In the AV streaming test portal, IRT continuously offers new audio and video streams with different media encoding profiles for PCs, smartphones, tablet PCs and HbbTV devices. A uniform interface provides progressive downloads or adaptive versions for MPEG-DASH, Apple HLS, fragmented MP4 or CMAF in different encodings (AV1, VP9, H.264, H.265, HE/AAC, E/AC3), container formats (MP4, MPEG-TS) and resolutions (SDTV, HDTV, UHD/2180p , 576i, 720p, 1080i, 1080p, 50Hz...) as well as page formats (16:9, 1:1, 9:16) and various color variants (HDR, SDR, HLG10, PQ10, SDR10) without access barriers for download and offline use.
This makes it easy for broadcasters, manufacturers, service providers and interested users to test the playback capabilities of their networked terminals with different AV encodings. All encoding parameters can be viewed and compared. The same elementary data streams for audio and video can be retrieved in different container formats individually as well as in adaptive video sets and audio sets, so that the reproduction capabilities of both transport variants can be tested on the same terminal. In addition, a selection of several web-based media players, including the ARD player used in ARD, is offered to evaluate the interoperability in the respective browser.
Special test sequences allow a simple visual check of important criteria such as safe area, frame rate, interlaced modes, time code, overscan, audio channel assignment, etc. for the present transmission chain. The streams presented here reflect, among other things, the coding specifications of the media libraries valid for ARD. Since the tests are continuously updated and the available parameter profiles exceed the capabilities of many end devices, failed playback attempts should also be regarded as test results.
The following freeware is used for encoding most test cases: GPAC MP4box, VideoLAN x264, ffmpeg, x265, DASH.js, MediaInfo, BITMOVIN and video.js. On the occasion of the cooperation with GPAQ an HbbTV 1.5 compliant segmentation for MPEG-DASH in MP4box is available. For all streams created with open source software, the complete log files can be viewed and the complete executable command line can be taken. This ensures complete transparency of all test streams and unrestricted verifiability of the entire workflow.