StreamDecoder

One decoder driven explicitly by the caller.

The send/receive shape preserves FFmpeg's state machine: one packet can produce no frames or several frames, and the decoder may need its output queue drained before accepting more input.

A false send means the packet was not consumed: drain receive, then retry the same packet. Send null at input EOF, receive until isDrained, and call flush after every seek only after discarding packets and frames from the old position. Sending a closed packet is rejected at the call site rather than allowing a dangling payload to reach the decoder.

One decoder driven explicitly by the caller.

The send/receive shape preserves FFmpeg's state machine: one packet can produce no frames or several frames, and the decoder may need its output queue drained before accepting more input.

A false send means the packet was not consumed: drain receive, then retry the same packet. Send null at input EOF, receive until isDrained, and call flush after every seek only after discarding packets and frames from the old position. Sending a closed packet is rejected at the call site rather than allowing a dangling payload to reach the decoder.

One decoder, driven by the caller.

The send and receive shape mirrors libavcodec, including the cases a simpler interface cannot express: one packet producing no frames, one packet producing several, and a decoder that must be drained before it accepts more input.

Three rules that are easy to get wrong and expensive to debug:

1. Drain with receive until it returns null before assuming send will accept anything.

2. When send returns false the packet was not consumed. Drain, then offer the same packet again. Discarding it loses frames silently.

3. flush after every seek, and only after the caller has cleared its own queues. Flushing first lets a packet from the old position reach a freshly reset decoder.

One decoder driven explicitly by the caller.

The send/receive shape preserves FFmpeg's state machine: one packet can produce no frames or several frames, and the decoder may need its output queue drained before accepting more input.

A false send means the packet was not consumed: drain receive, then retry the same packet. Send null at input EOF, receive until isDrained, and call flush after every seek only after discarding packets and frames from the old position. Sending a closed packet is rejected at the call site rather than allowing a dangling payload to reach the decoder.

One decoder driven explicitly by the caller.

The send/receive shape preserves FFmpeg's state machine: one packet can produce no frames or several frames, and the decoder may need its output queue drained before accepting more input.

A false send means the packet was not consumed: drain receive, then retry the same packet. Send null at input EOF, receive until isDrained, and call flush after every seek only after discarding packets and frames from the old position. Sending a closed packet is rejected at the call site rather than allowing a dangling payload to reach the decoder.