227865 2021-07-11 20:04:14 -0700 [MSE] SourceBuffer.appendState is only ever WaitingForSegment 2021-07-11 20:04:33 -0700 1 1 1 Unclassified WebKit Media WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 jean-yves.avenard webkit-unassigned webkit-bug-importer oldest_to_newest 1776248 0 jean-yves.avenard 2021-07-11 20:04:14 -0700 Per MSE spec, a source buffer has a parsing state attribute that can be of any 3 values: WAITING_FOR_SEGMENT, PARSING_INIT_SEGMENT, PARSING_MEDIA_SEGMENT https://w3c.github.io/media-source/#sourcebuffer-segment-parser-loop This internal state is used to safeguard incorrectly calling SourceBuffer.setAppendMode [1] or modifying SourceBuffer.timeStampOffset [2] while we're in the middle of processing a media segment and to throw an exception if we are. https://w3c.github.io/media-source/#dom-sourcebuffer-mode https://w3c.github.io/media-source/#dom-sourcebuffer-timestampoffset However, in the current code, SourceBuffer::m_appendState is only ever set to AppendStateType::WaitingForSegment The state value should be updated in the Segment Parser Loop that is handled by SourceBufferPrivate but isn't. 1776249 1 webkit-bug-importer 2021-07-11 20:04:33 -0700 <rdar://problem/80445668>