Training
Introducing the GPAC WebAssembly (WASM) Platform - Elevating Multimedia Streaming
Introducing the GPAC WebAssembly (WASM) Platform: Elevating Multimedia Streaming Are you ready to transform your multimedia streaming experience and learn more about GPAC? Following our insightful comparisons of open source packaging tools, we are excited to introduce the GPAC WebAssembly (WASM) Platform. At Motion Spell, our dedication to advancing streaming...
HLS posts updated to RFC8216-bis (revision 12)
HLS posts updated until revision 12 of RFC8216-bis Dear readers, We have updated our blog posts on HLS until draft revision 12 of the new RFC8216 "bis" draft: Apple HLS: introduction Apple HLS: comparing versions Apple HLS: technical in-depth The HLS specification itself is better structured. These documents are only...
An unexpected source of latency (part 2)
An unexpected source of latency (part 2) Part 1 is here. CPB Removal Delay What we see here is that the moment at which we *display* a picture doesn't necessarily correspond to the moment at which we *finish receiving* a picture. There's a variable delay between these two moments, depending...
An unexpected source of latency (part 1)
An unexpected source of latency (part 1) Introduction In digital video streaming, there's a source of latency which is rather subtle, although it's most often a major one. It's related to the way video compression works, and it cannot be mitigated by costly equipment. The setup Let's suppose a perfect...
Self-contained codecs considered harmful
Self-contained codecs considered harmful A stream of compressed video is composed of many successive top-level units of video. These units are, most of the time, considered atomic by encapsulators and muxers. In some codecs, like VP9, these top-level units represent a whole compressed picture. In some other codecs, like H.264...
Three sources of latency
Three sources of latency What is latency? Latency is the time elapsed between two events, which in a perfect world, would be simultaneous. In a live video streaming scenario, the latency is typically the time elapsed between the capture of a video frame, and this frame being displayed on the...
The perils of start codes
The perils of start codes In many video codecs, each top-level unit of video is prefixed with a predefined sequence of bytes, known as a "start code". This start code acts as a robust delimiter between top-level units. This sequence is generally 3 or 4 byte long. Its content is...
Guidelines on how to embed TTML in MP4 and DASH
Guidelines on how to embed TTML in MP4 and DASH Introduction After a discussion at IBC 2015 with our partners from BBC, IRT and EBU, we found that there was a lot of confusion when it came to distributing TTML content in ISOBMF/MP4, especially with MPEG-DASH. Practical use-cases include HbbTV...
HomerHEVC encoder and GPAC
HomerHEVC encoder and GPAC This is an invited article from Juan Casal of HomerHEVC. This article belongs the "GPAC industry use-cases" category which shows how industry actors use GPAC in their projects. Please click here to read the original version of this article. Creating HEVC videos in .mp4 and .ts...