RealAudio and RealVideo Technology Compatibility Kits


RealAudio and RealVideo Technology Compatibility Kits

The RealAudio/RealVideo Technology Compatibility Kits (TCKs) are documents which establish the criteria used to certify modified RealAudio and RealVideo implementations and ports to some hardware platforms or operating system.

Supported Codecs

Support for all codecs in the Helix Client is not required. However, the licensee must define what codecs are supported by their product prior to certification and codecs supported by the licensee technology must perform equal to or greater than the same codecs used by the Helix DNA Client.

A group of defined tests determines that the licensee technology supports the decoding of verification bitstreams and that the decoded output meets acceptable quality tolerances.

Verification Process

The process of verifying a decoder implementation or port is to compare the output of that decoder, using the verification bitstreams, to the reference decoded output.

In the case of RealVideo G2 and RealVideo 8, the reference decoded output is reconstructed prior to any post-filtering that may be included in the RealVideo G2 and RealVideo 8 decoder.

The verification process defined in the TCK uses the command line application associated with the codec you are attempting to verify. These command line applications are built within the Helix code module for that codec.

The following steps demonstrate how to compare the reference decoded output
to the tested decoded output.

  1. Acquire the reference bitstreams for the codec you are porting and run the command line decoder on these bitstream.
  2. Save the resulting file containing the reference decoded output (decoded raw frames).
  3. Run the reference bitstreams through the decoder to be tested and save the resulting file containing the tested decoded output (decoded raw frames).
  4. Use a utility, such as snrcomp.exe, to compare these two files.
  5. Ensure that difference measured are within the established criteria for that codec (see Section 4, below).

In order to successfully verify a decoder under test all of the reference bitstreams provided for that codec must pass the given criteria. Sometimes the target platform for the RealVideo implementation is unable to support playback of some or all of the reference bitstreams. This situation may occur if, for example, there is insufficient memory to decode certain frame sizes. In this circumstance, contact RealNetworks.

Reference bitstreams for all RealVideo codecs, along with reference decoded audio and video files, will be provided by RealNetworks. Software tools for measuring and analyzing raw audio and video files may be provided by RealNetworks to aid the verification process.

Under limited circumstances decoders that do not meet the above criteria may still pass decoder verification, at the discretion of RealNetworks.

Access to the TCK

Access to the RealAudio and RealVideo TCKs are limited to those that have signed the proper licenses, in particular, RCSL Attachment G-1.1. Once you have gone through the source code licensing process, you will be given access to the RealAudio/RealVideo TCK download area.

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