Expand description
Reconstruct the H.264 picture order count (POC) from a bitstream.
The POC (ITU-T H.264 §8.2.1) is the one signal that cannot lie about a
stream’s true display order: every slice header carries enough information
to recover the relative presentation order of samples, independent of any
container metadata (stts/ctts) or of what a (possibly buggy) writer put
in a per-frame timestamp SEI. Within a coded video sequence (delimited by
IDR pictures), sorting frames by POC yields presentation order.
This module is used both to reorder frames into presentation order (see
crate::FrameDataSource::presentation_order_iter) and by
mp4-bframe-doctor to detect/repair files whose timing disagrees with the
bitstream’s real display order.
Structs§
- PocReader
- Accumulates the H.264 parsing context (SPS/PPS) and the POC strategy as samples are read, so a whole file can be walked (in decode order) and each frame’s picture order count reconstructed the same way.