Tag: mp4

Legacy Filters, Modern Solutions: MP4 Support in DirectShow

Microsoft #DirectShow API was introduced long before the widespread adoption of MPEG-4. As MPEG-4 codecs and container formats became standard, DirectShow was, by Microsoft’s own admission, nearing the end of its life.

That’s how this once-popular media framework for Windows found itself without support for MP4 files. Fortunately, there was a handy solution: freely available filters https://gdcl.co.uk/mpeg4/ developed by Geraint Davies. Originally published in 2006, these filters gained popularity over time. Since Geraint had other commitments after the last update, we took the liberty of placing a copy of his work on GitHub https://lnkd.in/dPsZEfpE somewhere around 2015.

Despite the state of DirectShow, these filters still play a role in DirectShow applications. We’ve even made a few updates ourselves — a little bit of everything: a unit test project, some modern C++ and #COM code based on Microsoft WIL https://lnkd.in/de5nxif, a COM type library with an integration interface, and various features. One particularly valuable addition is the ability to recover broken recordings.

You see, sometimes applications crash — whether due to external factors or just plain bad luck. And sometimes the cost of “re-doing things right” is too high. Oh, and the cost of data loss is high too! In such cases, we can salvage the broken recording from the crashed application and recover its content. It’s like a digital rescue mission. And in some instances, it’s even automated — like in our partner’s medical software https://lnkd.in/dCrJJRjy, where multi-hour recordings are the norm these days.

Microsoft Media Foundation and HoloLens: Enabling Real-Time Video Communication

A customer approached us with a specific request: they needed a code snippet that could compress video into the H.264/AVC video format. Additionally, they were developing an application for the hashtag#Microsoft hashtag#HoloLens, which was the previous generation of hashtag#mixedreality headsets.

Upon closer examination, we realized that the purpose was to enable video encoding and decoding in a hashtag#lowlatency, hashtag#realtime, multi-party video conferencing application. The challenge lay in achieving this on low-powered hardware with its unique platform and limitations.

The HoloLens utilizes the Microsoft UWP platform, which typically allows developers to avoid rewriting software for different platform devices. However, in this particular case, adaptation was necessary. The only viable approach for handling real-time video was to leverage hardware-assisted video encoding and decoding through Microsoft Media Foundation.

These devices come equipped with specialized GPUs that share similarities with traditional desktop graphics adapters but also have their own distinct characteristics. Essentially, we developed a subsystem specifically tailored for Microsoft HoloLens 1, enabling real-time video capture, compression, decompression, seamless camera integration, hashtag#unity3d integration, and audio hardware support.

Support for FLAC in ISO BMFF with MSE in StreamingServer application

Chrome platform supports FLAC encoding in ISO BMFF (fragmented MP4) media since version 62 (October 2017), however the support for FLAC (and Opus) overall did not become standard and comprehensive since then. I hooked up Microsoft FLAC Audio Encoder MFT into media streaming application to produce media and check browser compatibility. /audio.mp4?flac – produces FLAC…

Read the full article