flavor is a single output file with its specific file type, bit-rate, GOP size, that may be used for playback, download or editing. The Kaltura platform supports ingestion of all forms of rich media (including video, images, audio, PDF, SWF files, etc.), and allows you to define different transcoding profiles, depending on your publishing needs. Additional transcoding flavors can easily be added for publishing across different devices, network bandwidths and screen sizes. Kaltura's transcoding decision layer engine supports more than 60 video and image formats as well as 140 video and audio codecs. When you upload content you determine what type of flavors you want to associate with your output. There are three transcoding profiles that are automatically created for new accounts:
- Default - the flavors included in the default transcoding profile of the account These flavors appear in the main Transcoding Settings page.
- Source Only - uploads the source file, but does not transcode it; the source is the original file uploaded as is. Other flavors will not be created.
- All Flavors - transcodes uploaded files into all of the flavors defined in the main Transcoding Settings page.
[collapsed title="How to display the default flavors for transcoding your content?"]
To display the default flavors for transcoding your content:
- Select the Settings tab and then select Transcoding Settings. The Default Transcoding Profiles window is displayed which contains list of the Transcoding Profiles and Live Transcoding profiles. Each file uploaded to the system is transcoded into the flavors that are checked in the Transcoding Profile.
- Select a Transcoding Profile and go to the Flavors tab.
[collapsed title="How to edit transcoding profile?"]
Follow the steps here to edit transcoding profile.
[collapsed title="How to create a transcoding profile?"]
This guide describes how to create transcoding profiles. Click here.
[collapsed title="What are the editing profiles for flavors in a transcoding profile?"]
The following options may be edited for each transcoding flavor selected in a Transcoding Profile:
Impact on Entry Readiness –Determines the impact of each specific transcoding flavor on entry readiness for publishing. The options are:
- No impact
Click here to learn more.
[collapsed title="How to assign a transcoding profile to a bulk upload?"]
A default transcoding profile is included with the KMC. After you create a Transcoding Profile, an ID is created and listed in the Transcoding Profiles page.
To assign a transcoding profile other than the default profile, to a bulk upload
- Set the ID from the Transcoding Profiles to the conversionProfileId in your CSV.
- Set the ID from the Transcoding Profiles List to the conversionProfileId in your XML file.
[collapsed title="What are the best practices for Multi-Device Transcoding?"]
The challenge of streaming video is to find the right balance between bitrate and resolution as it relates to an end user’s connection speed and system ability. There are far too many variables that could interrupt playback for us to account for them all, at least as of the time of this writing. Here is a short list of potential stream killing variables:
- Device and Screen size
- Internet Service Provider Connection Speed or Cap
- Bandwidth available through the wireless router due to distance or usage
- Network traffic to and from the sever hosting the video
- The CPU and GPU abilities on the playing device
- Browser brand and version
- Available plugins such as Flash and Silverlight
- Other programs running in the background.
[collapsed title="How to use Flavors Tab?"]
The Flavors tab in the Edit Entry window allows you to manage the flavors that are available as well as replace media files and their transcoding flavors. Learn more.
[collapsed title="How do I ingest content recorded from webcam?"]
To upload media files recorded from a webcam
- Select the Upload tab.
- Click Record from Webcam.
- Select the Transcoding Profile and click Next. See Configuring Transcoding Profiles.
- Select a webcam from the dropdown list and click Allow.
- Press Record to record your media file.
- When done, click Next.
- Enter a Name and all other relevant information for the webcam recording and click Next.
The recording is processed and added to the Entries table.
[collapsed title="What are the supported transcoding formats for SaaS edition?"]
To learn more about the supported transcoding formats Click here.
[collapsed title="How is Trancoding Usage Measured?"]
Transcoding usage is defined as the volume in MB of transcoded assets, that are the output of transcoding. Transcoding usage is measured and billed one time per transcode, unlike Storage for example, which is measured and billed repeatedly per the consumed storage even if a new entry was not added.
[collapsed title="What are failed Transcoding jobs?"]
Failed transcoded jobs are not counted, even if the failure was due to a corrupted source file (which may have been uploaded by the user) or due to a Kaltura transcoding malfunction.
- A partner is uploading 10GB of source for transcoding.
- Transcoding is done on the 10GB and outputs with 7 flavors of total 25GB (including the source).
- Transcoding Usage will be 15GB (25GB - 10GB of source files)
A more complex example may be as follows:
- A partner is uploading 10GB of source for transcoding as well as 2GB of ready-made flavors (not for transcoding).
- Transcoding is done on the 10GB and outputs with 7 flavors. The total storage is 27GB.
- The partner then deletes 1GB of flavors.
- The total storage for this partner is 26GB.
- Transcoding Usage in this case is 15GB (27GB – 2GB – 10GB).
- All the deleted flavors and the ready-made flavors do not impact the transcoding usage.