kiteffmpeg/io.github.yuroyami.kiteffmpeg/MediaByteSink

MediaByteSink

Where an output's bytes go instead of a path: the custom I/O door for writing, and the output half of MediaByteSource. An in-memory buffer, encrypted storage, a virtual file system or an upload stream takes the bytes a muxer writes, through MediaSink.open.

Threading and blocking. Every call arrives on the thread that writes the output, one call at a time, never concurrently. A call that blocks holds the muxer, and that is how a slow consumer bounds the buffering: the muxer holds at most 64 KiB it has not handed over. Failures are thrown, not encoded: an exception fails the write that triggered it with an FFmpegException whose cause is that exception, and the sink cannot write again after it.

Lifetime. The MediaSink opened over this owns it: after the last byte it calls flush once, then close once, and the instance must stay valid until then. Closing that MediaSink from inside write or seek is refused, because the muxer is still using it.

Properties

seekable

abstract val seekable: Boolean

False when the sink cannot go back, and then seek is never called. A container that has to seek, such as MP4 without fragments, is refused when its header is written; pass "movflags" to "frag_keyframe+empty_moov" to write fragmented MP4 instead.

Functions

expect abstract fun close()

flush

open fun flush()

Hands on whatever the sink still buffers. Called once, after the last write.

seek

abstract fun seek(position: Long)

Moves the position to position bytes from the start. Only called when seekable.

write

abstract fun write(bytes: ByteArray, offset: Int, length: Int)

Takes all length bytes of bytes from offset at the current position, and moves past them.