Subscribe to our Newsletter

Training

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...